Laser-Induced Breakdown Spectroscopy (LIBS) in a Novel Molten Salt Aerosol System.

PubMed

Williams, Ammon N; Phongikaroon, Supathorn

2017-04-01

In the pyrochemical separation of used nuclear fuel (UNF), fission product, rare earth, and actinide chlorides accumulate in the molten salt electrolyte over time. Measuring this salt composition in near real-time is advantageous for operational efficiency, material accountability, and nuclear safeguards. Laser-induced breakdown spectroscopy (LIBS) has been proposed and demonstrated as a potential analytical approach for molten LiCl-KCl salts. However, all the studies conducted to date have used a static surface approach which can lead to issues with splashing, low repeatability, and poor sample homogeneity. In this initial study, a novel molten salt aerosol approach has been developed and explored to measure the composition of the salt via LIBS. The functionality of the system has been demonstrated as well as a basic optimization of the laser energy and nebulizer gas pressure used. Initial results have shown that this molten salt aerosol-LIBS system has a great potential as an analytical technique for measuring the molten salt electrolyte used in this UNF reprocessing technology.

Optimized laser-induced breakdown spectroscopy for determination of xenobiotic silver in monosodium glutamate and its verification using ICP-AES.

PubMed

Rehan, I; Gondal, M A; Rehan, K

2018-04-20

Laser-induced breakdown spectroscopy (LIBS) was applied as a potential tool for the determination of xenobiotic metal in monosodium glutamate (MSG). In order to achieve a high-sensitivity LIBS system required to determine trace amounts of metallic silver in MSG and to attain the best detection limit, the parameters used in our experiment (impact of focusing laser energy on the intensity of LIBS emission signals, the influence of focusing lens distance on the intensity of LIBS signals, and time responses of the plasma emissions) were optimized. The spectra of MSG were obtained in air using a suitable detector with an optical resolution of 0.06 nm, covering a spectral region from 220 to 720 nm. Along with the detection of xenobiotic silver, other elements such as Ca, Mg, S, and Na were also detected in MSG. To determine the concentration of xenobiotic silver in MSG, the calibration curve was plotted by preparing standard samples having different silver abundances in an MSG matrix. The LIBS results of each sample were cross-verified by analyzing with a standard analytical technique such as inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Both (LIBS and ICP-AES) results were in mutual agreement. The limit of detection of the LIBS setup was found to be 0.57 ppm for silver present in MSG samples.

The influence of ns- and fs-LA plume local conditions on the performance of a combined LIBS/LA-ICP-MS sensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

LaHaye, Nicole L.; Phillips, Mark C.; Duffin, Andrew M.

2016-01-01

Both laser-induced breakdown spectroscopy (LIBS) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) are well-established analytical techniques with their own unique advantages and disadvantages. The combination of the two analytical methods is a very promising way to overcome the challenges faced by each method individually. We made a comprehensive comparison of local plasma conditions between nanosecond (ns) and femtosecond (fs) laser ablation (LA) sources in a combined LIBS and LA-ICP-MS system. The optical emission spectra and ICP-MS signal were recorded simultaneously for both ns- and fs-LA and figures of merit of the system were analyzed. Characterization of the plasma was conductedmore » by evaluating temperature and density of the plume under various irradiation conditions using optical emission spectroscopy, and correlations to ns- and fs-LIBS and LA-ICP-MS signal were made. The present study is very useful for providing conditions for a multimodal system as well as giving insight into how laser ablation plume parameters are related to LA-ICP-MS and LIBS results for both ns- and fs-LA.« less

Tandem Laser Induced Breakdown Spectroscopy (LIBS), Laser Ablation Inductively Coupled Plasma Mass Spectroscopy (LA-ICP-MS) and/or Laser Ablation Inductively Coupled Plasma Optical Emission Spectroscopy (LA-ICP-OES) for the analysis of samples of geological interest

NASA Astrophysics Data System (ADS)

Oropeza, D.

2016-12-01

A highly innovative laser ablation sampling instrument (J200 Tandem LA - LIBS) that combines the capabilities and analytical benefits of LIBS, LA-ICP-MS and LA-ICP-OES was used for micrometer-scale, spatially-resolved, elemental analysis of a wide variety of samples of geological interest. Data collected using ablation systems consisted of nanosecond (Nd:YAG operated 266nm) and femtosecond lasers (1030 and 343nm). An ICCD LIBS detector and Quadrupole based mass spectrometer were selected for LIBS and ICP-MS detection, respectively. This tandem instrument allows simultaneous determination of major and minor elements (for example, Si, Ca, Na, and Al, and trace elements such as Li, Ce, Cr, Sr, Y, Zn, Zr among others). The research also focused on elemental mapping and calibration strategies, specifically the use of emission and mass spectra for multivariate data analysis. Partial Least Square Regression (PLSR) is shown to minimize and compensate for matrix effects in the emission and mass spectra improving quantitative analysis by LIBS and LA-ICP-MS, respectively. The study provides a benchmark to evaluate analytical results for more complex geological sample matrices.

Parametric study of a fiber-optic laser-induced breakdown spectroscopy probe for analysis of aluminum alloys

NASA Astrophysics Data System (ADS)

Rai, Awadhesh K.; Zhang, Hansheng; Yueh, Fang Yu; Singh, Jagdish P.; Weisberg, Arel

2001-12-01

In the present work we demonstrate a fiber-optic laser-induced breakdown spectroscopy (FO LIBS) system for delivering laser energy to a sample surface to produce a spark as well as to collect the resulting radiation from the laser-induced spark. In order to improve the signal/background (S/B) ratio, various experimental parameters, such as laser energy, gate delay and width, detector gain, lenses of different focal lengths and sample surface, were tested. In order to provide high reliability and repeatability in the analysis, we also measured plasma parameters, such as electron density and plasma temperature, and determined their influence on the measurement results. The performance of FO LIBS was also compared with that of a LIBS system that does not use a fiber to transmit the laser beam. LIBS spectra with a good S/B were recorded at 2-μs gate delay and width. LIBS spectra of six different Al alloy samples were recorded to obtain calibration data. We were able to obtain linear calibration data for numerous elements (Cr, Zn, Fe, Ni, Mn, Mg and Cu). A linear calibration curve for LIBS intensity ratio vs. concentration ratio reduces the effect of physical variables (i.e. shot-to-shot power fluctuation, sample-to-surface distance, and physical properties of the samples). Our results reveal that this system may be useful in designing a high-temperature LIBS probe for measuring the elemental composition of Al melt.

Direct spectral analysis and determination of high content of carcinogenic bromine in bread using UV pulsed laser induced breakdown spectroscopy.

PubMed

Mehder, A O; Gondal, Mohammed A; Dastageer, Mohamed A; Habibullah, Yusuf B; Iqbal, Mohammed A; Oloore, Luqman E; Gondal, Bilal

2016-01-01

Laser induced breakdown spectroscopy (LIBS) was applied for the detection of carcinogenic elements like bromine in four representative brands of loaf bread samples and the measured bromine concentrations were 352, 157, 451, and 311 ppm, using Br I (827.2 nm) atomic transition line as the finger print atomic transition. Our LIBS system is equipped with a pulsed laser of wavelength 266 nm with energy 25 mJ pulse(-1), 8 ns pulse duration, 20 Hz repetition rate, and a gated ICCD camera. The LIBS system was calibrated with the standards of known concentrations in the sample (bread) matrix and such plot is linear in 20-500 ppm range. The capability of our system in terms of limit of detection and relative accuracy with respect to the standard inductively coupled plasma mass spectrometry (ICPMS) technique was evaluated and these values were 5.09 ppm and 0.01-0.05, respectively, which ensures the applicability of our system for Br trace level detection, and LIBS results are in excellent agreement with that of ICPMS results.

Novel high-density packaging of solid state diode pumped eye-safe laser for LIBS

NASA Astrophysics Data System (ADS)

Bares, Kim; Torgerson, Justin; McNeil, Laine; Maine, Patrick; Patterson, Steve

2018-02-01

Laser-Induced Breakdown Spectroscopy (LIBS) has proven to be a useful research tool for material analysis for decades. However, because of the amount of energy required in a few nanosecond pulse to generate a stable and reliable LIBS signal, the lasers are often large and inefficient, relegating their implementation to research facilities, factory floors, and assembly lines. Small portable LIBS systems are now possible without having to compromise on energy needs by leveraging off of advances in high-density packaging of electronics, opto-mechanics, and highly efficient laser resonator architecture. This paper explores the integration of these techniques to achieve a mJ class eye-safe LIBS laser source, while retaining a small, light-weight package suitable for handheld systems.

Elemental profiling of laser cladded multilayer coatings by laser induced breakdown spectroscopy and energy dispersive X-ray spectroscopy

NASA Astrophysics Data System (ADS)

Lednev, V. N.; Sdvizhenskii, P. A.; Filippov, M. N.; Grishin, M. Ya.; Filichkina, V. A.; Stavertiy, A. Ya.; Tretyakov, R. S.; Bunkin, A. F.; Pershin, S. M.

2017-09-01

Multilayer tungsten carbide wear resistant coatings were analyzed by laser induced breakdown spectroscopy (LIBS) and energy dispersive X-ray (EDX) spectroscopy. Coaxial laser cladding technique was utilized to produce tungsten carbide coating deposited on low alloy steel substrate with additional inconel 625 interlayer. EDX and LIBS techniques were used for elemental profiling of major components (Ni, W, C, Fe, etc.) in the coating. A good correlation between EDX and LIBS data was observed while LIBS provided additional information on light element distribution (carbon). A non-uniform distribution of tungsten carbide grains along coating depth was detected by both LIBS and EDX. In contrast, horizontal elemental profiling showed a uniform tungsten carbide particles distribution. Depth elemental profiling by layer-by-layer LIBS analysis was demonstrated to be an effective method for studying tungsten carbide grains distribution in wear resistant coating without any sample preparation.

Laser-induced breakdown spectroscopy of dental lesions: diagnostic and therapeutic monitoring tool

NASA Astrophysics Data System (ADS)

Borisova, Ekaterina; Uzunov, Tzonko; Penev, Dimitar; Genova, Tsanislava; Avramov, Latchezar

2016-01-01

The carious decay develops a tiny area of demineralization on the enamel, which could be detected by element analytic techniques such as laser-induced breakdown spectroscopy (LIBS). That demineralization can quickly turn into a large lesion inside the tooth, it is often discovered too late to prevent the kind of decay that leads to cavities. The same optical LIBS detection approach could be used for monitoring of the caries removal using laser ablation or drilling techniques. For LIBS measurements we applied LIBS 2500Plus (Ocean Optics Inc., Dunedin, USA) system, which consists of seven spectrometric channels, covering spectral region from 200 to 980 nm, which optical resolution 0,05 nm, the spectrometers are connected with sample fiber bundle for 7-channels spectral system to the chamber for solid and liquid samples, Q-switched Nd:YAG laser, at 1 064 nm, with energy per pulse - 40 mJ, which is applied to induce plasma in the samples. LIBS spectra were obtained after single shot of the laser in the region of pathology. Samples investigated by LIBS are extracted teeth from patients, with periodontal problems on different stage of carious lesions, and their LIBS spectra are compared with the LIBS signals obtained from normal enamel and dentine tissues to receive complete picture of the carious lesion development. The major line of our investigations is related to the development of a methodology for real-time optical feedback control during selective ablation of tooth tissues using LIBS. Tooth structures, with and without pathological changes, are compared and their LIBS element analysis is used to differentiate major changes, which occur during tooth carious process and growth.

Detection of carcinogenic metals in kidney stones using ultraviolet laser-induced breakdown spectroscopy.

PubMed

Khalil, Ahmed Asaad I; Gondal, Mohammed A; Shemis, Mohamed; Khan, Irfan S

2015-03-10

The UV single-pulsed (SP) laser-induced breakdown spectroscopy (LIBS) system was developed to detect the carcinogenic metals in human kidney stones extracted through the surgical operation. A neodymium yttrium aluminium garnet laser operating at 266 nm wavelength and 20 Hz repetition rate along with a spectrometer interfaced with an intensified CCD (ICCD) was applied for spectral analysis of kidney stones. The ICCD camera shutter was synchronized with the laser-trigger pulse and the effect of laser energy and delay time on LIBS signal intensity was investigated. The experimental parameters were optimized to obtain the LIBS plasma in local thermodynamic equilibrium. Laser energy was varied from 25 to 50 mJ in order to enhance the LIBS signal intensity and attain the best signal to noise ratio. The parametric dependence studies were important to improve the limit of detection of trace amounts of toxic elements present inside stones. The carcinogenic metals detected in kidney stones were chromium, cadmium, lead, zinc, phosphate, and vanadium. The results achieved from LIBS system were also compared with the inductively coupled plasma-mass spectrometry analysis and the concentration detected with both techniques was in very good agreement. The plasma parameters (electron temperature and density) for SP-LIBS system were also studied and their dependence on incident laser energy and delay time was investigated as well.

Combined LIBS-Raman for remote detection and characterization of biological samples

DOE PAGES

Anderson, Aaron S.; Mukundan, Harshini; Mcinroy, Rhonda E.; ...

2015-02-07

Laser-Induced Breakdown Spectroscopy (LIBS) and Raman Spectroscopy have rich histories in the analysis of a wide variety of samples in both in situ and remote configurations. Our team is working on building a deployable, integrated Raman and LIBS spectrometer (RLS) for the parallel elucidation of elemental and molecular signatures under Earth and Martian surface conditions. Herein, results from remote LIBS and Raman analysis of biological samples such as amino acids, small peptides, mono- and disaccharides, and nucleic acids acquired under terrestrial and Mars conditions are reported, giving rise to some interesting differences. A library of spectra and peaks of interestmore » were compiled, and will be used to inform the analysis of more complex systems, such as large peptides, dried bacterial spores, and biofilms. Lastly, these results will be presented and future applications will be discussed, including the assembly of a combined RLS spectroscopic system and stand-off detection in a variety of environments.« less

Assessment of statistical uncertainty in the quantitative analysis of solid samples in motion using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Cabalín, L. M.; González, A.; Ruiz, J.; Laserna, J. J.

2010-08-01

Statistical uncertainty in the quantitative analysis of solid samples in motion by laser-induced breakdown spectroscopy (LIBS) has been assessed. For this purpose, a LIBS demonstrator was designed and constructed in our laboratory. The LIBS system consisted of a laboratory-scale conveyor belt, a compact optical module and a Nd:YAG laser operating at 532 nm. The speed of the conveyor belt was variable and could be adjusted up to a maximum speed of 2 m s - 1 . Statistical uncertainty in the analytical measurements was estimated in terms of precision (reproducibility and repeatability) and accuracy. The results obtained by LIBS on shredded scrap samples under real conditions have demonstrated that the analytical precision and accuracy of LIBS is dependent on the sample geometry, position on the conveyor belt and surface cleanliness. Flat, relatively clean scrap samples exhibited acceptable reproducibility and repeatability; by contrast, samples with an irregular shape or a dirty surface exhibited a poor relative standard deviation.

Spectrochemical analysis of powdered biological samples using transversely excited atmospheric carbon dioxide laser plasma excitation

NASA Astrophysics Data System (ADS)

Zivkovic, Sanja; Momcilovic, Milos; Staicu, Angela; Mutic, Jelena; Trtica, Milan; Savovic, Jelena

2017-02-01

The aim of this study was to develop a simple laser induced breakdown spectroscopy (LIBS) method for quantitative elemental analysis of powdered biological materials based on laboratory prepared calibration samples. The analysis was done using ungated single pulse LIBS in ambient air at atmospheric pressure. Transversely-Excited Atmospheric pressure (TEA) CO2 laser was used as an energy source for plasma generation on samples. The material used for the analysis was a blue-green alga Spirulina, widely used in food and pharmaceutical industries and also in a few biotechnological applications. To demonstrate the analytical potential of this particular LIBS system the obtained spectra were compared to the spectra obtained using a commercial LIBS system based on pulsed Nd:YAG laser. A single sample of known concentration was used to estimate detection limits for Ba, Ca, Fe, Mg, Mn, Si and Sr and compare detection power of these two LIBS systems. TEA CO2 laser based LIBS was also applied for quantitative analysis of the elements in powder Spirulina samples. Analytical curves for Ba, Fe, Mg, Mn and Sr were constructed using laboratory produced matrix-matched calibration samples. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used as the reference technique for elemental quantification, and reasonably well agreement between ICP and LIBS data was obtained. Results confirm that, in respect to its sensitivity and precision, TEA CO2 laser based LIBS can be successfully applied for quantitative analysis of macro and micro-elements in algal samples. The fact that nearly all classes of materials can be prepared as powders implies that the proposed method could be easily extended to a quantitative analysis of different kinds of materials, organic, biological or inorganic.

Combined raman spectrometer/laser-induced breakdown spectrometer design concept

NASA Astrophysics Data System (ADS)

Bazalgette Courrèges-Lacoste, Gregory; Ahlers, Berit; Boslooper, Erik; Rull-Perez, Fernando; Maurice, Sylvestre

2017-11-01

Amongst the different instruments that have been preselected to be on-board the Pasteur payload on ExoMars is the Raman/ Laser Induced Breakdown Spectroscopy (LIBS) instrument. Raman spectroscopy and LIBS will be integrated into a single instrument sharing many hardware commonalities. An international team under the lead of TNO has been gathered to produce a design concept for a combined Raman Spectrometer/ LIBS Elegant Bread-Board (EBB). The instrument is based on a specifically designed extremely compact spectrometer with high resolution over a large wavelength range, suitable for both Raman spectroscopy and LIBS measurements. Low mass, size and resources are the main drivers of the instrument's design concept. The proposed design concept, realization and testing programme for the combined Raman/ LIBS EBB is presented as well as background information on Raman and LIBS.

Accuracy Enhancement of Raman Spectroscopy Using Complementary Laser-Induced Breakdown Spectroscopy (LIBS) with Geologically Mixed Samples.

PubMed

Choi, Soojin; Kim, Dongyoung; Yang, Junho; Yoh, Jack J

2017-04-01

Quantitative Raman analysis was carried out with geologically mixed samples that have various matrices. In order to compensate the matrix effect in Raman shift, laser-induced breakdown spectroscopy (LIBS) analysis was performed. Raman spectroscopy revealed the geological materials contained in the mixed samples. However, the analysis of a mixture containing different matrices was inaccurate due to the weak signal of the Raman shift, interference, and the strong matrix effect. On the other hand, the LIBS quantitative analysis of atomic carbon and calcium in mixed samples showed high accuracy. In the case of the calcite and gypsum mixture, the coefficient of determination of atomic carbon using LIBS was 0.99, while the signal using Raman was less than 0.9. Therefore, the geological composition of the mixed samples is first obtained using Raman and the LIBS-based quantitative analysis is then applied to the Raman outcome in order to construct highly accurate univariate calibration curves. The study also focuses on a method to overcome matrix effects through the two complementary spectroscopic techniques of Raman spectroscopy and LIBS.

Prospects for laser-induced breakdown spectroscopy for biomedical applications: a review.

PubMed

Singh, Vivek Kumar; Rai, Awadhesh Kumar

2011-09-01

We review the different spectroscopic techniques including the most recent laser-induced breakdown spectroscopy (LIBS) for the characterization of materials in any phase (solid, liquid or gas) including biological materials. A brief history of the laser and its application in bioscience is presented. The development of LIBS, its working principle and its instrumentation (different parts of the experimental set up) are briefly summarized. The generation of laser-induced plasma and detection of light emitted from this plasma are also discussed. The merit and demerits of LIBS are discussed in comparison with other conventional analytical techniques. The work done using the laser in the biomedical field is also summarized. The analysis of different tissues, mineral analysis in different organs of the human body, characterization of different types of stone formed in the human body, analysis of biological aerosols using the LIBS technique are also summarized. The unique abilities of LIBS including detection of molecular species and calibration-free LIBS are compared with those of other conventional techniques including atomic absorption spectroscopy, inductively coupled plasma atomic emission spectroscopy and mass spectroscopy, and X-ray fluorescence.

Spectroscopic detection of health hazardous contaminants in lipstick using Laser Induced Breakdown Spectroscopy.

PubMed

Gondal, M A; Seddigi, Z S; Nasr, M M; Gondal, B

2010-03-15

Laser Induced Breakdown Spectroscopy (LIBS) technique was applied to determine the concentrations of different toxic elements like lead, chromium, cadmium and zinc in four different lipstick brands sold at local markets in Saudi Arabia. These samples contain toxic elements like lead, cadmium and chromium which are carcinogen dermatitis, allergic and eczematous. Their extraction from human body takes over 40 years and accumulation in the body cause problems like disruption of nervous systems and kidney damage. They could trigger to systemic lupus erythematosus (SLE). In order to test the validity of our LIBS results, standard technique like (ICP-AES) was also applied. To the best of our knowledge, this is the first study where LIBS technique was applied for the measurement of toxic substances in lipsticks. The maximum concentration detected in four lipstick brands was much higher than the permissible safe limits for human use and could lead to serious health problems. It is worth mentioning that the lipstick is not a solid rather is in fluid state which is not trivial to analyze using LIBS technique. For this purpose, special treatment of the lipstick samples was necessary to analyze with our LIBS method. (c) 2009 Elsevier B.V. All rights reserved.

Application of Handheld Laser-Induced Breakdown Spectroscopy (LIBS) to Geochemical Analysis.

PubMed

Connors, Brendan; Somers, Andrew; Day, David

2016-05-01

While laser-induced breakdown spectroscopy (LIBS) has been in use for decades, only within the last two years has technology progressed to the point of enabling true handheld, self-contained instruments. Several instruments are now commercially available with a range of capabilities and features. In this paper, the SciAps Z-500 handheld LIBS instrument functionality and sub-systems are reviewed. Several assayed geochemical sample sets, including igneous rocks and soils, are investigated. Calibration data are presented for multiple elements of interest along with examples of elemental mapping in heterogeneous samples. Sample preparation and the data collection method from multiple locations and data analysis are discussed. © The Author(s) 2016.

Calibration-free quantitative analysis of elemental ratios in intermetallic nanoalloys and nanocomposites using Laser Induced Breakdown Spectroscopy (LIBS).

PubMed

Davari, Seyyed Ali; Hu, Sheng; Mukherjee, Dibyendu

2017-03-01

Intermetallic nanoalloys (NAs) and nanocomposites (NCs) have increasingly gained prominence as efficient catalytic materials in electrochemical energy conversion and storage systems. But their morphology and chemical compositions play critical role in tuning their catalytic activities, and precious metal contents. While advanced microscopy techniques facilitate morphological characterizations, traditional chemical characterizations are either qualitative or extremely involved. In this study, we apply Laser Induced Breakdown Spectroscopy (LIBS) for quantitative compositional analysis of NAs and NCs synthesized with varied elemental ratios by our in-house built pulsed laser ablation technique. Specifically, elemental ratios of binary PtNi, PdCo (NAs) and PtCo (NCs) of different compositions are determined from LIBS measurements employing an internal calibration scheme using the bulk matrix species as internal standards. Morphology and qualitative elemental compositions of the aforesaid NAs and NCs are confirmed from Transmission Electron Microscopy (TEM) images and Energy Dispersive X-ray Spectroscopy (EDX) measurements. LIBS experiments are carried out in ambient conditions with the NA and NC samples drop cast on silicon wafers after centrifugation to increase their concentrations. The technique does not call for cumbersome sample preparations including acid digestions and external calibration standards commonly required in Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) techniques. Yet the quantitative LIBS results are in good agreement with the results from ICP-OES measurements. Our results indicate the feasibility of using LIBS in future for rapid and in-situ quantitative chemical characterizations of wide classes of synthesized NAs and NCs. Copyright © 2016 Elsevier B.V. All rights reserved.

Mid-infrared, long wave infrared (4-12 μm) molecular emission signatures from pharmaceuticals using laser-induced breakdown spectroscopy (LIBS).

PubMed

Yang, Clayton S-C; Brown, Ei E; Kumi-Barimah, Eric; Hommerich, Uwe H; Jin, Feng; Trivedi, Sudhir B; Samuels, Alan C; Snyder, A Peter

2014-01-01

In an effort to augment the atomic emission spectra of conventional laser-induced breakdown spectroscopy (LIBS) and to provide an increase in selectivity, mid-wave to long-wave infrared (IR), LIBS studies were performed on several organic pharmaceuticals. Laser-induced breakdown spectroscopy signature molecular emissions of target organic compounds are observed for the first time in the IR fingerprint spectral region between 4-12 μm. The IR emission spectra of select organic pharmaceuticals closely correlate with their respective standard Fourier transform infrared spectra. Intact and/or fragment sample molecular species evidently survive the LIBS event. The combination of atomic emission signatures derived from conventional ultraviolet-visible-near-infrared LIBS with fingerprints of intact molecular entities determined from IR LIBS promises to be a powerful tool for chemical detection.

Quantitative determination of copper in a glass matrix using double pulse laser induced breakdown and electron paramagnetic resonance spectroscopic techniques.

PubMed

Khalil, Ahmed A I; Morsy, Mohamed A

2016-07-01

A series of lithium-lead-borate glasses of a variable copper oxide loading were quantitatively analyzed in this work using two distinct spectroscopic techniques, namely double pulse laser induced breakdown spectroscopy (DP-LIBS) and electron paramagnetic resonance (EPR). DP-LIBS results measured upon a combined nanosecond lasers irradiation running at 266nm and 1064nm pulses of a collinear configuration directed to the surface of borate glass samples with a known composition. This arrangement was employed to predict the electron's temperature (Te) and density (Ne) of the excited plasma from the recorded spectra. The intensity of elements' responses using this scheme is higher than that of single-pulse laser induced breakdown spectroscopy (SP-LIBS) setup under the same experimental conditions. On the other hand, the EPR data shows typical Cu (II) EPR-signals in the borate glass system that is networked at a distorted tetragonal Borate-arrangement. The signal intensity of the Cu (II) peak at g⊥=2.0596 has been used to quantify the Cu-content accurately in the glass matrix. Both techniques produced linear calibration curves of Cu-metals in glasses with excellent linear regression coefficient (R(2)) values. This study establishes a good correlation between DP-LIBS analysis of glass and the results obtained using EPR spectroscopy. The proposed protocols prove the great advantage of DP-LIBS system for the detection of a trace copper on the surface of glasses. Copyright © 2016 Elsevier B.V. All rights reserved.

Trace metal mapping by laser-induced breakdown spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaiser, Jozef; Novotny, Dr. Karel; Hrdlicka, A

2012-01-01

Abstract: Laser-Induced Breakdown Spectroscopy (LIBS) is a sensitive optical technique capable of fast multi-elemental analysis of solid, gaseous and liquid samples. The potential applications of lasers for spectrochemical analysis were developed shortly after its invention; however the massive development of LIBS is connected with the availability of powerful pulsed laser sources. Since the late 80s of 20th century LIBS dominated the analytical atomic spectroscopy scene and its application are developed continuously. Here we review the utilization of LIBS for trace elements mapping in different matrices. The main emphasis is on trace metal mapping in biological samples.

Preliminary design of laser-induced breakdown spectroscopy for proto-Material Plasma Exposure eXperiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shaw, G., E-mail: shawgc@ornl.gov; University of Tennessee, Knoxville, Tennessee 37996; Martin, M. Z.

2014-11-15

Laser-induced breakdown spectroscopy (LIBS) is a technique for measuring surface matter composition. LIBS is performed by focusing laser radiation onto a target surface, ablating the surface, forming a plasma, and analyzing the light produced. LIBS surface analysis is a possible diagnostic for characterizing plasma-facing materials in ITER. Oak Ridge National Laboratory has enabled the initial installation of a laser-induced breakdown spectroscopy diagnostic on the prototype Material-Plasma Exposure eXperiment (Proto-MPEX), which strives to mimic the conditions found at the surface of the ITER divertor. This paper will discuss the LIBS implementation on Proto-MPEX, preliminary design of the fiber optic LIBS collectionmore » probe, and the expected results.« less

Long-wave, infrared laser-induced breakdown (LIBS) spectroscopy emissions from energetic materials.

PubMed

Yang, Clayton S-C; Brown, Ei E; Hommerich, Uwe; Jin, Feng; Trivedi, Sudhir B; Samuels, Alan C; Snyder, A Peter

2012-12-01

Laser-induced breakdown spectroscopy (LIBS) has shown great promise for applications in chemical, biological, and explosives sensing and has significant potential for real-time standoff detection and analysis. In this study, LIBS emissions were obtained in the mid-infrared (MIR) and long-wave infrared (LWIR) spectral regions for potential applications in explosive material sensing. The IR spectroscopy region revealed vibrational and rotational signatures of functional groups in molecules and fragments thereof. The silicon-based detector for conventional ultraviolet-visible LIBS operations was replaced with a mercury-cadmium-telluride detector for MIR-LWIR spectral detection. The IR spectral signature region between 4 and 12 μm was mined for the appearance of MIR and LWIR-LIBS emissions directly indicative of oxygenated breakdown products as well as dissociated, and/or recombined sample molecular fragments. Distinct LWIR-LIBS emission signatures from dissociated-recombination sample molecular fragments between 4 and 12 μm are observed for the first time.

A fundamental study of laser-induced breakdown spectroscopy using fiber optics for remote measurements of trace metals. Interim progress report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goode, S.R.; Angel, S.M.

1997-01-01

'The long-term goal of this project is to develop a system to measure the elemental composition of unprepared samples using laser-induced breakdown spectroscopy, LIBS, with a fiber-optic probe. From images shown in this report it is evident that the temporal and spatial behavior of laser-induced plasmas IS a complex process. However, through the use of spectral imaging, optimal conditions can be determined for collecting the atomic emission signal in these plasmas. By tailoring signal collection to the regions of the plasma that contain the highest emission signal with the least amount of background interference both the detection limits and themore » precision of LIBS measurements could be improved. The optimal regions for both gated and possibly non-gated LIBS measurements have been shown to correspond to the inner regions and outer regions, respectively, in an axial plasma. By using this data fiber-optic LIBS probe designs can be optimized for collecting plasma emission at the optimal regions for improved detection limits and precision in a LIBS measurement.'« less

Long-Wave Infrared (LWIR) Molecular Laser-Induced Breakdown Spectroscopy (LIBS) Emissions of Thin Solid Explosive Powder Films Deposited on Aluminum Substrates.

PubMed

Yang, Clayton S-C; Jin, Feng; Trivedi, Sudhir B; Brown, Ei E; Hommerich, Uwe; Tripathi, Ashish; Samuels, Alan C

2017-04-01

Thin solid films made of high nitro (NO 2 )/nitrate (NO 3 ) content explosives were deposited on sand-blasted aluminum substrates and then studied using a mercury-cadmium-telluride (MCT) linear array detection system that is capable of rapidly capturing a broad spectrum of atomic and molecular laser-induced breakdown spectroscopy (LIBS) emissions in the long-wave infrared region (LWIR; ∼5.6-10 µm). Despite the similarities of their chemical compositions and structures, thin films of three commonly used explosives (RDX, HMX, and PETN) studied in this work can be rapidly identified in the ambient air by their molecular LIBS emission signatures in the LWIR region. A preliminary assessment of the detection limit for a thin film of RDX on aluminum appears to be much lower than 60 µg/cm 2 . This LWIR LIBS setup is capable of rapidly probing and charactering samples without the need for elaborate sample preparation and also offers the possibility of a simultaneous ultraviolet visible and LWIR LIBS measurement.

Remote quantitative analysis of minerals based on multispectral line-calibrated laser-induced breakdown spectroscopy (LIBS).

PubMed

Wan, Xiong; Wang, Peng

2014-01-01

Laser-induced breakdown spectroscopy (LIBS) is a feasible remote sensing technique used for mineral analysis in some unapproachable places where in situ probing is needed, such as analysis of radioactive elements in a nuclear leak or the detection of elemental compositions and contents of minerals on planetary and lunar surfaces. Here a compact custom 15 m focus optical component, combining a six times beam expander with a telescope, has been built, with which the laser beam of a 1064 nm Nd ; YAG laser is focused on remote minerals. The excited LIBS signals that reveal the elemental compositions of minerals are collected by another compact single lens-based signal acquisition system. In our remote LIBS investigations, the LIBS spectra of an unknown ore have been detected, from which the metal compositions are obtained. In addition, a multi-spectral line calibration (MSLC) method is proposed for the quantitative analysis of elements. The feasibility of the MSLC and its superiority over a single-wavelength determination have been confirmed by comparison with traditional chemical analysis of the copper content in the ore.

Apparatus, system, and method for laser-induced breakdown spectroscopy

DOEpatents

Effenberger, Jr., Andrew J; Scott, Jill R; McJunkin, Timothy R

2014-11-18

In laser-induced breakdown spectroscopy (LIBS), an apparatus includes a pulsed laser configured to generate a pulsed laser signal toward a sample, a constructive interference object and an optical element, each located in a path of light from the sample. The constructive interference object is configured to generate constructive interference patterns of the light. The optical element is configured to disperse the light. A LIBS system includes a first and a second optical element, and a data acquisition module. The data acquisition module is configured to determine an isotope measurement based, at least in part, on light received by an image sensor from the first and second optical elements. A method for performing LIBS includes generating a pulsed laser on a sample to generate light from a plasma, generating constructive interference patterns of the light, and dispersing the light into a plurality of wavelengths.

Proof of Principle for a Real-Time Pathogen Isolation Media Diagnostic: The Use of Laser-Induced Breakdown Spectroscopy to Discriminate Bacterial Pathogens and Antimicrobial-Resistant Staphylococcus aureus Strains Grown on Blood Agar

PubMed Central

Multari, Rosalie A.; Cremers, David A.; Bostian, Melissa L.; Dupre, Joanne M.

2013-01-01

Laser-Induced Breakdown Spectroscopy (LIBS) is a rapid, in situ, diagnostic technique in which light emissions from a laser plasma formed on the sample are used for analysis allowing automated analysis results to be available in seconds to minutes. This speed of analysis coupled with little or no sample preparation makes LIBS an attractive detection tool. In this study, it is demonstrated that LIBS can be utilized to discriminate both the bacterial species and strains of bacterial colonies grown on blood agar. A discrimination algorithm was created based on multivariate regression analysis of spectral data. The algorithm was deployed on a simulated LIBS instrument system to demonstrate discrimination capability using 6 species. Genetically altered Staphylococcus aureus strains grown on BA, including isogenic sets that differed only by the acquisition of mutations that increase fusidic acid or vancomycin resistance, were also discriminated. The algorithm successfully identified all thirteen cultures used in this study in a time period of 2 minutes. This work provides proof of principle for a LIBS instrumentation system that could be developed for the rapid discrimination of bacterial species and strains demonstrating relatively minor genomic alterations using data collected directly from pathogen isolation media. PMID:24109513

Smart surgical tool

NASA Astrophysics Data System (ADS)

Huang, Huan; Yang, Lih-Mei; Bai, Shuang; Liu, Jian

2015-02-01

A laser-induced breakdown spectroscopy (LIBS) guided smart surgical tool using a femtosecond fiber laser is developed. This system provides real-time material identification by processing and analyzing the peak intensity and ratio of atomic emissions of LIBS signals. Algorithms to identify emissions of different tissues and metals are developed and implemented into the real-time control system. This system provides a powerful smart surgical tool for precise robotic microsurgery applications with real-time feedback and control.

Utilization of selected laser-ablation-based diagnostic methods for study of elemental distribution in various solid samples

NASA Astrophysics Data System (ADS)

Kaiser, J.; Novotný, K.; Hrdlička, A.; Malina, R.; Novotný, J.; Prochazka, D.; Petrilak, M.; Krajcarová, L.; Vítková, G.; Kučerová, P.

2010-12-01

Here we report on the recent developments and upgrades of our Laser-Induced Breakdown Spectroscopy setups and their different modification for high-resolution mapping. Mapping capabilities of Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry are compared. The applied improvements as an autofocus algorithm, together with the realization of double-pulse LIBS or combination of LIBS by Laser-Induced Fluorescence Spectroscopy (LIFS) with technique are detailed. The signal enhancement obtained by double-pulse approach is demonstrated. The state of the art on development of portable remote LIBS apparatus is also presented.

Optical-fiber-based laser-induced breakdown spectroscopy for detection of early caries

NASA Astrophysics Data System (ADS)

Sasazawa, Shuhei; Kakino, Satoko; Matsuura, Yuji

2015-06-01

A laser-induced breakdown spectroscopy (LIBS) system targeting for the in vivo analysis of tooth enamel is described. The system is planned to enable real-time analysis of teeth during laser dental treatment by utilizing a hollow optical fiber that transmits both Q-switched Nd:YAG laser light for LIBS and infrared Er:YAG laser light for tooth ablation. The sensitivity of caries detection was substantially improved by expanding the spectral region under analysis to ultraviolet (UV) light and by focusing on emission peaks of Zn in the UV region. Subsequently, early caries were distinguished from healthy teeth with accuracy rates above 80% in vitro.

Double-pulse standoff laser-induced breakdown spectroscopy for versatile hazardous materials detection

NASA Astrophysics Data System (ADS)

Gottfried, Jennifer L.; De Lucia, Frank C.; Munson, Chase A.; Miziolek, Andrzej W.

2007-12-01

We have developed a double-pulse standoff laser-induced breakdown spectroscopy (ST-LIBS) system capable of detecting a variety of hazardous materials at tens of meters. The use of a double-pulse laser improves the sensitivity and selectivity of ST-LIBS, especially for the detection of energetic materials. In addition to various metallic and plastic materials, the system has been used to detect bulk explosives RDX and Composition-B, explosive residues, biological species such as the anthrax surrogate Bacillus subtilis, and chemical warfare simulants at 20 m. We have also demonstrated the discrimination of explosive residues from various interferents on an aluminum substrate.

Double pulse laser induced breakdown spectroscopy: A potential tool for the analysis of contaminants and macro/micronutrients in organic mineral fertilizers.

PubMed

Nicolodelli, Gustavo; Senesi, Giorgio Saverio; de Oliveira Perazzoli, Ivan Luiz; Marangoni, Bruno Spolon; De Melo Benites, Vinícius; Milori, Débora Marcondes Bastos Pereira

2016-09-15

Organic fertilizers are obtained from waste of plant or animal origin. One of the advantages of organic fertilizers is that, from the composting, it recycles waste-organic of urban and agriculture origin, whose disposal would cause environmental impacts. Fast and accurate analysis of both major and minor/trace elements contained in organic mineral and inorganic fertilizers of new generation have promoted the application of modern analytical techniques. In particular, laser induced breakdown spectroscopy (LIBS) is showing to be a very promising, quick and practical technique to detect and measure contaminants and nutrients in fertilizers. Although, this technique presents some limitations, such as a low sensitivity, if compared to other spectroscopic techniques, the use of double pulse (DP) LIBS is an alternative to the conventional LIBS in single pulse (SP). The macronutrients (Ca, Mg, K, P), micronutrients (Cu, Fe, Na, Mn, Zn) and contaminant (Cr) in fertilizer using LIBS in SP and DP configurations were evaluated. A comparative study for both configurations was performed using optimized key parameters for improving LIBS performance. The limit of detection (LOD) values obtained by DP LIBS increased up to seven times as compared to SP LIBS. In general, the marked improvement obtained when using DP system in the simultaneous LIBS quantitative determination for fertilizers analysis could be ascribed to the larger ablated mass of the sample. The results presented in this study show the promising potential of the DP LIBS technique for a qualitative analysis in fertilizers, without requiring sample preparation with chemical reagents. Copyright © 2016 Elsevier B.V. All rights reserved.

Probing organic residues on Martian regolith simulants using a long-wave infrared Laser-induced breakdown spectroscopy linear array detection system

NASA Astrophysics Data System (ADS)

Prasad, Narasimha S.; Yang, Clayton S.-C.; Jin, Feng; Jia, Ken; Brown, EiEi; Hömmerich, Uwe; Jia, Yingqing; Trivedi, Sudhir; Wijewarnasuriya, Priyalal; Decuir, Eric; Samuels, Alan C.

2016-09-01

Recently, a mercury-cadmium-telluride (MCT) linear array detection system that is capable of rapidly capturing ( 1-5 second) a broad spectrum of atomic and molecular laser-induced breakdown spectroscopy (LIBS) emissions in the longwave infrarμed region (LWIR, 5.6 to 10 μm) has been developed. Similar to the conventional Ultraviolet (UV)-Visible (Vis) LIBS, a broad band emission spectrum of condensed phase samples covering the entire 5.6 to 10 μm region can be acquired from just a single laser-induced micro-plasma or averaging a few single laser-induced micro-plasmas. This setup has enabled probing samples "as is" without the need for extensive sample preparation and also offers the possibility of a simultaneous UV-Vis and LWIR LIBS measurement. A Martian regolith simulant (JSC Mars-1A) was studied with this novel Vis + LWIR LIBS array system. A broad SiO2 vibrational emission feature around 9.5 μm and multiple strong emission features between 6.5 to 8 μm can be clearly identified. The 6.5 to 8 μm features are possibly from biological impurities of the simulant. JSC Mars-1A samples with organic methyl salicylate (MeS, wintergreen oil) and Dimethyl methyl-phosphonate (DMMP) residues were also probed using the LWIR LIBS array system. Both molecular spectral signature around 6.5 μm and 9.5 μm of Martian regolith simulant and MeS and DMMP molecular signature emissions, such as Aromatic CC stretching band at 7.5 μm, C-CH3O asymmetric deformation at 7.6 μm, and P=O stretching band at 7.9 μm, are clearly observed from the LIBS emission spectra in the LWIR region.

Analysis of heterogeneous gallstones using laser-induced breakdown spectroscopy (LIBS) and wavelength dispersive X-ray fluorescence (WD-XRF).

PubMed

Jaswal, Brij Bir S; Kumar, Vinay; Sharma, Jitendra; Rai, Pradeep K; Gondal, Mohammed A; Gondal, Bilal; Singh, Vivek K

2016-04-01

Laser-induced breakdown spectroscopy (LIBS) is an emerging analytical technique with numerous advantages such as rapidity, multi-elemental analysis, no specific sample preparation requirements, non-destructiveness, and versatility. It has been proven to be a robust elemental analysis tool attracting interest because of being applied to a wide range of materials including biomaterials. In this paper, we have performed spectroscopic studies on gallstones which are heterogeneous in nature using LIBS and wavelength dispersive X-ray fluorescence (WD-XRF) techniques. It has been observed that the presence and relative concentrations of trace elements in different kind of gallstones (cholesterol and pigment gallstones) can easily be determined using LIBS technique. From the experiments carried out on gallstones for trace elemental mapping and detection, it was found that LIBS is a robust tool for such biomedical applications. The stone samples studied in the present paper were classified using the Fourier transform infrared (FTIR) spectroscopy. WD-XRF spectroscopy has been applied for the qualitative and quantitative analysis of major and trace elements present in the gallstone which was compared with the LIBS data. The results obtained in the present paper show interesting prospects for LIBS and WD-XRF to study cholelithiasis better.

Laser-Induced Breakdown Spectroscopy for Qualitative Analysis of Metals in Simulated Martian Soils

ERIC Educational Resources Information Center

Mowry, Curtis; Milofsky, Rob; Collins, William; Pimentel, Adam S.

2017-01-01

This laboratory introduces students to laser-induced breakdown spectroscopy (LIBS) for the analysis of metals in soil and rock samples. LIBS employs a laser-initiated spark to induce electronic excitation of metal atoms. Ensuing atomic emission allows for qualitative and semiquantitative analysis. The students use LIBS to analyze a series of…

Elemental Analysis of Soils by Laser Induced Breakdown Spectroscopy

NASA Astrophysics Data System (ADS)

Gondal, Mohammed Ashraf; Dastageer, Mohamed A.

The chemical and elemental composition of soil is very complex as it contains many constituents like minerals, organic matters, living organisms, fossils, air and water. Considering the diversity of soil contents, quality and usability, a systematic scientific study on the elemental and chemical composition of soil is very important. In order to study the chemical composition of soil, Laser induced breakdown spectroscopy (LIBS) has been applied recently. The important features of LIBS system and its applications for the measurement of nutrients in green house soil, on-line monitoring of remediation process of chromium polluted soil, determination of trace elements in volcanic erupted soil samples collected from ancient cenozoic lava eruption sites and detection of toxic metals in Gulf war oil spill contaminated soil using LIBS are described in this chapter.

Elemental content of enamel and dentin after bleaching of teeth (a comparative study between laser-induced breakdown spectroscopy and x-ray photoelectron spectroscopy)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Imam, H.; Ahmed, Doaa; Eldakrouri, Ashraf

2013-06-21

The elemental content of the superficial and inner enamel as well as that of dentin was analyzed using laser-induced breakdown spectroscopy (LIBS) and x-ray photoelectron spectroscopy (XPS) of bleached and unbleached tooth specimens. It is thus clear from the spectral analysis using both the LIBS and XPS technique that elemental changes (though insignificant within the scopes of this study) of variable intensities do occur on the surface of the enamel and extend deeper to reach dentin. The results of the LIBS revealed a slight reduction in the calcium levels in the bleached compared to the control specimens in all themore » different bleaching groups and in both enamel and dentin. The good correlation found between the LIBS and XPS results demonstrates the possibility of LIBS technique for detection of minor loss in calcium and phosphorus in enamel and dentin.« less

Depth-resolved multilayer pigment identification in paintings: combined use of laser-induced breakdown spectroscopy (LIBS) and optical coherence tomography (OCT).

PubMed

Kaszewska, Ewa A; Sylwestrzak, Marcin; Marczak, Jan; Skrzeczanowski, Wojciech; Iwanicka, Magdalena; Szmit-Naud, Elżbieta; Anglos, Demetrios; Targowski, Piotr

2013-08-01

A detailed feasibility study on the combined use of laser-induced breakdown spectroscopy with optical coherence tomography (LIBS/OCT), aiming at a realistic depth-resolved elemental analysis of multilayer stratigraphies in paintings, is presented. Merging a high spectral resolution LIBS system with a high spatial resolution spectral OCT instrument significantly enhances the quality and accuracy of stratigraphic analysis. First, OCT mapping is employed prior to LIBS analysis in order to assist the selection of specific areas of interest on the painting surface to be examined in detail. Then, intertwined with LIBS, the OCT instrument is used as a precise profilometer for the online determination of the depth of the ablation crater formed by individual laser pulses during LIBS depth-profile analysis. This approach is novel and enables (i) the precise in-depth scaling of elemental concentration profiles, and (ii) the recognition of layer boundaries by estimating the corresponding differences in material ablation rate. Additionally, the latter is supported, within the transparency of the object, by analysis of the OCT cross-sectional views. The potential of this method is illustrated by presenting results on the detailed analysis of the structure of an historic painting on canvas performed to aid planned restoration of the artwork.

Optimal boiler control through real-time monitoring of unburned carbon in fly ash by laser-induced breakdown spectroscopy.

PubMed

Kurihara, Miki; Ikeda, Koji; Izawa, Yoshinori; Deguchi, Yoshihiro; Tarui, Hitoshi

2003-10-20

A laser-induced breakdown spectroscopy (LIBS) technique has been applied for detection of unburned carbon in fly ash, and an automated LIBS unit has been developed and applied in a 1000-MW pulverized-coal-fired power plant for real-time measurement, specifically of unburned carbon in fly ash. Good agreement was found between measurement results from the LIBS method and those from the conventional method (Japanese Industrial Standard 8815), with a standard deviation of 0.27%. This result confirms that the measurement of unburned carbon in fly ash by use of LIBS is sufficiently accurate for boiler control. Measurements taken by this apparatus were also integrated into a boiler-control system with the objective of achieving optimal and stable combustion. By control of the rotating speed of a mill rotary separator relative to measured unburned-carbon content, it has been demonstrated that boiler control is possible in an optimized manner by use of the value of the unburned-carbon content of fly ash.

Inclusion Detection in Aluminum Alloys Via Laser-Induced Breakdown Spectroscopy

NASA Astrophysics Data System (ADS)

Hudson, Shaymus W.; Craparo, Joseph; De Saro, Robert; Apelian, Diran

2018-04-01

Laser-induced breakdown spectroscopy (LIBS) has shown promise as a technique to quickly determine molten metal chemistry in real time. Because of its characteristics, LIBS could also be used as a technique to sense for unwanted inclusions and impurities. Simulated Al2O3 inclusions were added to molten aluminum via a metal-matrix composite. LIBS was performed in situ to determine whether particles could be detected. Outlier analysis on oxygen signal was performed on LIBS data and compared to oxide volume fraction measured through metallography. It was determined that LIBS could differentiate between melts with different amounts of inclusions by monitoring the fluctuations in signal for elements of interest. LIBS shows promise as an enabling tool for monitoring metal cleanliness.

Research progress in Asia on methods of processing laser-induced breakdown spectroscopy data

NASA Astrophysics Data System (ADS)

Guo, Yang-Min; Guo, Lian-Bo; Li, Jia-Ming; Liu, Hong-Di; Zhu, Zhi-Hao; Li, Xiang-You; Lu, Yong-Feng; Zeng, Xiao-Yan

2016-10-01

Laser-induced breakdown spectroscopy (LIBS) has attracted much attention in terms of both scientific research and industrial application. An important branch of LIBS research in Asia, the development of data processing methods for LIBS, is reviewed. First, the basic principle of LIBS and the characteristics of spectral data are briefly introduced. Next, two aspects of research on and problems with data processing methods are described: i) the basic principles of data preprocessing methods are elaborated in detail on the basis of the characteristics of spectral data; ii) the performance of data analysis methods in qualitative and quantitative analysis of LIBS is described. Finally, a direction for future development of data processing methods for LIBS is also proposed.

The SuperCam Remote Sensing Suite for MARS 2020: Nested and Co-Aligned LIBS, Raman, and VISIR Spectroscopies, and color micro-imaging

NASA Astrophysics Data System (ADS)

Fouchet, Thierry; Wiens, Roger; Maurice, Sylvestre; Johnson, Jeffrey R.; Clegg, Samuel; Sharma, Shiv; Rull, Fernando; Montmessin, Franck; Anderson, Ryan; Beyssac, Olivier; Bonal, Lydie; Deflores, Lauren; Dromart, Gilles; Fischer, William; Forni, Olivier; Gasnault, Olivier; Grotzinger, John P.; Mangold, Nicolas; Martinez-Frias, Jesus; MacLennan, Scott; McCabe, Kevin; cais, Philippe; Nelson, Tony; Angel, Stanley; Beck, Pierre; Benzerara, Karim; Bernard, Sylvain; Bousquet, Bruno; Bridges, Nathan; Cloutis, Edward; Fabre, Cécile; Grasset, Olivier; Lanza, Nina; Lasue, Jeremie; Le Mouélic, Stéphane; Leveille, Rich; Lewin, Eric; McConnochie, Timothy H.; Melikechi, Noureddine; Meslin, Pierre-Yves; Misra, Anupam; Montagnac, Gilles; Newsom, Horton; Ollila, Ann; Pinet, Patrick; Poulet, Francois; Sobron, Pablo

2016-10-01

As chartered by the Science Definition Team, the Mars 2020 mission addresses four primary objectives: A. Characterize the processes that formed and modified the geologic record within an astrobiologically relevant ancient environment, B. Perform astrobiologically relevant investigations to determine habitability, search for materials with biosignature presentation potential, and search for evidence of past life, C. Assemble a returnable cache of samples and D. Contribute to preparation for human exploration of Mars. The SuperCam instrument, selected for the Mars 2020 rover, as a suite of four instruments, provides nested and co-aligned remote investigations: Laser Induced Breakdown Spectroscopy (LIBS), Raman spectroscopy and time-resolved fluorescence (TRF), visible and near-infrared spectroscopy (VISIR), and high resolution color imaging (RMI). SuperCam appeals broadly to the four Mars 2020 objectives.In detail, SuperCam will perform:1. Microscale mineral identification by combining LIBS elemental and VISIR mineralogical spectroscopies, especially targeting secondary minerals2. Determine the sedimental stratigraphy through color imaging and LIBS and VISIR spectroscopy3. Search for organics and bio-signatures with LIBS and Raman spectroscopy4. Quantify the volatile content of the rocks by LIBS spectroscopy to determine the degree of aquaeous alteration5. Characterize the texture of the rocks by color imaging to determine their alteration processes6. Characterize the rocks' coatings by LIBS spectroscopy7. Characterize the soil and its potential for biosignature preservation8. Monitor the odd-oxygen atmospheric chemistry.To meet these goals SuperCam will perform LIBS spectroscopy on 0.5 mm spot up to 7-meter distance, perform Raman and time-resolved fluoresence up to 12-m distance with a 0.8 mrad angular resolution, a 100 ns time gating in the 534-850 nm spectral range, acquire VISIR spectra in the range 0.4-0.85 μm with a resolution of 0.35 nm, and in the IR range over 1.3-2.6 μm, rich in mineral signatures, with a resolution of 20 nm, and provide RGB images with an angular resolution of 40 μrad over a FOV of 20 mrad.We will present the science performances of SuperCam and the forecasted operation plans.

Combined Raman/LIBS spectrometer elegant breadboard: built and tested - and flight model spectrometer unit

NASA Astrophysics Data System (ADS)

Ahlers, B.; Hutchinson, I.; Ingley, R.

2017-11-01

A spectrometer for combined Raman and Laser Induced Breakdown Spectroscopy (LIBS) is amongst the different instruments that have been pre-selected for the Pasteur payload of the ExoMars rover. It is regarded as a fundamental, next-generation instrument for organic, mineralogical and elemental characterisation of Martian soil, rock samples and organic molecules. Raman spectroscopy and LIBS will be integrated into a single instrument sharing many hardware commonalities [1]. The combined Raman / LIBS instrument has been recommended as the highest priority mineralogy instrument to be included in the rover's analytical laboratory for the following tasks: Analyse surface and sub-surface soil and rocks on Mars, identify organics in the search for life and determine soil origin & toxicity. The synergy of the system is evident: the Raman spectrometer is dedicated to molecular analysis of organics and minerals; the LIBS provides information on the sample's elemental composition. An international team, under ESA contract and with the leadership of TNO Science and Industry, has built and tested an Elegant Bread Board (EBB) of the combined Raman / LIBS instrument. The EBB comprises a specifically designed, extremely compact, spectrometer with high resolution over a large wavelength range, suitable for both Raman spectroscopy and LIBS measurements. The EBB also includes lasers, illumination and imaging optics as well as fibre optics for light transfer. A summary of the functional and environmental requirements together with a description of the optical design and its expected performance are described in [2]. The EBB was developed and constructed to verify the instruments' end-to-end functional performance with natural samples. The combined Raman / LIBS EBB realisation and test results of natural samples will be presented. For the Flight Model (FM) instrument, currently in the design phase, the Netherlands will be responsible for the design, development and verification of the spectrometer unit, while the UK provides the detector. The differences between the EBB and the FM will be demonstrated.

Temperature and Electron Density Determination on Laser-Induced Breakdown Spectroscopy (LIBS) Plasmas: A Physical Chemistry Experiment

ERIC Educational Resources Information Center

Najarian, Maya L.; Chinni, Rosemarie C.

2013-01-01

This laboratory is designed for physical chemistry students to gain experience using laser-induced breakdown spectroscopy (LIBS) in understanding plasma diagnostics. LIBS uses a high-powered laser that is focused on the sample causing a plasma to form. The emission of this plasma is then spectrally resolved and detected. Temperature and electron…

Feasibility of laser-induced breakdown spectroscopy (LIBS) for classification of sea salts.

PubMed

Tan, Man Minh; Cui, Sheng; Yoo, Jonghyun; Han, Song-Hee; Ham, Kyung-Sik; Nam, Sang-Ho; Lee, Yonghoon

2012-03-01

We have investigated the feasibility of laser-induced breakdown spectroscopy (LIBS) as a fast, reliable classification tool for sea salts. For 11 kinds of sea salts, potassium (K), magnesium (Mg), calcium (Ca), and aluminum (Al), concentrations were measured by inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and the LIBS spectra were recorded in the narrow wavelength region between 760 and 800 nm where K (I), Mg (I), Ca (II), Al (I), and cyanide (CN) band emissions are observed. The ICP-AES measurements revealed that the K, Mg, Ca, and Al concentrations varied significantly with the provenance of each salt. The relative intensities of the K (I), Mg (I), Ca (II), and Al (I) peaks observed in the LIBS spectra are consistent with the results using ICP-AES. The principal component analysis of the LIBS spectra provided the score plot with quite a high degree of clustering. This indicates that classification of sea salts by chemometric analysis of LIBS spectra is very promising. Classification models were developed by partial least squares discriminant analysis (PLS-DA) and evaluated. In addition, the Al (I) peaks enabled us to discriminate between different production methods of the salts. © 2012 Society for Applied Spectroscopy

Relative spectral response calibration using Ti plasma lines

NASA Astrophysics Data System (ADS)

Teng, FEI; Congyuan, PAN; Qiang, ZENG; Qiuping, WANG; Xuewei, DU

2018-04-01

This work introduces the branching ratio (BR) method for determining relative spectral responses, which are needed routinely in laser induced breakdown spectroscopy (LIBS). Neutral and singly ionized Ti lines in the 250–498 nm spectral range are investigated by measuring laser-induced micro plasma near a Ti plate and used to calculate the relative spectral response of an entire LIBS detection system. The results are compared with those of the conventional relative spectral response calibration method using a tungsten halogen lamp, and certain lines available for the BR method are selected. The study supports the common manner of using BRs to calibrate the detection system in LIBS setups.

Fabrication and testing of a standoff trace explosives detection system

NASA Astrophysics Data System (ADS)

Waterbury, Robert; Rose, Jeremy; Vunck, Darius; Blank, Thomas; Pohl, Ken; Ford, Alan; McVay, Troy; Dottery, Ed

2011-05-01

In order to stop the transportation of materials used for IED manufacture, a standoff checkpoint explosives detection system (CPEDS) has recently been fabricated. The system incorporates multi-wavelength Raman spectroscopy and laser induced breakdown spectroscopy (LIBS) modalities with a LIBS enhancement technique called TEPS to be added later into a single unit for trace detection of explosives at military checkpoints. Newly developed spectrometers and other required sensors all integrated with a custom graphical user interface for producing simplified, real-time detection results are also included in the system. All equipment is housed in a military ruggedized shelter for potential deployment intheater for signature collection. Laboratory and performance data, as well as the construction of the CPEDS system and its potential deployment capabilities, will be presented in the current work.

Determination of lead content in drilling fueled soil using laser induced spectral analysis and its cross validation using ICP/OES method.

PubMed

Rehan, I; Gondal, M A; Rehan, K

2018-05-15

A detection system based on Laser Induced Breakdown Spectroscopy (LIBS) was designed, optimized, and successfully employed for the estimation of lead (Pb) content in drilling fueled soil (DFS) collected from oil field drilling areas in Pakistan. The concentration of Pb was evaluated by the standard calibration curve method as well as by using an approach based on the integrated intensity of strongest emission of an element of interest. Remarkably, our investigation clearly demonstrated that the concentration of Pb in drilling fueled soil collected at the exact drilling site was greater than the safe permissible limits. Furthermore, the Pb concentration was observed to decline with increasing distance away from the specific drilling point. Analytical determinations were carried out under the assumptions that laser generated plasma was optically thin and in local thermodynamic equilibrium (LTE). In order to improve the sensitivity of our LIBS detection system, various parametric dependence studies were performed. To further validate the precision of our LIBS results, the concentration of Pb present in the acquired samples were also quantified via a standard analytical tool like inductively coupled plasma/optical emission spectroscopy (ICP/OES). Both results were in excellent agreement, implying remarkable reliability for the LIBS data. Furthermore, the Limit of detection (LOD) of our LIBS system for Pb was estimated to be 125.14 mg L -1 . Copyright © 2018 Elsevier B.V. All rights reserved.

Preliminary study on detection sediment contamination in soil affected by the Indian Ocean giant tsunami 2004 in Aceh, Indonesia using laser-induced breakdown spectroscopy (LIBS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Idris, Nasrullah, E-mail: nasrullah.idris@unsyiah.ac.id; Ramli, Muliadi; Hedwig, Rinda

This work is intended to asses the capability of LIBS for the detection of the tsunami sediment contamination in soil. LIBS apparatus used in this work consist of a laser system and an optical multichannel analyzer (OMA) system. The soil sample was collected from in Banda Aceh City, Aceh, Indonesia, the most affected region by the giant Indian Ocean tsunami 2004. The laser beam was focused onto surface of the soil pellet using a focusing lens to produce luminous plasma. The experiment was conducted under air as surrounding gas at 1 atmosphere. The emission spectral lines from the plasma weremore » detected by the OMA system. It was found that metal including heavy metals can surely be detected, thus implying the potent of LIBS technique as a fast screening tools of tsunami sediment contamination.« less

Development of a compact underwater laser-induced breakdown spectroscopy (LIBS) system and preliminary results in sea trials.

PubMed

Guo, Jinjia; Lu, Yuan; Cheng, Kai; Song, Jiaojian; Ye, Wangquan; Li, Nan; Zheng, Ronger

2017-10-10

The exploitation and research of deep-sea hydrothermal vent has been an issue of great interest in ocean research in recent years. Laser-induced breakdown spectroscopy (LIBS) has great potential for ocean application due to the capabilities of stand-off, multiphase, and multielement analysis. In this work, a newly developed compact 4000 m rated LIBS system (LIBSea) is introduced with preliminary results of sea trials. The underwater system consists of an Nd:YAG single-pulsed laser operating at 1064 nm, an optical fiber spectrometer, an optics module, and an electronic controller module. The whole system is housed in an L800  mm×ϕ258  mm pressure housing with an optical window on the end cap. It was deployed on the remote operated vehicle Faxian on the research vessel Kexue, and in June 2015 was successfully applied for hydrothermal field measurements at the Manus area. The obtained results are shown that the LIBS system is capable of detecting elements Li, Na, K, Ca, and Mg in the hydrothermal area. Profiles of LIBS signals of elements K and Ca have also been obtained during the sea trial. The results show that the K emission line is gradually broadened with depth from sea surface to sea floor (1800 m or so); the K intensity shows a hump shape with maximum value at about 1050 m. The Ca emission line is rapidly broadened below 400 m and slowly narrowed to the sea floor; the Ca intensity shows no obvious change below 400 m and increases continuously to sea floor. A very interesting finding is that the small fluctuations of intensity profile curve of Ca show a degree of correlation with seawater temperature change. The sea trial results prove the performance of LIBSea. After further optimization, it is hoped to apply the LIBS system to the in situ mineral deposits and hydrothermal vent fluid detection in deep sea.

Study of archaeological coins of different dynasties using libs coupled with multivariate analysis

NASA Astrophysics Data System (ADS)

Awasthi, Shikha; Kumar, Rohit; Rai, G. K.; Rai, A. K.

2016-04-01

Laser Induced Breakdown Spectroscopy (LIBS) is an atomic emission spectroscopic technique having unique capability of an in-situ monitoring tool for detection and quantification of elements present in different artifacts. Archaeological coins collected form G.R. Sharma Memorial Museum; University of Allahabad, India has been analyzed using LIBS technique. These coins were obtained from excavation of Kausambi, Uttar Pradesh, India. LIBS system assembled in the laboratory (laser Nd:YAG 532 nm, 4 ns pulse width FWHM with Ocean Optics LIBS 2000+ spectrometer) is employed for spectral acquisition. The spectral lines of Ag, Cu, Ca, Sn, Si, Fe and Mg are identified in the LIBS spectra of different coins. LIBS along with Multivariate Analysis play an effective role for classification and contribution of spectral lines in different coins. The discrimination between five coins with Archaeological interest has been carried out using Principal Component Analysis (PCA). The results show the potential relevancy of the methodology used in the elemental identification and classification of artifacts with high accuracy and robustness.

A compact LIBS system for industrial applications

NASA Astrophysics Data System (ADS)

Noharet, B.; Sterner, C.; Irebo, T.; Gurell, J.; Bengtson, A.; Vainik, R.; Karlsson, H.; Illy, E.

2015-03-01

In recent years, laser-induced breakdown spectroscopy (LIBS) has been established as a promising analytical tool for online chemical analysis. The emitted light spectrum is analyzed for instantaneous determination of the elemental composition of the sample, enabling on-line classification of materials. Two major strengths of the technique are the possibilities to perform both fast and remote chemical analysis to determine the elemental composition of the samples under test. In order to reduce the size of LIBS systems, the use of a compact Q-switched diode-pumped solid-state laser (DPSSL) in a LIBS system is evaluated for the industrial sorting of aluminium alloys. The DPSSL, which delivers 150μJ pulses of high beam quality at more than 7KHz repetition rate, provides irradiance on the target that is appropriate for LIBS measurements. The experimental results indicate that alloy classification and quantitative analysis are possible on scrap aluminium samples placed 50 cm apart from the focusing and collecting lenses, without sample preparation. Similar calibration curves and limits of detection are obtained for traditional high-energy low-frequency flashlamp-pumped and low-energy high-frequency diode-pumped lasers, showing the applicability of compact diode-pumped lasers for industrial LIBS applications.

Laser ablation-laser induced breakdown spectroscopy for the measurement of total elemental concentration in soils.

PubMed

Pareja, Jhon; López, Sebastian; Jaramillo, Daniel; Hahn, David W; Molina, Alejandro

2013-04-10

The performances of traditional laser-induced breakdown spectroscopy (LIBS) and laser ablation-LIBS (LA-LIBS) were compared by quantifying the total elemental concentration of potassium in highly heterogeneous solid samples, namely soils. Calibration curves for a set of fifteen samples with a wide range of potassium concentrations were generated. The LA-LIBS approach produced a superior linear response different than the traditional LIBS scheme. The analytical response of LA-LIBS was tested with a large set of different soil samples for the quantification of the total concentration of Fe, Mn, Mg, Ca, Na, and K. Results showed an acceptable linear response for Ca, Fe, Mg, and K while poor signal responses were found for Na and Mn. Signs of remaining matrix effects for the LA-LIBS approach in the case of soil analysis were found and discussed. Finally, some improvements and possibilities for future studies toward quantitative soil analysis with the LA-LIBS technique are suggested.

Laser-induced breakdown spectroscopy (LIBS): applications in environmental issues

NASA Astrophysics Data System (ADS)

Couris, Stelios; Hatziapostolou, A.; Anglos, Dmitrios; Mavromanolakis, A.; Fotakis, Costas

1996-11-01

Results are presented from three different applications of laser induced breakdown spectroscopy (LIBS) in problems of environmental interest. In one case, LIBS is applied in the on-line control of the nickel recovery process, by monitoring the nickel content of molten ferronickel slabs, in a laboratory scale experiment. In a second case, LIBS is used in the identification of polymer materials, and on the basis of spectral features, criteria are proposed for the distinction among different types of plastic materials. Also, in preliminary experiments, the use of LIBS with respect to the detection of heavy and toxic metals in paints and the possibility of performing depth profile analysis of multiple paint layers is examined.

Laser-induced breakdown spectroscopy using mid-infrared femtosecond pulses

DOE PAGES

Hartig, K. C.; Colgan, J.; Kilcrease, D. P.; ...

2015-07-30

Here, we report on a laser-induced breakdown spectroscopy (LIBS) experiment driven by mid-infrared (2.05-μm) fs pulses, in which time-resolved emission spectra of copper were studied. Ab-initio modeling is consistent with the results of new fs measurements at 2.05 μm and traditional 800-nm fs-LIBS. Ablation by mid-infrared fs pulses results in a plasma with a lower plasma density and temperature compared to fs-LIBS performed at shorter laser wavelength. LIBS driven by mid-infrared fs pulses results in a signal-to-background ratio ~50% greater and a signal-to-noise ratio ~40% lower than fs-LIBS at near-infrared laser wavelength.

Design optimization of Cassegrain telescope for remote explosive trace detection

NASA Astrophysics Data System (ADS)

Bhavsar, Kaushalkumar; Eseller, K. E.; Prabhu, Radhakrishna

2017-10-01

The past three years have seen a global increase in explosive-based terror attacks. The widespread use of improvised explosives and anti-personnel landmines have caused thousands of civilian casualties across the world. Current scenario of globalized civilization threat from terror drives the need to improve the performance and capabilities of standoff explosive trace detection devices to be able to anticipate the threat from a safe distance to prevent explosions and save human lives. In recent years, laser-induced breakdown spectroscopy (LIBS) is an emerging approach for material or elemental investigations. All the principle elements on the surface are detectable in a single measurement using LIBS and hence, a standoff LIBS based method has been used to remotely detect explosive traces from several to tens of metres distance. The most important component of LIBS based standoff explosive trace detection system is the telescope which enables remote identification of chemical constituents of the explosives. However, in a compact LIBS system where Cassegrain telescope serves the purpose of laser beam delivery and light collection, need a design optimization of the telescope system. This paper reports design optimization of a Cassegrain telescope to detect explosives remotely for LIBS system. A design optimization of Schmidt corrector plate was carried out for Nd:YAG laser. Effect of different design parameters was investigated to eliminate spherical aberration in the system. Effect of different laser wavelengths on the Schmidt corrector design was also investigated for the standoff LIBS system.

Non-Gated Laser Induced Breakdown Spectroscopy Provides a Powerful Segmentation Tool on Concomitant Treatment of Characteristic and Continuum Emission

PubMed Central

Dasari, Ramachandra Rao; Barman, Ishan; Gundawar, Manoj Kumar

2014-01-01

We demonstrate the application of non-gated laser induced breakdown spectroscopy (LIBS) for characterization and classification of organic materials with similar chemical composition. While use of such a system introduces substantive continuum background in the spectral dataset, we show that appropriate treatment of the continuum and characteristic emission results in accurate discrimination of pharmaceutical formulations of similar stoichiometry. Specifically, our results suggest that near-perfect classification can be obtained by employing suitable multivariate analysis on the acquired spectra, without prior removal of the continuum background. Indeed, we conjecture that pre-processing in the form of background removal may introduce spurious features in the signal. Our findings in this report significantly advance the prior results in time-integrated LIBS application and suggest the possibility of a portable, non-gated LIBS system as a process analytical tool, given its simple instrumentation needs, real-time capability and lack of sample preparation requirements. PMID:25084522

Rapid long-wave infrared laser-induced breakdown spectroscopy measurements using a mercury-cadmium-telluride linear array detection system.

PubMed

Yang, Clayton S-C; Brown, Eiei; Kumi-Barimah, Eric; Hommerich, Uwe; Jin, Feng; Jia, Yingqing; Trivedi, Sudhir; D'souza, Arvind I; Decuir, Eric A; Wijewarnasuriya, Priyalal S; Samuels, Alan C

2015-11-20

In this work, we develop a mercury-cadmium-telluride linear array detection system that is capable of rapidly capturing (∼1-5  s) a broad spectrum of atomic and molecular laser-induced breakdown spectroscopy (LIBS) emissions in the long-wave infrared (LWIR) region (∼5.6-10  μm). Similar to the conventional UV-Vis LIBS, a broadband emission spectrum of condensed phase samples covering the whole 5.6-10 μm region can be acquired from just a single laser-induced microplasma or averaging a few single laser-induced microplasmas. Atomic and molecular signature emission spectra of solid inorganic and organic tablets and thin liquid films deposited on a rough asphalt surface are observed. This setup is capable of rapidly probing samples "as is" without the need of elaborate sample preparation and also offers the possibility of a simultaneous UV-Vis and LWIR LIBS measurement.

Laser-Induced Breakdown Spectroscopy (LIBS) Measurement of Uranium in Molten Salt.

PubMed

Williams, Ammon; Phongikaroon, Supathorn

2018-01-01

In this current study, the molten salt aerosol-laser-induced breakdown spectroscopy (LIBS) system was used to measure the uranium (U) content in a ternary UCl 3 -LiCl-KCl salt to investigate and assess a near real-time analytical approach for material safeguards and accountability. Experiments were conducted using five different U concentrations to determine the analytical figures of merit for the system with respect to U. In the analysis, three U lines were used to develop univariate calibration curves at the 367.01 nm, 385.96 nm, and 387.10 nm lines. The 367.01 nm line had the lowest limit of detection (LOD) of 0.065 wt% U. The 385.96 nm line had the best root mean square error of cross-validation (RMSECV) of 0.20 wt% U. In addition to the univariate calibration approach, a multivariate partial least squares (PLS) model was developed to further analyze the data. Using partial least squares (PLS) modeling, an RMSECV of 0.085 wt% U was determined. The RMSECV from the multivariate approach was significantly better than the univariate case and the PLS model is recommended for future LIBS analysis. Overall, the aerosol-LIBS system performed well in monitoring the U concentration and it is expected that the system could be used to quantitatively determine the U compositions within the normal operational concentrations of U in pyroprocessing molten salts.

Emission Characteristics of Laser-Induced Plasma Using Collinear Long and Short Dual-Pulse Laser-Induced Breakdown Spectroscopy (LIBS).

PubMed

Wang, Zhenzhen; Deguchi, Yoshihiro; Liu, Renwei; Ikutomo, Akihiro; Zhang, Zhenzhen; Chong, Daotong; Yan, Junjie; Liu, Jiping; Shiou, Fang-Jung

2017-09-01

Collinear long and short dual-pulse laser-induced breakdown spectroscopy (DP-LIBS) was employed to clarify the emission characteristics from laser-induced plasma. The plasma was sustained and became stable by the long pulse-width laser with the pulse width of 60 μs under free running (FR) conditions as an external energy source. Comparing the measurement results of stainless steel in air using single-pulse LIBS (SP-LIBS) and DP-LIBS, the emission intensity was markedly enhanced using DP-LIBS. The temperature of plasma induced by DP-LIBS was maintained at a higher temperature under different gate delay time and short pulse-width laser power conditions compared with those measured using short SP-LIBS. Moreover, the variation rates of plasma temperatures measured using DP-LIBS were also lower. The superior detection ability was verified by the measurement of aluminum sample in water. The spectra were clearly detected using DP-LIBS, whereas it cannot be identified using SP-LIBS of short and long pulse widths. The effects of gate delay time and short pulse-width laser power were also discussed. These results demonstrate the feasibility and enhanced detection ability of the proposed collinear long and short DP-LIBS method.

Evaluation of Optical Depths and Self-Absorption of Strontium and Aluminum Emission Lines in Laser-Induced Breakdown Spectroscopy (LIBS).

PubMed

Alfarraj, Bader A; Bhatt, Chet R; Yueh, Fang Yu; Singh, Jagdish P

2017-04-01

Laser-induced breakdown spectroscopy (LIBS) is a widely used laser spectroscopic technique in various fields, such as material science, forensic science, biological science, and the chemical and pharmaceutical industries. In most LIBS work, the analysis is performed using radiative transitions from atomic emissions. In this study, the plasma temperature and the product [Formula: see text] (the number density N and the absorption path length [Formula: see text]) were determined to evaluate the optical depths and the self-absorption of Sr and Al lines. A binary mixture of strontium nitrate and aluminum oxide was used as a sample, consisting of variety of different concentrations in powder form. Laser-induced breakdown spectroscopy spectra were collected by varying various parameters, such as laser energy, gate delay time, and gate width time to optimize the LIBS signals. Atomic emission from Sr and Al lines, as observed in the LIBS spectra of different sample compositions, was used to characterize the laser induced plasma and evaluate the optical depths and self-absorption of LIBS.

Laser-induced breakdown spectroscopy (LIBS), part II: review of instrumental and methodological approaches to material analysis and applications to different fields.

PubMed

Hahn, David W; Omenetto, Nicoló

2012-04-01

The first part of this two-part review focused on the fundamental and diagnostics aspects of laser-induced plasmas, only touching briefly upon concepts such as sensitivity and detection limits and largely omitting any discussion of the vast panorama of the practical applications of the technique. Clearly a true LIBS community has emerged, which promises to quicken the pace of LIBS developments, applications, and implementations. With this second part, a more applied flavor is taken, and its intended goal is summarizing the current state-of-the-art of analytical LIBS, providing a contemporary snapshot of LIBS applications, and highlighting new directions in laser-induced breakdown spectroscopy, such as novel approaches, instrumental developments, and advanced use of chemometric tools. More specifically, we discuss instrumental and analytical approaches (e.g., double- and multi-pulse LIBS to improve the sensitivity), calibration-free approaches, hyphenated approaches in which techniques such as Raman and fluorescence are coupled with LIBS to increase sensitivity and information power, resonantly enhanced LIBS approaches, signal processing and optimization (e.g., signal-to-noise analysis), and finally applications. An attempt is made to provide an updated view of the role played by LIBS in the various fields, with emphasis on applications considered to be unique. We finally try to assess where LIBS is going as an analytical field, where in our opinion it should go, and what should still be done for consolidating the technique as a mature method of chemical analysis. © 2012 Society for Applied Spectroscopy

Comparative measurements of mineral elements in milk powders with laser-induced breakdown spectroscopy and inductively coupled plasma atomic emission spectroscopy.

PubMed

Lei, W Q; El Haddad, J; Motto-Ros, V; Gilon-Delepine, N; Stankova, A; Ma, Q L; Bai, X S; Zheng, L J; Zeng, H P; Yu, J

2011-07-01

Mineral elements contained in commercially available milk powders, including seven infant formulae and one adult milk, were analyzed with inductively coupled plasma atomic emission spectrometry (ICP-AES) and laser-induced breakdown spectroscopy (LIBS). The purpose of this work was, through a direct comparison of the analytical results, to provide an assessment of the performance of LIBS, and especially of the procedure of calibration-free LIBS (CF-LIBS), to deal with organic compounds such as milk powders. In our experiments, the matrix effect was clearly observed affecting the analytical results each time laser ablation was employed for sampling. Such effect was in addition directly observed by determining the physical parameters of the plasmas induced on the different samples. The CF-LIBS procedure was implemented to deduce the concentrations of Mg and K with Ca as the internal reference element. Quantitative analytical results with CF-LIBS were validated with ICP-AES measurements and nominal concentrations specified for commercial milks. The obtained good results with the CF-LIBS procedure demonstrate its capacity to take into account the difference in physical parameters of the plasma in the calculation of the concentrations of mineral elements, which allows a significant reduction of the matrix effect related to laser ablation. We finally discuss the way to optimize the implementation of the CF-LIBS procedure for the analysis of mineral elements in organic materials.

Development of a Method for the Determination of Chromium and Cadmium in Tannery Wastewater Using Laser-Induced Breakdown Spectroscopy

PubMed Central

Bukhari, Mahwish; Awan, M. Ali; Qazi, Ishtiaq A.; Baig, M. Anwar

2012-01-01

This paper illustrates systematic development of a convenient analytical method for the determination of chromium and cadmium in tannery wastewater using laser-induced breakdown spectroscopy (LIBS). A new approach was developed by which liquid was converted into solid phase sample surface using absorption paper for subsequent LIBS analysis. The optimized values of LIBS parameters were 146.7 mJ for chromium and 89.5 mJ for cadmium (laser pulse energy), 4.5 μs (delay time), 70 mm (lens to sample surface distance), and 7 mm (light collection system to sample surface distance). Optimized values of LIBS parameters demonstrated strong spectrum lines for each metal keeping the background noise at minimum level. The new method of preparing metal standards on absorption papers exhibited calibration curves with good linearity with correlation coefficients, R2 in the range of 0.992 to 0.998. The developed method was tested on real tannery wastewater samples for determination of chromium and cadmium. PMID:22567570

Effect of Atmosphere on Collinear Double-Pulse Laser-Induced Breakdown Spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andrew J. Effenberger, Jr; Jill R. Scott

2011-07-01

Double pulse laser induced breakdown spectroscopy (DP-LIBS) has been shown to enhance LIBS spectra. Several researches have reported significant increases in signal-to-noise and or spectral intensity. In addition to DP-LIBS, atmospheric conditions can also increase spectra intensity. For example, He and Ar both increase LIBS intensity compared to air at one 1 atm. It was also found that as the pressure was decreased to 100 Torr, LIBS intensity increased in Ar and air for single pulse (SP) LIBS. In this study, a collinear DP-LIBS scheme is used along with manipulation of the atmospheric conditions. The DP-LIBS scheme consists of amore » 355 nm ablative pulse fired into a sample contained in a vacuum chamber. A second analytical 1064 nm pulse is then fired 100 ns to 10 {micro}s after and along the same path of the first pulse. Ar, He and air at pressures ranging from atmospheric pressure (630 Torr at elevation) to 10{sup -5} Torr are introduced during DP-LIBS and SP-LIBS experiments. For a brass sample, a significant increase in spectral intensity of Cu and Zn lines were observed in DP-LIBS under Ar compared to DP-LIBS in air. It was also found that Cu and Zn lines acquired with SP-LIBS in Ar are nearly as intense as DP-LIBS in air. Signal-to-noise for lines from various samples will be reported for both DP-LIBS and SP-LIBS in Ar, He, and air at pressures ranging from 630 Torr to 10{sup -5} Torr.« less

Effect of atmosphere on collinear double-pulse laser-induced breakdown spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andrew J. Effenberger, Jr.; Jill R. Scott

2010-09-01

Double pulse laser induced breakdown spectroscopy (DP-LIBS) has been shown to enhance LIBS spectra. Several researches have reported significant increases in signal-to-noise and or spectral intensity [1-4]. In addition to DP-LIBS, atmospheric conditions can also increase spectra intensity. For example, Iida [5] found that He and Ar both increase LIBS intensity compared to air at one 1 atm. It was also found that as the pressure was decreased to 100 Torr, LIBS intensity increased in Ar and air for single pulse (SP) LIBS. In this study, a collinear DP-LIBS scheme is used along with manipulation of the atmospheric conditions. Themore » DP-LIBS scheme consists of a 355 nm ablative pulse fired into a sample contained in a vacuum chamber. A second analytical 1064 nm pulse is then fired 100 ns to 10 µs after and along the same path of the first pulse. Ar, He and air at pressures ranging from atmospheric pressure (630 Torr at elevation) to 10-5 Torr are introduced during DP-LIBS and SP-LIBS experiments. For a brass sample, a significant increase in spectral intensity of Cu and Zn lines were observed in DP-LIBS under Ar compared to DP-LIBS in air (Figure 1). It was also found that Cu and Zn lines acquired with SP-LIBS in Ar are nearly as intense as DP-LIBS in air. Signal-to-noise for lines from various samples will be reported for both DP-LIBS and SP-LIBS in Ar, He, and air at pressures ranging from 630 Torr to 10-5 Torr.« less

Novel Estimation of the Humification Degree of Soil Organic Matter by Laser-Induced Breakdown Spectroscopy (LIBS) Compared to Laser-Induced Fluorescence Spectroscopy (LIFS)

NASA Astrophysics Data System (ADS)

Ferreira, Edilene; Ferreira, Ednaldo; Villas-Boas, Paulino; Senesi, Giorgio; Carvalho, Camila; Romano, Renan; Martin-Neto, Ladislau; Milori, Debora

2014-05-01

Soil organic matter (SOM) constitutes an important reservoir of terrestrial carbon and can be considered an alternative for atmospheric carbon storage, contributing to global warming mitigation. Soil management can favor atmospheric carbon incorporation into SOM or its release from SOM to atmosphere. Thus, the evaluation of the humification degree (HD), which is an indication of the recalcitrance of SOM, can provide an estimation of the capacity of carbon sequestration in soils under various managements. The HD of SOM can be estimated by using various analytical techniques including fluorescence spectroscopy. In the present work, the potential of Laser-Induced Breakdown Spectroscopy (LIBS) to estimate the HD of SOM was evaluated for the first time. In a LIBS experiment a high-energy laser pulse irradiates the sample and the energy absorbed by the sample causes a local heating of the material that results in its evaporation or sublimation. The high temperature of the ablated material generates a small plasma plume and, as a result of the plasma temperature, the ablated material breaks down into excited atomic and ionic species. During the plasma cooling, the excited species return to their lower energy state emitting electromagnetic radiation at characteristic wavelengths. In a LIBS spectrum the measurement of the characteristic emission wavelengths provides qualitative information about the elemental composition of the sample, whereas the intensities of the signals can be used for quantitative determinations. The LIBS potential for the analysis of organic compounds has been explored recently by using the emission lines of elements that are commonly present in organic compounds, such as the predominant C, H, P, O and N. LIBS elemental emissions were correlated to fluorescence emissions determined by Laser-Induced Fluorescence Spectroscopy (LIFS), which was considered as the reference technique. The HD of SOM determined by LIBS showed a strong correlation to that determined by LIFS, suggesting a great potential of LIBS for this novel application.

Elemental and mineralogical imaging of a weathered limestone rock by double-pulse micro-Laser-Induced Breakdown Spectroscopy

NASA Astrophysics Data System (ADS)

Senesi, Giorgio S.; Campanella, Beatrice; Grifoni, Emanuela; Legnaioli, Stefano; Lorenzetti, Giulia; Pagnotta, Stefano; Poggialini, Francesco; Palleschi, Vincenzo; De Pascale, Olga

2018-05-01

The present work aims to evaluate the alteration conditions of historical limestone rocks exposed to urban environment using the Laser-Induced Breakdown Spectroscopy (LIBS) technique. The approach proposed is based on the microscale three dimensional (3D) compositional imaging of the sample through double-pulse micro-Laser-Induced Breakdown Spectroscopy (DP-μLIBS) in conjunction with optical microscopy. DP-μLIBS allows to perform a quick and detailed in-depth analysis of the composition of the weathered artifact by creating a 'virtual thin section' (VTS) of the sample which can estimate the extent of the alteration processes occurred at the limestone surface. The DP-μLIBS analysis of these thin sections showed a reduction with depth of the elements (mainly Fe, Si and Na) originating from atmospheric dust, particulate deposition and the surrounding environment (due to the proximity of the sea), whereas, the LIBS signal of Ca increased in intensity from the black crust to the limestone underneath.

Enhancement and stabilization of plasma using collinear long-short double-pulse laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Cui, Minchao; Deguchi, Yoshihiro; Wang, Zhenzhen; Fujita, Yuki; Liu, Renwei; Shiou, Fang-Jung; Zhao, Shengdun

2018-04-01

A collinear long-short dual-pulse laser-induced breakdown spectroscopy (DP-LIBS) method was employed to enhance and stabilize the laser-induced plasma from steel sample. The long-pulse-width laser beam with the pulse width of 60 μs was generated by a Nd: YAG laser which was operated at FR (free running) mode. The comparative experiments were carried out between single pulse LIBS (SP-LIBS) and long-short DP-LIBS. The recorded results showed that the emission intensities and the temperature of plasma were enhanced by long-short DP-LIBS. The plasma images showed that the plasma was bigger and had a longer lifetime in long-short DP-LIBS situation. Through the calculation of time-resolved plasma temperature and intensity ratio, it can be concluded that the plasma was stabilized by the long-pulse-width laser beam. The long-short DP-LIBS method also generated the stable plasma condition from the samples with different initial temperatures, which overcame the difficulties of LIBS in the online measurement for steel production line.

Application of laser induced breakdown spectroscopy (LIBS) instrumentation for international safeguards

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barefield Ii, James E; Clegg, Samuel M; Lopez, Leon N

2010-01-01

Advanced methodologies and improvements to current measurements techniques are needed to strengthen the effectiveness and efficiency of international safeguards. This need was recognized and discussed at a Technical Meeting on 'The Application of Laser Spectrometry Techniques in IAEA Safeguards' held at IAEA headquarters (September 2006). One of the principal recommendations from that meeting was the need to pursue the development of novel complementary access instrumentation based on Laser Induced Breakdown Spectroscopy (UBS) for the detection of gaseous and solid signatures and indicators of nuclear fuel cycle processes and associated materials'. Pursuant to this recommendation the Department of Safeguards (SG) undermore » the Division of Technical Support (SGTS) convened the 'Experts and Users Advisory Meeting on Laser Induced Breakdown Spectroscopy (LIBS) for Safeguards Applications' also held at IAEA headquarters (July 2008). This meeting was attended by 12 LlBS experts from the Czech Republic, the European Commission, France, the Republic of South Korea, the United States of America, Germany, the United Kingdom of Great Britain, Canada, and Northern Ireland. Following a presentation of the needs of the IAEA inspectors, the LIBS experts agreed that needs as presented could be partially or fully fulfilled using LIBS instrumentation. Inspectors needs were grouped into the following broad categories: (1) Improvements to in-field measurements/environmental sampling; (2) Monitoring status of activities in Hot Cells; (3) Verify status of activity at a declared facility via process monitoring; and (4) Need for pre-screening of environmental samples before analysis. The primary tool employed by the IAEA to detect undeclared processes and activities at special nuclear material facilities and sites is environmental sampling. One of the objectives of the Next Generation Safeguards Initiative (NGSI) Program Plan calls for the development of advanced tools and methodologies to detect and analyze undeclared processing or production of special nuclear material. Los Alamos National Laboratory is currently investigating potential uses of LIBS for safeguards applications, including (1) a user-friendly man-portable LIBS system to characterize samples in real to near-real time (typical analysis time are on the order of minutes) across a wide range of elements in the periodic table from hydrogen up to heavy elements like plutonium and uranium, (2) a LIBS system that can be deployed in harsh environments such as hot cells and glove boxes providing relative compositional analysis of process streams for example ratios like Cm/Up and Cm/U, (3) an inspector field deployable system that can be used to analyze the elemental composition of microscopic quantities of samples containing plutonium and uranium, and (4) a high resolution LIBS system that can be used to determine the isotopic composition of samples containing for example uranium, plutonium... etc. In this paper, we will describe our current development and performance testing results for LIBS instrumentation both in a fixed lab and measurements in field deployable configurations.« less

Laser-induced breakdown spectroscopy (LIBS): an overview of recent progress and future potential for biomedical applications.

PubMed

Rehse, S J; Salimnia, H; Miziolek, A W

2012-02-01

The recent progress made in developing laser-induced breakdown spectroscopy (LIBS) has transformed LIBS from an elemental analysis technique to one that can be applied for the reagentless analysis of molecularly complex biological materials or clinical specimens. Rapid advances in the LIBS technology have spawned a growing number of recently published articles in peer-reviewed journals which have consistently demonstrated the capability of LIBS to rapidly detect, biochemically characterize and analyse, and/or accurately identify various biological, biomedical or clinical samples. These analyses are inherently real-time, require no sample preparation, and offer high sensitivity and specificity. This overview of the biomedical applications of LIBS is meant to summarize the research that has been performed to date, as well as to suggest to health care providers several possible specific future applications which, if successfully implemented, would be significantly beneficial to humankind.

Double-pulse laser-induced breakdown spectroscopy analysis of scales from petroleum pipelines

NASA Astrophysics Data System (ADS)

Cavalcanti, G. H.; Rocha, A. A.; Damasceno, R. N.; Legnaioli, S.; Lorenzetti, G.; Pardini, L.; Palleschi, V.

2013-09-01

Pipeline scales from the Campos Bay Petroleum Field near Rio de Janeiro, Brazil have been analyzed by both Raman spectroscopy and by laser-induced breakdown spectroscopy (LIBS) using a double-pulse, calibration-free approach. Elements that are characteristic of petroleum (e.g. C, H, N, O, Mg, Na, Fe and V) were detected, in addition to the Ca, Al, and Si which form the matrix of the scale. The LIBS results were compared with the results of micro-Raman spectroscopy, which confirmed the nature of the incrustations inferred by the LIBS analysis. Results of this preliminary study suggest that diffusion of pipe material into the pipeline intake column plays an important role in the growth of scale. Thanks to the simplicity and relative low cost of equipment and to the fact that no special chemical pre-treatment of the samples is needed, LIBS can offer very fast acquisition of data and the possibility of in situ measurements. LIBS could thus represent an alternative or complementary method for the chemical characterization of the scales by comparison to conventional analytical techniques, such as X-ray diffraction or X-ray fluorescence.

Detection and quantification of a toxic salt substitute (LiCl) by using laser induced breakdown spectroscopy (LIBS).

PubMed

Sezer, Banu; Velioglu, Hasan Murat; Bilge, Gonca; Berkkan, Aysel; Ozdinc, Nese; Tamer, Ugur; Boyaci, Ismail Hakkı

2018-01-01

The use of Li salts in foods has been prohibited due to their negative effects on central nervous system; however, they might still be used especially in meat products as Na substitutes. Lithium can be toxic and even lethal at higher concentrations and it is not approved in foods. The present study focuses on Li analysis in meatballs by using laser induced breakdown spectroscopy (LIBS). Meatball samples were analyzed using LIBS and flame atomic absorption spectroscopy. Calibration curves were obtained by utilizing Li emission lines at 610nm and 670nm for univariate calibration. The results showed that Li calibration curve at 670nm provided successful determination of Li with 0.965 of R 2 and 4.64ppm of limit of detection (LOD) value. While Li Calibration curve obtained using emission line at 610nm generated R 2 of 0.991 and LOD of 22.6ppm, calibration curve obtained at 670nm below 1300ppm generated R 2 of 0.965 and LOD of 4.64ppm. Copyright © 2017. Published by Elsevier Ltd.

Surface characterization of stainless HP-40 steel using laser induced μ-breakdown spectroscopy (μ -LIBS)

NASA Astrophysics Data System (ADS)

Pinto, M.; Calderón, X.; Mejía Ospino, E.; Cabanzo, R.; Poveda, Juan C.

2016-02-01

In the present study, optical microscopy in stereoscopic mode coupled to laser- induced p-breakdown spectroscopy (μ-LIBS) was applied for analysing HP-40 steel samples. microLIBS (μ-LIBS) is a new growing area that employs low energy laser pulses for the generation of plasma emission, which allow the realization of localized microanalysis [1]. This new LIBS instrument was used for the surface characterization of the steel samples in the spectral range from 356 to 401nm. Elements such as Cr, Ni, Fe, Nb, Pb, Mo, C, Mn and Si in the steel samples were investigated. The results allowed the construction of elemental distribution profiles of the samples. Complementary the HP-40 steel samples were superficially characterized by Scanning Electron Microscope (SEM).

Laser-Induced Breakdown Spectroscopy (LIBS) for Monitoring the Formation of Hydroxyapatite Porous Layers

PubMed Central

Sola, Daniel; Paulés, Daniel; Grima, Lorena

2017-01-01

Laser-induced breakdown spectroscopy (LIBS) is applied to characterize the formation of porous hydroxyapatite layers on the surface of 0.8CaSiO3-0.2Ca3(PO4)2 biocompatible eutectic glass immersed in simulated body fluid (SBF). Compositional and structural characterization analyses were also conducted by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), and micro-Raman spectroscopy. PMID:29211006

Applications of Laser-Induced Breakdown Spectroscopy (LIBS) in Molten Metal Processing

NASA Astrophysics Data System (ADS)

Hudson, Shaymus W.; Craparo, Joseph; De Saro, Robert; Apelian, Diran

2017-10-01

In order for metals to meet the demand for critical applications in the automotive, aerospace, and defense industries, tight control over the composition and cleanliness of the metal must be achieved. The use of laser-induced breakdown spectroscopy (LIBS) for applications in metal processing has generated significant interest for its ability to perform quick analyses in situ. The fundamentals of LIBS, current techniques for deployment on molten metal, demonstrated capabilities, and possible avenues for development are reviewed and discussed.

Generation of a Database of Laboratory Laser-Induced Breakdown Spectroscopy (LIBS) Spectra and Associated Analysis Software

NASA Astrophysics Data System (ADS)

Anderson, R. B.; Clegg, S. M.; Graff, T.; Morris, R. V.; Laura, J.

2015-06-01

We describe plans to generate a database of LIBS spectra of planetary analog materials and develop free, open-source software to enable the planetary community to analyze LIBS (and other spectral) data.

Feasibility of atomic and molecular laser induced breakdown spectroscopy (LIBS) to in-situ determination of chlorine in concrete : final report.

DOT National Transportation Integrated Search

2016-10-01

Laser-induced breakdown spectroscopy (LIBS) has been studied as a fast method of detecting chlorine in concrete samples. Both single pulse (SP) and double pulse (DP) experiments have been tested. Several combinations of lasers (Neodymium-Yttrium Alum...

Detection of Anomalies in Citrus Leaves Using Laser-Induced Breakdown Spectroscopy (LIBS).

PubMed

Sankaran, Sindhuja; Ehsani, Reza; Morgan, Kelly T

2015-08-01

Nutrient assessment and management are important to maintain productivity in citrus orchards. In this study, laser-induced breakdown spectroscopy (LIBS) was applied for rapid and real-time detection of citrus anomalies. Laser-induced breakdown spectroscopy spectra were collected from citrus leaves with anomalies such as diseases (Huanglongbing, citrus canker) and nutrient deficiencies (iron, manganese, magnesium, zinc), and compared with those of healthy leaves. Baseline correction, wavelet multivariate denoising, and normalization techniques were applied to the LIBS spectra before analysis. After spectral pre-processing, features were extracted using principal component analysis and classified using two models, quadratic discriminant analysis and support vector machine (SVM). The SVM resulted in a high average classification accuracy of 97.5%, with high average canker classification accuracy (96.5%). LIBS peak analysis indicated that high intensities at 229.7, 247.9, 280.3, 393.5, 397.0, and 769.8 nm were observed of 11 peaks found in all the samples. Future studies using controlled experiments with variable nutrient applications are required for quantification of foliar nutrients by using LIBS-based sensing.

Application of Laser Induced Breakdown Spectroscopy to Monitor Rare Earth Ions in Glass Matrix

NASA Astrophysics Data System (ADS)

Sharma, Prakash; Carter, Michael; Kumar, Akshaya

2013-05-01

The Laser Induced breakdown spectroscopy (LIBS) is a real time online technique that can be used to monitor the concentration of rare earth ions in amorphous glass matrix. This study has significant application in the glass industry where the composition of the glass can be monitored in real time using LIBS technology for quality control. The Eu3 + ions doped silicate glasses were developed via sol gel method. The glasses of varying molar percentages of Eu3 + (0.02, 0.05 and 0.08 mole percent), were prepared to study the effect of variation in concentration of Eu3 + ions on the LIBS signal and to calculate its limit of detection (LOD). The spectral assignment of the observed LIBS spectrum has been made. In order to find the maximum signal to noise ratio, we also recorded the intensity of LIBS signal for various integration start delay (ISD) time at a constant power of (pulsed Nd: YAG) laser. The ocean optics LIBS 2500plus spectrometer along with a Q switched Nd:YAG laser (Quantel, Big Sky) were used to record the LIBS spectrum.

Qualitative and quantitative analysis of human nails to find correlation between nutrients and vitamin D deficiency using LIBS and ICP-AES.

PubMed

Almessiere, M A; Altuwiriqi, R; Gondal, M A; AlDakheel, R K; Alotaibi, H F

2018-08-01

In this work, we analysed human fingernails of people who suffer from vitamin D deficiency using the laser-induced breakdown spectroscopy(LIBS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES)techniques. The measurements have been conducted on 71 nail samples collected randomly from volunteers of different genders and ages ranged between 20 and 50 years. The main aim of this study is to find the correlation between vitamin D deficiency and the intensity of some dominated lines in the LIBS spectra. A LIBS spectrum consists of dominant lines of fifteen elements including calcium, magnesium, sodium, potassium, titanium, iron, chloride, sulphur, copper, chromium, zinc, nitrogen, phosphor, and oxygen. By recording the spectrum in specific ranges and focusing on calcium, magnesium, sodium, and potassium, we found a correlation between the intensity of the potassium (K) lines at (766.5 and 769.9 nm)and vitamin D level in both age groups (20 and 25 years old), with weak correlation for the calcium (Ca), magnesium (Mg), and sodium (Na) lines. To verify the validity of the LIBS results, we analysed the nail samples with ICP, a standard analytical technique. The elements detected with our LIBS technique are in a good agreement with those identified by ICP-AES. From the health and physiological perspectives, the LIBS system, which is used for spectral analysis in this work, is appropriate for diagnostic purposes such as to find the correlation between vitamin D deficiency and potassium content, especially for hypertensive patients who simultaneously take potassium-based medication and vitamin D supplement. Copyright © 2018 Elsevier B.V. All rights reserved.

Quantification of trace metals in infant formula premixes using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Cama-Moncunill, Raquel; Casado-Gavalda, Maria P.; Cama-Moncunill, Xavier; Markiewicz-Keszycka, Maria; Dixit, Yash; Cullen, Patrick J.; Sullivan, Carl

2017-09-01

Infant formula is a human milk substitute generally based upon fortified cow milk components. In order to mimic the composition of breast milk, trace elements such as copper, iron and zinc are usually added in a single operation using a premix. The correct addition of premixes must be verified to ensure that the target levels in infant formulae are achieved. In this study, a laser-induced breakdown spectroscopy (LIBS) system was assessed as a fast validation tool for trace element premixes. LIBS is a promising emission spectroscopic technique for elemental analysis, which offers real-time analyses, little to no sample preparation and ease of use. LIBS was employed for copper and iron determinations of premix samples ranging approximately from 0 to 120 mg/kg Cu/1640 mg/kg Fe. LIBS spectra are affected by several parameters, hindering subsequent quantitative analyses. This work aimed at testing three matrix-matched calibration approaches (simple-linear regression, multi-linear regression and partial least squares regression (PLS)) as means for precision and accuracy enhancement of LIBS quantitative analysis. All calibration models were first developed using a training set and then validated with an independent test set. PLS yielded the best results. For instance, the PLS model for copper provided a coefficient of determination (R2) of 0.995 and a root mean square error of prediction (RMSEP) of 14 mg/kg. Furthermore, LIBS was employed to penetrate through the samples by repetitively measuring the same spot. Consequently, LIBS spectra can be obtained as a function of sample layers. This information was used to explore whether measuring deeper into the sample could reduce possible surface-contaminant effects and provide better quantifications.

Novel estimation of the humification degree of soil organic matter by laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Ferreira, Edilene Cristina; Ferreira, Ednaldo José; Villas-Boas, Paulino Ribeiro; Senesi, Giorgio Saverio; Carvalho, Camila Miranda; Romano, Renan Arnon; Martin-Neto, Ladislau; Milori, Débora Marcondes Bastos Pereira

2014-09-01

Soil organic matter (SOM) constitutes an important reservoir of terrestrial carbon and can be considered an alternative for atmospheric carbon storage, contributing to global warming mitigation. Soil management can favor atmospheric carbon incorporation into SOM or its release from SOM to atmosphere. Thus, the evaluation of the humification degree (HD), which is an indication of the recalcitrance of SOM, can provide an estimation of the capacity of carbon sequestration by soils under various managements. The HD of SOM can be estimated by using various analytical techniques including fluorescence spectroscopy. In the present work, the potential of laser-induced breakdown spectroscopy (LIBS) to estimate the HD of SOM was evaluated for the first time. Intensities of emission lines of Al, Mg and Ca from LIBS spectra showing correlation with fluorescence emissions determined by laser-induced fluorescence spectroscopy (LIFS) reference technique were used to obtain a multivaried calibration model based on the k-nearest neighbor (k-NN) method. The values predicted by the proposed model (A-LIBS) showed strong correlation with LIFS results with a Pearson's coefficient of 0.87. The HD of SOM obtained after normalizing A-LIBS by total carbon in the sample showed a strong correlation to that determined by LIFS (0.94), thus suggesting the great potential of LIBS for this novel application.

Testing a laser-induced breakdown spectroscopy technique on the Arctic sediments

NASA Astrophysics Data System (ADS)

Han, D.; Nam, S. I.

2017-12-01

Physical and geochemical investigations coupled with the Laser-induced Breakdown Spectroscopy (LIBS) were performed on three surface sediment cores (ARA03B/24BOX, ARA02B/01(A)MUC, ARA02B/02MUC and ARA02B/03(A)MUC) recovered from the western Arctic Ocean (Chukchi Sea) during IBRV ARON expeditions in 2012. The LIBS technique was applied to carry out elemental chemical analysis of the Arctic sediments and compared with that measured by ITRAX X-ray fuorescence (XRF) core scanning. LIBS and XRF have shown similar elemental composition within each sediment core. In this study, mineral composition (XRD), grain size distribution and organic carbon content as well as elemental composition (LIBS) were all considered to understand paleoenvironmental changes (ocean circulation, sea-ice drift, iceberg discharge, and etc.) recorded in the Arctic Holocene sediment. Quantitative LIBS analysis shows a gradually varying distribution of the elements along the sampled core and clear separation between the cores. The cores are geochemically characterized by elevated Mn profile. The gradient of mineral composition and grain sizes among the cores shows regional distribution and variation in sedimentary condition due to geological distance between East Siberian and North America. The present study reveals that a LIBS technique can be employed for in-situ sediment analyses for the Arctic Ocean. Furthermore, LIBS does not require costly equipment, trained operators, and complicated sample pre-treatment processes compared to Atomic absorption spectroscopy (AAS) and inductively coupled plasma emission spectroscopy (ICP), and also known to show relatively high levels of sensitivity, precision, and distinction than XRF analysis, scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), and electron probe X-ray microanalysis (EPMA).

Simple and direct method for detecting phosphorus in air at normal pressure and temperature using a combination of LIBS and LIFS techniques

NASA Astrophysics Data System (ADS)

Al-Jeffery, Mohammad O.; Kondou, H.; Belenkevitch, Alexander; Azzeer, Abdallah M.

2002-05-01

The Environmental Protection Agency (EAP) designated phosphorus as hazardous material; it is flammable and poisonous. Phosphorus attacks the respiratory system, liver, kidneys, jaw, teeth, blood, eyes, and skin. Phosphorus is an element that has a high detection limit when using laser-induced breakdown spectroscopy (LIBS) techniques. In order to improve on detection limits, laser-induced fluorescence spectroscopy (LIFS) has been proposed, as an extension to LIBS. The ultimate goal of this work is to use the combined LIBS & LIFS techniques to detect the presence of phosphorus in air and to measure its level. In order to provide 'proof-of-concept' results, the sample used for our experiment was prepared using the 'igniting' strip of a safety match box. The spectrally and temporally resolved detection of the specific atomic emission revealed analytical information about the elemental composition of the sample. A tunable Ti: sapphire laser, at the resonance wavelength of 253.4 nm, was then used to probe the plume by exciting the phosphorus element and we measured the fluorescence from the atoms at 213.62 nm and 214.91 nm. The whole experiment was carried out in a few minutes. We have thus demonstrated for the first time, to our knowledge, the use of LIBS and LIFS in air quality monitoring and in particular for phosphorus detection.

Classification of alloys using laser induced breakdown spectroscopy with principle component analysis

NASA Astrophysics Data System (ADS)

Syuhada Mangsor, Aneez; Haider Rizvi, Zuhaib; Chaudhary, Kashif; Safwan Aziz, Muhammad

2018-05-01

The study of atomic spectroscopy has contributed to a wide range of scientific applications. In principle, laser induced breakdown spectroscopy (LIBS) method has been used to analyse various types of matter regardless of its physical state, either it is solid, liquid or gas because all elements emit light of characteristic frequencies when it is excited to sufficiently high energy. The aim of this work was to analyse the signature spectrums of each element contained in three different types of samples. Metal alloys of Aluminium, Titanium and Brass with the purities of 75%, 80%, 85%, 90% and 95% were used as the manipulated variable and their LIBS spectra were recorded. The characteristic emission lines of main elements were identified from the spectra as well as its corresponding contents. Principal component analysis (PCA) was carried out using the data from LIBS spectra. Three obvious clusters were observed in 3-dimensional PCA plot which corresponding to the different group of alloys. Findings from this study showed that LIBS technology with the help of principle component analysis could conduct the variety discrimination of alloys demonstrating the capability of LIBS-PCA method in field of spectro-analysis. Thus, LIBS-PCA method is believed to be an effective method for classifying alloys with different percentage of purifications, which was high-cost and time-consuming before.

Monitoring of Cr, Cu, Pb, V and Zn in polluted soils by laser induced breakdown spectroscopy (LIBS).

PubMed

Dell'Aglio, Marcella; Gaudiuso, Rosalba; Senesi, Giorgio S; De Giacomo, Alessandro; Zaccone, Claudio; Miano, Teodoro M; De Pascale, Olga

2011-05-01

Laser Induced Breakdown Spectroscopy (LIBS) is a fast and multi-elemental analytical technique particularly suitable for the qualitative and quantitative analysis of heavy metals in solid samples, including environmental ones. Although LIBS is often recognised in the literature as a well-established analytical technique, results about quantitative analysis of elements in chemically complex matrices such as soils are quite contrasting. In this work, soil samples of various origins have been analyzed by LIBS and data compared to those obtained by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). The emission intensities of one selected line for each of the five analytes (i.e., Cr, Cu, Pb, V, and Zn) were normalized to the background signal, and plotted as a function of the concentration values previously determined by ICP-OES. Data showed a good linearity for all calibration lines drawn, and the correlation between ICP-OES and LIBS was confirmed by the satisfactory agreement obtained between the corresponding values. Consequently, LIBS method can be used at least for metal monitoring in soils. In this respect, a simple method for the estimation of the soil pollution degree by heavy metals, based on the determination of an anthropogenic index, was proposed and determined for Cr and Zn.

The effect of bacterial environmental and metabolic stresses on a laser-induced breakdown spectroscopy (LIBS) based identification of Escherichia coli and Streptococcus viridans.

PubMed

Mohaidat, Qassem; Palchaudhuri, Sunil; Rehse, Steven J

2011-04-01

In this paper we investigate the effect that adverse environmental and metabolic stresses have on the laser-induced breakdown spectroscopy (LIBS) identification of bacterial specimens. Single-pulse LIBS spectra were acquired from a non-pathogenic strain of Escherichia coli cultured in two different nutrient media: a trypticase soy agar and a MacConkey agar with a 0.01% concentration of deoxycholate. A chemometric discriminant function analysis showed that the LIBS spectra acquired from bacteria grown in these two media were indistinguishable and easily discriminated from spectra acquired from two other non-pathogenic E. coli strains. LIBS spectra were obtained from specimens of a nonpathogenic E. coli strain and an avirulent derivative of the pathogen Streptococcus viridans in three different metabolic situations: live bacteria reproducing in the log-phase, bacteria inactivated on an abiotic surface by exposure to bactericidal ultraviolet irradiation, and bacteria killed via autoclaving. All bacteria were correctly identified regardless of their metabolic state. This successful identification suggests the possibility of testing specimens that have been rendered safe for handling prior to LIBS identification. This would greatly enhance personnel safety and lower the cost of a LIBS-based diagnostic test. LIBS spectra were obtained from pathogenic and non-pathogenic bacteria that were deprived of nutrition for a period of time ranging from one day to nine days by deposition on an abiotic surface at room temperature. All specimens were successfully classified by species regardless of the duration of nutrient deprivation. © 2011 Society for Applied Spectroscopy

A hybrid LIBS-Raman system combined with chemometrics: an efficient tool for plastic identification and sorting.

PubMed

Shameem, K M Muhammed; Choudhari, Khoobaram S; Bankapur, Aseefhali; Kulkarni, Suresh D; Unnikrishnan, V K; George, Sajan D; Kartha, V B; Santhosh, C

2017-05-01

Classification of plastics is of great importance in the recycling industry as the littering of plastic wastes increases day by day as a result of its extensive use. In this paper, we demonstrate the efficacy of a combined laser-induced breakdown spectroscopy (LIBS)-Raman system for the rapid identification and classification of post-consumer plastics. The atomic information and molecular information of polyethylene terephthalate, polyethylene, polypropylene, and polystyrene were studied using plasma emission spectra and scattered signal obtained in the LIBS and Raman technique, respectively. The collected spectral features of the samples were analyzed using statistical tools (principal component analysis, Mahalanobis distance) to categorize the plastics. The analyses of the data clearly show that elemental information and molecular information obtained from these techniques are efficient for classification of plastics. In addition, the molecular information collected via Raman spectroscopy exhibits clearly distinct features for the transparent plastics (100% discrimination), whereas the LIBS technique shows better spectral feature differences for the colored samples. The study shows that the information obtained from these complementary techniques allows the complete classification of the plastic samples, irrespective of the color or additives. This work further throws some light on the fact that the potential limitations of any of these techniques for sample identification can be overcome by the complementarity of these two techniques. Graphical Abstract ᅟ.

[Comparative investigation of underwater-LIBS using 532 and 1 064 nm lasers].

PubMed

Song, Jiao-Jian; Tian, Ye; Lu, Yuan; Li, Ying; Zheng, Rong-Er

2014-11-01

With the hope of applying laser induced breakdown spectroscopy (LIBS) to the ocean applications, the laser energy at 532 and 1 064 nm wavelength with 3 and 40 mj respectively was used, which was near their breakdown threshold. Extensive experimental investigations of LIBS from CaCl2 water solution were carried out in this paper using different laser wavelengths of 532 and 1 064 nm. The obtained results show that compared with the 532 nm laser, the 1 064 nm laser can induce the plasma in water with higher emission intensity and longer lifetime, while the reproducibility of LIBS signal under 1 064 nm laser is poorer. On the other hand, due to the different attenuation ratios of 532 and 1 064 nm laser energies in water, the LIBS signal of 1 064 nm laser decreases a lot within the transmission distance range 2-5 cm, while LIBS signal of 532 nm remains the same, because that the wavelength of 532 nm lies in the "transmission window" of the water solution. This study will provide valuable design considerations for the development of LIBS-sea system in near future.

Effect of sample preparation on the discrimination of bacterial isolates cultured in liquid nutrient media using laser induced breakdown spectroscopy

USDA-ARS?s Scientific Manuscript database

Laser induced breakdown spectroscopy (LIBS) is used as the basis for discrimination between 2 genera of gram-negative bacteria and 2 genera of gram-positive bacteria representing pathogenic threats commonly found in poultry processing rinse waters. Because LIBS-based discrimination relies primarily ...

Micro-Laser-Induced Breakdown Spectroscopy (Micro-LIBS) Study on Ancient Roman Mortars.

PubMed

Pagnotta, Stefano; Lezzerini, Marco; Ripoll-Seguer, Laura; Hidalgo, Montserrat; Grifoni, Emanuela; Legnaioli, Stefano; Lorenzetti, Giulia; Poggialini, Francesco; Palleschi, Vincenzo

2017-04-01

The laser-induced breakdown spectroscopy (LIBS) technique was used for analyzing the composition of an ancient Roman mortar (5th century A.D.), exploiting an experimental setup which allows the determination of the compositions of binder and aggregate in few minutes, without the need for sample treatment. Four thousand LIBS spectra were acquired from an area of 10 mm 2 , with a 50 µm lateral resolution. The elements of interest in the mortar sample (H, C, O, Na, Mg, Al, Si, K, Ca, Ti, Mn, Fe) were detected and mapped. The collected data graphically shown as compositional images were interpreted using different statistical approaches for the determination of the chemical composition of the binder and aggregate fraction. The methods of false color imaging, blind separation, and self-organizing maps were applied and their results are discussed in this paper. In particular, the method based on the use of self-organizing maps gives well interpretable results in very short times, without any reduction in the dimensionality of the system.

Elemental composition of Arctic soils and aerosols in Ny-Ålesund measured using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Kim, Gibaek; Yoon, Young-Jun; Kim, Hyun-A.; Cho, Hee-joo; Park, Kihong

2017-08-01

Two laser-induced breakdown spectroscopy (LIBS) systems (soil LIBS and aerosol LIBS) were used to determine the elemental composition of soils and ambient aerosols less than 2.5 μm in Ny-Ålesund, Svalbard (the world's most northerly human settlement). For soil LIBS measurements, matrix effects such as moisture content, soil grain size, and surrounding gas on the LIBS response were minimized. When Ar gas was supplied onto the soil sample surfaces, a significant enhancement in LIBS emission lines was observed. Arctic soil samples were collected at 10 locations, and various elements (Al, Ba, C, Ca, Cu, Fe, H, K, Mg, Mn, N, Na, O, Pb, and Si) were detected in soils. The elemental distribution in arctic soils was clearly distinguishable from those in urban and abandoned mining soils in Korea. Moreover, the concentrations of most of anthropogenic metals were fairly low, and localized sources in extremely close proximity affected the elevated level of Cu in the soil samples derived from Ny-Ålesund. The number of elements detected in aerosols (C, Ca, H, K, Mg, Na, and O) was lower than those determined in soils. The elements in aerosols can mainly originate from minerals and sea salts. The elemental distribution in aerosols was also clearly distinguishable from that in soils, suggesting that the resuspension of local soil particles by wind erosion into aerosols was minimal. The daily variation of particle number concentration (RSD = 71%) and the elements in aerosols (RSD = 25%) varied substantially, possibly due to fluctuating air masses and meteorological conditions.

Experimental investigation of effective parameters on signal enhancement in spark assisted laser induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Hassanimatin, M. M.; Tavassoli, S. H.

2018-05-01

A combination of electrical spark and laser induced breakdown spectroscopy (LIBS), which is called spark assisted LIBS (SA-LIBS), has shown its capability in plasma spectral emission enhancement. The aim of this paper is a detailed study of plasma emission to determine the effect of plasma and experimental parameters on increasing the spectral signal. An enhancement ratio of SA-LIBS spectral lines compared with LIBS is theoretically introduced. The parameters affecting the spectral enhancement ratio including ablated mass, plasma temperature, the lifetime of neutral and ionic spectral lines, plasma volume, and electron density are experimentally investigated and discussed. By substitution of the effective parameters, the theoretical spectral enhancement ratio is calculated and compared with the experimental one. Two samples of granite as a dielectric and aluminum as a metal at different laser pulse energies are studied. There is a good agreement between the calculated and the experimental enhancement ratio.

Qualitative and quantitative spectro-chemical analysis of dates using UV-pulsed laser induced breakdown spectroscopy and inductively coupled plasma mass spectrometry.

PubMed

Mehder, A O; Habibullah, Y B; Gondal, M A; Baig, Umair

2016-08-01

Laser Induced Breakdown Spectroscopy (LIBS) is demonstrated for the spectral analysis of nutritional and toxic elements present in several varieties of date fruit samples available in the Saudi Arabia market. The method analyzes the optical emission of a test sample when subjected to pulsed laser ablation. In this demonstration, our primary focus is on calcium (Ca) and magnesium (Mg), as nutritional elements, and on chromium (Cr), as a toxic element. The local thermodynamic equilibrium (LTE) condition was confirmed prior to the elemental characterization of date samples to ensure accuracy of the LIBS analysis. This was achieved by measuring parameters associated with the plasma, such as the electron temperature and the electron number density. These plasma parameters aid interpretation of processes such as ionization, dissociation, and excitation occurring in the plasma plume formed by ablating the date palm sample. The minimum detection limit was established from calibration curves that involved plotting the LIBS signal intensity as a function of standard date samples with known concentrations. The concentration of Ca and Mg detected in different varieties of date samples was between 187 and 515 and 35-196mgL(-1) respectively, while Cr concentration measured between 1.72 and 7.76mgL(-1). In order to optimize our LIBS system, we have studied how the LIBS signal intensity depends on the incident laser energy and the delay time. In order to validate our LIBS analysis results, standard techniques such as inductively coupled plasma mass spectrometry (ICP-MS) were also applied on an identical (duplicate) date samples as those used for the LIBS analysis. The LIBS results exhibit remarkable agreement with those obtained from the ICP-MS analysis. In addition, the finger print wavelengths of other elements present in date samples were also identified and are reported here, which has not been previously reported, to the best of our knowledge. Copyright © 2016 Elsevier B.V. All rights reserved.

The effect of nutrient media water purity on LIBS based identification of bacteria

USDA-ARS?s Scientific Manuscript database

Single pulse laser induced breakdown spectroscopy (LIBS) is used as the basis for discrimination between 3 genera of Gram-negative bacteria and 2 genera of gram-positive bacteria representing pathogenic threats commonly found in poultry processing rinse waters. Because LIBS-based discrimination reli...

Biomedical applications of laser-induced breakdown spectroscopy (LIBS)

NASA Astrophysics Data System (ADS)

Unnikrishnan, V. K.; Nayak, Rajesh; Bhat, Sujatha; Mathew, Stanley; Kartha, V. B.; Santhosh, C.

2015-03-01

LIBS has been proven to be a robust elemental analysis tool attracting interest because of the wide applications. LIBS can be used for analysis of any type of samples i.e. environmental/physiological, regardless of its state of matter. Conventional spectroscopy techniques are good in analytical performance, but their sample preparation method is mostly destructive and time consuming. Also, almost all these methods are incapable of analysing multi elements simaltaneously. On the other hand, LIBS has many potential advantages such as simplicity in the experimental setup, less sample preparation, less destructive analysis of sample etc. In this paper, we report some of the biomedical applications of LIBS. From the experiments carried out on clinical samples (calcified tissues or teeth and gall stones) for trace elemental mapping and detection, it was found that LIBS is a robust tool for such applications. It is seen that the presence and relative concentrations of major elements (calcium, phosphorus and magnesium) in human calcified tissue (tooth) can be easily determined using LIBS technique. The importance of this study comes in anthropology where tooth and bone are main samples from which reliable data can be easily retrieved. Similarly, elemental composition of bile juice and gall stone collected from the same subject using LIBS was found to be similar. The results show interesting prospects for LIBS to study cholelithiasis (the presence of stones in the gall bladder, is a common disease of the gastrointestinal tract) better.

Effect of Atmospheric Conditions on LIBS Spectra

PubMed Central

Effenberger, Andrew J.; Scott, Jill R.

2010-01-01

Laser-induced breakdown spectroscopy (LIBS) is typically performed at ambient Earth atmospheric conditions. However, interest in LIBS in other atmospheric conditions has increased in recent years, especially for use in space exploration (e.g., Mars and Lunar) or to improve resolution for isotopic signatures. This review focuses on what has been reported about the performance of LIBS in reduced pressure environments as well as in various gases other than air. PMID:22399914

Laser Induced Breakdown Spectroscopy Based on Single Beam Splitting and Geometric Configuration for Effective Signal Enhancement

PubMed Central

Yang, Guang; Lin, Qingyu; Ding, Yu; Tian, Di; Duan, Yixiang

2015-01-01

A new laser induced breakdown spectroscopy (LIBS) based on single-beam-splitting (SBS) and proper optical geometric configuration has been initially explored in this work for effective signal enhancement. In order to improve the interaction efficiency of laser energy with the ablated material, a laser beam operated in pulse mode was divided into two streams to ablate/excite the target sample in different directions instead of the conventional one beam excitation in single pulse LIBS (SP-LIBS). In spatial configuration, the laser beam geometry plays an important role in the emission signal enhancement. Thus, an adjustable geometric configuration with variable incident angle between the two splitted laser beams was constructed for achieving maximum signal enhancement. With the optimized angles of 60° and 70° for Al and Cu atomic emission lines at 396.15 nm and 324.75 nm respectively, about 5.6- and 4.8-folds signal enhancements were achieved for aluminum alloy and copper alloy samples compared to SP-LIBS. Furthermore, the temporal analysis, in which the intensity of atomic lines in SP-LIBS decayed at least ten times faster than the SBS-LIBS, proved that the energy coupling efficiency of SBS-LIBS was significantly higher than that of SP-LIBS. PMID:25557721

Combining Raman and laser induced breakdown spectroscopy by double pulse lasing.

PubMed

Lednev, Vasily N; Pershin, Sergey M; Sdvizhenskii, Pavel A; Grishin, Mikhail Ya; Fedorov, Alexander N; Bukin, Vladimir V; Oshurko, Vadim B; Shchegolikhin, Alexander N

2018-01-01

A new approach combining Raman spectrometry and laser induced breakdown spectrometry (LIBS) within a single laser event was suggested. A pulsed solid state Nd:YAG laser running in double pulse mode (two frequency-doubled sequential nanosecond laser pulses with dozens microseconds delay) was used to combine two spectrometry methods within a single instrument (Raman/LIBS spectrometer). First, a low-energy laser pulse (power density far below ablation threshold) was used for Raman measurements while a second powerful laser pulse created the plasma suitable for LIBS analysis. A short time delay between two successive pulses allows measuring LIBS and Raman spectra at different moments but within a single laser flash-lamp pumping. Principal advantages of the developed instrument include high quality Raman/LIBS spectra acquisition (due to optimal gating for Raman/LIBS independently) and absence of target thermal alteration during Raman measurements. A series of high quality Raman and LIBS spectra were acquired for inorganic salts (gypsum, anhydrite) as well as for pharmaceutical samples (acetylsalicylic acid). To the best of our knowledge, the quantitative analysis feasibility by combined Raman/LIBS instrument was demonstrated for the first time by calibration curves construction for acetylsalicylic acid (Raman) and copper (LIBS) in gypsum matrix. Combining ablation pulses and Raman measurements (LIBS/Raman measurements) within a single instrument makes it an efficient tool for identification of samples hidden by non-transparent covering or performing depth profiling analysis including remote sensing. Graphical abstract Combining Raman and laser induced breakdown spectroscopy by double pulse lasing.

Feasibility study for detecting copper contaminants in transformer insulation using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Aparna, N.; Vasa, Nilesh J.; Sarathi, R.; Rajan, J. Sundara

2014-10-01

In recent times, copper sulphide (Cu2S) diffusion in the transformer insulation is a major problem reducing the life of transformers. It is therefore essential to identify a simple methodology to understand the diffusion of Cu2S into the solid insulation [oil impregnated pressboard (OIP)]. In the present work, laser-induced breakdown spectroscopy (LIBS) was adopted to study the diffusion of Cu2S into the pressboard insulation and to determine the depth of diffusion. The diffusion of Cu2S in pressboard was confirmed by electrical discharge studies. In general, flashover voltage and increase in ageing duration of pressboard insulation/Cu concentration had inverse relationship. The characteristic emission lines were also studied through optical emission spectroscopy. Based on LIBS studies with Cu powder dispersed pressboard samples, Cu I emission lines were found to be resolvable up to a lowest concentration of 5 μg/cm2. The LIBS intensity ratio of Cu I-Ca II emission lines were found to increase with increase in the ageing duration of the OIP sample. LIBS studies with OIP samples showed an increase in the optical emission lifetime. LIBS results were in agreement with the electrical discharge studies.

Quantitative analysis of gallstones using laser-induced breakdown spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Vivek K.; Singh, Vinita; Rai, Awadhesh K.

2008-11-01

The utility of laser-induced breakdown spectroscopy (LIBS) for categorizing different types of gallbladder stone has been demonstrated by analyzing their major and minor constituents. LIBS spectra of three types of gallstone have been recorded in the 200-900 nm spectral region. Calcium is found to be the major element in all types of gallbladder stone. The spectrophotometric method has been used to classify the stones. A calibration-free LIBS method has been used for the quantitative analysis of metal elements, and the results have been compared with those obtained from inductively coupled plasma atomic emission spectroscopy (ICP-AES) measurements. The single-shot LIBS spectramore » from different points on the cross section (in steps of 0.5 mm from one end to the other) of gallstones have also been recorded to study the variation of constituents from the center to the surface. The presence of different metal elements and their possible role in gallstone formation is discussed.« less

Investigation of Laser Induced Breakdown Spectroscopy (LIBS) for the Differentiation of Nerve and Gland Tissue—A Possible Application for a Laser Surgery Feedback Control Mechanism

NASA Astrophysics Data System (ADS)

Mehari, F.; Rohde, M.; Knipfer, C.; Kanawade, R.; Klämpfl, F.; W., Adler; Oetter, N.; Stelzle, F.; Schmidt, M.

2016-06-01

Laser surgery provides clean, fast and accurate modeling of tissue. However, the inability to determine what kind of tissue is being ablated at the bottom of the cut may lead to the iatrogenic damage of structures that were meant to be preserved. In this context, nerve preservation is one of the key challenges in any surgical procedure. One example is the treatment of parotid gland pathologies, where the facial nerve (N. VII) and its main branches run through and fan out inside the glands parenchyma. A feedback system that automatically stops the ablation to prevent nerve-tissue damage could greatly increase the applicability and safety of surgical laser systems. In the present study, Laser Induced Breakdown Spectroscopy (LIBS) is used to differentiate between nerve and gland tissue of an ex-vivo pig animal model. The LIBS results obtained in this preliminary experiment suggest that the measured spectra, containing atomic and molecular emissions, can be used to differentiate between the two tissue types. The measurements and differentiation were performed in open air and under normal stray light conditions.

Application of laser-induced breakdown spectroscopy (LIBS) as a tool to determine the origin of 'conflict minerals'

NASA Astrophysics Data System (ADS)

Hark, R. R.; Harmon, R. S.; Remus, J. J.; East, L. J.; Wise, M. A.; Tansi, B. M.; Shughrue, K. M.; Dunsin, K. S.; Liu, C.

2012-04-01

Laser-induced breakdown spectroscopy (LIBS) offers a means of rapidly distinguishing different places of origin for a mineral because the LIBS plasma emission spectrum provides the complete chemical composition (i.e. geochemical fingerprint) of a mineral in real-time. An application of this approach with potentially significant commercial and political importance is the spectral fingerprinting of the 'conflict minerals' columbite-tantalite ("coltan"). Following a successful pilot study of three columbite-tantalite suites from the United States and Canada, a more geographically diverse set of samples from 37 locations worldwide were analyzed using a commercial laboratory LIBS system and a subset of samples also analyzed using a prototype broadband field-portable system. The spectral range from 250-490 nm was chosen for the laboratory analysis to encompass many of the intense emission lines for the major elements (Ta, Nb, Fe, Mn) and the significant trace elements (e.g., W, Ti, Zr, Sn, U, Sb, Ca, Zn, Pb, Y, Mg, and Sc) known to commonly substitute in the columbite-tantalite solid solution series crystal structure and in the columbite group minerals. The field-portable instrument offered an increased spectral range (198-1005 nm), over which all elements have spectral emission lines, and higher resolution than the laboratory instrument. In both cases, the LIBS spectra were analyzed using advanced multivariate statistical signal processing techniques. Partial Least Squares Discriminant Analysis (PLSDA) resulted in a correct place-level geographic classification at success rates between 90 and 100%. The possible role of rare-earth elements (REE's) as a factor contributing to the high levels of sample discrimination was explored. Given the fact that it can be deployed as a man-portable analytical technology, these results lend additional evidence that LIBS has the potential to be utilized in the field as a real-time tool to discriminate between columbite-tantalite ores of different provenance.

Insights in the laser induced breakdown spectroscopy signal generation underwater using dual pulse excitation — Part II: Plasma emission intensity as a function of interpulse delay

NASA Astrophysics Data System (ADS)

Lazic, V.; Laserna, J. J.; Jovicevic, S.

2013-04-01

Influence of time delay between two laser pulses on the LIBS (laser induced breakdown spectroscopy) signal inside liquids was investigated and the results are compared with data from literature. Plasma was produced by laser ablation (LA) of aluminum inside water and its emission after the second laser pulse was characterized by spectrally and time resolved detection. Light propagation through the vapor bubble formed by the first laser pulse was studied by measurements of beam scattering and transmission. Optical absorption by the evolving bubble is not significant, but its growth is accompanied by lowering of its refraction index nb with respect to surrounding liquid; this effect increases defocusing both of the incident beam and of the out-coming plasma radiation. Collection efficiency of the secondary plasma emission rapidly degrades with the cavity growth, but close to its full expansion the LIBS signal partially recovers through Snell's reflections at the liquid-vapor interface, which produce a bright spot close to the bubble center. Such a light redistribution allows detecting of the emission from external plasma volume, otherwise deflected out of the collection system. Except for strong line transitions from the main sample constituents, self-absorbed inside the high-pressure cavity, we observed the highest LIBS signal when sending the second pulse well before the bubble is fully expanded. Transitions of the pressure wave through the focal volume, formed by the first laser pulse and reflected from the cell's walls and sample back-plane, enhances the LIBS signal importantly. The measured lifetime of the secondary plasma rapidly decreases with the bubble expansion. Here, we also discuss the optimization of the optical collection system and some analytical aspects of double-pulse (DP) LIBS inside liquids.

Analysis of geological materials containing uranium using laser-induced breakdown spectroscopy (LIBS)

NASA Astrophysics Data System (ADS)

Barefield, James E.; Judge, Elizabeth J.; Campbell, Keri R.; Colgan, James P.; Kilcrease, David P.; Johns, Heather M.; Wiens, Roger C.; McInroy, Rhonda E.; Martinez, Ronald K.; Clegg, Samuel M.

2016-06-01

Laser induced breakdown spectroscopy (LIBS) is a rapid atomic emission spectroscopy technique that can be configured for a variety of applications including space, forensics, and industry. LIBS can also be configured for stand-off distances or in-situ, under vacuum, high pressure, atmospheric or different gas environments, and with different resolving-power spectrometers. The detection of uranium in a complex geological matrix under different measurement schemes is explored in this paper. Although many investigations have been completed in an attempt to detect and quantify uranium in different matrices at in-situ and standoff distances, this work detects and quantifies uranium in a complex matrix under Martian and ambient air conditions. Investigation of uranium detection using a low resolving-power LIBS system at stand-off distances (1.6 m) is also reported. The results are compared to an in-situ LIBS system with medium resolving power and under ambient air conditions. Uranium has many thousands of emission lines in the 200-800 nm spectral region. In the presence of other matrix elements and at lower concentrations, the limit of detection of uranium is significantly reduced. The two measurement methods (low and high resolving-power spectrometers) are compared for limit of detection (LOD). Of the twenty-one potential diagnostic uranium emission lines, seven (409, 424, 434, 435, 436, 591, and 682 nm) have been used to determine the LOD for pitchblende in a dunite matrix using the ChemCam test bed LIBS system. The LOD values determined for uranium transitions in air are 409.013 nm (24,700 ppm), 424.167 nm (23,780 ppm), 434.169 nm (24,390 ppm), 435.574 nm (35,880 ppm), 436.205 nm (19,340 ppm), 591.539 nm (47,310 ppm), and 682.692 nm (18,580 ppm). The corresponding LOD values determined for uranium transitions in 7 Torr CO2 are 424.167 nm (25,760 ppm), 434.169 nm (40,800 ppm), 436.205 nm (32,050 ppm), 591.539 nm (15,340 ppm), and 682.692 nm (29,080 ppm). The LOD values determine for uranium emission lines using the medium resolving power (10,000 λ/Δλ) LIBS system for the dunite matrix in air are 409.013 nm (6120 ppm), 424.167 nm (5356 ppm), 434.169 nm (5693 ppm), 435.574 nm (6329 ppm), 436.205 nm (2142 ppm), and 682.692 nm (10,741 ppm). The corresponding LOD values determined for uranium transitions in a SiO2 matrix are 409.013 nm (272 ppm), 424.167 nm (268 ppm), 434.169 nm (402 ppm), 435.574 nm (1067 ppm), 436.205 nm (482 ppm), and 682.692 nm (720 ppm). The impact of spectral resolution, atmospheric conditions, matrix elements, and measurement distances on LOD is discussed. The measurements will assist one in selecting the proper system components based upon the application and the required analytical performance.

A review of the development of portable laser induced breakdown spectroscopy and its applications

NASA Astrophysics Data System (ADS)

Rakovský, J.; Čermák, P.; Musset, O.; Veis, P.

2014-11-01

In this review, we present person-transportable laser induced breakdown spectroscopy (LIBS) devices that have previously been developed and reported in the literature as well as their applications. They are compared with X-ray fluorescent (XRF) devices, which represent their strongest competition. Although LIBS devices have advantages over XRF devices, such as sensitivity to the light elements, high spatial resolution and the possibility to distinguish between different layers of the sample, there are also disadvantages and both are discussed here. Furthermore, the essential portable LIBS instrumentation (laser, spectrograph and detector) is presented, and published results related to new laser sources (diode-pumped solid-state, microchip and fiber lasers) used in LIBS are overviewed. Compared to conventional compact flashlamp pumped solid-state lasers, the new laser sources provide higher repetition rates, higher efficiency (less power consumption) and higher beam quality, resulting in higher fluences, even for lower energies, and could potentially increase the figure of merit of portable LIBS instruments. Compact spectrometers used in portable LIBS devices and their parts (spectrograph, detector) are also discussed.

Nd:YAG-CO(2) double-pulse laser induced breakdown spectroscopy of organic films.

PubMed

Weidman, Matthew; Baudelet, Matthieu; Palanco, Santiago; Sigman, Michael; Dagdigian, Paul J; Richardson, Martin

2010-01-04

Laser-induced breakdown spectroscopy (LIBS) using double-pulse irradiation with Nd:YAG and CO(2) lasers was applied to the analysis of a polystyrene film on a silicon substrate. An enhanced emission signal, compared to single-pulse LIBS using a Nd:YAG laser, was observed from atomic carbon, as well as enhanced molecular emission from C(2) and CN. This double-pulse technique was further applied to 2,4,6-trinitrotoluene residues, and enhanced LIBS signals for both atomic carbon and molecular CN emission were observed; however, no molecular C(2) emission was detected.

Comparative study on fast classification of brick samples by combination of principal component analysis and linear discriminant analysis using stand-off and table-top laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Vítková, Gabriela; Prokeš, Lubomír; Novotný, Karel; Pořízka, Pavel; Novotný, Jan; Všianský, Dalibor; Čelko, Ladislav; Kaiser, Jozef

2014-11-01

Focusing on historical aspect, during archeological excavation or restoration works of buildings or different structures built from bricks it is important to determine, preferably in-situ and in real-time, the locality of bricks origin. Fast classification of bricks on the base of Laser-Induced Breakdown Spectroscopy (LIBS) spectra is possible using multivariate statistical methods. Combination of principal component analysis (PCA) and linear discriminant analysis (LDA) was applied in this case. LIBS was used to classify altogether the 29 brick samples from 7 different localities. Realizing comparative study using two different LIBS setups - stand-off and table-top it is shown that stand-off LIBS has a big potential for archeological in-field measurements.

Wavelength comparison for laser induced breakdown spectroscopy caries detection

NASA Astrophysics Data System (ADS)

Amaral, Marcello M.; Raele, Marcus P.; Ana, Patrícia A.; Núñez, Sílvia C.; Zamataro, Claudia B.; Zezell, Denise M.

2018-02-01

Laser Induced Breakdown Spectroscopy (LIBS) is a technique capable to perform elemental analyses of a variety of samples, independent of matter state. Other spectroscopy techniques may require a destructive and time-consuming sample preparation. On the other hand, LIBS is a less destructive technique with no (or considerably less) sample preparation, using a relatively simple experimental setup. LIBS also provides a multielement analysis into one single spectrum acquisition, applying a Nd:YAG short-pulsed laser to ensure the stoichiometry between the sample and the generated plasma. LIBS have been applied on the study of carious lesions using a Nd:YAG into its fundamental emission at 1064 nm. It was shown that ratio of P/Ca and Zn/Ca can be used to monitor the cariogenic process. Another minor elements, e.g. C and Cu, associated with bacteria biofilm were also measured with the Nd:YAG laser. The fundamental wavelength emission (1064 nm) of Nd:YAG is coincident with a hydroxyapatite transmission window and it may affect the result. In order to address this issue a study used the second harmonic of the Nd:YAG laser at 532 nm. It was show that it is also possible perform LIBS on carious lesion using the Nd:YAG at 532 nm. However, there is not a work direct comparing the LIBS at 532 nm and 1064 nm for carious lesion detection. So, the aim of this work was to investigate the influence of laser wavelength on the LIBS performance for carious lesion detection. In both cases the carious lesion was detected with the advantage of no interference with hydroxyapatite at 532 nm.

Cropland Field Monitoring: MMV Page 1 Montana Cropland Enrolled Farm Fields Carbon Sequestration Field Sampling, Measurement, Monitoring, and Verification: Application of Visible-Near Infrared Diffuse Reflectance Spectroscopy (VNIR) and Laser-induced Breakdown Spectroscopy (LIBS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee Spangler; Ross Bricklemyer; David Brown

2012-03-15

There is growing need for rapid, accurate, and inexpensive methods to measure, and verify soil organic carbon (SOC) change for national greenhouse gas accounting and the development of a soil carbon trading market. Laboratory based soil characterization typically requires significant soil processing, which is time and resource intensive. This severely limits application for large-region soil characterization. Thus, development of rapid and accurate methods for characterizing soils are needed to map soil properties for precision agriculture applications, improve regional and global soil carbon (C) stock and flux estimates and efficiently map sub-surface metal contamination, among others. The greatest gains for efficientmore » soil characterization will come from collecting soil data in situ, thus minimizing soil sample transportation, processing, and lab-based measurement costs. Visible and near-infrared diffuse reflectance spectroscopy (VisNIR) and laser-induced breakdown spectroscopy (LIBS) are two complementary, yet fundamentally different spectroscopic techniques that have the potential to meet this need. These sensors have the potential to be mounted on a soil penetrometer and deployed for rapid soil profile characterization at field and landscape scales. Details of sensor interaction, efficient data management, and appropriate statistical analysis techniques for model calibrations are first needed. In situ or on-the-go VisNIR spectroscopy has been proposed as a rapid and inexpensive tool for intensively mapping soil texture and organic carbon (SOC). While lab-based VisNIR has been established as a viable technique for estimating various soil properties, few experiments have compared the predictive accuracy of on-the-go and lab-based VisNIR. Eight north central Montana wheat fields were intensively interrogated using on-the-go and lab-based VisNIR. Lab-based spectral data consistently provided more accurate predictions than on-the-go data. However, neither in situ nor lab-based spectroscopy yielded even semi-quantitative SOC predictions. There was little SOC variability to explain across the eight fields, and on-the-go VisNIR was not able to capture the subtle SOC variability in these Montana soils. With more variation in soil clay content compared to SOC, both lab and on-the-go VisNIR showed better explanatory power. There are several potential explanations for poor on-the-go predictive accuracy: soil heterogeneity, field moisture, consistent sample presentation, and a difference between the spatial support of on-the-go measurements and soil samples collected for laboratory analyses. Though the current configuration of a commercially available on-the-go VisNIR system allows for rapid field scanning, on-the-go soil processing (i.e. drying, crushing, and sieving) could improve soil carbon predictions. Laser-induced breakdown spectroscopy (LIBS) is an emerging elemental analysis technology with the potential to provide rapid, accurate and precise analysis of soil constituents, such as carbon, in situ across landscapes. The research team evaluated the accuracy of LIBS for measuring soil profile carbon in field-moist, intact soil cores simulating conditions that might be encountered by a probe-mounted LIBS instrument measuring soil profile carbon in situ. Over the course of three experiments, more than120 intact soil cores from eight north central Montana wheat fields and the Washington State University (WSU) Cook Agronomy Farm near Pullman, WA were interrogated with LIBS for rapid total carbon (TC), inorganic carbon (IC), and SOC determination. Partial least squares regression models were derived and independently validated at field- and regional scales. Researchers obtained the best LIBS validation predictions for IC followed by TC and SOC. Laser-induced breakdown spectroscopy is fundamentally an elemental analysis technique, yet LIBS PLS2 models appeared to discriminate IC from TC. Regression coefficients from initial models suggested a reliance upon stoichiometric relationships between carbon (247.8 nm) and other elements related to total and inorganic carbon in the soil matrix [Ca (210.2 nm, 211.3 nm, and 220.9 nm), Mg (279.55-280.4 nm, 285.26 nm), and Si (251.6 nm, 288.1 nm)]. Expanding the LIBS spectral range to capture emissions from a broader range of elements related to soil organic matter was explored using two spectrometer systems to improve SOC predictions. Results for increasing the spectral range of LIBS to the full 200-800 nm found modest gains in prediction accuracy for IC, but no gains for predicting TC or SOC. Poor SOC predictions are likely a function of (1) the lack of a consistent/definable molecular composition of SOC, (2) relatively little variation in SOC across field sites, and (3) inorganic carbon constituting the primary form of soil carbon, particularly for Montana soils.« less

Quantification of metals in preservatively-treated lumber using laser induced breakdown spectroscopy

Treesearch

Brad Gething; John Janowiak; Bob Falk

2006-01-01

The laser induced breakdown spectroscopy (LIBS) technique was evaluated for its capability of quantifying CCA in preservative-treated wood. The results of the study reveal that the LIBS technique can be used to predict the amount of preservative based on chromium peak analysis, but further refinement of the process is necessary before the technique is practiced. The...

Laser Induced Breakdown Spectroscopy for Elemental Analysis in Environmental, Cultural Heritage and Space Applications: A Review of Methods and Results

PubMed Central

Gaudiuso, Rosalba; Dell’Aglio, Marcella; De Pascale, Olga; Senesi, Giorgio S.; De Giacomo, Alessandro

2010-01-01

Analytical applications of Laser Induced Breakdown Spectroscopy (LIBS), namely optical emission spectroscopy of laser-induced plasmas, have been constantly growing thanks to its intrinsic conceptual simplicity and versatility. Qualitative and quantitative analysis can be performed by LIBS both by drawing calibration lines and by using calibration-free methods and some of its features, so as fast multi-elemental response, micro-destructiveness, instrumentation portability, have rendered it particularly suitable for analytical applications in the field of environmental science, space exploration and cultural heritage. This review reports and discusses LIBS achievements in these areas and results obtained for soils and aqueous samples, meteorites and terrestrial samples simulating extraterrestrial planets, and cultural heritage samples, including buildings and objects of various kinds. PMID:22163611

Laser induced breakdown spectroscopy for elemental analysis in environmental, cultural heritage and space applications: a review of methods and results.

PubMed

Gaudiuso, Rosalba; Dell'Aglio, Marcella; De Pascale, Olga; Senesi, Giorgio S; De Giacomo, Alessandro

2010-01-01

Analytical applications of Laser Induced Breakdown Spectroscopy (LIBS), namely optical emission spectroscopy of laser-induced plasmas, have been constantly growing thanks to its intrinsic conceptual simplicity and versatility. Qualitative and quantitative analysis can be performed by LIBS both by drawing calibration lines and by using calibration-free methods and some of its features, so as fast multi-elemental response, micro-destructiveness, instrumentation portability, have rendered it particularly suitable for analytical applications in the field of environmental science, space exploration and cultural heritage. This review reports and discusses LIBS achievements in these areas and results obtained for soils and aqueous samples, meteorites and terrestrial samples simulating extraterrestrial planets, and cultural heritage samples, including buildings and objects of various kinds.

Laser-induced breakdown spectroscopy application in environmental monitoring of water quality: a review.

PubMed

Yu, Xiaodong; Li, Yang; Gu, Xiaofeng; Bao, Jiming; Yang, Huizhong; Sun, Li

2014-12-01

Water quality monitoring is a critical part of environmental management and protection, and to be able to qualitatively and quantitatively determine contamination and impurity levels in water is especially important. Compared to the currently available water quality monitoring methods and techniques, laser-induced breakdown spectroscopy (LIBS) has several advantages, including no need for sample pre-preparation, fast and easy operation, and chemical free during the process. Therefore, it is of great importance to understand the fundamentals of aqueous LIBS analysis and effectively apply this technique to environmental monitoring. This article reviews the research conducted on LIBS analysis for liquid samples, and the article content includes LIBS theory, history and applications, quantitative analysis of metallic species in liquids, LIBS signal enhancement methods and data processing, characteristics of plasma generated by laser in water, and the factors affecting accuracy of analysis results. Although there have been many research works focusing on aqueous LIBS analysis, detection limit and stability of this technique still need to be improved to satisfy the requirements of environmental monitoring standard. In addition, determination of nonmetallic species in liquid by LIBS is equally important and needs immediate attention from the community. This comprehensive review will assist the readers to better understand the aqueous LIBS technique and help to identify current research needs for environmental monitoring of water quality.

Determination of elemental composition of shale rocks by laser induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Sanghapi, Hervé K.; Jain, Jinesh; Bol'shakov, Alexander; Lopano, Christina; McIntyre, Dustin; Russo, Richard

2016-08-01

In this study laser induced breakdown spectroscopy (LIBS) is used for elemental characterization of outcrop samples from the Marcellus Shale. Powdered samples were pressed to form pellets and used for LIBS analysis. Partial least squares regression (PLS-R) and univariate calibration curves were used for quantification of analytes. The matrix effect is substantially reduced using the partial least squares calibration method. Predicted results with LIBS are compared to ICP-OES results for Si, Al, Ti, Mg, and Ca. As for C, its results are compared to those obtained by a carbon analyzer. Relative errors of the LIBS measurements are in the range of 1.7 to 12.6%. The limits of detection (LODs) obtained for Si, Al, Ti, Mg and Ca are 60.9, 33.0, 15.6, 4.2 and 0.03 ppm, respectively. An LOD of 0.4 wt.% was obtained for carbon. This study shows that the LIBS method can provide a rapid analysis of shale samples and can potentially benefit depleted gas shale carbon storage research.

Quantitative analysis of titanium concentration using calibration-free laser-induced breakdown spectroscopy (LIBS)

NASA Astrophysics Data System (ADS)

Zaitun; Prasetyo, S.; Suliyanti, M. M.; Isnaeni; Herbani, Y.

2018-03-01

Laser-induced breakdown spectroscopy (LIBS) can be used for quantitative and qualitative analysis. Calibration-free LIBS (CF-LIBS) is a method to quantitatively analyze concentration of elements in a sample in local thermodynamic equilibrium conditions without using available matrix-matched calibration. In this study, we apply CF-LIBS for quantitative analysis of Ti in TiO2 sample. TiO2 powder sample was mixed with polyvinyl alcohol and formed into pellets. An Nd:YAG pulsed laser at a wavelength of 1064 nm was focused onto the sample to generate plasma. The spectrum of plasma was recorded using spectrophotometer then compared to NIST spectral line to determine energy levels and other parameters. The value of plasma temperature obtained using Boltzmann plot is 8127.29 K and electron density from calculation is 2.49×1016 cm-3. Finally, the concentration of Ti in TiO2 sample from this study is 97% that is in proximity with the sample certificate.

Combination of laser-induced breakdown spectroscopy and Raman spectroscopy for multivariate classification of bacteria

NASA Astrophysics Data System (ADS)

Prochazka, D.; Mazura, M.; Samek, O.; Rebrošová, K.; Pořízka, P.; Klus, J.; Prochazková, P.; Novotný, J.; Novotný, K.; Kaiser, J.

2018-01-01

In this work, we investigate the impact of data provided by complementary laser-based spectroscopic methods on multivariate classification accuracy. Discrimination and classification of five Staphylococcus bacterial strains and one strain of Escherichia coli is presented. The technique that we used for measurements is a combination of Raman spectroscopy and Laser-Induced Breakdown Spectroscopy (LIBS). Obtained spectroscopic data were then processed using Multivariate Data Analysis algorithms. Principal Components Analysis (PCA) was selected as the most suitable technique for visualization of bacterial strains data. To classify the bacterial strains, we used Neural Networks, namely a supervised version of Kohonen's self-organizing maps (SOM). We were processing results in three different ways - separately from LIBS measurements, from Raman measurements, and we also merged data from both mentioned methods. The three types of results were then compared. By applying the PCA to Raman spectroscopy data, we observed that two bacterial strains were fully distinguished from the rest of the data set. In the case of LIBS data, three bacterial strains were fully discriminated. Using a combination of data from both methods, we achieved the complete discrimination of all bacterial strains. All the data were classified with a high success rate using SOM algorithm. The most accurate classification was obtained using a combination of data from both techniques. The classification accuracy varied, depending on specific samples and techniques. As for LIBS, the classification accuracy ranged from 45% to 100%, as for Raman Spectroscopy from 50% to 100% and in case of merged data, all samples were classified correctly. Based on the results of the experiments presented in this work, we can assume that the combination of Raman spectroscopy and LIBS significantly enhances discrimination and classification accuracy of bacterial species and strains. The reason is the complementarity in obtained chemical information while using these two methods.

Green-synthetized silver nanoparticles for Nanoparticle-Enhanced Laser Induced Breakdown Spectroscopy (NELIBS) using a mobile instrument

NASA Astrophysics Data System (ADS)

Poggialini, F.; Campanella, B.; Giannarelli, S.; Grifoni, E.; Legnaioli, S.; Lorenzetti, G.; Pagnotta, S.; Safi, A.; Palleschi, V.

2018-03-01

When compared to other analytical techniques, LIBS shows relatively low precision and, generally, high Limits of Detection (LODs). Until recently, the attempts in improving the LIBS performances have been based on the use of more stable/powerful lasers, high sensitivity detectors or controlled environmental parameters. This can hinder the competitiveness of LIBS by increasing the instrumental setup cost and the difficulty of operation. Sample treatment has proved to be a viable and simple way to increase the LIBS signal; in particular, the Nanoparticle-Enhanced Laser Induced Breakdown Spectroscopy (NELIBS) methodology uses a deposition of metal nanoparticles on the sample to greatly increase the emission of the LIBS plasma. In this work, we used a simple, fast, "green" and low-cost method to synthetize silver nanoparticles by using coffee extract as reducing agents for a silver nitrate solution. This allowed us to obtain nanoparticles of about 25 nm in diameter. We then explored the application of such nanoparticles to the NELIBS analysis of metallic samples with a mobile LIBS instrument. By adjusting the laser parameters and optimizing the sample preparation procedure, we obtained a NELIBS signal that is 4 times the LIBS one. This showed the potential of green-synthetized nanoparticle for NELIBS applications and suggests the possibility of an in-situ application of the technique.

Rapid detection of soils contaminated with heavy metals and oils by laser induced breakdown spectroscopy (LIBS).

PubMed

Kim, Gibaek; Kwak, Jihyun; Kim, Ki-Rak; Lee, Heesung; Kim, Kyoung-Woong; Yang, Hyeon; Park, Kihong

2013-12-15

A laser induced breakdown spectroscopy (LIBS) coupled with the chemometric method was applied to rapidly discriminate between soils contaminated with heavy metals or oils and clean soils. The effects of the water contents and grain sizes of soil samples on LIBS emissions were also investigated. The LIBS emission lines decreased by 59-75% when the water content increased from 1.2% to 7.8%, and soil samples with a grain size of 75 μm displayed higher LIBS emission lines with lower relative standard deviations than those with a 2mm grain size. The water content was found to have a more pronounced effect on the LIBS emission lines than the grain size. Pelletizing and sieving were conducted for all samples collected from abandoned mining areas and military camp to have similar water contents and grain sizes before being analyzed by the LIBS with the chemometric analysis. The data show that three types of soil samples were clearly discerned by using the first three principal components from the spectral data of soil samples. A blind test was conducted with a 100% correction rate for soil samples contaminated with heavy metals and oil residues. Copyright © 2013 Elsevier B.V. All rights reserved.

Comparison of field portable measurements of ultrafine TiO2: X-ray fluorescence, laser-induced breakdown spectroscopy, and Fourier-transform infrared spectroscopy.

PubMed

LeBouf, Ryan F; Miller, Arthur L; Stipe, Christopher; Brown, Jonathan; Murphy, Nate; Stefaniak, Aleksandr B

2013-06-01

Laboratory measurements of ultrafine titanium dioxide (TiO2) particulate matter loaded on filters were made using three field portable methods (X-ray fluorescence (XRF), laser-induced breakdown spectroscopy (LIBS), and Fourier-transform infrared (FTIR) spectroscopy) to assess their potential for determining end-of-shift exposure. Ultrafine TiO2 particles were aerosolized and collected onto 37 mm polycarbonate track-etched (PCTE) filters in the range of 3 to 578 μg titanium (Ti). Limit of detection (LOD), limit of quantification (LOQ), and calibration fit were determined for each measurement method. The LOD's were 11.8, 0.032, and 108 μg Ti per filter, for XRF, LIBS, and FTIR, respectively and the LOQ's were 39.2, 0.11, and 361 μg Ti per filter, respectively. The XRF calibration curve was linear over the widest dynamic range, up to the maximum loading tested (578 μg Ti per filter). LIBS was more sensitive but, due to the sample preparation method, the highest loaded filter measurable was 252 μg Ti per filter. XRF and LIBS had good predictability measured by regressing the predicted mass to the gravimetric mass on the filter. XRF and LIBS produced overestimations of 4% and 2%, respectively, with coefficients of determination (R(2)) of 0.995 and 0.998. FTIR measurements were less dependable due to interference from the PCTE filter media and overestimated mass by 2% with an R(2) of 0.831.

LIBS: a new versatile field-deployable real-time detector system with potential for landmine detection

NASA Astrophysics Data System (ADS)

Harmon, Russell S.; De Lucia, Frank C.; Winkel, Raymond J., Jr.; LaPointe, Aaron; Grossman, Scott L.; McNesby, Kevin L.; Miziolek, Andrzej W.

2003-09-01

Laser Induced Breakdown Spectroscopy (LIBS) is an atomic emission spectroscopic technique that utilizes a pulsed laser to create a microplasma on the target together with an array spectrometer to capture the transient light for elemental identification and quantification. LIBS has certain important characteristics that make it a very attractive sensor technology for military uses. Such attributes include that facts that LIBS (1) is relatively simple and straightforward, (2) requires no sample preparation, (3) generates a real-time response, and (4) only engages a very small sample (pg-ng) of matter in each laser shot and microplasma event, (5) has inherent high sensitivity, and (6) responds to all forms of unknowns, and, therefore, is particularly suited for the sensing of dangerous materials. Additionally, a LIBS sensor system can be inexpensive, configured to be man-portable, and designed for both in-situ point sensing and remote stand-off detection with distances of up to 20-25 meters. Broadband LIBS results covering the spectral region from 200-970 nm acquired at the Army Research Laboratory (ARL) under laboratory conditions for a variety of landmine casings and explosive materials. This data will illustrate the potential that LIBS has to be developed into a hand-deployable device that could be utilized as a confirmatory sensor in landmine detection. The concept envisioned is a backpack-size system in which an eyesafe micro-laser is contained in the handle of a deminer's probe and light is delivered and collected through an optical fiber in the tapered tip of the probe. In such a configuration, analyses can be made readily by touching the buried object that one is interested in identifying.

Incorporation of support vector machines in the LIBS toolbox for sensitive and robust classification amidst unexpected sample and system variability

PubMed Central

ChariDingari, Narahara; Barman, Ishan; Myakalwar, Ashwin Kumar; Tewari, Surya P.; Kumar, G. Manoj

2012-01-01

Despite the intrinsic elemental analysis capability and lack of sample preparation requirements, laser-induced breakdown spectroscopy (LIBS) has not been extensively used for real world applications, e.g. quality assurance and process monitoring. Specifically, variability in sample, system and experimental parameters in LIBS studies present a substantive hurdle for robust classification, even when standard multivariate chemometric techniques are used for analysis. Considering pharmaceutical sample investigation as an example, we propose the use of support vector machines (SVM) as a non-linear classification method over conventional linear techniques such as soft independent modeling of class analogy (SIMCA) and partial least-squares discriminant analysis (PLS-DA) for discrimination based on LIBS measurements. Using over-the-counter pharmaceutical samples, we demonstrate that application of SVM enables statistically significant improvements in prospective classification accuracy (sensitivity), due to its ability to address variability in LIBS sample ablation and plasma self-absorption behavior. Furthermore, our results reveal that SVM provides nearly 10% improvement in correct allocation rate and a concomitant reduction in misclassification rates of 75% (cf. PLS-DA) and 80% (cf. SIMCA)-when measurements from samples not included in the training set are incorporated in the test data – highlighting its robustness. While further studies on a wider matrix of sample types performed using different LIBS systems is needed to fully characterize the capability of SVM to provide superior predictions, we anticipate that the improved sensitivity and robustness observed here will facilitate application of the proposed LIBS-SVM toolbox for screening drugs and detecting counterfeit samples as well as in related areas of forensic and biological sample analysis. PMID:22292496

Incorporation of support vector machines in the LIBS toolbox for sensitive and robust classification amidst unexpected sample and system variability.

PubMed

Dingari, Narahara Chari; Barman, Ishan; Myakalwar, Ashwin Kumar; Tewari, Surya P; Kumar Gundawar, Manoj

2012-03-20

Despite the intrinsic elemental analysis capability and lack of sample preparation requirements, laser-induced breakdown spectroscopy (LIBS) has not been extensively used for real-world applications, e.g., quality assurance and process monitoring. Specifically, variability in sample, system, and experimental parameters in LIBS studies present a substantive hurdle for robust classification, even when standard multivariate chemometric techniques are used for analysis. Considering pharmaceutical sample investigation as an example, we propose the use of support vector machines (SVM) as a nonlinear classification method over conventional linear techniques such as soft independent modeling of class analogy (SIMCA) and partial least-squares discriminant analysis (PLS-DA) for discrimination based on LIBS measurements. Using over-the-counter pharmaceutical samples, we demonstrate that the application of SVM enables statistically significant improvements in prospective classification accuracy (sensitivity), because of its ability to address variability in LIBS sample ablation and plasma self-absorption behavior. Furthermore, our results reveal that SVM provides nearly 10% improvement in correct allocation rate and a concomitant reduction in misclassification rates of 75% (cf. PLS-DA) and 80% (cf. SIMCA)-when measurements from samples not included in the training set are incorporated in the test data-highlighting its robustness. While further studies on a wider matrix of sample types performed using different LIBS systems is needed to fully characterize the capability of SVM to provide superior predictions, we anticipate that the improved sensitivity and robustness observed here will facilitate application of the proposed LIBS-SVM toolbox for screening drugs and detecting counterfeit samples, as well as in related areas of forensic and biological sample analysis.

A combined remote Raman and LIBS instrument for characterizing minerals with 532 nm laser excitation.

PubMed

Sharma, Shiv K; Misra, Anupam K; Lucey, Paul G; Lentz, Rachel C F

2009-08-01

The authors have developed an integrated remote Raman and laser-induced breakdown spectroscopy (LIBS) system for measuring both the Raman and LIBS spectra of minerals with a single 532 nm laser line of 35 mJ/pulse and 20 Hz. The instrument has been used for analyzing both Raman and LIBS spectra of carbonates, sulfates, hydrous and anhydrous silicates, and iron oxide minerals in air. These experiments demonstrate that by focusing a frequency-doubled 532 nm Nd:YAG pulsed laser beam with a 10x beam expander to a 529-microm diameter spot on a mineral surface located at 9 m, it is possible to measure simultaneously both the remote Raman and LIBS spectra of calcite, gypsum and olivine by adjusting the laser power electronically. The spectra of calcite, gypsum, and olivine contain fingerprint Raman lines; however, it was not possible to measure the remote Raman spectra of magnetite and hematite at 9 m because of strong absorption of 532 nm laser radiation and low intensities of Raman lines from these minerals. The remote LIBS spectra of both magnetite and hematite contain common iron emission lines but show difference in the minor amount of Li present in these two minerals. Remote Raman and LIBS spectra of a number of carbonates, sulfates, feldspars and phyllosilicates at a distance of 9 m were measured with a 532-nm laser operating at 35 mJ/pulse and by changing photon flux density at the sample by varying the spot diameter from 10 mm for Raman to 530 microm for LIBS measurements. The complementary nature of these spectra is highlighted and discussed. The combined Raman and LIBS system can also be re-configured to perform micro-Raman and micro-LIBS analyses, which have applications in trace/residue analysis and analysis of very small samples in the nano-gram range.

Detection and identification of amino acids in Ficoll solutions with femtosecond laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Markushin, Y.; Sivakumar, P.; Melikechi, N.; Boukari, H.

2018-02-01

We report femtosecond Laser-induced Breakdown Spectroscopy (fs-LIBS) measurements on several amino acids (Serine, Glutamine, and Cysteine) and Albumin protein solutions mixed with Ficoll polysaccharide at different proportions. The goal is to assess the effects of a host matrix on the identification and spectral characterization of amino acids by fs-LIBS. fs-LIBS utilizes an intense short laser pulse to obliterate a sample into basic constituents and to record the emission spectrum of atoms, ions, and molecules in the cooling down of the plasma plume. Several spectral peaks associated primarily with elemental composition of a sample were observed in the fs-LIBS spectra in a range from 200 to 950 nm. In addition, some molecular information associated with diatomic vibrational modes in certain molecules such as C-C and C-N were also obtained. The presence of Ficoll affects the relative intensity and broadening of the CN band, which could be considered as signatures of the amino acids. The fs-LIBS data and their analysis compare favorably with those derived from Fourier Transform Infrared Spectroscopy (FTIR). Interpretation of the spectral information enclosed in the emission of the diatomic molecules during laser ablation may lead to a better understanding of plume chemistry with a direct consequence on chemical analysis of complex samples such as amino acids. Altogether, the results demonstrate the potential of fs-LIBS technique as a detection method of biomolecules and for probing interactions of these biomolecules with a host matrix.

Standoff detection of chemical and biological threats using laser-induced breakdown spectroscopy.

PubMed

Gottfried, Jennifer L; De Lucia, Frank C; Munson, Chase A; Miziolek, Andrzej W

2008-04-01

Laser-induced breakdown spectroscopy (LIBS) is a promising technique for real-time chemical and biological warfare agent detection in the field. We have demonstrated the detection and discrimination of the biological warfare agent surrogates Bacillus subtilis (BG) (2% false negatives, 0% false positives) and ovalbumin (0% false negatives, 1% false positives) at 20 meters using standoff laser-induced breakdown spectroscopy (ST-LIBS) and linear correlation. Unknown interferent samples (not included in the model), samples on different substrates, and mixtures of BG and Arizona road dust have been classified with reasonable success using partial least squares discriminant analysis (PLS-DA). A few of the samples tested such as the soot (not included in the model) and the 25% BG:75% dust mixture resulted in a significant number of false positives or false negatives, respectively. Our preliminary results indicate that while LIBS is able to discriminate biomaterials with similar elemental compositions at standoff distances based on differences in key intensity ratios, further work is needed to reduce the number of false positives/negatives by refining the PLS-DA model to include a sufficient range of material classes and carefully selecting a detection threshold. In addition, we have demonstrated that LIBS can distinguish five different organophosphate nerve agent simulants at 20 meters, despite their similar stoichiometric formulas. Finally, a combined PLS-DA model for chemical, biological, and explosives detection using a single ST-LIBS sensor has been developed in order to demonstrate the potential of standoff LIBS for universal hazardous materials detection.

Assessment and forensic application of laser-induced breakdown spectroscopy (LIBS) for the discrimination of Australian window glass.

PubMed

El-Deftar, Moteaa M; Speers, Naomi; Eggins, Stephen; Foster, Simon; Robertson, James; Lennard, Chris

2014-08-01

A commercially available laser-induced breakdown spectroscopy (LIBS) instrument was evaluated for the determination of elemental composition of twenty Australian window glass samples, consisting of 14 laminated samples and 6 non-laminated samples (or not otherwise specified) collected from broken windows at crime scenes. In this study, the LIBS figures of merit were assessed in terms of accuracy, limits of detection and precision using three standard reference materials (NIST 610, 612, and 1831). The discrimination potential of LIBS was compared to that obtained using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), X-ray microfluorescence spectroscopy (μXRF) and scanning electron microscopy energy dispersive X-ray spectrometry (SEM-EDX) for the analysis of architectural window glass samples collected from crime scenes in the Canberra region, Australia. Pairwise comparisons were performed using a three-sigma rule, two-way ANOVA and Tukey's HSD test at 95% confidence limit in order to investigate the discrimination power for window glass analysis. The results show that the elemental analysis of glass by LIBS provides a discrimination power greater than 97% (>98% when combined with refractive index data), which was comparable to the discrimination powers obtained by LA-ICP-MS and μXRF. These results indicate that LIBS is a feasible alternative to the more expensive LA-ICP-MS and μXRF options for the routine forensic analysis of window glass samples. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Evaluation of the efficacy of a portable LIBS system for detection of CWA on surfaces.

PubMed

L'Hermite, D; Vors, E; Vercouter, T; Moutiers, G

2016-05-01

Laser-induced breakdown spectroscopy (LIBS) is a laser-based optical technique particularly suited for in situ surface analysis. A portable LIBS instrument was tested to detect surface chemical contamination by chemical warfare agents (CWAs). Test of detection of surface contamination was carried out in a toxlab facility with four CWAs, sarin (GB), lewisite (L1), mustard gas (HD), and VX, which were deposited on different substrates, wood, concrete, military green paint, gloves, and ceramic. The CWAs were detected by means of the detection of atomic markers (As, P, F, Cl, and S). The LIBS instrument can give a direct response in terms of detection thanks to an integrated interface for non-expert users or so called end-users. We have evaluated the capability of automatic detection of the selected CWAs. The sensitivity of our portable LIBS instrument was confirmed for the detection of a CWA at surface concentrations above 15 μg/cm(2). The simultaneous detection of two markers may lead to a decrease of the number of false positive.

The 1064 nm laser-induced breakdown spectroscopy (LIBS) inspection to detect the nutrient elements in freshly cut carrot samples

NASA Astrophysics Data System (ADS)

Yudasari, N.; Prasetyo, S.; Suliyanti, M. M.

2018-03-01

The laser-induced breakdown spectroscopy (LIBS) technique was applied to detect the nutrient elements contained in fresh carrot. Nd:YAG laser the wavelength of 1064 nm was employed in the experiments for ablation. Employing simple set-up of LIBS and preparing the sample with less step method, we are able to detect 18 chemical elements including some fundamental element of carrot, i.e Mg, Al, Fe, Mn, Ti, Ca, and Mn. By applying normalized profiles calculation on some of the element, we are able to compare the concentration level of each element of the outer and inner part of carrot.

Use of Laser-Induced Breakdown Spectroscopy for the Detection of Glycemic Elements in Indian Medicinal Plants

PubMed Central

Rai, Prashant Kumar; Srivastava, Amrita Kumari; Sharma, Bechan; Dhar, Preeti; Mishra, Ajay Kumar; Watal, Geeta

2013-01-01

The demand for interdisciplinary research is increasing in the new millennium to help us understand complex problems and find solutions by integrating the knowledge from different disciplines. The present review is an excellent example of this and shows how unique combination of physics, chemistry, and biological techniques can be used for the evaluation of Indian medicinal herbs used for treating diabetes mellitus. Laser-induced breakdown spectroscopy (LIBS) is a sensitive optical technique that is widely used for its simplicity and versatility. This review presents the most recent application of LIBS for detection of glycemic elements in medicinal plants. The characteristics of matrices, object analysis, use of laser system, and analytical performances with respect to Indian herbs are discussed. PMID:24228060

[Element distribution analysis of welded fusion zone by laser-induced breakdown spectroscopy].

PubMed

Yang, Chun; Zhang, Yong; Jia, Yun-Hai; Wang, Hai-Zhou

2014-04-01

Over the past decade there has been intense activity in the study and development of laser-induced breakdown spectroscopy (LIBS). As a new tool for surface microanalysis, it caused widespread in materials science because of the advantage of rapid and high sensitivity. In the present paper, the distribution of Ni, Mn, C and Si near weld fusion line was analyzed on two kinds of weld sample. Line scanning mode analysis was carried out by three different kinds of methods, namely laser-induced breakdown spectroscopy (LIBS), scanning electron microscope/energy dispersive spectrometer (SEM/EDS) and electron probe X-ray microanalyser (EPMA). The concentration variation trend of Ni and Mn acquired by LIBS is coincident with SEM/EDS and EPMA. The result shows that the content of Ni and Mn was significantly different between weld seam and base metal on both the samples. The content of Ni and Mn was much higher in weld seam than in base metal, and a sharp concentration gradient was analyzed in the fusion zone. According to the distribution of Ni and Mn, all the three methods got a similar value of welded fusion zone width. The concentration variation trend of C and Si acquired by LIBS is not coincident with SEM/EDS and EPMA. The concentration difference between weld seam and base metal was analyzed by LIBS, but had not by SEM/EDS and EPMA, because of the low concentration and slight difference. The concentration gradient of C and Si in fusion zone was shows clearly by LIBS. For higher sensitivity performance, LIBS is much more adapted to analyze low content element than SEM/EDS and EPMA.

On-line/on-site analysis of heavy metals in water and soils by laser induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Meng, Deshuo; Zhao, Nanjing; Wang, Yuanyuan; Ma, Mingjun; Fang, Li; Gu, Yanhong; Jia, Yao; Liu, Jianguo

2017-11-01

The enrichment method of heavy metal in water with graphite and aluminum electrode was studied, and combined with plasma restraint device for improving the sensitivity of detection and reducing the limit of detection (LOD) of elements. For aluminum electrode enrichment, the LODs of Cd, Pb and Ni can be as low as several ppb. For graphite enrichment, the measurement time can be less than 3 min. The results showed that the graphite enrichment and aluminum electrode enrichment method can effectively improve the LIBS detection ability. The graphite enrichment method combined with plasma spatial confinement is more suitable for on-line monitoring of industrial waste water, the aluminum electrode enrichment method can be used for trace heavy metal detection in water. A LIBS method and device for soil heavy metals analysis was also developed, and a mobile LIBS system was tested in outfield. The measurement results deduced from LIBS and ICP-MS had a good consistency. The results provided an important application support for rapid and on-site monitoring of heavy metals in soil. (Left: the mobile LIBS system for analysis of heavy metals in soils. Top right: the spatial confinement device. Bottom right: automatic graphite enrichment device for on0line analysis of heavy metals in water).

Laser spectrum detection methods for substance of Mars surface

NASA Astrophysics Data System (ADS)

Zhang, Dan; Xue, Bin; Zhao, Yi-yi

2014-11-01

The chemical element and mineral rock's abundance and distribution are the basic material of planetary geology evolution research [1], hence preterit detection for composition of Mars surface substance contains both elements sorts and mineral ingredients. This article introduced new ways to detect Mars elements and mineral components, Laser Induced Breakdown Spectroscopy (LIBS) and Raman Spectroscopy (RS) which have distinct advantages, such as work over a long distance, detect rapidly, accuratly and nondestructively. LIBS and RS both use laser excitation to shoot the substance of Mars exciting new wavelengths. The techniques of LIBS and RS in laboratory are mature, besides the technique of LIBS is being used in MSL (Chemcam) now and RS will be used in ExoMars. Comparing LIBS and RS's detection results with XRF and APXS, Mossbauer spectrometer, these existed Mars surface material detection instruments,and the Infrared spectrometer, Mid-IR, they have more accurate detection results. So LIBS and RS are competent for Mars surface substance detection instead of X-ray spectrometer and Mossbauer spectrometer which were already used in 'Viking 1' and 'Opportunity'. Only accurate detection results about Mars surface substance can lead to scientist's right analysis in inversing geological evolution of the planet.

Laser Induced Breakdown Spectroscopy of Glass and Crystal Samples

NASA Astrophysics Data System (ADS)

Sharma, Prakash; Sandoval, Alejandra; Carter, Michael; Kumar, Akshaya

2015-03-01

Different types of quartz crystals and rare earth ions doped glasses have been identified using the laser induced breakdown spectroscopy (LIBS) technique. LIBS is a real time technique, can be used to identify samples in solid, liquid and gas phases. The advantage of LIBS technique is that no sample preparation is required and laser causes extremely minimal damage to the sample surface. The LIBS spectrum of silicate glasses, prepared by sol-gel method and doped with different concentration of rare earth ions, has been recorded. The limit of detection of rare earth ions in glass samples has been calculated. Total 10 spectrums of each sample were recorded and then averaged to get a final spectrum. The ocean optics LIBS2500 plus spectrometer along with a Q- switched Nd: YAG laser (Quantel, Big Sky) were used to record the LIBS spectrum. This spectrometer can analyze the sample in the spectral range of 200 nm to 980 nm. The spectrum was processed by OOILIBS-plus (v1.0) software. This study has application in the industry where different crystals can be easily identified before they go for shaping and polishing. Also, concentration of rare earth ions in glass can be monitored in real time for quality control.

Monitoring of toxic elements present in sludge of industrial waste using CF-LIBS.

PubMed

Kumar, Rohit; Rai, Awadhesh K; Alamelu, Devanathan; Aggarwal, Suresh K

2013-01-01

Industrial waste is one of the main causes of environmental pollution. Laser-induced breakdown spectroscopy (LIBS) was applied to detect the toxic metals in the sludge of industrial waste water. Sludge on filter paper was obtained after filtering the collected waste water samples from different sections of a water treatment plant situated in an industrial area of Kanpur City. The LIBS spectra of the sludge samples were recorded in the spectral range of 200 to 500 nm by focusing the laser light on sludge. Calibration-free laser-induced breakdown spectroscopy (CF-LIBS) technique was used for the quantitative measurement of toxic elements such as Cr and Pb present in the sample. We also used the traditional calibration curve approach to quantify these elements. The results obtained from CF-LIBS are in good agreement with the results from the calibration curve approach. Thus, our results demonstrate that CF-LIBS is an appropriate technique for quantitative analysis where reference/standard samples are not available to make the calibration curve. The results of the present experiment are alarming to the people living nearby areas of industrial activities, as the concentrations of toxic elements are quite high compared to the admissible limits of these substances.

A matrix effect and accuracy evaluation for the determination of elements in milk powder LIBS and laser ablation/ICP-OES spectrometry.

PubMed

Gilon, N; El-Haddad, J; Stankova, A; Lei, W; Ma, Q; Motto-Ros, V; Yu, J

2011-11-01

Laser ablation coupled to inductively coupled plasma optical emission spectrometry (LA-ICP-OES) and laser-induced breakdown spectroscopy (LIBS) were investigated for the determination of Ca, Mg, Zn and Na in milk samples. The accuracy of both methods was evaluated by comparison of the concentration found using LA-ICP-OES and LIBS with classical wet digestion associated with ICP-OES determination. The results were not fully acceptable, with biases from less than 1% to more than 60%. Matrix effects were also investigated. The sample matrix can influence the temperature, electron number density (n (e)) and other excitation characteristics in the ICP. These ICP characteristics were studied and evaluated during ablation of eight milk samples. Differences in n (e) (from 8.9 to 13.8 × 10(14) cm(-3)) and rotational temperature (ranging from 3,400 to 4,400 K) occurred with no correlation with trueness. LIBS results obtained after classical external calibration procedure gave degraded accuracy, indicating a strong matrix effect. The LIBS measurements clearly showed that the major problem in LA-ICP was related to the ablation process and that LIBS spectroscopy is an excellent diagnostic tool for LA-ICP techniques.

Contaminant concentration in environmental samples using LIBS and CF-LIBS

NASA Astrophysics Data System (ADS)

Pandhija, S.; Rai, N. K.; Rai, A. K.; Thakur, S. N.

2010-01-01

The present paper deals with the detection and quantification of toxic heavy metals like Cd, Co, Pb, Zn, Cr, etc. in environmental samples by using the technique of laser-induced breakdown spectroscopy (LIBS) and calibration-free LIBS (CF-LIBS). A MATLABTM program has been developed based on the CF-LIBS algorithm given by earlier workers and concentrations of pollutants present in industrial area soil have been determined. LIBS spectra of a number of certified reference soil samples with varying concentrations of toxic elements (Cd, Zn) have been recorded to obtain calibration curves. The concentrations of Cd and Zn in soil samples from the Jajmau area, Kanpur (India) have been determined by using these calibration curves and also by the CF-LIBS approach. Our results clearly demonstrate that the combination of LIBS and CF-LIBS is very useful for the study of pollutants in the environment. Some of the results have also been found to be in good agreement with those of ICP-OES.

Adaptive Multi-sensor Data Fusion Model for In-situ Exploration of Mars

NASA Astrophysics Data System (ADS)

Schneiderman, T.; Sobron, P.

2014-12-01

Laser Raman spectroscopy (LRS) and laser-induced breakdown spectroscopy (LIBS) can be used synergistically to characterize the geochemistry and mineralogy of potential microbial habitats and biosignatures. The value of LRS and LIBS has been recognized by the planetary science community: (i) NASA's Mars2020 mission features a combined LRS-LIBS instrument, SuperCam, and an LRS instrument, SHERLOC; (ii) an LRS instrument, RLS, will fly on ESA's 2018 ExoMars mission. The advantages of combining LRS and LIBS are evident: (1) LRS/LIBS can share hardware components; (2) LIBS reveals the relative concentration of major (and often trace) elements present in a sample; and (3) LRS yields information on the individual mineral species and their chemical/structural nature. Combining data from LRS and LIBS enables definitive mineral phase identification with precise chemical characterization of major, minor, and trace mineral species. New approaches to data processing are needed to analyze large amounts of LRS+LIBS data efficiently and maximize the scientific return of integrated measurements. Multi-sensor data fusion (MSDF) is a method that allows for robust sample identification through automated acquisition, processing, and combination of data. It optimizes information usage, yielding a more robust characterization of a target than could be acquired through single sensor use. We have developed a prototype fuzzy logic adaptive MSDF model aimed towards the unsupervised characterization of Martian habitats and their biosignatures using LRS and LIBS datasets. Our model also incorporates fusion of microimaging (MI) data - critical for placing analyses in geological and spatial context. Here, we discuss the performance of our novel MSDF model and demonstrate that automated quantification of the salt abundance in sulfate/clay/phyllosilicate mixtures is possible through data fusion of collocated LRS, LIBS, and MI data.

Improved intact soil-core carbon determination applying regression shrinkage and variable selection techniques to complete spectrum laser-induced breakdown spectroscopy (LIBS).

PubMed

Bricklemyer, Ross S; Brown, David J; Turk, Philip J; Clegg, Sam M

2013-10-01

Laser-induced breakdown spectroscopy (LIBS) provides a potential method for rapid, in situ soil C measurement. In previous research on the application of LIBS to intact soil cores, we hypothesized that ultraviolet (UV) spectrum LIBS (200-300 nm) might not provide sufficient elemental information to reliably discriminate between soil organic C (SOC) and inorganic C (IC). In this study, using a custom complete spectrum (245-925 nm) core-scanning LIBS instrument, we analyzed 60 intact soil cores from six wheat fields. Predictive multi-response partial least squares (PLS2) models using full and reduced spectrum LIBS were compared for directly determining soil total C (TC), IC, and SOC. Two regression shrinkage and variable selection approaches, the least absolute shrinkage and selection operator (LASSO) and sparse multivariate regression with covariance estimation (MRCE), were tested for soil C predictions and the identification of wavelengths important for soil C prediction. Using complete spectrum LIBS for PLS2 modeling reduced the calibration standard error of prediction (SEP) 15 and 19% for TC and IC, respectively, compared to UV spectrum LIBS. The LASSO and MRCE approaches provided significantly improved calibration accuracy and reduced SEP 32-55% over UV spectrum PLS2 models. We conclude that (1) complete spectrum LIBS is superior to UV spectrum LIBS for predicting soil C for intact soil cores without pretreatment; (2) LASSO and MRCE approaches provide improved calibration prediction accuracy over PLS2 but require additional testing with increased soil and target analyte diversity; and (3) measurement errors associated with analyzing intact cores (e.g., sample density and surface roughness) require further study and quantification.

In situ semi-quantitative analysis of polluted soils by laser-induced breakdown spectroscopy (LIBS).

PubMed

Ismaël, Amina; Bousquet, Bruno; Michel-Le Pierrès, Karine; Travaillé, Grégoire; Canioni, Lionel; Roy, Stéphane

2011-05-01

Time-saving, low-cost analyses of soil contamination are required to ensure fast and efficient pollution removal and remedial operations. In this work, laser-induced breakdown spectroscopy (LIBS) has been successfully applied to in situ analyses of polluted soils, providing direct semi-quantitative information about the extent of pollution. A field campaign has been carried out in Brittany (France) on a site presenting high levels of heavy metal concentrations. Results on iron as a major component as well as on lead and copper as minor components are reported. Soil samples were dried and prepared as pressed pellets to minimize the effects of moisture and density on the results. LIBS analyses were performed with a Nd:YAG laser operating at 1064 nm, 60 mJ per 10 ns pulse, at a repetition rate of 10 Hz with a diameter of 500 μm on the sample surface. Good correlations were obtained between the LIBS signals and the values of concentrations deduced from inductively coupled plasma atomic emission spectroscopy (ICP-AES). This result proves that LIBS is an efficient method for optimizing sampling operations. Indeed, "LIBS maps" were established directly on-site, providing valuable assistance in optimizing the selection of the most relevant samples for future expensive and time-consuming laboratory analysis and avoiding useless analyses of very similar samples. Finally, it is emphasized that in situ LIBS is not described here as an alternative quantitative analytical method to the usual laboratory measurements but simply as an efficient time-saving tool to optimize sampling operations and to drastically reduce the number of soil samples to be analyzed, thus reducing costs. The detection limits of 200 ppm for lead and 80 ppm for copper reported here are compatible with the thresholds of toxicity; thus, this in situ LIBS campaign was fully validated for these two elements. Consequently, further experiments are planned to extend this study to other chemical elements and other matrices of soils.

Development of double-pulse lasers ablation system and electron paramagnetic resonance spectroscopy for direct spectral analysis of manganese doped PVA polymer

NASA Astrophysics Data System (ADS)

Khalil, A. A. I.; Morsy, M. A.; El-Deen, H. Z.

2017-11-01

Series of manganese-co-precipitated poly (vinyl alcohol) (PVA) polymer were quantitatively and qualitatively analyzed using laser ablation system (LAS) based on double-pulse laser induced breakdown spectroscopy (DP-LIBS) and electron paramagnetic resonance (EPR) spectroscopy. The collinear nanosecond laser beams of 266 and 1064 nm were optimized to focus on the surface of the PVA polymer target. Both laser beams were employed to estimate the natural properties of the excited Mn-PVA plasma, such as electron number density (Ne), electron temperature (Te), and Mn concentration. Individual transition lines of manganese (Mn), carbon (C), lithium (Li), hydrogen (H) and oxygen (O) atoms are identified based on the NIST spectral database. The results show better responses with DP-LIBS than the single-pulse laser induced breakdown spectroscopy (SP-LIBS). On the other hand, the EPR investigation shows characteristic broad peak of Mn-nano-particles (Mn-NPs) in the range of quantum dots of superparamagnetic materials. The line width (peak-to-peak, ΔHpp) and g-value of the observed Mn-EPR peak are ∼20 mT and 2.0046, respectively. The intensities of Mn-emission line at a wavelength 403.07 nm and the Mn-EPR absorption peak were used to accurate quantify the Mn-content in the polymer matrix. The results produce linear trends within the studied concentration range with regression coefficient (R2) value of ∼0.99, and limit of detection (LOD) of 0.026 mol.% and 0.016 mol.%, respectively. The LOD values are at a fold change of about -0.2 of the studied lowest mol.%. The proposed protocols of trace element detection are of significant advantage and can be applied to the other metal analysis.

In-vitro analysis of early calcification in aortic valvular interstitial cells using Laser-Induced Breakdown Spectroscopy (LIBS).

PubMed

Davari, Seyyed Ali; Masjedi, Shirin; Ferdous, Zannatul; Mukherjee, Dibyendu

2018-01-01

Calcific aortic valve disease (CAVD) is a major cardiovascular disorder caused by osteogenic differentiation of valvular interstitial cells (VICs) within aortic valves. Conventional methods like colorimetric assays and histology fail to detect small calcium depositions during in-vitro VIC cultures. Laser-induced breakdown spectroscopy (LIBS) is a robust analytical tool used for inorganic materials characterizations, but relatively new to biomedical applications. We employ LIBS, for the first time, for quantitative in-vitro detection of calcium depositions in VICs at various osteogenic differentiation stages. VICs isolated from porcine aortic valves were cultured in osteogenic media over various days. Colorimetric calcium assays based on arsenazo dye and Von Kossa staining measured the calcium depositions within VICs. Simultaneously, LIBS signatures for Ca I (422.67 nm) atomic emission lines were collected for estimating calcium depositions in lyophilized VIC samples. Our results indicate excellent linear correlation between the calcium assay and our LIBS measurements. Furthermore, unlike the assay results, the LIBS results could resolve calcium signals from cell samples with as early as 2 days of osteogenic culture. Quantitatively, the LIBS measurements establish the limit of detection for calcium content in VICs to be ∼0.17±0.04 μg which indicates a 5-fold improvement over calcium assay. Picture: Quantitative LIBS enables in-vitro analysis for early stage detection of calcium deposition within aortic valvular interstitial cells (VICs). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Spectroscopic identification of rare earth elements in phosphate glass

NASA Astrophysics Data System (ADS)

Devangad, Praveen; Tamboli, Maktum; Muhammed Shameem, K. M.; Nayak, Rajesh; Patil, Ajeetkumar; Unnikrishnan, V. K.; Santhosh, C.; Kumar, G. A.

2018-01-01

In this work, rare earth-doped phosphate glasses were synthesized and characterized using three different spectroscopic techniques. The absorption spectra of the prepared praseodymium (Pr) and samarium (Sm) doped glasses, recorded by a UV-VIS-NIR spectrophotometer, show the characteristic absorption bands of these elements. To confirm this inference, laser-induced fluorescence spectra of Pr and Sm were obtained at a laser excitation of 442 nm. Their emission bands are reported here. The elemental analysis of these samples was carried out using a laser-induced breakdown spectroscopy (LIBS) system. Characteristic emission lines of Pr and Sm have been identified and reported by the recorded LIBS spectra of glass samples. Results prove that using these three complimentary spectroscopic techniques (absorption, fluorescence and LIBS), we can meaningfully characterize rare earth-doped glass samples.

Post-mortem characterization of fs laser-generated micro-pillars in Li(Ni1/3Mn1/3Co1/3)O2 electrodes by laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Smyrek, P.; Zheng, Y.; Seifert, H. J.; Pfleging, W.

2016-03-01

NMC thick films were prepared by tape-casting and subsequent ultrafast laser-structuring. The lithium distribution in electrochemically cycled and unstructured or fs laser-structured NMC cathodes was investigated by using Laser-Induced Breakdown Spectroscopy (LIBS). The main goal is to develop an optimized three dimensional cell architecture with improved electrochemical properties based on studies of the homogeneity of the local State-of-Charge. LIBS experiments were carried out using a LIBS workstation equipped with a mode-locked diode pumped solid state Nd:YAG laser operating at a wavelength of 1063 nm. The element distribution was investigated using two different techniques: element mapping and element depth-profiling of the unstructured / fs laser-structured electrode surface. Results achieved from post-mortem studies using LIBS will be presented.

Study of atomic and molecular emission spectra of Sr by laser induced breakdown spectroscopy (LIBS).

PubMed

Bhatt, Chet R; Alfarraj, Bader; Ayyalasomayajula, Krishna K; Ghany, Charles; Yueh, Fang Y; Singh, Jagdish P

2015-12-01

Laser Induced Breakdown Spectroscopy (LIBS) is an ideal analytical technique for in situ analysis of elemental composition. We have performed a comparative study of the quantitative and qualitative analysis of atomic and molecular emission from LIBS spectra. In our experiments, a mixture of SrCl2 and Al2O3 in powder form was used as a sample. The atomic emission from Sr and molecular emission from SrCl and SrO observed in LIBS spectra were analyzed. The optimum laser energies, gate delays, and gate widths for selected atomic lines and molecular bands were determined from spectra recorded at various experimental parameters. These optimum experimental conditions were used to collect calibration data, and the calibration curves were used to predict the Sr concentration. Limits of detection (LODs) for selected atomic and molecular emission spectra were determined.

Direct Determination of Contaminants and Major and Minor Nutrients in Solid Fertilizers Using Laser-Induced Breakdown Spectroscopy (LIBS).

PubMed

Andrade, Daniel F; Pereira-Filho, Edenir Rodrigues

2016-10-11

Contaminants (Cd, Cr, and Pb) as well as minor (B, Cu, Mn, Na, and Zn) and major (Ca and Mg) elements were directly determined in solid fertilizer samples using laser-induced breakdown spectroscopy (LIBS). Factorial designs were used to define the most appropriate LIBS parameters and pellet pressure on solid fertilizers. Emission lines for all of the analytes were collected and employed 12 signal normalization modes. The best results were obtained using a laser energy of 75 mJ, a spot size of 50 μm, a pressure of 10 t/in., and a delay of 2.0 μs. Good correlation was obtained between the calibration model's prediction using the proposed LIBS method and the reference values obtained with ICP-OES. The limits of detection (LOD) for the proposed method varied from 2 mg/kg (for Cd) to 1% (for Zn).

Investigations of calcium spectral lines in laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Ching, Sim Yit; Tariq, Usman; Haider, Zuhaib; Tufail, Kashif; Sabri, Salwanie; Imran, Muhammad; Ali, Jalil

2017-03-01

Laser-induced breakdown spectroscopy (LIBS) is a direct and versatile analytical technique that performs the elemental composition analysis based on optical emission produced by laser induced-plasma, with a little or no sample preparation. The performance of the LIBS technique relies on the choice of experimental conditions which must be thoroughly explored and optimized for each application. The main parameters affecting the LIBS performance are the laser energy, laser wavelength, pulse duration, gate delay, geometrical set-up of the focusing and collecting optics. In LIBS quantitative analysis, the gate delay and laser energy are very important parameters that have pronounced impact on the accuracy of the elemental composition information of the materials. The determination of calcium elements in the pelletized samples was investigated and served for the purpose of optimizing the gate delay and laser energy by studying and analyzing the results from emission intensities collected and signal to background ratio (S/B) for the specified wavelengths.

Proof-of-concept experiment for on-line laser induced breakdown spectroscopy analysis of impurity layer deposited on optical window and other plasma facing components of Aditya tokamak

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maurya, Gulab Singh; Kumar, Rohit; Rai, Awadhesh Kumar, E-mail: awadheshkrai@rediffmail.com

2015-12-15

In the present manuscript, we demonstrate the design of an experimental setup for on-line laser induced breakdown spectroscopy (LIBS) analysis of impurity layers deposited on specimens of interest for fusion technology, namely, plasma-facing components (PFCs) of a tokamak. For investigation of impurities deposited on PFCs, LIBS spectra of a tokamak wall material like a stainless steel sample (SS304) have been recorded through contaminated and cleaned optical windows. To address the problem of identification of dust and gases present inside the tokamak, we have shown the capability of the apparatus to record LIBS spectra of gases. A new approach known asmore » “back collection method” to record LIBS spectra of impurities deposited on the inner surface of optical window is presented.« less

Analysis of major elements in pigmented melanocytic chicken skin using laser-induced breakdown spectroscopy.

PubMed

Lee, Jong Jin; Moon, Youngmin; Han, Jung Hyun; Jeong, Sungho

2017-04-01

The concentration difference of major elements in melanocytic skin with respect to pigmentation level is analysed by laser-induced breakdown spectroscopy (LIBS) to investigate the applicability of LIBS as an in situ feedback tool for selective and complete laser removal of melanocytic skin tissue like nevus. The skin of black silkie chicken which had a characteristic darkly pigmented perifollicular skin surrounded by lightly pigmented extrafollicular skin was used as the sample. The results showed higher LIBS signal intensities of Ca 2+ and Mg 2+ but lower intensities of Na + , Cl - and K + in the perifollicular skin than in the extrafollicular skin, which demonstrated the feasibility to use LIBS as a reliable method to distinguish skin tissues with difference in pigmentation level. Plasma emission of biochemical elements generated with a laser irradiation on melanocytic skin lesion. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preliminary results of in situ laser-induced breakdown spectroscopy for the first wall diagnostics on EAST

NASA Astrophysics Data System (ADS)

Hu, Zhenhua; Li, Cong; Xiao, Qingmei; Liu, Ping; Fang, Ding; Mao, Hongmin; Wu, Jing; Zhao, Dongye; Ding, Hongbin; Luo, Guang-Nan; EAST Team

2017-02-01

Post-mortem methods cannot fulfill the requirement of monitoring the lifetime of the plasma facing components (PFC) and measuring the tritium inventory for the safety evaluation. Laser-induced breakdown spectroscopy (LIBS) is proposed as a promising method for the in situ study of fuel retention and impurity deposition in a tokamak. In this study, an in situ LIBS system was successfully established on EAST to investigate fuel retention and impurity deposition on the first wall without the need of removal tiles between plasma discharges. Spectral lines of D, H and impurities (Mo, Li, Si, … ) in laser-induced plasma were observed and identified within the wavelength range of 500-700 nm. Qualitative measurements such as thickness of the deposition layers, element depth profile and fuel retention on the wall are obtained by means of in situ LIBS. The results demonstrated the potential applications of LIBS for in situ characterization of fuel retention and co-deposition on the first wall of EAST. Supported by the National Magnetic Confinement Fusion Science Program of China (Nos. 2013GB105002, 2015GB109001, and 2013GB109005), National Natural Science Foundation of China (Nos. 11575243, 11605238, 11605023), Chinesisch-Deutsches Forschungs Project (GZ765), and Korea Research Council of Fundamental Science and Technology (KRCF) under the international collaboration & research in Asian countries (PG1314).

Quantification of calcium using localized normalization on laser-induced breakdown spectroscopy data

NASA Astrophysics Data System (ADS)

Sabri, Nursalwanie Mohd; Haider, Zuhaib; Tufail, Kashif; Aziz, Safwan; Ali, Jalil; Wahab, Zaidan Abdul; Abbas, Zulkifly

2017-03-01

This paper focuses on localized normalization for improved calibration curves in laser-induced breakdown spectroscopy (LIBS) measurements. The calibration curves have been obtained using five samples consisting of different concentrations of calcium (Ca) in potassium bromide (KBr) matrix. The work has utilized Q-switched Nd:YAG laser installed in LIBS2500plus system with fundamental wavelength and laser energy of 650 mJ. Optimization of gate delay can be obtained from signal-to-background ratio (SBR) of Ca II 315.9 and 317.9 nm. The optimum conditions are determined in which having high spectral intensity and SBR. The highest spectral lines of ionic and emission lines of Ca at gate delay of 0.83 µs. From SBR, the optimized gate delay is at 5.42 µs for both Ca II spectral lines. Calibration curves consist of three parts; original intensity from LIBS experimentation, normalization and localized normalization of the spectral line intensity. The R2 values of the calibration curves plotted using locally normalized intensities of Ca I 610.3, 612.2 and 616.2 nm spectral lines are 0.96329, 0.97042, and 0.96131, respectively. The enhancement from calibration curves using the regression coefficient allows more accurate analysis in LIBS. At the request of all authors of the paper, and with the agreement of the Proceedings Editor, an updated version of this article was published on 24 May 2017.

Laser-Induced Breakdown Spectroscopy: Capabilities and Applications

DTIC Science & Technology

2010-07-01

substances such as drugs, counterfeit goods, and laundered money . It may even be possible to pinpoint specific manufacturing facilities based on...point detection or standoff mode operation. LIBS used in conjunction with broadband detectors (ultraviolet [ UV ]-visible[VIS]-near-infrared[NIR] spectral...lines in the UV -VIS-NIR spectral range. Although most early LIBS applications involved metal targets, LIBS has recently been applied to a variety

Application of Laser Induced Breakdown Spectroscopy to the identification of emeralds from different synthetic processes

NASA Astrophysics Data System (ADS)

Agrosì, G.; Tempesta, G.; Scandale, E.; Legnaioli, S.; Lorenzetti, G.; Pagnotta, S.; Palleschi, V.; Mangone, A.; Lezzerini, M.

2014-12-01

Laser Induced Breakdown Spectroscopy can provide a useful contribution in mineralogical field in which the quantitative chemical analyses (including the evaluation of light elements) can play a key role in the studies on the origin of the emeralds. In particular, the chemical analyses permit to determine those trace elements, known as fingerprints, that can be useful to study their provenance. This technique, not requiring sample preparation results particularly suitable for gemstones, that obviously must be studied in a non-destructive way. In this paper, the LIBS technique was applied to distinguish synthetic emeralds grown by Biron hydrothermal method from those grown by Chatham flux method. The analyses performed by collinear double-pulse LIBS give a signal enhancement useful for the quantitative chemical analyses while guaranteeing a minimal sample damage. In this way it was obtained a considerable improvement on the detection limit of the trace elements, whose determination is essential for determining the origin of emerald gemstone. The trace elements V, Cr, and Fe and their relative amounts allowed the correct attribution of the manufacturer. Two different methods for quantitative analyses were used for this study: the standard Calibration-Free LIBS (CF-LIBS) method and its recent evolution, the One Point Calibration LIBS (OPC-LIBS). This is the first approach to the evaluation of the emerald origin by means of the LIBS technique.

Determination of Rare Earth Elements in Geological Samples Using Laser-Induced Breakdown Spectroscopy (LIBS).

PubMed

Bhatt, Chet R; Jain, Jinesh C; Goueguel, Christian L; McIntyre, Dustin L; Singh, Jagdish P

2018-01-01

Laser-induced breakdown spectroscopy (LIBS) was used to detect rare earth elements (REEs) in natural geological samples. Low and high intensity emission lines of Ce, La, Nd, Y, Pr, Sm, Eu, Gd, and Dy were identified in the spectra recorded from the samples to claim the presence of these REEs. Multivariate analysis was executed by developing partial least squares regression (PLS-R) models for the quantification of Ce, La, and Nd. Analysis of unknown samples indicated that the prediction results of these samples were found comparable to those obtained by inductively coupled plasma mass spectrometry analysis. Data support that LIBS has potential to quantify REEs in geological minerals/ores.

Multivariate classification of edible salts: Simultaneous Laser-Induced Breakdown Spectroscopy and Laser-Ablation Inductively Coupled Plasma Mass Spectrometry Analysis

NASA Astrophysics Data System (ADS)

Lee, Yonghoon; Nam, Sang-Ho; Ham, Kyung-Sik; Gonzalez, Jhanis; Oropeza, Dayana; Quarles, Derrick; Yoo, Jonghyun; Russo, Richard E.

2016-04-01

Laser-Induced Breakdown Spectroscopy (LIBS) and Laser-Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS), both based on laser ablation sampling, can be employed simultaneously to obtain different chemical fingerprints from a sample. We demonstrated that this analysis approach can provide complementary information for improved classification of edible salts. LIBS could detect several of the minor metallic elements along with Na and Cl, while LA-ICP-MS spectra were used to measure non-metallic and trace heavy metal elements. Principal component analysis using LIBS and LA-ICP-MS spectra showed that their major spectral variations classified the sample salts in different ways. Three classification models were developed by using partial least squares-discriminant analysis based on the LIBS, LA-ICP-MS, and their fused data. From the cross-validation performances and confusion matrices of these models, the minor metallic elements (Mg, Ca, and K) detected by LIBS and the non-metallic (I) and trace heavy metal (Ba, W, and Pb) elements detected by LA-ICP-MS provided complementary chemical information to distinguish particular salt samples.

Elemental analysis of cotton by laser-induced breakdown spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schenk, Emily R.; Almirall, Jose R.

Laser-induced breakdown spectroscopy (LIBS) has been applied to the elemental characterization of unprocessed cotton. This research is important in forensic and fraud detection applications to establish an elemental fingerprint of U.S. cotton by region, which can be used to determine the source of the cotton. To the best of our knowledge, this is the first report of a LIBS method for the elemental analysis of cotton. The experimental setup consists of a Nd:YAG laser that operates at the fundamental wavelength as the LIBS excitation source and an echelle spectrometer equipped with an intensified CCD camera. The relative concentrations of elementsmore » Al, Ba, Ca, Cr, Cu, Fe, Mg, and Sr from both nutrients and environmental contributions were determined by LIBS. Principal component analysis was used to visualize the differences between cotton samples based on the elemental composition by region in the U.S. Linear discriminant analysis of the LIBS data resulted in the correct classification of >97% of the cotton samples by U.S. region and >81% correct classification by state of origin.« less

Multivariate calibration in Laser-Induced Breakdown Spectroscopy quantitative analysis: The dangers of a 'black box' approach and how to avoid them

NASA Astrophysics Data System (ADS)

Safi, A.; Campanella, B.; Grifoni, E.; Legnaioli, S.; Lorenzetti, G.; Pagnotta, S.; Poggialini, F.; Ripoll-Seguer, L.; Hidalgo, M.; Palleschi, V.

2018-06-01

The introduction of multivariate calibration curve approach in Laser-Induced Breakdown Spectroscopy (LIBS) quantitative analysis has led to a general improvement of the LIBS analytical performances, since a multivariate approach allows to exploit the redundancy of elemental information that are typically present in a LIBS spectrum. Software packages implementing multivariate methods are available in the most diffused commercial and open source analytical programs; in most of the cases, the multivariate algorithms are robust against noise and operate in unsupervised mode. The reverse of the coin of the availability and ease of use of such packages is the (perceived) difficulty in assessing the reliability of the results obtained which often leads to the consideration of the multivariate algorithms as 'black boxes' whose inner mechanism is supposed to remain hidden to the user. In this paper, we will discuss the dangers of a 'black box' approach in LIBS multivariate analysis, and will discuss how to overcome them using the chemical-physical knowledge that is at the base of any LIBS quantitative analysis.

Application of Laser Induced Breakdown Spectroscopy in Early Detection of Red Palm Weevil: (Rhynchophorus ferrugineus) Infestation in Date Palm

NASA Astrophysics Data System (ADS)

A. Farooq, W.; G. Rasool, K.; Walid, Tawfik; S. Aldawood, A.

2015-11-01

The Kingdom of Saudi Arabia is one of the leading date producing countries. Unfortunately, this important fruit crop is under great threat from the red palm weevil (RPW) (Rhynchophorus ferrugineus), which is a highly invasive pest. Several techniques, including visual inspection, acoustic sensors, sniffer dogs, and pheromone traps have been tried to detect the early stages of a RPW infestation; however, each method has suffered certain logistical and implementation issues. We have applied laser induced breakdown spectroscopy (LIBS) for the early detection of RPW infestation. Through the analysis of the observed LIBS spectra of different infested and healthy samples, we have found presence of Ca, Mg, Na, C, K elements and OH, CN molecules. The spectra also reveal that with the population growth of the pest, the intensity of Mg and Ca atomic lines in LIBS spectra increases rapidly. Similar behavior is observed in the molecular lines of LIBS spectra. The obtained results indicate that the LIBS technique can be used for the early detection of RPW infestation without damaging the date palms.

High-Resolution Laser-Induced Breakdown Spectroscopy used in Homeland Security and Forensic Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Madhavi Z; Wullschleger, Stan D; Vass, Arpad Alexander

The technique of laser-induced breakdown spectroscopy (LIBS) to detect elements for a variety of homeland security applications such as nuclear materials identification and inventory,and forensic applications has been demonstrated. For nuclear materials applications, we detected and profiled metals in coatings that were used to encapsulate nuclear fuel. Multivariate analysis has been successfully employed in the quantification of elements present in treated wood and engineered wood composites. These examples demonstrate that LIBS-based techniques are inherently well suited for diverse environmental applications related to homeland security. Three key advantages are evident: (1) small samples (mg) are sufficient; (2) samples can be analyzedmore » by LIBS very rapidly, and (3) biological materials such as human and animal bones and wood can be analyzed with minimal sample preparation. For forensic applications they have used LIBS to determine differences in animal and human bones. They have also applied this technique in the determination of counterfeit and non-counterfeit currency. They recently applied LIBS in helping to solve a murder case.« less

Determination of the deuterium/hydrogen ratio in gas reaction products by laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

D'Ulivo, A.; Onor, M.; Pitzalis, E.; Spiniello, R.; Lampugnani, L.; Cristoforetti, G.; Legnaioli, S.; Palleschi, V.; Salvetti, A.; Tognoni, E.

2006-07-01

This paper reports the first application of laser-induced breakdown spectroscopy technique (LIBS) to the determination of deuterium/hydrogen numeric ratio ( β) in the headspace gases, essentially HD + H 2, that are generated by the hydrolysis of NaBD 4-NaBH 4 mixtures (molar fraction of NaBD 4, x = 50-100%) in acidic H 2O media (0 < pH < 1). The LIBS measurement of β can be easily achieved with a coefficient of variation better than 5% (over four replicates). The value of β allowed the calculation of the molar fraction of NaBD 4, xLIBS, with a coefficient of variation better than 2.5%. The comparison of x vs. xLIBS gives results that are in good agreement, within an average deviation of 3%, for x in the range of 50-100%. The best performances are obtained for β close to unit, which makes LIBS perfectly suited for the detection of H-D exchange taking place during aqueous hydrolysis of NaBD 4 or NaBH 4.

Study of Bacterial Samples Using Laser Induced Breakdown Spectroscopy

NASA Astrophysics Data System (ADS)

W, A. Farooq; M, Atif; W, Tawfik; M, S. Alsalhi; Z, A. Alahmed; M, Sarfraz; J, P. Singh

2014-12-01

Laser-induced breakdown spectroscopy (LIBS) technique has been applied to investigate two different types of bacteria, Escherichia coli (B1) and Micrococcus luteus (B2) deposited on glass slides using Spectrolaser 7000. LIBS spectra were analyzed using spectrolaser software. LIBS spectrum of glass substrate was compared with bacteria spectra. Ca, Mg, Na, K, P, S, Cl, Fe, Al, Mn, Cu, C, H and CN-band appeared in bacterial samples in air. Two carbon lines at 193.02 nm, 247.88 nm and one hydrogen line at 656.28 nm with intensity ratios of 1.9, 1.83 and 1.53 appeared in bacterial samples B1 and B2 respectively. Carbon and hydrogen are the important components of the bio-samples like bacteria and other cancer cells. Investigation on LIBS spectra of the samples in He and Ar atmospheres is also presented. Ni lines appeared only in B2 sample in Ar atmosphere. From the present experimental results we are able to show that LIBS technique has a potential in the identification and discrimination of different types of bacteria.

Potential of Laser Induced Breakdown Spectroscopy for analyzing the quality of unroasted and ground coffee

NASA Astrophysics Data System (ADS)

Silva, Tiago Varão; Hubinger, Silviane Zanni; Gomes Neto, José Anchieta; Milori, Débora Marcondes Bastos Pereira; Ferreira, Ednaldo José; Ferreira, Edilene Cristina

2017-09-01

Coffee is an important commodity and a very popular beverage around the world. Its economic value as well as beverage quality are strongly dependent of the quality of beans. The presence of defective beans in coffee blends has caused a negative impact on the beverage Global Quality (GQ) assessed by cupping tests. The main defective beans observed in the productive chain has been those Blacks, Greens and Sours (BGS). Chemical composition of BGS has a damaging impact on beverage GQ. That is why analytical tools are needed for monitoring and controlling the GQ in coffee agro-industry. Near Infrared Spectroscopy (NIRS) has been successfully applied for assessment of coffee quality. Another potential technique for direct, clean and fast measurement of coffee GQ is Laser Induced Breakdown Spectroscopy (LIBS). Elements and diatomic molecules commonly present in organic compounds (structure) can be assessed by using LIBS. In this article is reported an evaluation of LIBS for the main interferents of GQ (BGS defects). Results confirm the great potential of LIBS for discriminating good beans from those with BGS defects by using emission lines of C, CN, C2 and N. Most importantly, some emission lines presented strong linear correlation (r > 0.9) with NIRS absorption bands assigned to proteins, lipids, sugar and carboxylic acids, suggesting LIBS potential to estimate these compounds in unroasted and ground coffee samples.

Remote in-situ laser-induced breakdown spectroscopy using optical fibers

NASA Astrophysics Data System (ADS)

Marquardt, Brian James

The following dissertation describes the development of methods for performing remote Laser-Induced Breakdown Spectroscopy (LIBS) using optical fibers. Studies were performed to determine the optimal excitation and collection parameters for remote LIBS measurements of glasses, soils and paint. A number of fiber-optic LIBS probes were developed and used to characterize various samples by plasma emission spectroscopy. A novel method for launching high-power laser pulses into optical fibers without causing catastrophic failure is introduced. A systematic study of a number of commercially available optical fibers was performed to determine which optical fibers were best suited for delivering high-power laser pulses. The general design of an all fiber-optic LIBS probe is described and applied to the determination of Pb in soil. A fiber-optic probe was developed for the microanalysis of solid samples remotely by LIBS, Raman spectroscopy and Raman imaging. The design of the probe allows for real-time sample imaging in-situ using coherent imaging fibers. This allows for precise atomic emission and Raman measurements to be performed remotely on samples in hostile or inaccessible environments. A novel technique was developed for collecting spectral plasma images using an acousto-optic tunable filter (AOTF). The spatial and temporal characteristics of the plasma were studied as a function of delay time. From the plasma images the distribution of Pb emission could be determined and fiber-optic designs could be optimized for signal collection. The performance of a two fiber LIBS probe is demonstrated for the determination of the amount of lead in samples of dry paint. It is shown that dry paint samples can be analyzed for their Pb content in-situ using a fiber-optic LIBS probe with detection limits well below the levels currently regulated by the Consumer Products Safety Commission. It is also shown that these measurements can be performed on both latex and enamel paints, and that Pb containing paint can be detected even under layers of non-lead containing paint. Experiments were performed to determine the optimal measurement parameters for performing LIBS studies of Department of Energy "waste" glasses. Calibration data for a Al and Ti metals contained in the waste glass is presented. The effects of laser power on plasma temperature, emission intensity and mass of sample ablated are introduced.

Hybrid interferometric/dispersive atomic spectroscopy of laser-induced uranium plasma

DOE PAGES

Morgan, Phyllis K.; Scott, Jill R.; Jovanovic, Igor

2015-12-19

An established optical emission spectroscopy technique, laser-induced breakdown spectroscopy (LIBS), holds promise for detection and rapid analysis of elements relevant for nuclear safeguards, nonproliferation, and nuclear power, including the measurement of isotope ratios. One such important application of LIBS is the measurement of uranium enrichment ( 235U/ 238U), which requires high spectral resolution (e.g., 25 pm for the 424.4 nm U II line). High-resolution dispersive spectrometers necessary for such measurements are typically bulky and expensive. We demonstrate the use of an alternative measurement approach, which is based on an inexpensive and compact Fabry–Perot etalon integrated with a low to moderatemore » resolution Czerny–Turner spectrometer, to achieve the resolution needed for isotope selectivity of LIBS of uranium in ambient air. Furthermore, spectral line widths of ~ 10 pm have been measured at a center wavelength 424.437 nm, clearly discriminating the natural from the highly enriched uranium.« less

Elemental analysis of fingernail of alcoholic and doping subjects by laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Bahreini, M.; Ashrafkhani, B.; Tavassoli, S. H.

2014-03-01

Laser-induced breakdown spectroscopy (LIBS) is applied to investigate the effect of alcoholism and doping on elemental composition of fingernails of subjects. Measurements are made on 36 fingernail clippings including 8 doping, 8 alcoholic and 20 normal subjects. Classification of normal, alcoholic and doping subjects based on 46 atomic and ionic emission lines belonging to 13 elements of fingernail is examined using discriminant function analysis (DFA) method. The most affecting elements in classification of groups are discussed. In order to improve the repeatability of LIBS measurements, an auto-focus system has been designed and used in experiments. Results are promising and show that by improving the repeatability of experiments through improving the setup, some evidence of the impact of the alcohol and doping on elemental composition of fingernails is observed.

Medical Applications of Laser Induced Breakdown Spectroscopy

NASA Astrophysics Data System (ADS)

Pathak, A. K.; Rai, N. K.; Singh, Ankita; Rai, A. K.; Rai, Pradeep K.; Rai, Pramod K.

2014-11-01

Sedentary lifestyle of human beings has resulted in various diseases and in turn we require a potential tool that can be used to address various issues related to human health. Laser Induced Breakdown Spectroscopy (LIBS) is one such potential optical analytical tool that has become quite popular because of its distinctive features that include applicability to any type/phase of samples with almost no sample preparation. Several reports are available that discusses the capabilities of LIBS, suitable for various applications in different branches of science which cannot be addressed by traditional analytical methods but only few reports are available for the medical applications of LIBS. In the present work, LIBS has been implemented to understand the role of various elements in the formation of gallstones (formed under the empyema and mucocele state of gallbladder) samples along with patient history that were collected from Purvancal region of Uttar Pradesh, India. The occurrence statistics of gallstones under the present study reveal higher occurrence of gallstones in female patients. The gallstone occurrence was found more prevalent for those male patients who were having the habit of either tobacco chewing, smoking or drinking alcohols. This work further reports in-situ LIBS study of deciduous tooth and in-vivo LIBS study of human nail.

Laser-Induced Breakdown Spectroscopy Coupled with Multivariate Chemometrics for Variety Discrimination of Soil

PubMed Central

Yu, Ke-Qiang; Zhao, Yan-Ru; Liu, Fei; He, Yong

2016-01-01

The aim of this work was to analyze the variety of soil by laser-induced breakdown spectroscopy (LIBS) coupled with chemometrics methods. 6 certified reference materials (CRMs) of soil samples were selected and their LIBS spectra were captured. Characteristic emission lines of main elements were identified based on the LIBS curves and corresponding contents. From the identified emission lines, LIBS spectra in 7 lines with high signal-to-noise ratio (SNR) were chosen for further analysis. Principal component analysis (PCA) was carried out using the LIBS spectra at 7 selected lines and an obvious cluster of 6 soils was observed. Soft independent modeling of class analogy (SIMCA) and least-squares support vector machine (LS-SVM) were introduced to establish discriminant models for classifying the 6 types of soils, and they offered the correct discrimination rates of 90% and 100%, respectively. Receiver operating characteristic (ROC) curve was used to evaluate the performance of models and the results demonstrated that the LS-SVM model was promising. Lastly, 8 types of soils from different places were gathered to conduct the same experiments for verifying the selected 7 emission lines and LS-SVM model. The research revealed that LIBS technology coupled with chemometrics could conduct the variety discrimination of soil. PMID:27279284

Laser-induced breakdown spectroscopy (LIBS) technique for the determination of the chemical composition of complex inorganic materials

NASA Astrophysics Data System (ADS)

Łazarek, Łukasz; Antończak, Arkadiusz J.; Wójcik, Michał R.; Kozioł, Paweł E.; Stepak, Bogusz; Abramski, Krzysztof M.

2014-08-01

Laser-induced breakdown spectroscopy (LIBS) is a fast, fully optical method, that needs little or no sample preparation. In this technique qualitative and quantitative analysis is based on comparison. The determination of composition is generally based on the construction of a calibration curve namely the LIBS signal versus the concentration of the analyte. Typically, to calibrate the system, certified reference materials with known elemental composition are used. Nevertheless, such samples due to differences in the overall composition with respect to the used complex inorganic materials can influence significantly on the accuracy. There are also some intermediate factors which can cause imprecision in measurements, such as optical absorption, surface structure, thermal conductivity etc. This paper presents the calibration procedure performed with especially prepared pellets from the tested materials, which composition was previously defined. We also proposed methods of post-processing which allowed for mitigation of the matrix effects and for a reliable and accurate analysis. This technique was implemented for determination of trace elements in industrial copper concentrates standardized by conventional atomic absorption spectroscopy with a flame atomizer. A series of copper flotation concentrate samples was analyzed for contents of three elements, that is silver, cobalt and vanadium. It has been shown that the described technique can be used to qualitative and quantitative analyses of complex inorganic materials, such as copper flotation concentrates.

Wavelength dependence of laser induced breakdown spectroscopy (LIBS) on questioned document investigation.

PubMed

Elsherbiny, Nany; Aied Nassef, O

2015-07-01

The fast and nearly non-destructive criteria of laser induced breakdown spectroscopy (LIBS) technique has been exploited for forensic purposes, specifically, document investigation. The dependence of the optical emission spectra of different black gel ink samples on the excitation laser wavelength, namely the visible wavelength at λ=532 nm and the IR wavelength at λ=1064 nm, was studied. The inks of thirty black gel-ink pens comprising ten brands were analyzed to determine the variation of the chemical composition of ink and to discriminate among them with minimum mass removal and minimum damage to the document's paper. Under the adopted experimental conditions, the ability of the visible LIBS to differentiate among the different ink samples was successful compared to IR LIBS at the same laser pulse energy (~25 mJ/pulse, laser fluence is ~1400J·cm(-2) for visible laser and ~1100J·cm(-2) for IR laser) which could be attributed to the IR absorption effects by the black ink. However, the visible LIBS produces deeper crater with respect to that produced by IR LIBS. Applying IR LIBS with higher pulse energy of ~87mJ (laser fluence is ~4100J·cm(-2)), identification and differentiation of the adopted samples was performed with producing a larger-diameter but superficial crater. The plasma parameters are discussed at the adopted experimental conditions. The results support the potential of LIBS technique using both the visible and IR lasers to be commercially developed for forensic document examination. Copyright © 2015 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

Ultrafast Laser-Based Spectroscopy and Sensing: Applications in LIBS, CARS, and THz Spectroscopy

PubMed Central

Leahy-Hoppa, Megan R.; Miragliotta, Joseph; Osiander, Robert; Burnett, Jennifer; Dikmelik, Yamac; McEnnis, Caroline; Spicer, James B.

2010-01-01

Ultrafast pulsed lasers find application in a range of spectroscopy and sensing techniques including laser induced breakdown spectroscopy (LIBS), coherent Raman spectroscopy, and terahertz (THz) spectroscopy. Whether based on absorption or emission processes, the characteristics of these techniques are heavily influenced by the use of ultrafast pulses in the signal generation process. Depending on the energy of the pulses used, the essential laser interaction process can primarily involve lattice vibrations, molecular rotations, or a combination of excited states produced by laser heating. While some of these techniques are currently confined to sensing at close ranges, others can be implemented for remote spectroscopic sensing owing principally to the laser pulse duration. We present a review of ultrafast laser-based spectroscopy techniques and discuss the use of these techniques to current and potential chemical and environmental sensing applications. PMID:22399883

Qualitative tissue differentiation by analysing the intensity ratios of atomic emission lines using laser induced breakdown spectroscopy (LIBS): prospects for a feedback mechanism for surgical laser systems.

PubMed

Kanawade, Rajesh; Mahari, Fanuel; Klämpfl, Florian; Rohde, Maximilian; Knipfer, Christian; Tangermann-Gerk, Katja; Adler, Werner; Schmidt, Michael; Stelzle, Florian

2015-01-01

The research work presented in this paper focuses on qualitative tissue differentiation by monitoring the intensity ratios of atomic emissions using 'Laser Induced Breakdown Spectroscopy' (LIBS) on the plasma plume created during laser tissue ablation. The background of this study is to establish a real time feedback control mechanism for clinical laser surgery systems during the laser ablation process. Ex-vivo domestic pig tissue samples (muscle, fat, nerve and skin) were used in this experiment. Atomic emission intensity ratios were analyzed to find a characteristic spectral line for each tissue. The results showed characteristic elemental emission intensity ratios for the respective tissues. The spectral lines and intensity ratios of these specific elements varied among the different tissue types. The main goal of this study is to qualitatively and precisely identify different tissue types for tissue specific laser surgery. © 2015 The Authors. Journal of Biophotonics published by WILEY-VCH Verlag.

Standoff detection of explosives: critical comparison for ensuing options on Raman spectroscopy-LIBS sensor fusion.

PubMed

Moros, J; Lorenzo, J A; Laserna, J J

2011-07-01

In general, any standoff sensor for the effective detection of explosives must meet two basic requirements: first, a capacity to detect the response generated from only a small amount of material located at a distance of several meters (high sensitivity) and second, the ability to provide easily distinguishable responses for different materials (high specificity). Raman spectroscopy and laser-induced breakdown spectroscopy (LIBS) are two analytical techniques which share similar instrumentation and, at the same time, generate complementary data. These factors have been taken into account recently for the design of sensors used in the detection of explosives. Similarly, research on the proper integration of both techniques has been around for a while. A priori, the different operational conditions required by the two techniques oblige the acquisition of the response for each sensor through sequential analysis, previously necessary to define the proper hierarchy of actuation. However, such an approach does not guarantee that Raman and LIBS responses obtained may relate to each other. Nonetheless, the possible advantages arising from the integration of the molecular and elemental spectroscopic information come with an obvious underlying requirement, simultaneous data acquisition. In the present paper, strong and weak points of Raman spectroscopy and LIBS for solving explosives detection problems, in terms of selectivity, sensitivity, and throughput, are critically examined, discussed, and compared for assessing the ensuing options on the fusion of the responses of both sensing technologies.

[Determination of Cu in Shell of Preserved Egg by LIBS Coupled with PLS].

PubMed

Hu, Hui-qin; Xu, Xue-hong; Liu, Mu-hua; Tu, Jian-ping; Huang, Le; Huang, Lin; Yao, Ming-yin; Chen, Tian-bing; Yang, Ping

2015-12-01

In this work, the content of copper in the shell of preserved eggs were determined directly by Laser induced breakdown spectroscopy (LIBS), and the characteristics lines of Cu was obtained. The samples of eggshell were pretreated by acid wet digestion, and the real content of Cu was obtained by atomic absorption spectrophotometer (AAS). Due to the test precision and accuracy of LIBS was influenced by a serious of factors, for example, the complex matrix effect of sample, the enviro nment noise, the system noise of the instrument, the stability of laser energy and so on. And the conventional unvariate linear calibration curve between LIBS intensity and content of element of sample, such as by use of Schiebe G-Lomakin equation, can not meet the requirement of quantitative analysis. In account of that, a kind of multivariate calibration method is needed. In this work, the data of LIBS spectra were processed by partial least squares (PLS), the precision and accuracy of PLS model were compared by different smoothing treatment and five pretreatment methods. The result showed that the correlation coefficient and the accuracy of the PLS model were improved, and the root mean square error and the average relative error were reduced effectively by 11 point smoothing with Multiplicative scatter correction (MSC) pretreatment. The results of the study show that, heavy metal Cu in preserved egg shells can be direct detected accurately by laser induced breakdown spectroscopy, and the next step batch tests will been conducted to find out the relationship of heavy metal Cu content in the preserved egg between the eggshell, egg white and egg yolk. And the goal of the contents of heavy metals in the egg white, egg yolk can be knew through determinate the eggshell by the LIBS can be achieved, to provide new method for rapid non-destructive testing technology for quality and satety of agricultural products.

Development of a remote laser-induced breakdown spectroscopy system for investigation of calcified tissue samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hrdlicka, Ales; Prokes, Lubomir; Stankova, Alice

2010-05-01

The development of a remote laser-induced breakdown spectroscopy (LIBS) setup with an off-axis Newtonian collection optics, Galilean-based focusing telescope, and a 532 nm flattop laser beam source is presented. The device was tested at a 6 m distance on a slice of bone to simulate its possible use in the field, e.g., during archaeological excavations. It is shown that this setup is sufficiently sensitive to both major (P, Mg) and minor elements (Na, Zn, Sr). The measured quantities of Mg, Zn, and Sr correspond to the values obtained by reference laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) measurements within an approximatelymore » 20% range of uncertainty. A single point calibration was performed by use of a bone meal standard . The radial element distribution is almost invariable by use of LA-ICP-MS, whereas the LIBS measurement showed a strong dependence on the sample porosity. Based on these results, this remote LIBS setup with a relatively large (350 mm) collecting mirror is capable of semiquantitative analysis at the level of units of mg kg{sup -1}.« less

Applications of LIBS for determination of ionic species (NaCl) in electrical cables for investigation of electrical breakdown

NASA Astrophysics Data System (ADS)

Gondal, M. A.; Shwehdi, M. H.; Khalil, A. A. I.

2011-12-01

The formation of water trees in high-voltage cables can wreak havoc to power systems. The water tree is produced within the high voltage cable insulator when impurities like sodium and magnesium present in the insulating material react with moist soil to form chlorides. This water tree causes electrical breakdown by short circuiting the metallic conductor and the earth. In this paper we use laser-induced breakdown spectroscopy (LIBS) to detect the potentially dangerous elements that form the water tree in the insulating cable. The LIBS system used for this work consists of the fundamental (1064 nm) of a Nd:YAG laser, four spectrometer modules that cover the visible and near-UV spectral ranges and an ICCD camera with proper delay and gating sequence. With this arrangement we were able to measure the elemental concentrations of trace metals present in the insulating cable. The concentrations measured with our LIBS system were counter checked by a standard technique like inductively coupled plasma (ICP) emission spectrometry. The maximum concentrations for ionic species such as Ba (455.40 nm), Ca (393.36 nm), Cr (267.71 nm), Fe (259.94 nm), Cl (542.3 nm), Mg (516.7 nm), Mn (257.61 nm), Na (589.59 nm) and Ti (334.18 nm) are 20.6, 43.2, 1.6, 148.4, 24.2, 22.1, 4.2, 39.56 and 4.35 ppm, respectively. The relative accuracy of our LIBS system for various elements as compared with the ICP method is in the range of 0.03-0.6 at 2.5% error confidence.

Laser-induced breakdown spectroscopy of bulk aqueous solutions at oceanic pressures: evaluation of key measurement parameters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michel, Anna P. M.; Lawrence-Snyder, Marion; Angel, S. Michael

The development of in situ chemical sensors is critical for present-day expeditionary oceanography and the new mode of ocean observing systems that we are entering. New sensors take a significant amount of time to develop; therefore, validation of techniques in the laboratory for use in the ocean environment is necessary. Laser-induced breakdown spectroscopy (LIBS) is a promising in situ technique for oceanography. Laboratory investigations on the feasibility of using LIBS to detect analytes in bulk liquids at oceanic pressures were carried out. LIBS was successfully used to detect dissolved Na, Mn, Ca, K, and Li at pressures up to 2.76x107more » Pa. The effects of pressure, laser-pulse energy, interpulse delay, gate delay, temperature, and NaCl concentration on the LIBS signal were examined. An optimal range of laser-pulse energies was found to exist for analyte detection in bulk aqueous solutions at both low and high pressures. No pressure effect was seen on the emission intensity for Ca and Na, and an increase in emission intensity with increased pressure was seen for Mn. Using the dual-pulse technique for several analytes, a very short interpulse delay resulted in the greatest emission intensity. The presence of NaCl enhanced the emission intensity for Ca, but had no effect on peak intensity of Mn or K. Overall, increased pressure, the addition of NaCl to a solution, and temperature did not inhibit detection of analytes in solution and sometimes even enhanced the ability to detect the analytes. The results suggest that LIBS is a viable chemical sensing method for in situ analyte detection in high-pressure environments such as the deep ocean.« less

Laser-induced breakdown spectroscopy is a reliable method for urinary stone analysis

PubMed Central

Mutlu, Nazım; Çiftçi, Seyfettin; Gülecen, Turgay; Öztoprak, Belgin Genç; Demir, Arif

2016-01-01

Objective We compared laser-induced breakdown spectroscopy (LIBS) with the traditionally used and recommended X-ray diffraction technique (XRD) for urinary stone analysis. Material and methods In total, 65 patients with urinary calculi were enrolled in this prospective study. Stones were obtained after surgical or extracorporeal shockwave lithotripsy procedures. All stones were divided into two equal pieces. One sample was analyzed by XRD and the other by LIBS. The results were compared by the kappa (κ) and Spearman’s correlation coefficient (rho) tests. Results Using LIBS, 95 components were identified from 65 stones, while XRD identified 88 components. LIBS identified 40 stones with a single pure component, 20 stones with two different components, and 5 stones with three components. XRD demonstrated 42 stones with a single component, 22 stones with two different components, and only 1 stone with three different components. There was a strong relationship in the detection of stone types between LIBS and XRD for stones components (Spearman rho, 0.866; p<0.001). There was excellent agreement between the two techniques among 38 patients with pure stones (κ index, 0.910; Spearman rho, 0.916; p<0.001). Conclusion Our study indicates that LIBS is a valid and reliable technique for determining urinary stone composition. Moreover, it is a simple, low-cost, and nondestructive technique. LIBS can be safely used in routine daily practice if our results are supported by studies with larger numbers of patients. PMID:27011877

Detection of biological contaminants on foods and food surfaces using laser-induced breakdown spectroscopy (LIBS).

PubMed

Multari, Rosalie A; Cremers, David A; Dupre, Jo Anne M; Gustafson, John E

2013-09-11

The rapid detection of biological contaminants, such as Escherichia coli O157:H7 and Salmonella enterica , on foods and food-processing surfaces is important to ensure food safety and streamline the food-monitoring process. Laser-induced breakdown spectroscopy (LIBS) is an ideal candidate technology for this application because sample preparation is minimal and results are available rapidly (seconds to minutes). Here, multivariate regression analysis of LIBS data is used to differentiate the live bacterial pathogens E. coli O157:H7 and S. enterica on various foods (eggshell, milk, bologna, ground beef, chicken, and lettuce) and surfaces (metal drain strainer and cutting board). The type (E. coli or S. enterica) of bacteria could be differentiated in all cases studied along with the metabolic state (viable or heat killed). This study provides data showing the potential of LIBS for the rapid identification of biological contaminants using spectra collected directly from foods and surfaces.

Laser-Induced Breakdown Spectroscopy of Cinematographic Film

NASA Astrophysics Data System (ADS)

Oujja, M.; Abrusci, C.; Gaspard, S.; Rebollar, E.; Amo, A. del; Catalina, F.; Castillejo, M.

Laser-induced breakdown spectroscopy (LIBS) was used to characterize the composition of black-and-white, silver-gelatine photographic films. LIB spectra of samples and reference gelatine (of various gel strengths, Bloom values 225 and 75 and crosslinking degrees) were acquired in vacuum by excitation at 266 nm. The elemental composition of the gelatine used in the upper protective layer and in the underlying emulsion is revealed by the stratigraphic analysis carried out by delivering successive pulses on the same spot of the sample. Silver (Ag) lines from the light-sensitive silver halide salts are accompanied by iron, lead and chrome lines. Fe and Pb are constituents of film developers and Cr is included in the hardening agent. The results demonstrate the analytical capacity of LIBS for study and classification of different gelatine types and the sensitivity of the technique to minor changes in gelatine composition. In addition LIBS analysis allows extracting important information on the chemicals used as developers and hardeners of archival cinematographic films.

Identification of meat species by using laser-induced breakdown spectroscopy.

PubMed

Bilge, Gonca; Velioglu, Hasan Murat; Sezer, Banu; Eseller, Kemal Efe; Boyaci, Ismail Hakki

2016-09-01

The aim of the present study is to identify meat species by using laser-induced breakdown spectroscopy (LIBS). Elemental composition differences between meat species were used for meat identification. For this purpose, certain amounts of pork, beef and chicken were collected from different sources and prepared as pellet form for LIBS measurements. The obtained LIBS spectra were evaluated with some chemometric methods, and meat species were qualitatively discriminated with principal component analysis (PCA) method with 83.37% ratio. Pork-beef and chicken-beef meat mixtures were also analyzed with partial least square (PLS) method quantitatively. Determination coefficient (R(2)) and limit of detection (LOD) values were found as 0.994 and 4.4% for pork adulterated beef, and 0.999 and 2.0% for chicken adulterated beef, respectively. In the light of the findings, it was seen that LIBS can be a valuable tool for quality control measurements of meat as a routine method. Copyright © 2016 Elsevier Ltd. All rights reserved.

Laser-induced breakdown spectroscopy (LIBS) for rapid analysis of ash, potassium and magnesium in gluten free flours.

PubMed

Markiewicz-Keszycka, Maria; Casado-Gavalda, Maria P; Cama-Moncunill, Xavier; Cama-Moncunill, Raquel; Dixit, Yash; Cullen, Patrick J; Sullivan, Carl

2018-04-01

Gluten free (GF) diets are prone to mineral deficiency, thus effective monitoring of the elemental composition of GF products is important to ensure a balanced micronutrient diet. The objective of this study was to test the potential of laser-induced breakdown spectroscopy (LIBS) analysis combined with chemometrics for at-line monitoring of ash, potassium and magnesium content of GF flours: tapioca, potato, maize, buckwheat, brown rice and a GF flour mixture. Concentrations of ash, potassium and magnesium were determined with reference methods and LIBS. PCA analysis was performed and presented the potential for discrimination of the six GF flours. For the quantification analysis PLSR models were developed; R 2 cal were 0.99 for magnesium and potassium and 0.97 for ash. The study revealed that LIBS combined with chemometrics is a convenient method to quantify concentrations of ash, potassium and magnesium and present the potential to classify different types of flours. Copyright © 2017 Elsevier Ltd. All rights reserved.

Identification of offal adulteration in beef by laser induced breakdown spectroscopy (LIBS).

PubMed

Velioglu, Hasan Murat; Sezer, Banu; Bilge, Gonca; Baytur, Süleyman Efe; Boyaci, Ismail Hakki

2018-04-01

Minced meat is the major ingredient in sausages, beef burgers, and similar products; and thus it is the main product subjected to adulteration with meat offal. Determination of this kind of meat adulteration is crucial due to religious, economic and ethical concerns. The aim of the present study is to discriminate the beef meat and offal samples by using laser induced breakdown spectroscopy (LIBS). To this end, LIBS and multivariate data analysis were used to discriminate pure beef and offal samples qualitatively and to determine the offal mixture adulteration quantitatively. In this analysis, meat samples were frozen and LIBS analysis were performed. The results indicate that by using principal component analysis (PCA), discrimination of pure offal and offal mixture adulterated beef samples can be achieved successfully. Besides, adulteration ratio can be determined using partial least square analysis method (PLS) with 0.947 coefficient of determination (R 2 ) and 3.8% of limit of detection (LOD) values for offal mixture adulterated beef samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

An in Situ Technique for Elemental Analysis of Lunar Surfaces

NASA Technical Reports Server (NTRS)

Kane, K. Y.; Cremers, D. A.

1992-01-01

An in situ analytical technique that can remotely determine the elemental constituents of solids has been demonstrated. Laser-Induced Breakdown Spectroscopy (LIBS) is a form of atomic emission spectroscopy in which a powerful laser pulse is focused on a solid to generate a laser spark, or microplasma. Material in the plasma is vaporized, and the resulting atoms are excited to emit light. The light is spectrally resolved to identify the emitting species. LIBS is a simple technique that can be automated for inclusion aboard a remotely operated vehicle. Since only optical access to a sample is required, areas inaccessible to a rover can be analyzed remotely. A single laser spark both vaporizes and excites the sample so that near real-time analysis (a few minutes) is possible. This technique provides simultaneous multielement detection and has good sensitivity for many elements. LIBS also eliminates the need for sample retrieval and preparation preventing possible sample contamination. These qualities make the LIBS technique uniquely suited for use in the lunar environment.

Forensic Discrimination of Latent Fingerprints Using Laser-Induced Breakdown Spectroscopy (LIBS) and Chemometric Approaches.

PubMed

Yang, Jun-Ho; Yoh, Jack J

2018-01-01

A novel technique is reported for separating overlapping latent fingerprints using chemometric approaches that combine laser-induced breakdown spectroscopy (LIBS) and multivariate analysis. The LIBS technique provides the capability of real time analysis and high frequency scanning as well as the data regarding the chemical composition of overlapping latent fingerprints. These spectra offer valuable information for the classification and reconstruction of overlapping latent fingerprints by implementing appropriate statistical multivariate analysis. The current study employs principal component analysis and partial least square methods for the classification of latent fingerprints from the LIBS spectra. This technique was successfully demonstrated through a classification study of four distinct latent fingerprints using classification methods such as soft independent modeling of class analogy (SIMCA) and partial least squares discriminant analysis (PLS-DA). The novel method yielded an accuracy of more than 85% and was proven to be sufficiently robust. Furthermore, through laser scanning analysis at a spatial interval of 125 µm, the overlapping fingerprints were reconstructed as separate two-dimensional forms.

Qualitative and quantitative analysis of milk for the detection of adulteration by Laser Induced Breakdown Spectroscopy (LIBS).

PubMed

Moncayo, S; Manzoor, S; Rosales, J D; Anzano, J; Caceres, J O

2017-10-01

The present work focuses on the development of a fast and cost effective method based on Laser Induced Breakdown Spectroscopy (LIBS) to the quality control, traceability and detection of adulteration in milk. Two adulteration cases have been studied; a qualitative analysis for the discrimination between different milk blends and quantification of melamine in adulterated toddler milk powder. Principal Component Analysis (PCA) and neural networks (NN) have been used to analyze LIBS spectra obtaining a correct classification rate of 98% with a 100% of robustness. For the quantification of melamine, two methodologies have been developed; univariate analysis using CN emission band and multivariate calibration NN model obtaining correlation coefficient (R 2 ) values of 0.982 and 0.999 respectively. The results of the use of LIBS technique coupled with chemometric analysis are discussed in terms of its potential use in the food industry to perform the quality control of this dairy product. Copyright © 2017 Elsevier Ltd. All rights reserved.

Multielemental analysis of prehistoric animal teeth by laser-induced breakdown spectroscopy and laser ablation inductively coupled plasma mass spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Galiova, Michaela; Kaiser, Jozef; Fortes, Francisco J.

2010-05-01

Laser-induced breakdown spectroscopy (LIBS) and laser ablation (LA) inductively coupled plasma (ICP) mass spectrometry (MS) were utilized for microspatial analyses of a prehistoric bear (Ursus arctos) tooth dentine. The distribution of selected trace elements (Sr, Ba, Fe) was measured on a 26 mmx15 mm large and 3 mm thick transverse cross section of a canine tooth. The Na and Mg content together with the distribution of matrix elements (Ca, P) was also monitored within this area. The depth of the LIBS craters was measured with an optical profilometer. As shown, both LIBS and LA-ICP-MS can be successfully used for themore » fast, spatially resolved analysis of prehistoric teeth samples. In addition to microchemical analysis, the sample hardness was calculated using LIBS plasma ionic-to-atomic line intensity ratios of Mg (or Ca). To validate the sample hardness calculations, the hardness was also measured with a Vickers microhardness tester.« less

Laser-induced breakdown spectroscopy study of silversmith pieces: the case of a Spanish canopy of the nineteenth century

NASA Astrophysics Data System (ADS)

Gómez-Morón, M. A.; Ortiz, P.; Ortiz, R.; Martín, J. M.; Mateo, M. P.; Nicolás, G.

2016-05-01

Canopies of needlework velvet or silversmith pieces placed on twelve or more battens are widely employed in Spanish catholic ceremonies to cover the image of the virgin. In this paper, we focus our interest on those pieces made of silver. These silver crafts suffered a revolution in the nineteenth century with the development of an electrolyte system that can be applied over carved metal pieces, in order to obtain a silver layer by electrodeposition similar in appearance to the original sterling silver and cheaper. The aim of this research was the application of laser-induced breakdown spectroscopy (LIBS) to the study of a canopy of the nineteenth century in order to assess the techniques used for its manufacturing and the identification of replacement and restoration of original pieces. The LIBS depth profiles show the presence of a micron silver layer over an alloy of copper and zinc in most of the surfaces. Corrosion products, alloy missing, and the restoration with copper layers were detected. These results are consistent with those obtained by scanning electron microscopy with energy-dispersive of X-ray with the advantage that LIBS is a methodology that allows analysing metal pieces without sampling or preparation. In summary, LIBS is a technique that allows the study of silversmith pieces with electrochemical preparation according to the Ruolz technique, and it is also possible to detect subsequent restoration or corrosion zones.

Partial Least Squares and Neural Networks for Quantitative Calibration of Laser-induced Breakdown Spectroscopy (LIBs) of Geologic Samples

NASA Technical Reports Server (NTRS)

Anderson, R. B.; Morris, Richard V.; Clegg, S. M.; Humphries, S. D.; Wiens, R. C.; Bell, J. F., III; Mertzman, S. A.

2010-01-01

The ChemCam instrument [1] on the Mars Science Laboratory (MSL) rover will be used to obtain the chemical composition of surface targets within 7 m of the rover using Laser Induced Breakdown Spectroscopy (LIBS). ChemCam analyzes atomic emission spectra (240-800 nm) from a plasma created by a pulsed Nd:KGW 1067 nm laser. The LIBS spectra can be used in a semiquantitative way to rapidly classify targets (e.g., basalt, andesite, carbonate, sulfate, etc.) and in a quantitative way to estimate their major and minor element chemical compositions. Quantitative chemical analysis from LIBS spectra is complicated by a number of factors, including chemical matrix effects [2]. Recent work has shown promising results using multivariate techniques such as partial least squares (PLS) regression and artificial neural networks (ANN) to predict elemental abundances in samples [e.g. 2-6]. To develop, refine, and evaluate analysis schemes for LIBS spectra of geologic materials, we collected spectra of a diverse set of well-characterized natural geologic samples and are comparing the predictive abilities of PLS, cascade correlation ANN (CC-ANN) and multilayer perceptron ANN (MLP-ANN) analysis procedures.

Detection of pesticides and dioxins in tissue fats and rendering oils using laser-induced breakdown spectroscopy (LIBS).

PubMed

Multari, Rosalie A; Cremers, David A; Scott, Thomas; Kendrick, Peter

2013-03-13

In laser-induced breakdown spectroscopy (LIBS), a series of powerful laser pulses are directed at a surface to form microplasmas from which light is collected and spectrally analyzed to identify the surface material. In most cases, no sample preparation is needed, and results can be automated and made available within seconds to minutes. Advances in LIBS spectral data analysis using multivariate regression techniques have led to the ability to detect organic chemicals in complex matrices such as foods. Here, the use of LIBS to differentiate samples contaminated with aldrin, 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin, chlorpyrifos, and dieldrin in the complex matrices of tissue fats and rendering oils is described. The pesticide concentrations in the samples ranged from 0.005 to 0.1 μg/g. All samples were successfully differentiated from each other and from control samples. Sample concentrations could also be differentiated for all of the pesticides and the dioxin included in this study. The results presented here provide first proof-of-principle data for the ability to create LIBS-based instrumentation for the rapid analysis of pesticide and dioxin contamination in tissue fat and rendered oils.

A spectroscopic tool for identifying sources of origin for materials of military interest

NASA Astrophysics Data System (ADS)

Miziolek, Andrzej W.; De Lucia, Frank C.

2014-05-01

There is a need to identify the source of origin for many items of military interest, including ammunition and weapons that may be circulated and traded in illicit markets. Both fieldable systems (man-portable or handheld) as well as benchtop systems in field and home base laboratories are desired for screening and attribution purposes. Laser Induced Breakdown Spectroscopy (LIBS) continues to show significant capability as a promising new tool for materials identification, matching, and provenance. With the use of the broadband, high resolution spectrometer systems, the LIBS devices can not only determine the elemental inventory of the sample, but they are also capable of elemental fingerprinting to signify sources of origin of various materials. We present the results of an initial study to differentiate and match spent cartridges from different manufacturers and countries. We have found that using Partial Least Squares Discriminant Analysis (PLS-DA) we are able to achieve on average 93.3% True Positives and 5.3% False Positives. These results add to the large body of publications that have demonstrated that LIBS is a particularly suitable tool for source of origin determinations.

Standard Reference Line Combined with One-Point Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS) to Quantitatively Analyze Stainless and Heat Resistant Steel.

PubMed

Fu, Hongbo; Wang, Huadong; Jia, Junwei; Ni, Zhibo; Dong, Fengzhong

2018-01-01

Due to the influence of major elements' self-absorption, scarce observable spectral lines of trace elements, and relative efficiency correction of experimental system, accurate quantitative analysis with calibration-free laser-induced breakdown spectroscopy (CF-LIBS) is in fact not easy. In order to overcome these difficulties, standard reference line (SRL) combined with one-point calibration (OPC) is used to analyze six elements in three stainless-steel and five heat-resistant steel samples. The Stark broadening and Saha - Boltzmann plot of Fe are used to calculate the electron density and the plasma temperature, respectively. In the present work, we tested the original SRL method, the SRL with the OPC method, and intercept with the OPC method. The final calculation results show that the latter two methods can effectively improve the overall accuracy of quantitative analysis and the detection limits of trace elements.

An Evaluation of Femtosecond/nanosecond Laser Induced Breakdown Spectroscopy (LIBS) for Measuring Total Particulate Emissions

DTIC Science & Technology

2009-05-07

would discourage the use of LIBS for distinguishing between gaseous and particulate species; however, recent studies by Prof. David Hahn at the...If a concept proved feasible, then it would be evaluated in more realistic environments. The program involved a joint effort between Prof. David ...multiphase ns-LIBS measurement that are most relevant to this study are illustrated in the research performed by Prof. David Hahn at the University of Florida

A Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS) Quantitative Analysis Method Based on the Auto-Selection of an Internal Reference Line and Optimized Estimation of Plasma Temperature.

PubMed

Yang, Jianhong; Li, Xiaomeng; Xu, Jinwu; Ma, Xianghong

2018-01-01

The quantitative analysis accuracy of calibration-free laser-induced breakdown spectroscopy (CF-LIBS) is severely affected by the self-absorption effect and estimation of plasma temperature. Herein, a CF-LIBS quantitative analysis method based on the auto-selection of internal reference line and the optimized estimation of plasma temperature is proposed. The internal reference line of each species is automatically selected from analytical lines by a programmable procedure through easily accessible parameters. Furthermore, the self-absorption effect of the internal reference line is considered during the correction procedure. To improve the analysis accuracy of CF-LIBS, the particle swarm optimization (PSO) algorithm is introduced to estimate the plasma temperature based on the calculation results from the Boltzmann plot. Thereafter, the species concentrations of a sample can be calculated according to the classical CF-LIBS method. A total of 15 certified alloy steel standard samples of known compositions and elemental weight percentages were used in the experiment. Using the proposed method, the average relative errors of Cr, Ni, and Fe calculated concentrations were 4.40%, 6.81%, and 2.29%, respectively. The quantitative results demonstrated an improvement compared with the classical CF-LIBS method and the promising potential of in situ and real-time application.

A Combined Remote LIBS and Raman Spectroscopic Study of Minerals

NASA Technical Reports Server (NTRS)

Hubble, H. W.; Ghosh, M.; Sharma, S. K.; Horton, K. A.; Lucey, P. G.; Angel, S. M.; Wiens, R. C.

2002-01-01

In this paper, we explore the use of remote LIBS combined with pulsed-laser Raman spectroscopy for mineral analysis at a distance of 10 meters. Samples analyzed include: carbonates (both biogenic and abiogenic), silicates, and sulfates. Additional information is contained in the original extended abstract.

Laer-induced Breakdown Spectroscopy Instrument for Element Analysis of Planetary Surfaces

NASA Technical Reports Server (NTRS)

Blacic, J.; Pettit, D.; Cremers, D.; Roessler, N.

1993-01-01

One of the most fundamental pieces of information about any planetary body is the elemental and mineralogical composition of its surface materials. We are developing an instrument to obtain such data at ranges of up to several hundreds of meters using the technique of Laser-Induced Breakdown Spectroscopy (LIBS). We envision our instrument being used from a spacecraft in close rendezvous with small bodies such as comets and asteroids, or deployed on surface-rover vehicles on large bodies such as Mars and the Moon. The elemental analysis is based on atomic emission spectroscopy of a laser-induced plasma or spark. A pulsed, diode pumped Nd:YAG laser of several hundred millijoules optical energy is used to vaporize and electronically excite the constituent elements of a rock surface remotely located from the laser. Light emitted from the excited plasma is collected and introduced to the entrance slit of a small grating spectrometer. The spectrally dispersed spark light is detected with either a linear photo diode array or area CCD array. When the latter detector is used, the optical and spectrometer components of the LIBS instrument can also be used in a passive imaging mode to collect and integrate reflected sunlight from the same rock surface. Absorption spectral analysis of this reflected light gives mineralogical information that provides a remote geochemical characterization of the rock surface. We performed laboratory calibrations in air and in vacuum on standard rock powders to quantify the LIBS analysis. We performed preliminary field tests using commercially available components to demonstrate remote LIBS analysis of terrestrial rock surfaces at ranges of over 25 m, and we have demonstrated compatibility with a six-wheeled Russian robotic rover vehicle. Based on these results, we believe that all major and most minor elements expected on planetary surfaces can be measured with absolute accuracy of 10-15 percent and much higher relative accuracy. We have performed preliminary systems analysis of a LIBS instrument to evaluate probable mass and power requirements; results of this analysis are summarized.

Atomization efficiency and photon yield in laser-induced breakdown spectroscopy analysis of single nanoparticles in an optical trap

NASA Astrophysics Data System (ADS)

Purohit, Pablo; Fortes, Francisco J.; Laserna, J. Javier

2017-04-01

Laser-induced breakdown spectroscopy (LIBS) was employed for investigating the influence of particle size on the dissociation efficiency and the absolute production of photons per mass unit of airborne solid graphite spheres under single-particle regime. Particles of average diameter of 400 nm were probed and compared with 2 μm particles. Samples were first catapulted into aerosol form and then secluded in an optical trap set by a 532 nm laser. Trap stability was quantified before subjecting particles to LIBS analysis. Fine alignment of the different lines comprising the optical catapulting-optical trapping-laser-induced breakdown spectroscopy instrument and tuning of excitation parameters conditioning the LIBS signal such as fluence and acquisition delay are described in detail with the ultimate goal of acquiring clear spectroscopic data on masses as low as 75 fg. The atomization efficiency and the photon yield increase as the particle size becomes smaller. Time-resolved plasma imaging studies were conducted to elucidate the mechanisms leading to particle disintegration and excitation.

Analytical application of femtosecond laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Melikechi, Noureddine; Markushin, Yuri

2015-05-01

We report on significant advantages provided by femtosecond laser-induced breakdown spectroscopy (LIBS) for analytical applications in fields as diverse as protein characterization and material science. We compare the results of a femto- and nanosecond-laser-induced breakdown spectroscopy analysis of dual-elemental pellets in terms of the shot-to-shot variations of the neutral/ionic emission line intensities. This study is complemented by a numerical model based on two-dimensional random close packing of disks in an enclosed geometry. In addition, we show that LIBS can be used to obtain quantitative identification of the hydrogen composition of bio-macromolecules in a heavy water solution. Finally, we show that simultaneous multi-elemental particle assay analysis combined with LIBS can significantly improve macromolecule detectability up to near single molecule per particle efficiency. Research was supported by grants from the National Science Foundation Centers of Research Excellence in Science and Technology (0630388), National Aeronautics and Space Administration (NX09AU90A). Our gratitude to Dr. D. Connolly, Fox Chase Cancer Center.

Rapid Elemental Analysis and Provenance Study of Blumea balsamifera DC Using Laser-Induced Breakdown Spectroscopy

PubMed Central

Liu, Xiaona; Zhang, Qiao; Wu, Zhisheng; Shi, Xinyuan; Zhao, Na; Qiao, Yanjiang

2015-01-01

Laser-induced breakdown spectroscopy (LIBS) was applied to perform a rapid elemental analysis and provenance study of Blumea balsamifera DC. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were implemented to exploit the multivariate nature of the LIBS data. Scores and loadings of computed principal components visually illustrated the differing spectral data. The PLS-DA algorithm showed good classification performance. The PLS-DA model using complete spectra as input variables had similar discrimination performance to using selected spectral lines as input variables. The down-selection of spectral lines was specifically focused on the major elements of B. balsamifera samples. Results indicated that LIBS could be used to rapidly analyze elements and to perform provenance study of B. balsamifera. PMID:25558999

Detection of Minerals in Green Leafy Vegetables Using Laser Induced Breakdown Spectroscopy

NASA Astrophysics Data System (ADS)

Shukla, P.; Kumar, R.; Raib, A. Kumar

2016-11-01

The distribution of minerals in different green leafy vegetables, such as spinach, chenopodium, chickpea, mustard, and fenugreek, was calculated using laser induced breakdown spectroscopy (LIBS). LIBS can provide an easy, reliable, efficient, low-cost, and in situ chemical analysis with a reasonable precision. In situ LIBS spectra in the range 200-500 nm were carried out using fresh leaves and leaves in the pellet form. As the spectra suggest, magnesium and calcium are present in each vegetable; however, the amount of them varies. It is observed that the amount of iron is maximal in spinach. The nutrition value of the plants was analyzed, and it was revealed that they are low in calories and fat and high in protein, fiber, iron, calcium, and phytochemicals.

The application of LIBS for the analysis of archaeological ceramic and metal artifacts

NASA Astrophysics Data System (ADS)

Melessanaki, Kristalia; Mateo, Maripaz; Ferrence, Susan C.; Betancourt, Philip P.; Anglos, Demetrios

2002-09-01

A bench-top laser-induced breakdown spectroscopy (LIBS) system has been used in the examination of pottery, jewelry and metal artifacts found in archaeological excavations in central and eastern Crete, Greece. The objects date from the Middle and Late Minoan periods (ca. 20th-13th century B. C.) through Byzantine and Venetian to Ottoman times (ca. 5th-19th century A.D.). The spectral data indicates the qualitative and often the semi-quantitative elemental composition of the examined materials. In the case of colored glazed ceramics, the identity of pigments was established while in the case of metal and jewelry analysis, the type of metal or metal alloy used was determined. The analyses demonstrate the potential of the LIBS technique for performing routine, rapid, on-site analysis of archaeological objects, which leads to the quick characterization or screening of different types of objects.

Application of spectroscopic techniques for the analysis of kidney stones: a pilot study

NASA Astrophysics Data System (ADS)

Shameem, K. M., Muhammed; Chawla, Arun; Bankapur, Aseefhali; Unnikrishnan, V. K.; Santhosh, C.

2016-03-01

Identification and characterization of kidney stone remains one of the important analytical tasks in the medical field. Kidney stone is a common health complication throughout the world, which may cause severe pain, obstruction and infection of urinary tract, and can lead to complete renal damage. It commonly occurs in both sexes regardless of age. Kidney stones have different composition, although each stones have a major single characteristic component. A complete understanding of a sample properties and their function can only be feasible by utilizing elemental and molecular information simultaneously. Two laser based analytical techniques; Laser Induced Breakdown spectroscopy (LIBS) and Raman spectroscopy have been used to study different types of kidney stones from different patients. LIBS and Raman spectroscopy are highly complementary spectroscopic techniques, which provide elemental and molecular information of a sample. Q-switched Nd:YAG laser at 355 nm laser having energy 17mJ per pulse at 10 Hz repetition rate was used for getting LIBS spectra. Raman measurements were carried out using a home assembled micro-Raman spectrometer. Using the recorded Raman spectra of kidney stones, we were able to differentiate different kinds of kidney stones. LIBS spectra of the same stones are showing the evidence of C, Ca, H, and O and also suggest the presence of certain pigments.

Chemical characterization of single micro- and nano-particles by optical catapulting-optical trapping-laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Fortes, Francisco J.; Fernández-Bravo, Angel; Javier Laserna, J.

2014-10-01

Spectral identification of individual micro- and nano-sized particles by the sequential intervention of optical catapulting, optical trapping and laser-induced breakdown spectroscopy is presented. The three techniques are used for different purposes. Optical catapulting (OC) serves to put the particulate material under inspection in aerosol form. Optical trapping (OT) permits the isolation and manipulation of individual particles from the aerosol, which are subsequently analyzed by laser-induced breakdown spectroscopy (LIBS). Once catapulted, the dynamics of particle trapping depends both on the laser beam characteristics (power and intensity gradient) and on the particle properties (size, mass and shape). Particles are stably trapped in air at atmospheric pressure and can be conveniently manipulated for a precise positioning for LIBS analysis. The spectra acquired from the individually trapped particles permit a straightforward identification of the material inspected. Variability of LIBS signal for the inspection of Ni microspheres was 30% relative standard deviation. OC-OT-LIBS permits the separation of particles in a heterogeneous mixture and the subsequent analysis of the isolated particle of interest. In order to evaluate the sensitivity of the approach, the number of absolute photons emitted by a single trapped particle was calculated. The limit of detection (LOD) for Al2O3 particles was calculated to be 200 attograms aluminium.

Spectral analysis of rare earth elements using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Martin, Madhavi Z.; Fox, Robert V.; Miziolek, Andrzej W.; DeLucia, Frank C.; André, Nicolas

2015-06-01

There is growing interest in rapid analysis of rare earth elements (REEs) both due to the need to find new natural sources to satisfy increased demand in their use in various electronic devices, as well as the fact that they are used to estimate actinide masses for nuclear safeguards and nonproliferation. Laser-Induced Breakdown Spectroscopy (LIBS) appears to be a particularly well-suited spectroscopy-based technology to rapidly and accurately analyze the REEs in various matrices at low concentration levels (parts-per-million). Although LIBS spectra of REEs have been reported for a number of years, further work is still necessary in order to be able to quantify the concentrations of various REEs in realworld complex samples. LIBS offers advantages over conventional solution-based radiochemistry in terms of cost, analytical turnaround, waste generation, personnel dose, and contamination risk. Rare earth elements of commercial interest are found in the following three matrix groups: 1) raw ores and unrefined materials, 2) as components in refined products such as magnets, lighting phosphors, consumer electronics (which are mostly magnets and phosphors), catalysts, batteries, etc., and 3) waste/recyclable materials (aka e-waste). LIBS spectra for REEs such as Gd, Nd, and Sm found in rare earth magnets are presented.

Spectral Analysis of Rare Earth Elements using Laser-Induced Breakdown Spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Madhavi Z; Fox, Dr. Richard V; Miziolek, Andrzej W

2015-01-01

There is growing interest in rapid analysis of rare earth elements (REEs) both due to the need to find new natural sources to satisfy increased demand in their use in various electronic devices, as well as the fact that they are used to estimate actinide masses for nuclear safeguards and nonproliferation. Laser-Induced Breakdown Spectroscopy (LIBS) appears to be a particularly well-suited spectroscopy-based technology to rapidly and accurately analyze the REEs in various matrices at low concentration levels (parts-per-million). Although LIBS spectra of REEs have been reported for a number of years, further work is still necessary in order to bemore » able to quantify the concentrations of various REEs in real-world complex samples. LIBS offers advantages over conventional solution-based radiochemistry in terms of cost, analytical turnaround, waste generation, personnel dose, and contamination risk. Rare earth elements of commercial interest are found in the following three matrix groups: 1) raw ores and unrefined materials, 2) as components in refined products such as magnets, lighting phosphors, consumer electronics (which are mostly magnets and phosphors), catalysts, batteries, etc., and 3) waste/recyclable materials (aka e-waste). LIBS spectra for REEs such as Gd, Nd, and Sm found in rare earth magnets are presented.« less

Spectral Analysis of Rare Earth Elements using Laser-Induced Breakdown Spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Madhavi Z; Fox, Dr. Richard V; Miziolek, Andrzej W

2015-01-01

There is growing interest in rapid analysis of rare earth elements (REEs) both due to the need to find new natural sources to satisfy increased demand in their use in various electronic devices, as well as the fact that they are used to estimate actinide masses for nuclear safeguards and nonproliferation. Laser-Induced Breakdown Spectroscopy (LIBS) appears to be a particularly well-suited spectroscopy-based technology to rapidly and accurately analyze the REEs in various matrices at low concentration levels (parts-per-million). Although LIBS spectra of REEs have been reported for a number of years, further work is still necessary in order to bemore » able to quantify the concentrations of various REEs in realworld complex samples. LIBS offers advantages over conventional solution-based radiochemistry in terms of cost, analytical turnaround, waste generation, personnel dose, and contamination risk. Rare earth elements of commercial interest are found in the following three matrix groups: 1) raw ores and unrefined materials, 2) as components in refined products such as magnets, lighting phosphors, consumer electronics (which are mostly magnets and phosphors), catalysts, batteries, etc., and 3) waste/recyclable materials (aka e-waste). LIBS spectra for REEs such as Gd, Nd, and Sm found in rare earth magnets are presented.« less

Spectral Analysis of Rare Earth Elements using Laser-Induced Breakdown Spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Madhavi Z. Martin; Robert V. Fox; Andrzej W. Miziolek

2001-05-01

There is growing interest in rapid analysis of rare earth elements (REEs) both due to the need to find new natural sources to satisfy increased demand in their use in various electronic devices, as well as the fact that they are used to estimate actinide masses for nuclear safeguards and nonproliferation. Laser-Induced Breakdown Spectroscopy (LIBS) appears to be a particularly well-suited spectroscopy-based technology to rapidly and accurately analyze the REEs in various matrices at low concentration levels (parts-per-million). Although LIBS spectra of REEs have been reported for a number of years, further work is still necessary in order to bemore » able to quantify the concentrations of various REEs in realworld complex samples. LIBS offers advantages over conventional solution-based radiochemistry in terms of cost, analytical turnaround, waste generation, personnel dose, and contamination risk. Rare earth elements of commercial interest are found in the following three matrix groups: 1) raw ores and unrefined materials, 2) as components in refined products such as magnets, lighting phosphors, consumer electronics (which are mostly magnets and phosphors), catalysts, batteries, etc., and 3) waste/recyclable materials (aka e-waste). LIBS spectra for REEs such as Gd, Nd, and Sm found in rare earth magnets are presented.« less

Characterization and forensic analysis of soil samples using laser-induced breakdown spectroscopy (LIBS).

PubMed

Jantzi, Sarah C; Almirall, José R

2011-07-01

A method for the quantitative elemental analysis of surface soil samples using laser-induced breakdown spectroscopy (LIBS) was developed and applied to the analysis of bulk soil samples for discrimination between specimens. The use of a 266 nm laser for LIBS analysis is reported for the first time in forensic soil analysis. Optimization of the LIBS method is discussed, and the results compared favorably to a laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) method previously developed. Precision for both methods was <10% for most elements. LIBS limits of detection were <33 ppm and bias <40% for most elements. In a proof of principle study, the LIBS method successfully discriminated samples from two different sites in Dade County, FL. Analysis of variance, Tukey's post hoc test and Student's t test resulted in 100% discrimination with no type I or type II errors. Principal components analysis (PCA) resulted in clear groupings of the two sites. A correct classification rate of 99.4% was obtained with linear discriminant analysis using leave-one-out validation. Similar results were obtained when the same samples were analyzed by LA-ICP-MS, showing that LIBS can provide similar information to LA-ICP-MS. In a forensic sampling/spatial heterogeneity study, the variation between sites, between sub-plots, between samples and within samples was examined on three similar Dade sites. The closer the sampling locations, the closer the grouping on a PCA plot and the higher the misclassification rate. These results underscore the importance of careful sampling for geographic site characterization.

[Quantitative analysis of Cu in water by collinear DP-LIBS].

PubMed

Zheng, Mei-Lan; Yao, Ming-Yin; Chen, Tian-Bing; Lin, Yong-Zeng; Li, Wen-Bing; Liu, Mu-Hua

2014-07-01

The purpose of this research is to study the influence of double pulse laser induced breakdown spectroscopy (DP-LIBS) on the sensitivity of Cu in water. The water solution of Cu was tested by collinear DP-LIBS in this article. The results show that spectral intensity of Cu can be enhanced obviously by DP-LIBS, compared with single pulse laser induced breakdown spectroscopy (SP-LIBS). Besides, the experimental results were significantly impacted by delay time between laser pulse and spectrometer acquisition, delay time of double laser pulse and energy of laser pulse and so on. The paper determined the best conditions for DP-LIBS detecting Cu in water. The optimal acquisition delay time was 1 380 ns. The best laser pulse delay time was 25 ns. The most appropriate energy of double laser pulse was 100 mJ. Characteristic analysis of spectra of Cu at 324.7 and 327.4 nm was done for quantitative analysis. The detection limit was 3.5 microg x mL(-1) at 324.7 nm, and the detection limit was 4.84 microg x mL(-1) at 327.4 nm. The relative standard deviation of the two characteristic spectral lines was within 10%. The calibration curve of characteristic spectral line, established by 327.4 nm, was verified with 500 microg x mL(-1) sample. Concentration of the sample was 446 microg x mL(-1) calculated by the calibration curve. This research shows that the detection sensitivity of Cu in water can be improved by DP-LIBS. At the same time, it had high stability.

Laser-induced breakdown spectroscopy (LIBS): An innovative tool for studying bacteria

NASA Astrophysics Data System (ADS)

Mohaidat, Qassem I.

Laser-induced breakdown spectroscopy (LIBS) has gained a reputation as a flexible and convenient technique for rapidly determining the elemental composition of samples with minimal or no sample preparation. In this dissertation, I will describe the benefits of using LIBS for the rapid discrimination and identification of bacteria (both pathogenic and non-pathogenic) based on the relative concentration of trace inorganic elements such as Mg, P, Ca, and Na. The speed, portability, and robustness of the technique suggest that LIBS may be applicable as a rapid point-of-care medical diagnostic technology. LIBS spectra of multiple genera of bacteria such as Escherichia, Streptococcus, Mycobacterium, and Staphylococcus were acquired and successfully analyzed using a computerized discriminant function analysis (DFA). It was shown that a LIBS-based bacterial identification might be insensitive to a wide range of biological changes that could occur in the bacterial cell due to a variety of environmental stresses that the cell may encounter. The effect of reducing the number of bacterial cells on the LIBS-based classification was also studied. These results showed that with 2500 bacteria, the identification of bacterial specimens was still possible. Importantly, it was shown that bacteria in mixed samples (more than one type of bacteria being present) were identifiable. The dominant or majority component of a two-component mixture was reliably identified as long as it comprised 70% of the mixture or more. Finally, to simulate a clinical specimen in a precursor to actual clinical tests, Staphylococcus epidermidis bacteria were collected from urine samples (to simulate a urinary tract infection specimen) and were tested via LIBS without washing. The analysis showed that these bacteria possessed exactly the same spectral fingerprint as control bacteria obtained from sterile deionized water, resulting in a 100% correct classification. This indicates that the presence of other trace background biochemicals from clinical fluids will not adversely disrupt a LIBS-based identification of bacteria.

Laboratory Evaluation of Laser-Induced Breakdown Spectroscopy (LIBS) as a New in situ Chemical Sensing Technique for the Deep Ocean

DTIC Science & Technology

2007-09-01

1.1.2 Advantages and Disadvantages of the LIBS Technique ..... .. 21 1.1.3 LIBS in Liquids ................................ 23 1.2 Scientific ...1.2 Scientific Application: Hydrothermal Vent Chemistry Study of in situ hydrothermal vent chemistry could benefit greatly from the develop- ment of a...4935, 1994. [50] K. L. Von Danim . Chemistry of hydrothermal vent fluids froin 90 - 100 N, East Pacific Rise: ’Time zero,’ The inmnediate posteruptive

Laser-induced emission, fluorescence and Raman hybrid setup: A versatile instrument to analyze materials from cultural heritage

NASA Astrophysics Data System (ADS)

Syvilay, D.; Bai, X. S.; Wilkie-Chancellier, N.; Texier, A.; Martinez, L.; Serfaty, S.; Detalle, V.

2018-02-01

The aim of this research project was the development of a hybrid system in laboratory coupling together three analytical techniques, namely laser-induced breakdown spectroscopy (LIBS), laser-induced fluorescence (LIF) and Raman spectroscopy in a single instrument. The rationale for combining these three spectroscopies was to identify a material (molecular and elemental analysis) without any preliminary preparation, regardless of its organic or inorganic nature, on the surface and in depth, without any surrounding light interference thanks to time resolution. Such instrumentation would allow characterizing different materials from cultural heritage. A complete study on LIBS-LIF-Raman hybrid was carried out, from its conception to instrumental achievement, in order to elaborate a strategy of analysis according to the material and to be able to address conservation issues. From an instrumental point of view, condensing the three spectroscopies was achieved by using a single laser for excitation and two spectrometers (time-integrated and not time-integrated) for light collection. A parabolic mirror was used as collecting system, while three excitation sources directed through this optical system ensured the examination of a similar probe area. Two categories of materials were chosen to test the hybrid instrumentation on cultural heritage applications (copper corrosion products and wall paintings). Some examples are reported to illustrate the wealth of information provided by the hybrid, thus demonstrating its great potential to be used for cultural heritage issues. Finally, several considerations are outlined aimed at further improving the hybrid.

[Rapid measurement of trace mercury in aqueous solutions with optical-electrical dual pulse LIBS technique].

PubMed

Zhang, Qian; Xiong, Wei; Chen, Yu-Qi; Li, Run-Hua

2011-02-01

A wood slice was used as absorber to transfer liquid sample to solid sample in order to solve the problems existing in directly analyzing aqueous solutions with laser-induced breakdown spectroscopy (LIBS). An optical-electrical dual pulse LIBS (OEDP-LIBS) technique was first used to enhance atomic emission of mercury in laser-induced plasma. The calibration curves of mercury were obtained by typical single pulse LIBS and OEDP-LIBS techniques. The limit of detection (LOD) of mercury in these two techniques reaches 2.4 and 0.3 mg x L(-1), respectively. Under current experimental conditions, the time-integrated a tomic emission of mercury at 253.65 nm was enhanced 50 times and the LOD of mercury was improved by one order, if comparing OEDP-LIBS to single pulse LIBS. The required time for a whole analysis process is less than 5 minutes. As the atomic emission of mercury decays slowly while increasing the delay time between electrical pulse and laser pulse, increasing the electrical pulse width can further enhance the time integrated intensity of mercury emission and improve the detection sensitivity of mercury by OEDP-LIBS technique.

Laser-induced breakdown spectroscopy-Raman: An effective complementary approach to analyze renal-calculi.

PubMed

Muhammed Shameem, K M; Chawla, Arun; Mallya, Madhukar; Barik, Bijay Kumar; Unnikrishnan, V K; Kartha, V B; Santhosh, C

2018-06-01

Presence of renal-calculi (kidney stones) in human urethra is being increasingly diagnosed over the last decade and is considered as one of the most painful urological disorders. Accurate analysis of such stones plays a vital role in the evaluation of urolithiasis patients and in turn helps the clinicians toward exact etiologies. Two highly complementary laser-based analytical techniques; laser-induced breakdown spectroscopy (LIBS) and micro-Raman spectroscopy have been used to identify the chemical composition of different types of renal-calculi. LIBS explores elemental characteristics while Raman spectroscopy provides molecular details of the sample. This complete information on the sample composition might help clinicians to identify the key aspects of the formation of kidney stones, hence assist in therapeutic management and to prevent recurrence. The complementarity of both techniques has been emphasized and discussed. LIBS spectra of different types of stones suggest the probable composition of it by virtue of the major, minor and trace elements detected from the sample. However, it failed to differentiate the crystalline form of different hydrates of calcium oxalate stone. This lacuna was overcome by the use of Raman spectroscopy and these results are compared with conventional chemical analysis. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Spectroscopic studies of different brands of cigarettes using laser-induced breakdown spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sayyad, M. H.; Saleem, M.; Shah, M.

In this work the technique of laser-induced breakdown spectroscopy (LIBS) has been used for the elemental analysis of cigarettes. For this purpose emission spectra have been measured of eleven different kinds of cigarette brands sold and/or produced in Pakistan. Analysis of the spectral peaks observed shows that Na, Mg, Al, K, Ca, Cr, Fe, Sr and Ba are contained in all brands. Exhibiting the LIBS results, the powerful potential of this method for the identification of the elemental content of cigarettes is demonstrated.

Spectroscopic studies of different brands of cigarettes using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Sayyad, M. H.; Saleem, M.; Shah, M.; Shaikh, N. M.; Baig, M. A.

2008-05-01

In this work the technique of laser-induced breakdown spectroscopy (LIBS) has been used for the elemental analysis of cigarettes. For this purpose emission spectra have been measured of eleven different kinds of cigarette brands sold and/or produced in Pakistan. Analysis of the spectral peaks observed shows that Na, Mg, Al, K, Ca, Cr, Fe, Sr and Ba are contained in all brands. Exhibiting the LIBS results, the powerful potential of this method for the identification of the elemental content of cigarettes is demonstrated.

Elemental analysis of tissue pellets for the differentiation of epidermal lesion and normal skin by laser-induced breakdown spectroscopy

PubMed Central

Moon, Youngmin; Han, Jung Hyun; Shin, Sungho; Kim, Yong-Chul; Jeong, Sungho

2016-01-01

By laser induced breakdown spectroscopy (LIBS) analysis of epidermal lesion and dermis tissue pellets of hairless mouse, it is shown that Ca intensity in the epidermal lesion is higher than that in dermis, whereas Na and K intensities have an opposite tendency. It is demonstrated that epidermal lesion and normal dermis can be differentiated with high selectivity either by univariate or multivariate analysis of LIBS spectra with an intensity ratio difference by factor of 8 or classification accuracy over 0.995, respectively. PMID:27231610

Comparison of the Detection Characteristics of Trace Species Using Laser-Induced Breakdown Spectroscopy and Laser Breakdown Time-of-Flight Mass Spectrometry

PubMed Central

Wang, Zhenzhen; Deguchi, Yoshihiro; Yan, Junjie; Liu, Jiping

2015-01-01

The rapid and precise element measurement of trace species, such as mercury, iodine, strontium, cesium, etc. is imperative for various applications, especially for industrial needs. The elements mercury and iodine were measured by two detection methods for comparison of the corresponding detection features. A laser beam was focused to induce plasma. Emission and ion signals were detected using laser-induced breakdown spectroscopy (LIBS) and laser breakdown time-of-flight mass spectrometry (LB-TOFMS). Multi-photon ionization and electron impact ionization in the plasma generation process can be controlled by the pressure and pulse width. The effect of electron impact ionization on continuum emission, coexisting molecular and atomic emissions became weakened in low pressure condition. When the pressure was less than 1 Pa, the plasma was induced by laser dissociation and multi-photon ionization in LB-TOFMS. According to the experimental results, the detection limits of mercury and iodine in N2 were 3.5 ppb and 60 ppb using low pressure LIBS. The mercury and iodine detection limits using LB-TOFMS were 1.2 ppb and 9.0 ppb, which were enhanced due to different detection features. The detection systems of LIBS and LB-TOFMS can be selected depending on the condition of each application. PMID:25769051

Detection and Classification of Live and Dead Escherichia coli by Laser-Induced Breakdown Spectroscopy

PubMed Central

Sivakumar, P.; Fernández-Bravo, A.; Taleh, L.; Biddle, J.F.

2015-01-01

Abstract A common goal for astrobiology is to detect organic materials that may indicate the presence of life. However, organic materials alone may not be representative of currently living systems. Thus, it would be valuable to have a method with which to determine the health of living materials. Here, we present progress toward this goal by reporting on the application of laser-induced breakdown spectroscopy (LIBS) to study characteristics of live and dead cells using Escherichia coli (E. coli) strain K12 cells as a model organism since its growth and death in the laboratory are well understood. Our goal is to determine whether LIBS, in its femto- and/or nanosecond forms, could ascertain the state of a living organism. E. coli strain K12 cells were grown, collected, and exposed to one of two types of inactivation treatments: autoclaving and sonication. Cells were also kept alive as a control. We found that LIBS yields key information that allows for the discrimination of live and dead E. coli bacteria based on ionic shifts reflective of cell membrane integrity. Key Words: E. coli—Trace elements—Live and dead cells—Laser-induced breakdown spectroscopy—Atomic force microscopy. Astrobiology 15, 144–153. PMID:25683088

Quantification of fluorine traces in solid samples using CaF molecular emission bands in atmospheric air Laser-Induced Breakdown Spectroscopy

NASA Astrophysics Data System (ADS)

Alvarez-Llamas, C.; Pisonero, J.; Bordel, N.

2016-09-01

Direct solid determination of trace amounts of fluorine using Laser-Induced Breakdown Spectroscopy (LIBS) is a challenging task due to the low excitation efficiency of this element. Several strategies have been developed to improve the detection capabilities, including the use of LIBS in a He atmosphere to enhance the signal to background ratios of F atomic emission lines. An alternative method is based on the detection of the molecular compounds that are formed with fluorine in the LIBS plasma. In this work, the detection of CaF molecular emission bands is investigated to improve the analytical capabilities of atmospheric air LIBS for the determination of fluorine traces in solid samples. In particular, Cu matrix samples containing different fluorine concentration (between 50 and 600 μg/g), and variable amounts of Ca, are used to demonstrate the linear relationships between CaF emission signal and F concentration. Limits of detection for fluorine are improved by more than 1 order of magnitude using CaF emission bands versus F atomic lines, in atmospheric-air LIBS. Furthermore, a toothpaste powder sample is used to validate this analytical method. Good agreement is observed between the nominal and the predicted fluorine mass-content.

Feasibility of detection and identification of individual bioaerosols using laser-induced breakdown spectroscopy.

PubMed

Dixon, P B; Hahn, D W

2005-01-15

The detection and identification of individual bioaerosols using laser-induced breakdown spectroscopy (LIBS) is investigated using aerosolized Bacillus spores. Spores of Bacillus atrophaeous, Bacillus pumilus, and Bacillus stearothemophilus were introduced into an aerosol flow stream in a prescribed manner such that single-particle LIBS detection was realized. Bacillus spores were successfully detected based on the presence of the 393.4- and 396.9-nm calcium atomic emission lines. Statistical analyses based on the aerosol number density, the LIBS-based spore sampling frequency, and the distribution of the resulting calcium mass loadings support the conclusion of individual spore detection within single-shot laser-induced plasmas. The average mass loadings were in the range of 2-3 fg of calcium/Bacillus spore, which corresponds to a calcium mass percentage of approximately 0.5%. While individual spores were detected based on calcium emission, the resulting Bacillus spectra were free from CN emission bands, which has implications for the detection of elemental carbon, and LIBS-based detection of single spores based on the presence of magnesium or sodium atomic emission was unsuccessful. Based on the current instrumental setup and analyses, real-time LIBS-based detection and identification of single Bacillus spores in ambient (i.e., real life) conditions appears unfeasible.

Evaluation of Laser-Induced Breakdown Spectroscopy (LIBS) for Measurement of Silica on Filter Samples of Coal Dust

PubMed Central

Stipe, Christopher B.; Miller, Arthur L.; Brown, Jonathan; Guevara, Edward; Cauda, Emanuele

2015-01-01

Airborne silica dust (quartz) is common in coal mines and represents a respiratory hazard that can lead to silicosis, a potentially fatal lung disease. With an eye toward developing a portable monitoring device for rapid analysis of silica dust, laser-induced breakdown spectroscopy (LIBS) was used to quantify quartz in coal dust samples collected on filter media. Pure silica (Min-U-Sil™ 5), Georgia kaolin, and Pittsburgh-4 and Illinois-6 coal dusts were deposited separately and at multiple mass loadings onto 37-mm polyvinylchloride (PVC) filters. LIBS-generated silicon emission was monitored at 288.16 nm, and non-silica contributions to that signal from kaolinite were removed by simultaneously detecting aluminum. Measurements of the four samples were used to calculate limits of detection (LOD) for silicon and aluminum of approximately 0.08 µg/cm2 and 0.05 µg/cm2, respectively (corresponding to 0.16 µg/cm2 and 0.20 µg/cm2 for silica and kaolinite, respectively). Relative errors of prediction are around 10%. Results demonstrate that LIBS can dependably quantify silica on filter samples of coal dust and confirm that accurate quantification can be achieved for very lightly loaded samples, which supports the potential application of LIBS for rapid, in-field monitoring. PMID:23146184

Evaluation of laser-induced breakdown spectroscopy (LIBS) for measurement of silica on filter samples of coal dust.

PubMed

Stipe, Christopher B; Miller, Arthur L; Brown, Jonathan; Guevara, Edward; Cauda, Emanuele

2012-11-01

Airborne silica dust (quartz) is common in coal mines and represents a respiratory hazard that can lead to silicosis, a potentially fatal lung disease. With an eye toward developing a portable monitoring device for rapid analysis of silica dust, laser-induced breakdown spectroscopy (LIBS) was used to quantify quartz in coal dust samples collected on filter media. Pure silica (Min-U-Sil™ 5), Georgia kaolin, and Pittsburgh-4 and Illinois-6 coal dusts were deposited separately and at multiple mass loadings onto 37-mm polyvinylchloride (PVC) filters. LIBS-generated silicon emission was monitored at 288.16 nm, and non-silica contributions to that signal from kaolinite were removed by simultaneously detecting aluminum. Measurements of the four samples were used to calculate limits of detection (LOD) for silicon and aluminum of approximately 0.08 μg/cm(2) and 0.05 μg/cm(2), respectively (corresponding to 0.16 μg/cm(2) and 0.20 μg/cm(2) for silica and kaolinite, respectively). Relative errors of prediction are around 10%. Results demonstrate that LIBS can dependably quantify silica on filter samples of coal dust and confirm that accurate quantification can be achieved for very lightly loaded samples, which supports the potential application of LIBS for rapid, in-field monitoring.

The Investigation of Laser Ignited Plasma with the Application of Current Probes

NASA Astrophysics Data System (ADS)

Olsson, Trevor; Amos, James; Ujj, Laszlo

Among a variety of atomic emission spectroscopy methods Laser-induced breakdown spectroscopy (LIBS) is the one which can analyze any solid, liquid or gas sample. The elemental composition and the relative abundance of the constituent elements in the samples can be determined when the emission spectra of short laser pulses igniting plasma is then recorded and analyzed(e.g.). In our studies we have made a LIBS system which includes, but is not limited to investigating the physical phenomena and properties of the emitting plasma. Active research is going on concerning Lithium-ion batteries to increase the stored charge and energy per volume properties of the device. LIBS is proposed to test the manufacturing process and analyze the chemical constituents of the newly developed batteries. The composition of the battery itself consists of two pieces of foil, typically aluminum and copper acting as a cathode and anode respectively. Separating these two pieces of foil is a lithium based compound. The general chemical composition is Lix [Metal]y Oz where [Metal] is the specific element that is used to achieve the purpose of the battery (one metal may increase the out-put while another helps with capacity etc.). We have chosen the Li-Ion battery composed of LiCoO2 from a mobile phone in order to investigate the Stark-effect (Stark shift and Stark broadening) of the lithium present in the sample. Effects of line broadening and reabsorption of the signals are addressed by recording LIBS spectra from the powder electrolyte extracted from a Lithium-ion battery.

Development of laser-induced breakdown spectroscopy sensor to assess groundwater quality impacts resulting from geologic carbon sequestration

NASA Astrophysics Data System (ADS)

Carson, Cantwell G.; Goueguel, Christian; Jain, Jinesh; McIntyre, Dustin

2015-05-01

The injection of CO2 into deep aquifers can potentially affect the quality of groundwater supplies were leakage to occur from the injection formation or fluids. Therefore, the detection of CO2 and/or entrained contaminants that migrate into shallow groundwater aquifers is important both to assess storage permanence and to evaluate impacts on water resources. Naturally occurring elements (i.e., Li, Sr) in conjunction with isotope ratios can be used to detect such leakage. We propose the use of laser induced breakdown spectroscopy (LIBS) as an analytical technique to detect a suite of elements in water samples. LIBS has real time monitoring capabilities and can be applied for elemental and isotopic analysis of solid, liquid, and gas samples. The flexibility of probe design and use of fiber optics make it a suitable technique for real time measurements in harsh conditions and in hard to reach places. The laboratory scale experiments to measure Li, K, Ca, and Sr composition of water samples indicate that the technique produces rapid and reliable data. Since CO2 leakage from saline aquifers may accompany a brine solution, we studied the effect of sodium salts on the accuracy of LIBS analysis. This work specifically also details the fabrication and application of a miniature ruggedized remotely operated diode pumped solid state passively Q-switched laser system for use as the plasma excitation source for a real time LIBS analysis. This work also proposes the optical distribution of many laser spark sources across a wide area for widespread leak detection and basin monitoring.

Investigation of non-uniformity and inclusions in 6LiInSe2 utilizing laser induced breakdown spectroscopy (LIBS)

NASA Astrophysics Data System (ADS)

Wiggins, Brenden; Tupitsyn, Eugene; Bhattacharya, Pijush; Rowe, Emmanuel; Lukosi, Eric; Chvala, Ondrej; Burger, Arnold; Stowe, Ashley

2013-09-01

Impurity analysis and compositional distribution studies have been conducted on a crystal of LiInSe2, a compound semiconductor which recently has been shown to respond to ionizing radiation. IR microscopy and laser induced breakdown spectroscopy (LIBS) revealed the presence of inclusions within the crystal lattice. These precipitates were revealed to be alkali and alkaline earth elemental impurities with non-uniform spatial distribution in the crystal. LIBS compositional maps correlate the presence of these impurities with visual color differences in the crystal as well as a significant shift of the band gap. Further, LIBS revealed variation in the ratio of I-III-VI2 elemental constituents throughout the crystal. Analysis of compositional variation and impurities will aid in discerning optimal synthesis and crystal growth parameters to maximize the mobility-lifetime product and charge collection efficiency in the LiInSe2 crystal. Preliminary charge trapping calculations have also been conducted with the Monte Carlo N-particle eXtended (MCNPx) package indicating preferential trapping of holes during irradiation with thermal neutrons.

2d distribution mapping of quantum dots injected onto filtration paper by laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Škarková, Pavlína; Novotný, Karel; Lubal, Přemysl; Jebavá, Alžběta; Pořízka, Pavel; Klus, Jakub; Farka, Zdeněk; Hrdlička, Aleš; Kaiser, Jozef

2017-05-01

In this study, the feasibility of Quantum dots (QDs) 2D distribution mapping on the substrate by Laser-Induced Breakdown Spectroscopy (LIBS) was examined. The major objective of this study was to describe phenomena occurring after applying aqueous solutions of QDs onto filtration paper. Especially, the influence of pH and presence of Cu2 + cations in QDs solutions on LIBS signal was investigated. Cadmium Telluride QDs (CdTe QDs) were prepared by formation of nanosized semiconductor particles in so called ;one-pot; synthesis. CdTe QDs were capped by glutathione or by 3-mercaptopropionic acid. The technique described in this work allows detection of QDs injected on the selected substrate - filtration paper. Results obtained from LIBS experiments were collated with a comparative method, fluorescence microscopy, which showed variations in the distribution of QDs on the substrate surface and possibilities for quenching. Due to the immediate signal response, relatively simple instrumentation and automatization possibility, LIBS offers promising and fast alternative to other techniques, as it is able to detect also nanoparticles with no visible luminescence.

Application of laser-induced breakdown spectroscopy to zirconium in aqueous solution

NASA Astrophysics Data System (ADS)

Ruas, Alexandre; Matsumoto, Ayumu; Ohba, Hironori; Akaoka, Katsuaki; Wakaida, Ikuo

2017-05-01

In the context of the Fukushima Dai-ichi Nuclear Power Plant (F1-NPP) decommissioning process, laser-induced breakdown spectroscopy (LIBS) has many advantages. The purpose of the present work is to demonstrate the on-line monitoring capability of the LIBS coupled with the ultra-thin liquid jet sampling method. The study focuses on zirconium in aqueous solution, considering that it is a major element in the F1-NPP fuel debris that has been subject to only a few LIBS studies in the past. The methodology of data acquisition and processing are described. In particular, two regions of interest with many high intensity zirconium lines have been observed around 350 nm in the case of the ionic lines and 478 nm in the case of atomic lines. The best analytical conditions for zirconium are different depending on the analysis of ionic lines or atomic lines. A low LOD of about 4 mg L- 1 could be obtained, showing that LIBS coupled with the ultra-thin liquid jet sampling technique is a promising alternative for more complex solutions found in the F1-NPP, namely mixtures containing zirconium.

Quantitative elemental imaging of heterogeneous catalysts using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Trichard, F.; Sorbier, L.; Moncayo, S.; Blouët, Y.; Lienemann, C.-P.; Motto-Ros, V.

2017-07-01

Currently, the use of catalysis is widespread in almost all industrial processes; its use improves productivity, synthesis yields and waste treatment as well as decreases energy costs. The increasingly stringent requirements, in terms of reaction selectivity and environmental standards, impose progressively increasing accuracy and control of operations. Meanwhile, the development of characterization techniques has been challenging, and the techniques often require equipment with high complexity. In this paper, we demonstrate a novel elemental approach for performing quantitative space-resolved analysis with ppm-scale quantification limits and μm-scale resolution. This approach, based on laser-induced breakdown spectroscopy (LIBS), is distinguished by its simplicity, all-optical design, and speed of operation. This work analyzes palladium-based porous alumina catalysts, which are commonly used in the selective hydrogenation process, using the LIBS method. We report an exhaustive study of the quantification capability of LIBS and its ability to perform imaging measurements over a large dynamic range, typically from a few ppm to wt%. These results offer new insight into the use of LIBS-based imaging in the industry and paves the way for innumerable applications.

Laser-induced breakdown spectroscopy in industrial and security applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bol'shakov, Alexander A.; Yoo, Jong H.; Liu Chunyi

2010-05-01

Laser-induced breakdown spectroscopy (LIBS) offers rapid, localized chemical analysis of solid or liquid materials with high spatial resolution in lateral and depth profiling, without the need for sample preparation. Principal component analysis and partial least squares algorithms were applied to identify a variety of complex organic and inorganic samples. This work illustrates how LIBS analyzers can answer a multitude of real-world needs for rapid analysis, such as determination of lead in paint and children's toys, analysis of electronic and solder materials, quality control of fiberglass panels, discrimination of coffee beans from different vendors, and identification of generic versus brand-name drugs.more » Lateral and depth profiling was performed on children's toys and paint layers. Traditional one-element calibration or multivariate chemometric procedures were applied for elemental quantification, from single laser shot determination of metal traces at {approx}10 {mu}g/g to determination of halogens at 90 {mu}g/g using 50-shot spectral accumulation. The effectiveness of LIBS for security applications was demonstrated in the field by testing the 50-m standoff LIBS rasterizing detector.« less

Analysis of the silicone polymer surface aging profile with laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Wang, Xilin; Hong, Xiao; Wang, Han; Chen, Can; Zhao, Chenlong; Jia, Zhidong; Wang, Liming; Zou, Lin

2017-10-01

Silicone rubber composite materials have been widely used in high voltage transmission lines for anti-pollution flashover. The aging surface of silicone rubber materials decreases service properties, causing loss of the anti-pollution ability. In this paper, as an analysis method requiring no sample preparation that is able to be conducted on site and suitable for nearly all types of materials, laser-induced breakdown spectroscopy (LIBS) was used for the analysis of newly prepared and aging (out of service) silicone rubber composites. With scanning electron microscopy (SEM) and hydrophobicity test, LIBS was proven to be nearly non-destructive for silicone rubber. Under the same LIBS testing parameters, a linear relationship was observed between ablation depth and laser pulses number. With the emission spectra, all types of elements and their distribution in samples along the depth direction from the surface to the inner part were acquired and verified with EDS results. This research showed that LIBS was suitable to detect the aging layer depth and element distribution of the silicone rubber surface.

The detection of He in tungsten following ion implantation by laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Shaw, G.; Bannister, M.; Biewer, T. M.; Martin, M. Z.; Meyer, F.; Wirth, B. D.

2018-01-01

Laser-induced breakdown spectroscopy (LIBS) results are presented that provide depth-resolved identification of He implanted in polycrystalline tungsten (PC-W) targets by a 200 keV He+ ion beam, with a surface temperature of approximately 900 °C and a peak fluence of 1023 m-2. He retention, and the influence of He on deuterium and tritium recycling, permeation, and retention in PC-W plasma facing components are important questions for the divertor and plasma facing components in a fusion reactor, yet are difficult to quantify. The purpose of this work is to demonstrate the ability of LIBS to identify helium in tungsten; to investigate the sensitivity of laser parameters including, laser energy and gate delay, that directly influence the sensitivity and depth resolution of LIBS; and to perform a proof-of-principle experiment using LIBS to measure relative He intensities as a function of depth. The results presented demonstrate the potential not only to identify helium but also to develop a methodology to quantify gaseous impurity concentration in PC-W as a function of depth.

Laser-induced breakdown spectroscopy for the remote detection of explosives at level of fingerprints

NASA Astrophysics Data System (ADS)

Almaviva, S.; Palucci, A.; Lazic, V.; Menicucci, I.; Nuvoli, M.; Pistilli, M.; De Dominicis, L.

2016-04-01

We report the results of the application of Laser-Induced Breakdown Spectroscopy (LIBS) for the detection of some common military explosives and theirs precursors deposited on white varnished car's external and black car's internal or external plastic. The residues were deposited by an artificial silicon finger, to simulate material manipulation by terrorists when preparing a car bomb, leaving traces of explosives on the parts of a car. LIBS spectra were acquired by using a first prototype laboratory stand-off device, developed in the framework of the EU FP7 313077 project EDEN (End-user driven DEmo for CBRNe). The system operates at working distances 8-30 m and collects the LIBS in the spectral range 240-840 nm. In this configuration, the target was moved precisely in X-Y direction to simulate the scanning system, to be implemented successively. The system is equipped with two colour cameras, one for wide scene view and another for imaging with a very high magnification, capable to discern fingerprints on a target. The spectral features of each examined substance were identified and compared to those belonging to the substrate and the surrounding air, and those belonging to possible common interferents. These spectral differences are discussed and interpreted. The obtained results show that the detection and discrimination of nitro-based compounds like RDX, PETN, ammonium nitrate (AN), and urea nitrate (UN) from organic interfering substances like diesel, greasy lubricants, greasy adhesives or oils in fingerprint concentration, at stand-off distance of some meters or tenths of meters is feasible.

Preliminary panoramic study of river calm muscle using neodymium:yttrium-aluminum-garnet (Nd: YAG) laser-induced breakdown spectroscopy (LIBS)

NASA Astrophysics Data System (ADS)

Idris, N.; Lahna, K.; Usmawanda, T. N.; Herman; Ramli, M.; Hedwig, R.; Marpaung, A. M.; Kurniawan, K. H.

2018-04-01

A wide coverage spectral investigation on the muscle of river calm sample has been carried out using laser-induced breakdown spectroscopy for examining the overall profile of the emission spectra from the produced plasma. The basic apparatus of LIBS system used is a Nd-YAG laser and wide coverage optical multichannel analyzer (OMA) system. The river clam samples used is collected from Panga River in Aceh Jaya Regency, Aceh, Indonesia up streaming in a mountain of Gunong Ujeun, which is used as a location of the intensive traditional mining activity. Assuming that heavy metal accumulated in the clam muscle, LIBS experiments were carried out on the muscle of the calm. The sample used was fresh muscle sliced and attached to a copper plate. Plasma was generated by focusing the laser beam on the sample surface under air surrounding gas at 1 atmosphere. It is found that there are only major elements of host organic, namely C, H, O, N and the minor element of salts can be detected from fresh the clam sample when using a high pulse laser energy under air surrounding at high pressure of 1 atmosphere. There is no emission lines from any metal can be detected. Several experimental parameters were explored to study the panoramic dynamic of the emission spectra. It is found that the lower energy and the lower pressure is better for obtaining better emission spectra showing the possibility for determination of the analyte.

Simulated In Situ Determination of Soil Profile Organic and Inorganic Carbon With LIBS and VisNIR

NASA Astrophysics Data System (ADS)

Bricklemyer, R. S.; Brown, D. J.; Clegg, S. M.; Barefield, J. E.

2008-12-01

There is growing need for rapid, accurate, and inexpensive methods to measure, and verify soil organic carbon (SOC) change for national greenhouse gas accounting and the development of a soil carbon trading market. Laser Induced Breakdown Spectroscopy (LIBS) and Visible and Near Infrared Spectroscopy (VisNIR) are complementary analytical techniques that have the potential to fill that need. The LIBS method provides precise elemental analysis of soils, but generally cannot distinguish between organic C and inorganic C. VisNIR has been established as a viable technique for measuring soil properties including SOC and inorganic carbon (IC). As part of the Big Sky Carbon Sequestration Regional Partnership, 240 intact core samples (3.8 x 50 cm) have been collected from six agricultural fields in north central Montana, USA. Each of these core samples were probed concurrently with LIBS and VisNIR at 2.5, 7.5, 12.5, 17.5, 22.5, 27.5, 35 and 45 cm (+/- 1.5 cm) depths. VisNIR measurements were taken using an Analytical Spectral Devices (ASD, Boulder, CO, USA) Agrispec spectrometer to determine the partition of SOC vs. IC in the samples. The LIBS scans were collected with the LANL LIBS Core Scanner Instrument which collected the entire 200 - 900 nm plasma emission including the 247.8 nm carbon emission line. This instrument also collected the emission from the elements typically found in inorganic carbon (Ca and Mg) and organic carbon (H, O, and N). Subsamples of soil (~ 4 g) were taken from interrogation points for laboratory determination of SOC and IC. Using this analytical data, we constructed several full spectrum multivariate VisNIR/LIBS calibration models for SOC and IC. These models were then applied to independent validation cores for model evaluation.

Calibration of the MSL/ChemCam/LIBS Remote Sensing Composition Instrument

NASA Technical Reports Server (NTRS)

Wiens, R. C.; Maurice S.; Bender, S.; Barraclough, B. L.; Cousin, A.; Forni, O.; Ollila, A.; Newsom, H.; Vaniman, D.; Clegg, S.;

Application of Laser Induced Breakdown Spectroscopy under Polar Conditions

NASA Astrophysics Data System (ADS)

Clausen, J. L.; Hark, R.; Bol'shakov, A.; Plumer, J.

2015-12-01

Over the past decade our research team has evaluated the use of commercial-off-the-shelf laser-induced breakdown spectroscopy (LIBS) for chemical analysis of snow and ice samples under polar conditions. One avenue of research explored LIBS suitability as a detector of paleo-climate proxy indicators (Ca, K, Mg, and Na) in ice as it relates to atmospheric circulation. LIBS results revealed detection of peaks for C and N, consistent with the presence of organic material, as well as major ions (Ca, K, Mg, and Na) and trace metals (Al, Cu, Fe, Mn, Ti). The detection of Ca, K, Mg, and Na confirmed that LIBS has sufficient sensitivity to be used as a tool for characterization of paleo-climate proxy indicators in ice-core samples. Techniques were developed for direct analysis of ice as well as indirect measurements of ice via melting and filtering. Pitfalls and issues of direct ice analysis using several cooling techniques to maintain ice integrity will be discussed. In addition, a new technique, laser ablation molecular isotopic spectroscopy (LAMIS) was applied to detection of hydrogen and oxygen isotopes in ice as isotopic analysis of ice is the main tool in paleoclimatology and glaciology studies. Our results demonstrated that spectra of hydroxyl isotopologues 16OH, 18OH, and 16OD can be recorded with a compact spectrograph to determine hydrogen and oxygen isotopes simultaneously. Quantitative isotopic calibration for ice analysis can be accomplished using multivariate chemometric regression as previously realized for water vapor. Analysis with LIBS and LAMIS required no special sample preparation and was about ten times faster than analysis using ICP-MS. Combination of the two techniques in one portable instrument for in-field analysis appears possible and would eliminate the logistical and cost issues associated with ice core management.

Feasibility of real-time geochemical analysis using LIBS (Laser-Induced Breakdown Spectroscopy) in oil wells

NASA Astrophysics Data System (ADS)

Shahin, Mohamed

2014-05-01

The oil and gas industry has attempted for many years to find new ways to analyze and determine the type of rocks drilled on a real time basis. Mud analysis logging is a direct method of detecting oil and gas in formations drilled, it depends on the "feel" of the bit to decide formation type, as well as, geochemical analysis which was introduced 30 years ago, starting with a pulsed-neutron generator (PNG) based wireline tool upon which LWD technology was based. In this paper, we are studying the feasibility of introducing a new technology for real-time geochemical analysis. Laser-induced breakdown spectroscopy (LIBS) is a type of atomic emission spectroscopy, It is a cutting-edge technology that is used for many applications such as determination of alloy composition, origin of manufacture (by monitoring trace components), and molecular analysis (unknown identification). LIBS can analyze any material regardless of its state (solid, liquid or gas), based upon that fact, we can analyze rocks, formation fluids' types and contacts between them. In cooperation with the National Institute of Laser Enhanced Science, Cairo University in Egypt, we've done tests on sandstone, limestone and coal samples acquired from different places using Nd: YAG Laser with in addition to other components that are explained in details through this paper to understand the ability of Laser to analyze rock samples and provide their elemental composition using LIBS technique. We've got promising results from the sample analysis via LIBS and discussed the possibility of deploying this technology in oilfields suggesting many applications and giving a base for achieving a quantitative elemental analysis method in view of its shortcomings and solutions.

Mineral content analysis of root canal dentin using laser-induced breakdown spectroscopy

PubMed Central

2018-01-01

Objectives This study aimed to introduce the use of laser-induced breakdown spectroscopy (LIBS) for evaluation of the mineral content of root canal dentin, and to assess whether a correlation exists between LIBS and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) methods by comparing the effects of irrigation solutions on the mineral content change of root canal dentin. Materials and Methods Forty teeth with a single root canal were decoronated and longitudinally sectioned to expose the canals. The root halves were divided into 4 groups (n = 10) according to the solution applied: group NaOCl, 5.25% sodium hypochlorite (NaOCl) for 1 hour; group EDTA, 17% ethylenediaminetetraacetic acid (EDTA) for 2 minutes; group NaOCl+EDTA, 5.25% NaOCl for 1 hour and 17% EDTA for 2 minutes; a control group. Each root half belonging to the same root was evaluated for mineral content with either LIBS or SEM/EDS methods. The data were analyzed statistically. Results In groups NaOCl and NaOCl+EDTA, the calcium (Ca)/phosphorus (P) ratio decreased while the sodium (Na) level increased compared with the other groups (p < 0.05). The magnesium (Mg) level changes were not significant among the groups. A significant positive correlation was found between the results of LIBS and SEM/EDS analyses (r = 0.84, p < 0.001). Conclusions Treatment with NaOCl for 1 hour altered the mineral content of dentin, while EDTA application for 2 minutes had no effect on the elemental composition. The LIBS method proved to be reliable while providing data for the elemental composition of root canal dentin. PMID:29487841

Study of different concentric rings inside gallstones with LIBS.

PubMed

Pathak, Ashok Kumar; Singh, Vivek Kumar; Rai, Nilesh Kumar; Rai, Awadhesh Kumar; Rai, Pradeep Kumar; Rai, Pramod Kumar; Rai, Suman; Baruah, G D

2011-07-01

Gallstones obtained from patients from the north-east region of India (Assam) were studied using laser-induced breakdown spectroscopy (LIBS) technique. LIBS spectra of the different layers (in cross-section) of the gallstones were recorded in the spectral region 200-900 nm. Several elements, including calcium, magnesium, manganese, copper, silicon, phosphorus, iron, sodium and potassium, were detected in the gallstones. Lighter elements, including carbon, hydrogen, nitrogen and oxygen were also detected, which demonstrates the superiority of the LIBS technique over other existing analytical techniques. The LIBS technique was applied to investigate the evolution of C(2) swan bands and CN violet bands in the LIBS spectra of the gallstones in air and an argon atmosphere. The different layers (dark and light layers) of the gallstones were discriminated on the basis of the presence and intensities of the spectral lines for carbon, hydrogen, nitrogen, oxygen and copper. An attempt was also made to correlate the presence of major and minor elements in the gallstones with the common diet of the population of Assam.

Detection of calculus by laser-induced breakdown spectroscopy (LIBS) using an ultra-short pulse laser system (USPL)

NASA Astrophysics Data System (ADS)

Schelle, F.; Brede, O.; Krueger, S.; Oehme, B.; Dehn, C.; Frentzen, M.; Braun, A.

2011-03-01

The aim of this study was to assess the detection of calculus by Laser Induced Breakdown Spectroscopy (LIBS). The study was performed with an Nd:YVO4 laser, emitting pulses with a duration of 8 ps at a wavelength of 1064 nm. A repetition rate of 500 kHz at an average power of 5 W was used. Employing a focusing lense, intensities of the order of 1011 W/cm2 were reached on the tooth surface. These high intensities led to the generation of a plasma. The light emitted by the plasma was collimated into a fibre and then analyzed by an echelle spectroscope in the wavelength region from 220 nm - 900 nm. A total number of 15 freshly extracted teeth was used for this study. For each tooth the spectra of calculus and cementum were assessed separately. Comprising all single measurements median values were calculated for the whole spectrum, leading to two specific spectra, one for calculus and one for cementum. For further statistical analysis 28 areas of interest were defined as wavelength regions, in which the signal strength differed regarding the material. In 7 areas the intensity of the calculus spectrum differed statistically significant from the intensity of the cementum spectrum (p < 0.05). Thus it can be concluded that Laser Induced Breakdown Spectroscopy is well suited as method for a reliable diagnostic of calculus. Further studies are necessary to verify that LIBS is a minimally invasive method allowing a safe application in laser-guided dentistry.

Multivariate analysis of standoff laser-induced breakdown spectroscopy spectra for classification of explosive-containing residues

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Lucia, Frank C. Jr.; Gottfried, Jennifer L.; Munson, Chase A.

2008-11-01

A technique being evaluated for standoff explosives detection is laser-induced breakdown spectroscopy (LIBS). LIBS is a real-time sensor technology that uses components that can be configured into a ruggedized standoff instrument. The U.S. Army Research Laboratory has been coupling standoff LIBS spectra with chemometrics for several years now in order to discriminate between explosives and nonexplosives. We have investigated the use of partial least squares discriminant analysis (PLS-DA) for explosives detection. We have extended our study of PLS-DA to more complex sample types, including binary mixtures, different types of explosives, and samples not included in the model. We demonstrate themore » importance of building the PLS-DA model by iteratively testing it against sample test sets. Independent test sets are used to test the robustness of the final model.« less

Measuring lanthanide concentrations in molten salt using laser-induced breakdown spectroscopy (LIBS).

PubMed

Weisberg, Arel; Lakis, Rollin E; Simpson, Michael F; Horowitz, Leo; Craparo, Joseph

2014-01-01

The versatility of laser-induced breakdown spectroscopy (LIBS) as an analytical method for high-temperature applications was demonstrated through measurement of the concentrations of the lanthanide elements europium (Eu) and praseodymium (Pr) in molten eutectic lithium chloride-potassium chloride (LiCl-KCl) salts at a temperature of 500 °C. Laser pulses (1064 nm, 7 ns, 120 mJ/pulse) were focused on the top surface of the molten salt samples in a laboratory furnace under an argon atmosphere, and the resulting LIBS signals were collected using a broadband Echelle-type spectrometer. Partial least squares (PLS) regression using leave-one-sample-out cross-validation was used to quantify the concentrations of Eu and Pr in the samples. The root mean square error of prediction (RMSEP) for Eu was 0.13% (absolute) over a concentration range of 0-3.01%, and for Pr was 0.13% (absolute) over a concentration range of 0-1.04%.

Investigation of the differentiation of ex vivo nerve and fat tissues using laser-induced breakdown spectroscopy (LIBS): Prospects for tissue-specific laser surgery.

PubMed

Mehari, Fanuel; Rohde, Maximillian; Kanawade, Rajesh; Knipfer, Christian; Adler, Werner; Klämpfl, Florian; Stelzle, Florian; Schmidt, Michael

2016-10-01

In the present study, the elemental compositions of fat and nerve tissue during their plasma mediated laser ablation are studied in the context of tissue differentiation for laser surgery applications by using Laser-Induced Breakdown Spectroscopy (LIBS). Tissue samples of porcine fat and nerve were prepared as ex vivo experimental objects. Plasma mediated laser ablation is performed using an Nd : YAG laser in open air and under normal stray light conditions. The performed measurements suggest that the two tissue types show a high similarity in terms of qualitative elemental composition while at the same time revealing a distinct difference in the concentration of the constituent elements. Different analysis approaches are evaluated and discussed to optimize the tissue-differentiation performance of the LIBS approach. Plasma mediated laser tissue ablation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cluster analysis of polymers using laser-induced breakdown spectroscopy with K-means

NASA Astrophysics Data System (ADS)

Yangmin, GUO; Yun, TANG; Yu, DU; Shisong, TANG; Lianbo, GUO; Xiangyou, LI; Yongfeng, LU; Xiaoyan, ZENG

2018-06-01

Laser-induced breakdown spectroscopy (LIBS) combined with K-means algorithm was employed to automatically differentiate industrial polymers under atmospheric conditions. The unsupervised learning algorithm K-means were utilized for the clustering of LIBS dataset measured from twenty kinds of industrial polymers. To prevent the interference from metallic elements, three atomic emission lines (C I 247.86 nm , H I 656.3 nm, and O I 777.3 nm) and one molecular line C–N (0, 0) 388.3 nm were used. The cluster analysis results were obtained through an iterative process. The Davies–Bouldin index was employed to determine the initial number of clusters. The average relative standard deviation values of characteristic spectral lines were used as the iterative criterion. With the proposed approach, the classification accuracy for twenty kinds of industrial polymers achieved 99.6%. The results demonstrated that this approach has great potential for industrial polymers recycling by LIBS.

Analysis of human nails by laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Hosseinimakarem, Zahra; Tavassoli, Seyed Hassan

2011-05-01

Laser-induced breakdown spectroscopy (LIBS) is applied to analyze human fingernails using nanosecond laser pulses. Measurements on 45 nail samples are carried out and 14 key species are identified. The elements detected with the present system are: Al, C, Ca, Fe, H, K, Mg, N, Na, O, Si, Sr, Ti as well as CN molecule. Sixty three emission lines have been identified in the spectrum that are dominated by calcium lines. A discriminant function analysis is used to discriminate among different genders and age groups. This analysis demonstrates efficient discrimination among these groups. The mean concentration of each element is compared between different groups. Correlation between concentrations of elements in fingernails is calculated. A strong correlation is found between sodium and potassium while calcium and magnesium levels are inversely correlated. A case report on high levels of sodium and potassium in patients with hyperthyroidism is presented. It is shown that LIBS could be a promising technique for the analysis of nails and therefore identification of health problems.

Multi-block analysis coupled to laser-induced breakdown spectroscopy for sorting geological materials from caves.

PubMed

Ammari, Faten; Bassel, Léna; Ferrier, Catherine; Lacanette, Delphine; Chapoulie, Rémy; Bousquet, Bruno

2016-10-01

In this study, multi-block analysis was applied for the first time to LIBS spectra provided by a portable LIBS system (IVEA Solution, France) equipped with three compact Czerny-Turner spectrometers covering the spectral ranges 200-397nm, 398-571nm and 572-1000nm. 41 geological samples taken from a laboratory-cave situated in the "Vézère valley", an area rich with prehistoric sites and decorated caves listed as a UNESCO world heritage in the south west of France, were analyzed. They were composed of limestone and clay considered as underlying supports and of two types of alterations referred as moonmilk and coralloid. Common Components and Specific Weights Analysis (CCSWA) allowed sorting moonmilk and coralloid samples. The loadings revealed higher amounts of magnesium, silicon, aluminum and strontium in coralloids and the saliences emphasized that among the three spectrometers installed in the LIBS instrument used in this work; that covering the range 572-1000nm was less contributive. This new approach for processing LIBS data not only provides good results for sorting geological materials but also clearly reveals which spectral range contains most of the information. This specific advantage of multi-block analysis could lead for some applications to simplify the design and to reduce the size of LIBS instruments. Copyright © 2016 Elsevier B.V. All rights reserved.

Sulfur determination in concrete samples using laser-induced breakdown spectroscopy and limestone standards

NASA Astrophysics Data System (ADS)

Hrdlička, Aleš; Hegrová, Jitka; Novotný, Karel; Kanický, Viktor; Prochazka, David; Novotný, Jan; Modlitbová, Pavlína; Sládková, Lucia; Pořízka, Pavel; Kaiser, Jozef

2018-04-01

A LIBS equipment operating at 532 nm was optimized and used for sulfur determination in concrete samples. The influence of He atmosphere in a gas-tight chamber (1000-200 mbar) on S I 921.29 nm line sensitivity, signal-to-background and signal-to-noise ratio was studied at gate delays 100-2000 ns. Wide range of gate delays from 500 to about 1000 ns and pressures from several hundreds of mbar to the atmospheric pressure can be used for the desired detection of sulfur. The LIBS quantification was done using a simple calibration method. A synthetic limestone enriched by defined amounts of sodium sulfate was newly employed for direct quantification of S in concrete. This powder material was pressed into pellets and ablated with the LIBS system. The average content of sulfur as SO3 in the samples was 0.41-0.70 wt% by LIBS and 0.43-0.61 wt% by a reference standard procedure employing gravimetry and Inductively Coupled Plasma Triple Quad Mass Spectrometry (ICP-QQQMS). The uncertainty of the yielded LIBS results covers also the dispersion of the points in the calibration line and ranges from 16 to 28% at the probability level of 95%. The uncertainty of the ICP-QQQMS results was almost 10%. No correction on different signal response on the limestone and on the concrete was necessary.

Analysis of pigments in polychromes by use of laser induced breakdown spectroscopy and Raman microscopy

NASA Astrophysics Data System (ADS)

Castillejo, M.; Martín, M.; Silva, D.; Stratoudaki, T.; Anglos, D.; Burgio, L.; Clark, R. J. H.

2000-09-01

Two laser-based analytical techniques, Laser Induced Breakdown Spectroscopy (LIBS) and Raman microscopy, have been used for the identification of pigments on a polychrome from the Rococo period. Detailed spectral data are presented from analyses performed on a fragment of a gilded altarpiece from the church of Escatrón, Zaragoza, Spain. LIBS measurements yielded elemental analytical data which suggest the presence of certain pigments and, in addition, provide information on the stratigraphy of the paint layers. Identification of most pigments and of the materials used in the preparation layer was performed by Raman microscopy.

Measurement of Rare Earth and Uranium Elements Using Laser-Induced Breakdown Spectroscopy (LIBS) in an Aerosol System for Nuclear Safeguards Applications

NASA Astrophysics Data System (ADS)

Williams, Ammon Ned

The primary objective of this research is to develop an applied technology and provide an assessment for remotely measuring and analyzing the real time or near real time concentrations of used nuclear fuel (UNF) elements in electroreners (ER). Here, Laser-Induced Breakdown Spectroscopy (LIBS) in UNF pyroprocessing facilities was investigated. LIBS is an elemental analysis method, which is based on the emission from plasma generated by focusing a laser beam into the medium. This technology has been reported to be applicable in solids, liquids (includes molten metals), and gases for detecting elements of special nuclear materials. The advantages of applying the technology for pyroprocessing facilities are: (i) Rapid real-time elemental analysis; (ii) Direct detection of elements and impurities in the system with low limits of detection (LOD); and (iii) Little to no sample preparation is required. One important challenge to overcome is achieving reproducible spectral data over time while being able to accurately quantify fission products, rare earth elements, and actinides in the molten salt. Another important challenge is related to the accessibility of molten salt, which is heated in a heavily insulated, remotely operated furnace in a high radiation environment within an argon gas atmosphere. This dissertation aims to address these challenges and approaches in the following phases with their highlighted outcomes: 1. Aerosol-LIBS system design and aqueous testing: An aerosol-LIBS system was designed around a Collison nebulizer and tested using deionized water with Ce, Gd, and Nd concentrations from 100 ppm to 10,000 ppm. The average %RSD values between the sample repetitions were 4.4% and 3.8% for the Ce and Gd lines, respectively. The univariate calibration curve for Ce using the peak intensities of the Ce 418.660 nm line was recommended and had an R 2 value, LOD, and RMSECV of 0.994, 189 ppm, and 390 ppm, respectively. The recommended Gd calibration curve was generated using the peak areas of the Gd 409.861 nm line and had an R2, LOD, and RMSECV of 0.992, 316 ppm, and 421 ppm, respectively. The partial least squares (PLS) calibration curves yielded similar results with RMSECV of 406 ppm and 417 ppm for the Ce and Gd curves, respectively. 2. High temperature aerosol-LIBS system design and CeCl3 testing: The aerosol-LIBS system was transitioned to a high temperature and used to measure Ce in molten LiCl-KCl salt within a glovebox environment. The concentration range studied was from 0.1 wt% to 5 wt% Ce. Normalization was necessary due to signal degradation over time; however, with the normalization the %RSD values averaged 5% for the mid and upper concentrations studied. The best univariate calibration curve was generated using the peak areas of the Ce 418.660 nm line. The LOD for this line was 148 ppm with the RMSECV of 647 ppm. The PLS calibration curve was made using 7 latent variables (LV) and resulting in the RMSECV of 622 ppm. The LOD value was below the expected rare earth concentration within the ER. 3. Aerosol-LIBS testing using UCl3: Samples containing UCl 3 with concentrations ranging from 0.3 wt% to 5 wt% were measured. The spectral response in this range was linear. The best univariate calibration curves were generated using the peak areas of the U 367.01 nm line and had an R2 value of 0.9917. Here, the LOD was 647 ppm and the RMSECV was 2,290 ppm. The PLS model was substantially better with a RMSECV of 1,110 ppm. The LOD found here is below the expected U concentrations in the ER. The successful completion of this study has demonstrated the feasibility of using an aerosol-LIBS analytical technique to measure rare earth elements and actinides in the pyroprocessing salt.

Quantification of rare earth elements using laser-induced breakdown spectroscopy

DOE PAGES

Martin, Madhavi; Martin, Rodger C.; Allman, Steve; ...

2015-10-21

In this paper, a study of the optical emission as a function of concentration of laser-ablated yttrium (Y) and of six rare earth elements, europium (Eu), gadolinium (Gd), lanthanum (La), praseodymium (Pr), neodymium (Nd), and samarium (Sm), has been evaluated using the laser-induced breakdown spectroscopy (LIBS) technique. Statistical methodology using multivariate analysis has been used to obtain the sampling errors, coefficient of regression, calibration, and cross-validation of measurements as they relate to the LIBS analysis in graphite-matrix pellets that were doped with elements at several concentrations. Each element (in oxide form) was mixed in the graphite matrix in percentages rangingmore » from 1% to 50% by weight and the LIBS spectra obtained for each composition as well as for pure oxide samples. Finally, a single pellet was mixed with all the elements in equal oxide masses to determine if we can identify the elemental peaks in a mixed pellet. This dataset is relevant for future application to studies of fission product content and distribution in irradiated nuclear fuels. These results demonstrate that LIBS technique is inherently well suited for the future challenge of in situ analysis of nuclear materials. Finally, these studies also show that LIBS spectral analysis using statistical methodology can provide quantitative results and suggest an approach in future to the far more challenging multielemental analysis of ~ 20 primary elements in high-burnup nuclear reactor fuel.« less

Infrared (1-12 μm) atomic and molecular emission signatures from energetic materials using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Kumi Barimah, E.; Hömmerich, U.; Brown, E.; Yang, C. S.-C.; Trivedi, S. B.; Jin, F.; Wijewarnasuriya, P. S.; Samuels, A. C.; Snyder, A. P.

2013-05-01

Laser-induced breakdown spectroscopy (LIBS) is a powerful analytical technique to detect the elemental composition of solids, liquids, and gases in real time. For example, recent advances in UV-VIS LIBS have shown great promise for applications in chemical, biological, and explosive sensing. The extension of conventional UVVIS LIBS to the near-IR (NIR), mid-IR (MIR) and long wave infrared (LWIR) regions (~1-12 μm) offers the potential to provide additional information due to IR atomic and molecular signatures. In this work, a Q-switched Nd: YAG laser operating at 1064 nm was employed as the excitation source and focused onto several chlorate and nitrate compounds including KClO3, NaClO3, KNO3, and NaNO3 to produce intense plasma at the target surface. IR LIBS studies on background air, KCl , and NaCl were also included for comparison. All potassium and sodium containing samples revealed narrow-band, atomic-like emissions assigned to transitions of neutral alkali-metal atoms in accordance with the NIST atomic spectra database. In addition, first evidence of broad-band molecular LIBS signatures from chlorate and nitrate compounds were observed at ~10 μm and ~7.3 μm, respectively. The observed molecular emissions showed strong correlation with FTIR absorption spectra of the investigated materials.

Review of methodological and experimental LIBS techniques for coal analysis and their application in power plants in China

NASA Astrophysics Data System (ADS)

Zhao, Yang; Zhang, Lei; Zhao, Shu-Xia; Li, Yu-Fang; Gong, Yao; Dong, Lei; Ma, Wei-Guang; Yin, Wang-Bao; Yao, Shun-Chun; Lu, Ji-Dong; Xiao, Lian-Tuan; Jia, Suo-Tang

2016-12-01

Laser-induced breakdown spectroscopy (LIBS) is an emerging analytical spectroscopy technique. This review presents the main recent developments in China regarding the implementation of LIBS for coal analysis. The paper mainly focuses on the progress of the past few years in the fundamentals, data pretreatment, calibration model, and experimental issues of LIBS and its application to coal analysis. Many important domestic studies focusing on coal quality analysis have been conducted. For example, a proposed novel hybrid quantification model can provide more reproducible quantitative analytical results; the model obtained the average absolute errors (AREs) of 0.42%, 0.05%, 0.07%, and 0.17% for carbon, hydrogen, volatiles, and ash, respectively, and a heat value of 0.07 MJ/kg. Atomic/ionic emission lines and molecular bands, such as CN and C2, have been employed to generate more accurate analysis results, achieving an ARE of 0.26% and a 0.16% limit of detection (LOD) for the prediction of unburned carbon in fly ashes. Both laboratory and on-line LIBS apparatuses have been developed for field application in coal-fired power plants. We consider that both the accuracy and the repeatability of the elemental and proximate analysis of coal have increased significantly and further efforts will be devoted to realizing large-scale commercialization of coal quality analyzer in China.

Dust Removal on Mars Using Laser-Induced Breakdown Spectroscopy

NASA Technical Reports Server (NTRS)

Graff, T. G.; Morris, R. V.; Clegg, S. M.; Wiens, R. C.; Anderson, R. B.

2011-01-01

Dust coatings on the surface of Mars complicate and, if sufficiently thick, mask the spectral characteristics and compositional determination of underlying material from in situ and remote sensing instrumentation. The Laser-Induced Breakdown Spectroscopy (LIBS) portion of the Chemistry & Camera (ChemCam) instrument, aboard the Mars Science Laboratory (MSL) rover, will be the first active remote sensing technique deployed on Mars able to remove dust. ChemCam utilizes a 5 ns pulsed 1067 nm high-powered laser focused to less than 400 m diameter on targets at distances up to 7 m [1,2]. With multiple laser pulses, dust and weathering coatings can be remotely analyzed and potentially removed using this technique [2,3]. A typical LIBS measurement during MSL surface operations is planned to consist of 50 laser pulses at 14 mJ, with the first 5 to 10 pulses used to analyze as well as remove any surface coating. Additionally, ChemCam's Remote Micro-Imager (RMI) is capable of resolving 200 m details at a distance of 2 m, or 1 mm at 10 m [1,4]. In this study, we report on initial laboratory experiments conducted to characterize the removal of dust coatings using similar LIBS parameters as ChemCam under Mars-like conditions. These experiments serve to better understand the removal of surface dust using LIBS and to facilitate the analysis of ChemCam LIBS spectral data and RMI images.

Enhanced Laser-Induced Breakdown Spectroscopy By Second-Pulse Selective Wavelength Excitation

NASA Astrophysics Data System (ADS)

Vidal, F.; Chaker, M.; Goueguel, C.; Laville, S.; Loudyi, H.; Rifai, K.; Sabsabi, M.

2008-09-01

We investigate the use of a second laser with a selected wavelength to improve the limit of detection (LoD) of trace elements in the Laser-Induced Breakdown Spectroscopy (LIBS) technique. We consider the combination of LIBS with Laser-Induced Fluorescence (LIF), in which the second laser is used to excite trace elements in the plasma. The influence of the main experimental parameters on the trace elements LIF signal, namely the ablation fluence, the excitation energy, and the inter-pulse delay, was studied experimentally and a physical interpretation of the results was presented. For illustrative purpose we considered detection of Pb in brass samples and in water. The plasma was produced by a Q-switched Nd:YAG laser and then re-excited by a nanosecond optical parametric oscillator laser. We found out that the optimal conditions for our experimental set-up were obtained for relatively weak ablation fluence of 2-3 J/cm2 and inter-pulse delay of 5-10 μs. Using the LIBS-LIFS technique, a single-shot LoD for detection of lead of about 1.5 part per million (ppm) was obtained for solids and 0.5 ppm for liquids. These LoDs represent an improvement of about two orders of magnitude with respect to LIBS. We also discuss resonance-enhanced LIBS (RELIBS), in which the second laser excites the main plasma component instead of the impurities. For the set of parameters used the RELIBS, Pb signal does not differ significantly from the LIBS signal except at low ablation fluence.

[Effect of Characteristic Variable Extraction on Accuracy of Cu in Navel Orange Peel by LIBS].

PubMed

Li, Wen-bing; Yao, Ming-yin; Huang, Lin; Chen, Tian-bing; Zheng, Jian-hong; Fan, Shi-quan; Liu Mu-hua HE, Mu-hua; Lin, Jin-long; Ouyang, Jing-yi

2015-07-01

Heavy metals pollution in foodstuffs is more and more serious. It is impossible to satisfy the modern agricultural development by conventional chemical analysis. Laser induced breakdown spectroscopy (LIBS) is an emerging technology with the characteristic of rapid and nondestructive detection. But LIBS' s repeatability, sensitivity and accuracy has much room to improve. In this work, heavy metal Cu in Gannan Navel Orange which is the Jiangxi specialty fruit will be predicted by LIBS. Firstly, the navel orange samples were contaminated in our lab. The spectra of samples were collected by irradiating the peel by optimized LIBS parameters. The laser energy was set as 20 mJ, delay time of Spectral Data Gathering was set as 1.2 micros, the integration time of Spectral data gathering was set as 2 ms. The real concentration in samples was obtained by AAS (atom absorption spectroscopy). The characteristic variables Cu I 324.7 and Cu I 327.4 were extracted. And the calibration model was constructed between LIBS spectra and real concentration about Cu. The results show that relative error of the predicted concentrations of three relational model were 7.01% or less, reached a minimum of 0.02%, 0.01% and 0.02% respectively. The average relative errors were 2.33%, 3.10% and 26.3%. Tests showed that different characteristic variables decided different accuracy. It is very important to choose suitable characteristic variable. At the same time, this work is helpful to explore the distribution of heavy metals between pulp and peel.

[Identification of Dendrobium varieties by Fourier transform infrared spectroscopy combined with spectral retrieval].

PubMed

Liu, Fei; Wang, Yuan-zhong; Deng, Xing-yan; Jin, Hang; Yang, Chun-yan

2014-06-01

The infrared spectral of stems of 165 trees of 23 Dendrobium varieties were obtained by means of Fourier transform infrared spectroscopy technique. The spectra show that the spectra of all the samples were similar, and the main components of stem of Dendrobium is cellulose. By the spectral professional software Omnic8.0, three spectral databases were constructed. Lib01 includes of the average spectral of the first four trees of every variety, while Lib02 and Lib03 are constructed from the first-derivative spectra and the second-derivative spectra of average spectra, separately. The correlation search, the square difference retrieval and the square differential difference retrieval of the spectra are performed with the spectral database Lib01 in the specified range of 1 800-500 cm(-1), and the yield correct rate of 92.7%, 74.5% and 92.7%, respectively. The square differential difference retrieval of the first-derivative spectra and the second-derivative spectra is carried out with Lib02 and Lib03 in the same specified range 1 800-500 cm(-1), and shows correct rate of 93.9% for the former and 90.3% for the later. The results show that the first-derivative spectral retrieval of square differential difference algorithm is more suitabe for discerning Dendrobium varieties, and FTIR combining with the spectral retrieval method can identify different varieties of Dendrobium, and the correlation retrieval, the square differential retrieval, the first-derivative spectra and second-derivative spectra retrieval in the specified spectral range are effective and simple way of distinguishing different varieties of Dendrobium.

Interaction of femtosecond laser pulses with plants: towards distinguishing weeds and crops using plasma temperature

NASA Astrophysics Data System (ADS)

Kunz, Jeremy N.; Voronine, Dmitri V.; Ko, Brian A.; Lee, Ho Wai Howard; Rana, Aman; Bagavathiannan, Muthukumar V.; Sokolov, Alexei V.; Scully, Marlan O.

2017-05-01

The ability to distinguish between crops and weeds using sensors from a distance will greatly benefit the farming community through improved and efficient scouting for weeds, reduced herbicide input costs and improved profitability. In the present study, we examined the utility of femtosecond laser-induced breakdown spectroscopy (LIBS) for plant species differentiation. Greenhouse-grown plants of dallisgrass, wheat, soybean and bell pepper were evaluated using LIBS under an ambient environment. LIBS experiments were performed on the leaf samples of different plant species using a femtosecond laser system with an inexpensive lightweight detector. Temperatures of laser-induced plasma in plants depend on many parameters and were determined for each of the study species by the constituent elements interacting with femtosecond laser pulses. Using elemental calcium transitions in plant tissue samples to measure plasma temperatures, we report consistent differences among the four study species, with average values ranging from 5090 ± 168 K (soybean) to 5647 ± 223 K (dallisgrass).

[An automatic peak detection method for LIBS spectrum based on continuous wavelet transform].

PubMed

Chen, Peng-Fei; Tian, Di; Qiao, Shu-Jun; Yang, Guang

2014-07-01

Spectrum peak detection in the laser-induced breakdown spectroscopy (LIBS) is an essential step, but the presence of background and noise seriously disturb the accuracy of peak position. The present paper proposed a method applied to automatic peak detection for LIBS spectrum in order to enhance the ability of overlapping peaks searching and adaptivity. We introduced the ridge peak detection method based on continuous wavelet transform to LIBS, and discussed the choice of the mother wavelet and optimized the scale factor and the shift factor. This method also improved the ridge peak detection method with a correcting ridge method. The experimental results show that compared with other peak detection methods (the direct comparison method, derivative method and ridge peak search method), our method had a significant advantage on the ability to distinguish overlapping peaks and the precision of peak detection, and could be be applied to data processing in LIBS.

Elemental misinterpretation in automated analysis of LIBS spectra.

PubMed

Hübert, Waldemar; Ankerhold, Georg

2011-07-01

In this work, the Stark effect is shown to be mainly responsible for wrong elemental allocation by automated laser-induced breakdown spectroscopy (LIBS) software solutions. Due to broadening and shift of an elemental emission line affected by the Stark effect, its measured spectral position might interfere with the line position of several other elements. The micro-plasma is generated by focusing a frequency-doubled 200 mJ pulsed Nd/YAG laser on an aluminum target and furthermore on a brass sample in air at atmospheric pressure. After laser pulse excitation, we have measured the temporal evolution of the Al(II) ion line at 281.6 nm (4s(1)S-3p(1)P) during the decay of the laser-induced plasma. Depending on laser pulse power, the center of the measured line is red-shifted by 130 pm (490 GHz) with respect to the exact line position. In this case, the well-known spectral line positions of two moderate and strong lines of other elements coincide with the actual shifted position of the Al(II) line. Consequently, a time-resolving software analysis can lead to an elemental misinterpretation. To avoid a wrong interpretation of LIBS spectra in automated analysis software for a given LIBS system, we recommend using larger gate delays incorporating Stark broadening parameters and using a range of tolerance, which is non-symmetric around the measured line center. These suggestions may help to improve time-resolving LIBS software promising a smaller probability of wrong elemental identification and making LIBS more attractive for industrial applications.

Lunar and Planetary Science XXXV: Missions and Instruments: Hopes and Hope Fulfilled

NASA Technical Reports Server (NTRS)

2004-01-01

The titles in this section include: 1) Mars Global Surveyor Mars Orbiter Camera in the Extended Mission: The MOC Toolkit; 2) Mars Odyssey THEMIS-VIS Calibration; 3) Early Science Operations and Results from the ESA Mars Express Mission: Focus on Imaging and Spectral Mapping; 4) The Mars Express/NASA Project at JPL; 5) Beagle 2: Mission to Mars - Current Status; 6) The Beagle 2 Microscope; 7) Mars Environmental Chamber for Dynamic Dust Deposition and Statics Analysis; 8) Locating Targets for CRISM Based on Surface Morphology and Interpretation of THEMIS Data; 9) The Phoenix Mission to Mars; 10) First Studies of Possible Landing Sites for the Phoenix Mars Scout Mission Using the BMST; 11) The 2009 Mars Telecommunications Orbiter; 12) The Aurora Exploration Program - The ExoMars Mission; 13) Electron-induced Luminescence and X-Ray Spectrometer (ELXS) System Development; 14) Remote-Raman and Micro-Raman Studies of Solid CO2, CH4, Gas Hydrates and Ice; 15) The Compact Microimaging Spectrometer (CMIS): A New Tool for In-Situ Planetary Science; 16) Preliminary Results of a New Type of Surface Property Measurement Ideal for a Future Mars Rover Mission; 17) Electrodynamic Dust Shield for Solar Panels on Mars; 18) Sensor Web for Spatio-Temporal Monitoring of a Hydrological Environment; 19) Field Testing of an In-Situ Neutron Spectrometer for Planetary Exploration: First Results; 20) A Miniature Solid-State Spectrometer for Space Applications - Field Tests; 21) Application of Laser Induced Breakdown Spectroscopy (LIBS) to Mars Polar Exploration: LIBS Analysis of Water Ice and Water Ice/Soil Mixtures; 22) LIBS Analysis of Geological Samples at Low Pressures: Application to Mars, the Moon, and Asteroids; 23) In-Situ 1-D and 2-D Mapping of Soil Core and Rock Samples Using the LIBS Long Spark; 24) Rocks Analysis at Stand Off Distance by LIBS in Martian Conditions; 25) Evaluation of a Compact Spectrograph/Detection System for a LIBS Instrument for In-Situ and Stand-Off Detection; 26) Analysis of Organic Compounds in Mars Analog Samples; 27) Report of the Organic Contamination Science Steering Group; 28) The Water-Wheel IR (WIR) - A Contact Survey Experiment for Water and Carbonates on Mars; 29) Mid-IR Fiber Optic Probe for In Situ Water Detection and Characterization; 30) Effects of Subsurface Sampling & Processing on Martian Simulant Containing Varying Quantities of Water; 31) The Subsurface Ice Probe (SIPR): A Low-Power Thermal Probe for the Martian Polar Layered Deposits; 32) Deploying Ground Penetrating Radar in Planetary Analog Sites to Evaluate Potential Instrument Capabilities on Future Mars Missions; 33) Evaluation of Rock Powdering Methods to Obtain Fine-grained Samples for CHEMIN, a Combined XRD/XRF Instrument; 34) Novel Sample-handling Approach for XRD Analysis with Minimal Sample Preparation; 35) A New Celestial Navigation Method for Mars Landers; 36) Mars Mineral Spectroscopy Web Site: A Resource for Remote Planetary Spectroscopy.

Planetary Surface Analysis Using Fast Laser Spectroscopic Techniques: Combined Microscopic Raman, LIBS, and Fluorescence Spectroscopy

NASA Astrophysics Data System (ADS)

Blacksberg, J.; Rossman, G. R.; Maruyama, Y.; Charbon, E.

2011-12-01

In situ exploration of planetary surfaces has to date required multiple techniques that, when used together, yield important information about their formation histories and evolution. We present a time-resolved laser spectroscopic technique that could potentially collect complementary sets of data providing information on mineral structure, composition, and hydration state. Using a picosecond-scale pulsed laser and a fast time-resolved detector we can simultaneously collect spectra from Raman, Laser Induced Breakdown Spectroscopy (LIBS), and fluorescence emissions that are separated in time due to the unique decay times of each process. The use of a laser with high rep rate (40 KHz) and low pulse energy (1 μJ/pulse) allows us to rapidly collect high signal to noise Raman spectra while minimizing sample damage. Increasing the pulse energy by about an order of magnitude creates a microscopic plasma near the surface and enables the collection of LIBS spectra at an unusually high rep rate and low pulse energy. Simultaneously, broader fluorescence peaks can be detected with lifetimes varying from nanosecond to microsecond. We will present Raman, LIBS, and fluorescence spectra obtained on natural mineral samples such as sulfates, clays, pyroxenes and carbonates that are of interest for Mars mineralogy. We demonstrate this technique using a photocathode-based streak camera detector as well as a newly-developed solid state Single Photon Avalanche Diode (SPAD) sensor array based on Complementary Metal-Oxide Semiconductor (CMOS) technology. We will discuss the impact of system design and detector choice on science return of a potential planetary surface mission, with a specific focus on size, weight, power, and complexity. The research described here was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (NASA).

The detection of He in tungsten following ion implantation by laser-induced breakdown spectroscopy

DOE PAGES

Shaw, Guinevere C.; Bannister, Mark E.; Biewer, Theodore M.; ...

2017-09-08

Laser-induced breakdown spectroscopy (LIBS) results are presented that provide depth-resolved identification of He implanted in polycrystalline tungsten (PC-W) targets by a 200 keV He+ ion beam, with a surface temperature of approximately 900 °C and a peak fluence of 10 23 m –2. He retention, and the influence of He on deuterium and tritium recycling, permeation, and retention in PC-W plasma facing components are important questions for the divertor and plasma facing components in a fusion reactor, yet are difficult to quantify. The purpose of this work is to demonstrate the ability of LIBS to identify helium in tungsten; tomore » investigate the sensitivity of laser parameters including, laser energy and gate delay, that directly influence the sensitivity and depth resolution of LIBS; and to perform a proof-of-principle experiment using LIBS to measure relative He intensities as a function of depth. In conclusion, the results presented demonstrate the potential not only to identify helium but also to develop a methodology to quantify gaseous impurity concentration in PC-W as a function of depth.« less

Remote imaging laser-induced breakdown spectroscopy and laser-induced fluorescence spectroscopy using nanosecond pulses from a mobile lidar system.

PubMed

Grönlund, Rasmus; Lundqvist, Mats; Svanberg, Sune

2006-08-01

A mobile lidar system was used in remote imaging laser-induced breakdown spectroscopy (LIBS) and laser-induced fluorescence (LIF) experiments. Also, computer-controlled remote ablation of a chosen area was demonstrated, relevant to cleaning of cultural heritage items. Nanosecond frequency-tripled Nd:YAG laser pulses at 355 nm were employed in experiments with a stand-off distance of 60 meters using pulse energies of up to 170 mJ. By coaxial transmission and common folding of the transmission and reception optical paths using a large computer-controlled mirror, full elemental imaging capability was achieved on composite targets. Different spectral identification algorithms were compared in producing thematic data based on plasma or fluorescence light.

Automated Interpretation of LIBS Spectra using a Fuzzy Logic Inference Engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeremy J. Hatch; Timothy R. McJunkin; Cynthia Hanson

2012-02-01

Automated interpretation of laser-induced breakdown spectroscopy (LIBS) data is necessary due to the plethora of spectra that can be acquired in a relatively short time. However, traditional chemometric and artificial neural network methods that have been employed are not always transparent to a skilled user. A fuzzy logic approach to data interpretation has now been adapted to LIBS spectral interpretation. A fuzzy logic inference engine (FLIE) was used to differentiate between various copper containing and stainless steel alloys as well as unknowns. Results using FLIE indicate a high degree of confidence in spectral assignment.

Spectroscopic analysis of high protein nigella seeds (Kalonji) using laser-induced breakdown spectroscopy and inductively coupled plasma/optical emission spectroscopy

NASA Astrophysics Data System (ADS)

Rehan, Imran; Khan, M. Zubair; Ali, Irfan; Rehan, Kamran; Sultana, Sabiha; Shah, Sher

2018-03-01

The spectroscopic analysis of high protein nigella seeds (also called Kalonji) was performed using pulsed nanosecond laser-induced breakdown spectroscopy (LIBS) at 532 nm. The emission spectrum of Kalonji recorded with an LIBS spectrometer exposed the presence of various elements like Al, B, Ba, Ca, Cr, K, P, Mg, Mn, Na, Ni, S, Si, Cu, Fe, Ti, Sn, Sr, and Zn. The plasma parameters (electron temperature and electron density) were estimated using Ca-I spectral lines and their behavior were studied against laser irradiance. The electron temperature and electron density was observed to show an increasing trend in the range of 5802-7849 K, and (1.2-3.9) × 1017 cm- 3, respectively, in the studied irradiance range of (1.2-12.6) × 109 W/cm2. Furthermore, the effect of varying laser energy on the integrated signal intensities was also studied. The quantitative analysis of the detected elements was performed via the calibration curves drawn for all the observed elements through typical samples made in the known concentration in the Kalonji matrix, and by setting the concentration of P as the calibration. The validity of our LIBS findings was verified via comparison of the results with the concentration of every element find in Kalonji using the standard analytical tool like ICP/OES. The results acquired using LIBS and ICP/OES were found in fine harmony. Moreover, limit of detection was measured for toxic metals only.

Portable, real-time alloy identification of metallic wear debris from machinery lubrication systems: laser-induced breakdown spectroscopy versus x-ray fluorescence

NASA Astrophysics Data System (ADS)

Suresh, Pooja

2014-05-01

Alloy identification of oil-borne wear debris captured on chip detectors, filters and magnetic plugs allows the machinery maintainer to assess the health of the engine or gearbox and identify specific component damage. Today, such identification can be achieved in real time using portable, at-line laser-induced breakdown spectroscopy (LIBS) and Xray fluorescence (XRF) instruments. Both techniques can be utilized in various industries including aviation, marine, railways, heavy diesel and other industrial machinery with, however, some substantial differences in application and instrument performance. In this work, the performances of a LIBS and an XRF instrument are compared based on measurements of a wide range of typical aerospace alloys including steels, titanium, aluminum and nickel alloys. Measurement results were analyzed with a staged correlation technique specifically developed for the purposes of this study - identifying the particle alloy composition using a pre-recorded library of spectral signatures. The analysis is performed in two stages: first, the base element of the alloy is determined by correlation with the stored elemental spectra and then, the alloy is identified by matching the particle's spectral signature using parametric correlation against the stored spectra of all alloys that have the same base element. The correlation analysis has achieved highly repeatable discrimination between alloys of similar composition. Portable LIBS demonstrates higher detection accuracy and better identification of alloys comprising lighter elements as compared to that of the portable XRF system, and reveals a significant reduction in the analysis time over XRF.

The Argon Geochronology Experiment (AGE)

NASA Technical Reports Server (NTRS)

Swindle, T. D.; Bode, R.; Fennema, A.; Chutjian, A.; MacAskill, J. A.; Darrach, M. R.; Clegg, S. M.; Wiens, R. C.; Cremers, D.

2006-01-01

This viewgraph presentation reviews the Argon Geochronology Experiment (AGE). Potassium-Argon dating is shown along with cosmic ray dating exposure. The contents include a flow diagram of the Argon Geochronology Experiment, and schematic diagrams of the mass spectrometer vacuum system, sample manipulation mechanism, mineral heater oven, and the quadrupole ion trap mass spectrometer. The Laser-Induced Breakdown Spectroscopy (LIBS) Operation with elemental abundances is also described.

Normalization of laser-induced breakdown spectroscopy spectra using a plastic optical fiber light collector and acoustic sensor device.

PubMed

Anabitarte, Francisco; Rodríguez-Cobo, Luis; López-Higuera, José-Miguel; Cobo, Adolfo

2012-12-01

To estimate the acoustic plasma energy in laser-induced breakdown spectroscopy (LIBS) experiments, a light collecting and acoustic sensing device based on a coil of plastic optical fiber (POF) is proposed. The speckle perturbation induced by the plasma acoustic energy was monitored using a CCD camera placed at the end of a coil of multimode POF and processed with an intraimage contrast ratio method. The results were successfully verified with the acoustic energy measured by a reference microphone. The proposed device is useful for normalizing LIBS spectra, enabling a better estimation of the sample's chemical composition.

Identification of vapor-phase chemical warfare agent simulants and rocket fuels using laser-induced breakdown spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stearns, Jaime A.; McElman, Sarah E.; Dodd, James A.

2010-05-01

Application of laser-induced breakdown spectroscopy (LIBS) to the identification of security threats is a growing area of research. This work presents LIBS spectra of vapor-phase chemical warfare agent simulants and typical rocket fuels. A large dataset of spectra was acquired using a variety of gas mixtures and background pressures and processed using partial least squares analysis. The five compounds studied were identified with a 99% success rate by the best method. The temporal behavior of the emission lines as a function of chamber pressure and gas mixture was also investigated, revealing some interesting trends that merit further study.

Detection of heavy metal Cd in polluted fresh leafy vegetables by laser-induced breakdown spectroscopy.

PubMed

Yao, Mingyin; Yang, Hui; Huang, Lin; Chen, Tianbing; Rao, Gangfu; Liu, Muhua

2017-05-10

In seeking a novel method with the ability of green analysis in monitoring toxic heavy metals residue in fresh leafy vegetables, laser-induced breakdown spectroscopy (LIBS) was applied to prove its capability in performing this work. The spectra of fresh vegetable samples polluted in the lab were collected by optimized LIBS experimental setup, and the reference concentrations of cadmium (Cd) from samples were obtained by conventional atomic absorption spectroscopy after wet digestion. The direct calibration employing intensity of single Cd line and Cd concentration exposed the weakness of this calibration method. Furthermore, the accuracy of linear calibration can be improved a little by triple Cd lines as characteristic variables, especially after the spectra were pretreated. However, it is not enough in predicting Cd in samples. Therefore, partial least-squares regression (PLSR) was utilized to enhance the robustness of quantitative analysis. The results of the PLSR model showed that the prediction accuracy of the Cd target can meet the requirement of determination in food safety. This investigation presented that LIBS is a promising and emerging method in analyzing toxic compositions in agricultural products, especially combined with suitable chemometrics.

Heavy metal concentrations in soils as determined by laser-induced breakdown spectroscopy (LIBS), with special emphasis on chromium.

PubMed

Senesi, G S; Dell'Aglio, M; Gaudiuso, R; De Giacomo, A; Zaccone, C; De Pascale, O; Miano, T M; Capitelli, M

2009-05-01

Soil is unanimously considered as one of the most important sink of heavy metals released by human activities. Heavy metal analysis of natural and polluted soils is generally conducted by the use of atomic absorption spectroscopy (AAS) or inductively coupled plasma optical emission spectroscopy (ICP-OES) on adequately obtained soil extracts. Although in recent years the emergent technique of laser-induced breakdown spectroscopy (LIBS) has been applied widely and with increasing success for the qualitative and quantitative analyses of a number of heavy metals in soil matrices with relevant simplification of the conventional methodologies, the technique still requires further confirmation before it can be applied fully successfully in soil analyses. The main objective of this work was to demonstrate that new developments in LIBS technique are able to provide reliable qualitative and quantitative analytical evaluation of several heavy metals in soils, with special focus on the element chromium (Cr), and with reference to the concentrations measured by conventional ICP spectroscopy. The preliminary qualitative LIBS analysis of five soil samples and one sewage sludge sample has allowed the detection of a number of elements including Al, Ca, Cr, Cu, Fe, Mg, Mn, Pb, Si, Ti, V and Zn. Of these, a quantitative analysis was also possible for the elements Cr, Cu, Pb, V and Zn based on the obtained linearity of the calibration curves constructed for each heavy metal, i.e., the proportionality between the intensity of the LIBS emission peaks and the concentration of each heavy metal in the sample measured by ICP. In particular, a triplet of emission lines for Cr could be used for its quantitative measurement. The consistency of experiments made on various samples was supported by the same characteristics of the laser-induced plasma (LIP), i.e., the typical linear distribution confirming the existence of local thermodynamic equilibrium (LTE) condition, and similar excitation temperatures and comparable electron number density measured for all samples. An index of the anthropogenic contribution of Cr in polluted soils was calculated in comparison to a non-polluted reference soil. Thus, the intensity ratios of the emission lines of heavy metal can be used to detect in few minutes the polluted areas for which a more detailed sampling and analysis can be useful.

Miniaturized Laser-Induced Breakdown Spectroscopy for the in-situ analysis of the Martian surface: Calibration and quantification

NASA Astrophysics Data System (ADS)

Rauschenbach, I.; Jessberger, E. K.; Pavlov, S. G.; Hübers, H.-W.

2010-08-01

We report on our ongoing studies to develop Laser-Induced Breakdown Spectroscopy (LIBS) for planetary surface missions to Mars and other planets and moons, like Jupiter's moon Europa or the Earth's moon. Since instruments for space missions are severely mass restricted, we are developing a light-weight miniaturized close-up LIBS instrument to be installed on a lander or rover for the in-situ geochemical analysis of planetary surface rocks and coarse fines. The total mass of the instrument will be ≈ 1 kg in flight configuration. Here we report on a systematic performance study of a LIBS instrument equipped with a prototype laser of 216 g total mass and an energy of 1.8 mJ. The LIBS measurements with the prototype laser and the comparative measurements with a regular 40 mJ laboratory laser were both performed under Martian atmospheric conditions. We calibrated 14 major and minor elements by analyzing 18 natural samples of certified composition. The calibration curves define the limits of detection that are > 5 ppm for the lab laser and > 400 ppm for the prototype laser, reflecting the different analyzed sample masses of ≈ 20 µg and ≈ 2 µg, respectively. To test the accuracy we compared the LIBS compositions, determined with both lasers, of Mars analogue rocks with certified or independently measured compositions and found agreements typically within 10-20%. In addition we verified that dust coverage is effectively removed from rock surfaces by the laser blast. Our study clearly demonstrates that a close-up LIBS instrument (spot size ≈ 50 µm) will decisively enhance the scientific output of planetary lander missions by providing a very large number of microscopic elemental analyses.

Laser-induced breakdown spectroscopy (LIBS), part I: review of basic diagnostics and plasma-particle interactions: still-challenging issues within the analytical plasma community.

PubMed

Hahn, David W; Omenetto, Nicoló

2010-12-01

Laser-induced breakdown spectroscopy (LIBS) has become a very popular analytical method in the last decade in view of some of its unique features such as applicability to any type of sample, practically no sample preparation, remote sensing capability, and speed of analysis. The technique has a remarkably wide applicability in many fields, and the number of applications is still growing. From an analytical point of view, the quantitative aspects of LIBS may be considered its Achilles' heel, first due to the complex nature of the laser-sample interaction processes, which depend upon both the laser characteristics and the sample material properties, and second due to the plasma-particle interaction processes, which are space and time dependent. Together, these may cause undesirable matrix effects. Ways of alleviating these problems rely upon the description of the plasma excitation-ionization processes through the use of classical equilibrium relations and therefore on the assumption that the laser-induced plasma is in local thermodynamic equilibrium (LTE). Even in this case, the transient nature of the plasma and its spatial inhomogeneity need to be considered and overcome in order to justify the theoretical assumptions made. This first article focuses on the basic diagnostics aspects and presents a review of the past and recent LIBS literature pertinent to this topic. Previous research on non-laser-based plasma literature, and the resulting knowledge, is also emphasized. The aim is, on one hand, to make the readers aware of such knowledge and on the other hand to trigger the interest of the LIBS community, as well as the larger analytical plasma community, in attempting some diagnostic approaches that have not yet been fully exploited in LIBS.

Correlating laser-induced breakdown spectroscopy with neutron activation analysis to determine the elemental concentration in the ionome of the Populus trichocarpa leaf

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Madhavi Z.; Glasgow, David C.; Tschaplinski, Timothy J.

The black cottonwood poplar (Populus trichocarpa) leaf ionome (inorganic trace elements and mineral nutrients) is an important aspect for determining the physiological and developmental processes contributing to biomass production. A number of techniques are used to measure the ionome, yet characterizing the leaf spatial heterogeneity remains a challenge, especially in solid samples. Laser-induced breakdown spectroscopy (LIBS) has been used to determine the elemental composition of leaves and is able to raster across solid matrixes at 10 μm resolution. Here, we evaluate the use of LIBS for solid sample leaf elemental characterization in relation to neutron activation. In fact, neutron activationmore » analysis is a laboratory-based technique which is used by the National Institute of Standards and Technology (NIST) to certify trace elements in candidate reference materials including plant leaf matrices. Introduction to the techniques used in this research has been presented in this manuscript. Neutron activation analysis (NAA) data has been correlated to the LIBS spectra to achieve quantification of the elements or ions present within poplar leaves. The regression coefficients of calibration and validation using multivariate analysis (MVA) methodology for six out of seven elements have been determined and vary between 0.810 and 0.998. LIBS and NAA data has been presented for the elements such as, calcium, magnesium, manganese, aluminum, copper, and potassium. Chlorine was also detected but it did not show good correlation between the LIBS and NAA techniques. This research shows that LIBS can be used as a fast, high-spatial resolution technique to quantify elements as part of large-scale field phenotyping projects.« less

Correlating laser-induced breakdown spectroscopy with neutron activation analysis to determine the elemental concentration in the ionome of the Populus trichocarpa leaf

NASA Astrophysics Data System (ADS)

Martin, Madhavi Z.; Glasgow, David C.; Tschaplinski, Timothy J.; Tuskan, Gerald A.; Gunter, Lee E.; Engle, Nancy L.; Wymore, Ann M.; Weston, David J.

2017-12-01

The black cottonwood poplar (Populus trichocarpa) leaf ionome (inorganic trace elements and mineral nutrients) is an important aspect for determining the physiological and developmental processes contributing to biomass production. A number of techniques are used to measure the ionome, yet characterizing the leaf spatial heterogeneity remains a challenge, especially in solid samples. Laser-induced breakdown spectroscopy (LIBS) has been used to determine the elemental composition of leaves and is able to raster across solid matrixes at 10 μm resolution. Here, we evaluate the use of LIBS for solid sample leaf elemental characterization in relation to neutron activation. In fact, neutron activation analysis is a laboratory-based technique which is used by the National Institute of Standards and Technology (NIST) to certify trace elements in candidate reference materials including plant leaf matrices. Introduction to the techniques used in this research has been presented in this manuscript. Neutron activation analysis (NAA) data has been correlated to the LIBS spectra to achieve quantification of the elements or ions present within poplar leaves. The regression coefficients of calibration and validation using multivariate analysis (MVA) methodology for six out of seven elements have been determined and vary between 0.810 and 0.998. LIBS and NAA data has been presented for the elements such as, calcium, magnesium, manganese, aluminum, copper, and potassium. Chlorine was also detected but it did not show good correlation between the LIBS and NAA techniques. This research shows that LIBS can be used as a fast, high-spatial resolution technique to quantify elements as part of large-scale field phenotyping projects.

Correlating laser-induced breakdown spectroscopy with neutron activation analysis to determine the elemental concentration in the ionome of the Populus trichocarpa leaf

DOE PAGES

Martin, Madhavi Z.; Glasgow, David C.; Tschaplinski, Timothy J.; ...

2017-10-17

The black cottonwood poplar (Populus trichocarpa) leaf ionome (inorganic trace elements and mineral nutrients) is an important aspect for determining the physiological and developmental processes contributing to biomass production. A number of techniques are used to measure the ionome, yet characterizing the leaf spatial heterogeneity remains a challenge, especially in solid samples. Laser-induced breakdown spectroscopy (LIBS) has been used to determine the elemental composition of leaves and is able to raster across solid matrixes at 10 μm resolution. Here, we evaluate the use of LIBS for solid sample leaf elemental characterization in relation to neutron activation. In fact, neutron activationmore » analysis is a laboratory-based technique which is used by the National Institute of Standards and Technology (NIST) to certify trace elements in candidate reference materials including plant leaf matrices. Introduction to the techniques used in this research has been presented in this manuscript. Neutron activation analysis (NAA) data has been correlated to the LIBS spectra to achieve quantification of the elements or ions present within poplar leaves. The regression coefficients of calibration and validation using multivariate analysis (MVA) methodology for six out of seven elements have been determined and vary between 0.810 and 0.998. LIBS and NAA data has been presented for the elements such as, calcium, magnesium, manganese, aluminum, copper, and potassium. Chlorine was also detected but it did not show good correlation between the LIBS and NAA techniques. This research shows that LIBS can be used as a fast, high-spatial resolution technique to quantify elements as part of large-scale field phenotyping projects.« less

Laser-induced breakdown spectroscopy (LIBS) to measure quantitatively soil carbon with emphasis on soil organic carbon. A review.

PubMed

Senesi, Giorgio S; Senesi, Nicola

2016-09-28

Soil organic carbon (OC) measurement is a crucial factor for quantifying soil C pools and inventories and monitoring the inherent temporal and spatial heterogeneity and changes of soil OC content. These are relevant issues in addressing sustainable management of terrestrial OC aiming to enhance C sequestration in soil, thus mitigating the impact of increasing CO2 concentration in the atmosphere and related effects on global climate change. Nowadays, dry combustion by an elemental analyzer or wet combustion by dichromate oxidation of the soil sample are the most recommended and commonly used methods for quantitative soil OC determination. However, the unanimously recognized uncertainties and limitations of these classical laboursome methods have prompted research efforts focusing on the development and application of more advanced and appealing techniques and methods for the measurement of soil OC in the laboratory and possibly in situ in the field. Among these laser-induced breakdown spectroscopy (LIBS) has raised the highest interest for its unique advantages. After an introduction and a highlight of the LIBS basic principles, instrumentation, methodologies and supporting chemometric methods, the main body of this review provides an historical and critical overview of the developments and results obtained up-to-now by the application of LIBS to the quantitative measurement of soil C and especially OC content. A brief critical summary of LIBS advantages and limitations/drawbacks including some final remarks and future perspectives concludes this review. Copyright © 2016 Elsevier B.V. All rights reserved.

Determination of a brass alloy concentration composition using calibration-free laser-induced breakdown spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Achouri, M.; Baba-Hamed, T.; Beldjilali, S. A., E-mail: sidahmed.beldjilali@univ-usto.dz

2015-09-15

Laser-induced breakdown spectroscopy (LIBS) is a technique that can provide qualitative and quantitative measurements of the characteristics of irradiated metals. In the present work, we have calculated the parameters of the plasma produced from a brass alloy sample under the action of a pulsed Nd: YAG laser operating at 1064 nm. The emission lines of copper atoms (Cu I), zinc atoms (Zn I), and lead atoms (Pb I), which are elements of a brass alloy composition, were used to investigate the parameters of the brass plasma. The spectral profiles of Cu, Zn, and Pb lines have been used to extractmore » the electron temperature and density of the brass alloy plasma. The characteristics of Cu, Zn, and Pb were determined quantatively by the calibration-free LIBS (CF-LIBS) method considering for accurate analysis that the laser-induced ablated plasma is optically thin in local thermodynamic equilibrium conditions and the plasma ablation is stoichiometric. The Boltzmann plot method was used to evaluate the plasma temperature, and the Stark broadened profiles were used to determine the electron density. An algorithm based on the experimentally measured values of the intensity of spectral lines and the basic laws of plasma physics was developed for the determination of Cu, Zn, and Pb concentrations in the brass sample. The concentrations C{sub CF-LIBS} calculated by CF-LIBS and the certified concentrations C{sub certified} were very close.« less

Detection of hazardous pollutants in chrome-tanned leather using locally developed laser-induced breakdown spectrometer.

PubMed

Nasr, M M; Gondal, Mohammed Asharf; Seddigi, Z S

2011-04-01

Highly toxic contaminants like Cr, As, and Pb were detected in chrome-tanning process of animal skin to produce leather by applying locally developed laser-induced breakdown spectrometer. An Nd-YAG laser with 1,064 nm wavelength was focused on the surface of leather samples (natural and manufactured) to generate a plasma spark and spectrally resolved spectra were used for identification and quantification of contaminants. The leather samples were collected from a tannery located in industrial cities of Riyadh and Jeddah, Saudi Arabia. The study was carried out on fully, half manufactured (wet blue leather), and natural hide (skin). To the best of our knowledge, this is the first attempt where laser-induced breakdown spectroscopy (LIBS) technique has been applied for the analysis of leather before and after tanning process. The maximum concentration of different elements of environmental significance like chromium, lead, arsenic, sulfur, magnesium were 199, 289, 31, 38, and 39 ppm, respectively, in one of the manufactured leather samples. The limit of detection (LOD) of our LIBS system for chromium, lead, arsenic, sulfur, and magnesium were 2, 3, 1.5,7, and 3 ppm, respectively. The safe permissible limit for tanned leather for highly toxic elements like chromium, lead, and arsenic are 1, 0.5, 0.01 ppm, respectively, as prescribed in Environmental Regulation Standards for Saudi Industries set by Royal Commission Jubail, Saudi Arabia. The LIBS technique is superior to other conventional techniques like ICP or atomic absorption that a little or no sample preparation is required, no chemicals are needed, multi-elemental analysis is possible for all kinds of samples (natural and anthropogenic materials), microgram of sample is essential, and LIBS could be applied for remote analysis. It is highly selective and sensitivity higher than ICP, and as no sample and chemicals are required, it is cost effective for multi-sample analysis per unit time as compared with other conventional techniques. The concentration of some toxic elements (Cr, Pb, As) is much higher than the safe permissible limits set by Occupational Safety and Health Administration in USA or Saudi environmental regulatory agencies. Results obtained with our LIBS systems were in close agreement with the results obtained using other standard analytical technique such as the inductively coupled plasma atomic emission spectroscopy.

On the improvement of signal repeatability in laser-induced air plasmas

NASA Astrophysics Data System (ADS)

Zhang, Shuai; Sheta, Sahar; Hou, Zong-Yu; Wang, Zhe

2018-04-01

The relatively low repeatability of laser-induced breakdown spectroscopy (LIBS) severely hinders its wide commercialization. In the present work, we investigate the optimization of LIBS system for repeatability improvement for both signal generation (plasma evolution) and signal collection. Timeintegrated spectra and images were obtained under different laser energies and focal lengths to investigate the optimum configuration for stable plasmas and repeatable signals. Using our experimental setup, the optimum conditions were found to be a laser energy of 250 mJ and a focus length of 100 mm. A stable and homogeneous plasma with the largest hot core area in the optimum condition yielded the most stable LIBS signal. Time-resolved images showed that the rebounding processes through the air plasma evolution caused the relative standard deviation (RSD) to increase with laser energies of > 250 mJ. In addition, the emission collection was improved by using a concave spherical mirror. The line intensities doubled as their RSDs decreased by approximately 25%. When the signal generation and collection were optimized simultaneously, the pulse-to-pulse RSDs were reduced to approximately 3% for O(I), N(I), and H(I) lines, which are better than the RSDs reported for solid samples and showed great potential for LIBS quantitative analysis by gasifying the solid or liquid samples.

Planetary Surface Exploration Using Time-Resolved Laser Spectroscopy on Rovers and Landers

NASA Astrophysics Data System (ADS)

Blacksberg, Jordana; Alerstam, Erik; Maruyama, Yuki; Charbon, Edoardo; Rossman, George

2013-04-01

Planetary surface exploration using laser spectroscopy has become increasingly relevant as these techniques become a reality on Mars surface missions. The ChemCam instrument onboard the Curiosity rover is currently using laser induced breakdown spectroscopy (LIBS) on a mast-mounted platform to measure elemental composition of target rocks. The RLS Raman Spectrometer is included on the payload for the ExoMars mission to be launched in 2018 and will identify minerals and organics on the Martian surface. We present a next-generation instrument that builds on these widely used techniques to provide a means for performing both Raman spectroscopy and LIBS in conjunction with microscopic imaging. Microscopic Raman spectroscopy with a laser spot size smaller than the grains of interest can provide surface mapping of mineralogy while preserving morphology. A very small laser spot size (~ 1 µm) is often necessary to identify minor phases that are often of greater interest than the matrix phases. In addition to the difficulties that can be posed by fine-grained material, fluorescence interference from the very same material is often problematic. This is particularly true for many of the minerals of interest that form in environments of aqueous alteration and can be highly fluorescent. We use time-resolved laser spectroscopy to eliminate fluorescence interference that can often make it difficult or impossible to obtain Raman spectra. As an added benefit, we have found that with small changes in operating parameters we can include microscopic LIBS using the same hardware. This new technique relies on sub-ns, high rep-rate lasers with relatively low pulse energy and compact solid state detectors with sub-ns time resolution. The detector technology that makes this instrument possible is a newly developed Single-Photon Avalanche Diode (SPAD) sensor array based on Complementary Metal-Oxide Semiconductor (CMOS) technology. The use of this solid state time-resolved detector offers a significant reduction in size, weight, power, and overall complexity - making time resolved detection feasible for planetary applications. We will discuss significant advances leading to the feasibility of a compact time-resolved spectrometer. We will present results on planetary analog minerals to demonstrate the instrument performance including fluorescence rejection and combined Raman-LIBS capability.

Sensitive and selective spectrochemical analysis of metallic samples: the combination of laser-induced breakdown spectroscopy and laser-induced fluorescence spectroscopy

NASA Astrophysics Data System (ADS)

Telle, H. H.; Beddows, D. C. S.; Morris, G. W.; Samek, O.

2001-06-01

In order to improve on analytical selectivity and sensitivity, the technique of laser-induced fluorescence spectroscopy (LIFS) was combined with laser-induced breakdown spectroscopy (LIBS). The main thrust of this investigation was to address analytical scenarios in which the measurement site may be difficult to access. Hence, a remote LIBS+LIFS arrangement was set up, and the experiments were carried out on samples surrounded by air at atmospheric pressure, rather than in a controlled buffer gas environment at reduced pressure. Representative for proof of principle, the detection of aluminium, chromium, iron and silicon at trace level concentrations was pursued. These elements are of importance in numerous chemical, medical and industrial applications, and they exhibit suitable resonance transitions, accessible by radiation from a pulsed Ti:sapphire laser system (its 2nd and 3rd harmonic outputs). All investigated elements have an energy level structure in which the laser-excited level is a member of a group of closely-spaced energy levels; thus, this allowed for easy off-resonant fluorescence detection (collisional energy transfer processes). Since numerous of the relevant transition wavelengths are within a narrow spectral interval, this opens the possibility for multi-element analysis; this was demonstrated here for Cr and Fe which were accessed by rapidly changing the tuneable laser wavelength.

On the elemental analysis of different cigarette brands using laser induced breakdown spectroscopy and laser-ablation time of flight mass spectrometry

NASA Astrophysics Data System (ADS)

Ahmed, Nasar; Umar, Zeshan A.; Ahmed, Rizwan; Aslam Baig, M.

2017-10-01

We present qualitative and quantitative analysis of the trace elements present in different brands of tobacco available in Pakistan using laser induced breakdown spectroscopy (LIBS) and Laser ablation Time of Flight Mass Spectrometer (LA-TOFMS). The compositional analysis using the calibration free LIBS technique is based on the observed emission spectra of the laser produced plasma plume whereas the elemental composition analysis using LA-TOFMS is based on the mass spectra of the ions produced by laser ablation. The optical emission spectra of these samples contain spectral lines of calcium, magnesium, sodium, potassium, silicon, strontium, barium, lithium and aluminum with varying intensities. The corresponding mass spectra of the elements were detected in LA-TOF-MS with their composition concentration. The analysis of different brands of cigarettes demonstrates that LIBS coupled with a LA-TOF-MS is a powerful technique for the elemental analysis of the trace elements in any solid sample.

Standoff Detection of Geological Samples of Metal, Rock, and Soil at Low Pressures Using Laser-Induced Breakdown Spectroscopy.

PubMed

Choi, Jae-Jun; Choi, Soo-Jin; Yoh, Jack J

2016-09-01

Categorized certified reference materials simulating metal, rock, soils, or dusts are used to demonstrate the standoff detection capability of laser-induced breakdown spectroscopy (LIBS) at severely low pressure conditions. A Q-switched Nd:YAG laser operating at 1064 nm with 17.2-50 mJ energy per pulse was used to obtain sample signals from a distance of 5.5 m; the detection sensitivity at pressures down to 0.01 torr was also analyzed. The signal intensity response to pressure changes is explained by the ionization energy and electronegativity of elements, and from the estimated full width half-maximum (FWHM) and electron density, the decrease in both background noise and line broadening makes it suitable for low pressure detection using the current standoff LIBS configuration. The univariate analyses further showed high correlation coefficients for geological samples. Therefore, the present work has extended the current state-of-the-art of standoff LIBS aimed at harsh environment detection. © The Author(s) 2016.

Analysis of waste electrical and electronic equipment (WEEE) using laser induced breakdown spectroscopy (LIBS) and multivariate analysis.

PubMed

Ángel Aguirre, Miguel; Hidalgo, Montserrat; Canals, Antonio; Nóbrega, Joaquim A; Pereira-Filho, Edenir R

2013-12-15

This study shows the application of laser induced breakdown spectroscopy (LIBS) for waste electrical and electronic equipment (WEEE) investigation. Several emission spectra were obtained for 7 different mobiles from 4 different manufacturers. Using the emission spectra of the black components it was possible to see some differences among the manufacturers and some emission lines from organic elements and molecules (N, O, CN and C2) led to the highest contribution for this differentiation. Some polymeric internal parts in contact with the inner pieces of the mobiles and covered with a special paint presented a strong emission signal for Cr. The white pieces presented mainly Al, Ba and Ti in their composition. Finally, this study developed a procedure for LIBS emission spectra using chemometric strategies and suitable information can be obtained for identification of manufacturer and counterfeit products. In addition, the results obtained can improve the classification for establishing recycling strategies of e-waste. © 2013 Elsevier B.V. All rights reserved.

Analysis of bakery products by laser-induced breakdown spectroscopy.

PubMed

Bilge, Gonca; Boyacı, İsmail Hakkı; Eseller, Kemal Efe; Tamer, Uğur; Çakır, Serhat

2015-08-15

In this study, we focused on the detection of Na in bakery products by using laser-induced breakdown spectroscopy (LIBS) as a quick and simple method. LIBS experiments were performed to examine the Na at 589 nm to quantify NaCl. A series of standard bread sample pellets containing various concentrations of NaCl (0.025-3.5%) were used to construct the calibration curves and to determine the detection limits of the measurements. Calibration graphs were drawn to indicate functions of NaCl and Na concentrations, which showed good linearity in the range of 0.025-3.5% NaCl and 0.01-1.4% Na concentrations with correlation coefficients (R(2)) values greater than 0.98 and 0.96. The obtained detection limits for NaCl and Na were 175 and 69 ppm, respectively. Performed experimental studies showed that LIBS is a convenient method for commercial bakery products to quantify NaCl concentrations as a rapid and in situ technique. Copyright © 2015 Elsevier Ltd. All rights reserved.

Development of a compact vertical-cavity surface-emitting laser end-pumped actively Q-switched laser for laser-induced breakdown spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Shuo; Chen, Rongzhang; Nelsen, Bryan

2016-03-15

This paper reports the development of a compact and portable actively Q-switched Nd:YAG laser and its applications in laser-induced breakdown spectroscopy (LIBS). The laser was end-pumped by a vertical-cavity surface-emitting laser (VCSEL). The cavity lases at a wavelength of 1064 nm and produced pulses of 16 ns with a maximum pulse energy of 12.9 mJ. The laser exhibits a reliable performance in terms of pulse-to-pulse stability and timing jitter. The LIBS experiments were carried out using this laser on NIST standard alloy samples. Shot-to-shot LIBS signal stability, crater profile, time evolution of emission spectra, plasma electron density and temperature, andmore » limits of detection were studied and reported in this paper. The test results demonstrate that the VCSEL-pumped solid-state laser is an effective and compact laser tool for laser remote sensing applications.« less

Analysis of water ice and water ice/soil mixtures using laser-induced breakdown spectroscopy: application to Mars polar exploration.

PubMed

Arp, Zane A; Cremers, David A; Wiens, Roger C; Wayne, David M; Sallé, Béatrice; Maurice, Sylvestre

2004-08-01

Recently, laser-induced breakdown spectroscopy (LIBS) has been developed for the elemental analysis of geological samples for application to space exploration. There is also interest in using the technique for the analysis of water ice and ice/dust mixtures located at the Mars polar regions. The application is a compact instrument for a lander or rover to the Martian poles to interrogate stratified layers of ice and dusts that contain a record of past geologic history, believed to date back several million years. Here we present results of a study of the use of LIBS for the analysis of water ice and ice/dust mixtures in situ and at short stand-off distances (< 6.5 m) using experimental parameters appropriate for a compact instrument. Characteristics of LIBS spectra of water ice, ice/soil mixtures, element detection limits, and the ability to ablate through ice samples to monitor subsurface dust deposits are discussed.

Evaluation of a commercially available passively Q-switched Nd:YAG laser with LiF: F2- saturable absorber for laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Carson, Cantwell G.; Goueguel, Christian L.; Sanghapi, Hervé; Jain, Jinesh; McIntyre, Dustin

2016-05-01

Interest in passively Q-switched microchip lasers as a means for miniaturization of laser-induced breakdown spectroscopy (LIBS) apparatus has rapidly grown in the last years. To explore the possibility of using a comparatively UV-vis transparent absorber, we herein present the first report on the evaluation of a commercially available flash lamp-pumped passively Q-switched Nd:YAG laser with LiF: F2- saturable absorber as an excitation source in LIBS. Quantitative measurements of barium, strontium, rubidium and lithium in granite, rhyolite, basalt and syenite whole-rock glass samples were performed. Using a gated intensified benchtop spectrometer, limits of detection of 0.97, 23, 37, and 144 ppm were obtained for Li, Sr, Rb, and Ba, respectively. Finally, we discuss the advantages of using such a laser unit for LIBS applications in terms of ablation efficiency, analytical performances, output energy, and standoff capabilities.

An assessment of the potential of laser-induced breakdown spectroscopy (LIBS) for the analysis of cesium in liquid samples of biological origin.

PubMed

Metzinger, Anikó; Kovács-Széles, Eva; Almási, István; Galbács, Gábor

2014-01-01

The present study describes the development of an analytical method for the determination of cesium in biological fluid samples (human urine and blood samples) by laser-induced breakdown spectroscopy (LIBS). The developed method is based on sample presentation by liquid-to-solid conversion, enhancing the emission signal by drying the liquid into small "pockets" created in a metal support (zinc plate), and allows the analysis to be carried out on as little as 1 μL of sample volume, in a closed sample cell. Absolute detection limits on the Cs I 852.1 nm spectral line were calculated by the IUPAC 3σ method to be 6 ng in the urine sample and 27 ng in the blood serum sample. It is estimated that LIBS may be used to detect highly elevated concentration levels of Cs in fluid samples taken from people potentially exposed to surges of Cs from non-natural sources.

Laser-Induced Breakdown Spectroscopy (LIBS) for the Measurement of Spatial Structures and Fuel Distribution in Flames.

PubMed

Kotzagianni, Maria; Kakkava, Eirini; Couris, Stelios

2016-04-01

Laser-induced breakdown spectroscopy (LIBS) is used for the mapping of local structures (i.e., reactants and products zones) and for the determination of fuel distribution by means of the local equivalence ratio ϕ in laminar, premixed air-hydrocarbon flames. The determination of laser threshold energy to induce breakdown in the different zones of flames is employed for the identification and demarcation of the local structures of a premixed laminar flame, while complementary results about fuel concentration were obtained from measurements of the cyanogen (CN) band Β(2)Σ(+)--Χ(2)Σ(+), (Δυ = 0) at 388.3 nm and the ratio of the atomic lines of hydrogen (Hα) and oxygen (O(I)), Hα/O. The combination of these LIBS-based methods provides a relatively simple to use, rapid, and accurate tool for online and in situ combustion diagnostics, providing valuable information about the fuel distribution and the spatial variations of the local structures of a flame. © The Author(s) 2016.

Comparison of SP-LIBS and DP-LIBS on metal and non-metal testing based on LIBS

NASA Astrophysics Data System (ADS)

Lin, Xiaomei; Sun, Haoran; Lin, Jingjun

2017-10-01

Laser-induced breakdown spectroscopy (LIBS) technology for metal and nonmetallic detection accuracy is the key technology to be solved in LIBS measurement, Due to metal elements and non-metallic elements in the lively, atomic structure and the degree of excitation of the laser are totally different, so the laser induced plasma evolution and spectral intensity are absolutely different. Among the many factors that affect measurement accuracy, the single and double pulse of the laser has a great influence on the measurement accuracy of metal and non-metal, they both have their own advantages, but also have their own shortcomings. In order to compare the effect of SP-LIBS and DP-LIBS on the measurement results of different elements, in this experiment, we put the metal element aluminum and non-metallic element carbon as the sample, the laser energy as a variable, using the high-speed camera shooting SP- LIBS and DP- LIBS plasma images. Using the spectral analyzer to record the spectral intensity of the elements, by calculating the relative RSD of the signal intensity and comparing the spectral intensity and the signal stability for different elements, develop an optimized experimental program. The experimental results show that under the same energy condition, the metal aluminum ion image under the DP- LIBS and the non-metallic carbon ion image under the SP- LIBS are the most suitable images. By considering the stability of the line intensity and the signal stability, we find that the sensitivity and stability of the signal strength of the metal elements under the double pulse are better than that of the single pulse, and for the non-metallic element, the single pulse laser is better than the double pulse.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Bo-Young; Choi, Daewoong; Park, Se Hwan

Korea Atomic Energy Research Institute (KAERI) have been developing the design and deployment methodology of Laser- Induced Breakdown Spectroscopy (LIBS) instrument for safeguards application within the argon hot cell environment at Advanced spent fuel Conditioning Process Facility (ACPF), where ACPF is a facility being refurbished for the laboratory-scaled demonstration of advanced spent fuel conditioning process. LIBS is an analysis technology used to measure the emission spectra of excited elements in the local plasma of a target material induced by a laser. The spectra measured by LIBS are analyzed to verify the quality and quantity of the specific element in themore » target matrix. Recently LIBS has been recognized as a promising technology for safeguards purposes in terms of several advantages including a simple sample preparation and in-situ analysis capability. In particular, a feasibility study of LIBS to remotely monitor the nuclear material in a high radiation environment has been carried out for supporting the IAEA safeguards implementation. Fiber-Optic LIBS (FO-LIBS) deployment was proposed by Applied Photonics Ltd because the use of fiber optics had benefited applications of LIBS by delivering the laser energy to the target and by collecting the plasma light. The design of FO-LIBS instrument for the measurement of actinides in the spent fuel and high temperature molten salt at ACPF had been developed in cooperation with Applied Photonics Ltd. FO-LIBS has some advantages as followings: the detectable plasma light wavelength range is not limited by the optical properties of the thick lead-glass shield window and the potential risk of laser damage to the lead-glass shield window is not considered. The remote LIBS instrument had been installed at ACPF and then the feasibility study for monitoring actinide elements such as uranium, plutonium, and curium in process materials has been carried out. (authors)« less

Effect of self-absorption correction on surface hardness estimation of Fe-Cr-Ni alloys via LIBS.

PubMed

Ramezanian, Zahra; Darbani, Seyyed Mohammad Reza; Majd, Abdollah Eslami

2017-08-20

The effect of self-absorption was investigated on the estimation of surface hardness of Fe-Cr-Ni metallic alloys by the laser-induced breakdown spectroscopy (LIBS) technique. For this purpose, the linear relationship between the ratio of chromium ionic to atomic line intensities (CrII/CrI) and surface hardness was studied, both before and after correcting the self-absorption effect. The correlation coefficient significantly increased from 47% to 90% after self-absorption correction. The results showed the measurements of surface hardness using LIBS can be more accurate and valid by correcting the self-absorption effect.

A membrane basis for bacterial identification and discrimination using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Rehse, Steven J.; Jeyasingham, Narmatha; Diedrich, Jonathan; Palchaudhuri, Sunil

2009-05-01

Nanosecond single-pulse laser-induced breakdown spectroscopy (LIBS) has been used to discriminate between two different genera of Gram-negative bacteria and between several strains of the Escherichia coli bacterium based on the relative concentration of trace inorganic elements in the bacteria. Of particular importance in all such studies to date has been the role of divalent cations, specifically Ca2+ and Mg2+, which are present in the membranes of Gram-negative bacteria and act to aggregate the highly polar lipopolysaccharide molecules. We have demonstrated that the source of emission from Ca and Mg atoms observed in LIBS plasmas from bacteria is at least partially located at the outer membrane by intentionally altering membrane biochemistry and correlating these changes with the observed changes in the LIBS spectra. The definitive assignment of some fraction of the LIBS emission to the outer membrane composition establishes a potential serological, or surface-antigen, basis for the laser-based identification. E. coli and Pseudomonas aeruginosa were cultured in three nutrient media: trypticase soy agar as a control, a MacConkey agar with a 0.01% concentration of bile salts including sodium deoxycholate, and a trypticase soy agar with a 0.4% deoxycholate concentration. The higher concentration of deoxycholate is known to disrupt bacterial outer membrane integrity and was expected to induce changes in the observed LIBS spectra. Altered LIBS emission was observed for bacteria cultured in this 0.4% medium and laser ablated in an all-argon environment. These spectra evidenced a reduced calcium emission and in the case of one species, a reduced magnesium emission. Culturing on the lower (0.01%) concentration of bile salts altered the LIBS spectra for both the P. aeruginosa and two strains of E. coli in a highly reproducible way, although not nearly as significantly as culturing in the higher concentration of deoxycholate did. This was possibly due to the accumulation of divalent cations around the bacteria by the formation of an extracellular polysaccharide capsule. Lastly, a discriminant function analysis demonstrated that in spite of alterations in the LIBS spectrum induced by growth in the three different media, the analysis could correctly identify all samples better than 90% of the time. This encouraging result illustrates the potential utility of LIBS as a rapid bacteriological identification technology.

[Research on fast classification based on LIBS technology and principle component analyses].

PubMed

Yu, Qi; Ma, Xiao-Hong; Wang, Rui; Zhao, Hua-Feng

2014-11-01

Laser-induced breakdown spectroscopy (LIBS) and the principle component analysis (PCA) were combined to study aluminum alloy classification in the present article. Classification experiments were done on thirteen different kinds of standard samples of aluminum alloy which belong to 4 different types, and the results suggested that the LIBS-PCA method can be used to aluminum alloy fast classification. PCA was used to analyze the spectrum data from LIBS experiments, three principle components were figured out that contribute the most, the principle component scores of the spectrums were calculated, and the scores of the spectrums data in three-dimensional coordinates were plotted. It was found that the spectrum sample points show clear convergence phenomenon according to the type of aluminum alloy they belong to. This result ensured the three principle components and the preliminary aluminum alloy type zoning. In order to verify its accuracy, 20 different aluminum alloy samples were used to do the same experiments to verify the aluminum alloy type zoning. The experimental result showed that the spectrum sample points all located in their corresponding area of the aluminum alloy type, and this proved the correctness of the earlier aluminum alloy standard sample type zoning method. Based on this, the identification of unknown type of aluminum alloy can be done. All the experimental results showed that the accuracy of principle component analyses method based on laser-induced breakdown spectroscopy is more than 97.14%, and it can classify the different type effectively. Compared to commonly used chemical methods, laser-induced breakdown spectroscopy can do the detection of the sample in situ and fast with little sample preparation, therefore, using the method of the combination of LIBS and PCA in the areas such as quality testing and on-line industrial controlling can save a lot of time and cost, and improve the efficiency of detection greatly.

Analysis of Rare Earth Elements in Uranium Using Handheld Laser-Induced Breakdown Spectroscopy (HH LIBS)

DOE PAGES

Manard, Benjamin T.; Wylie, E. Miller; Willson, Stephen P.

2018-05-22

In this paper, a portable handheld laser-induced breakdown spectroscopy (HH LIBS) instrument was evaluated as a rapid method to qualitatively analyze rare earth elements in a uranium oxide matrix. This research is motivated by the need for development of a method to perform rapid, at-line chemical analysis in a nuclear facility, particularly to provide a rapid first pass analysis to determine if additional actions or measurements are warranted. This will result in the minimization of handling and transport of radiological and nuclear material and subsequent exposure to their associated hazards. In this work, rare earth elements (Eu, Nd, and Yb)more » were quantitatively spiked into a uranium oxide powder and analyzed by the HH LIBS instrumentation. This method demonstrates the ability to rapidly identify elemental constituents in sub-percent levels in a uranium matrix. Preliminary limits of detection (LODs) were determined with values on the order of hundredths of a percent. Validity of this methodology was explored by employing a National Institute of Standards and Technology (NIST) standard reference materials (SRM) 610 and 612 (Trace Elements in Glass). Finally, it was determined that the HH LIBS method was able to clearly discern the rare earths elements of interest in the glass or uranium matrices.« less

Analysis of Rare Earth Elements in Uranium Using Handheld Laser-Induced Breakdown Spectroscopy (HH LIBS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manard, Benjamin T.; Wylie, E. Miller; Willson, Stephen P.

In this paper, a portable handheld laser-induced breakdown spectroscopy (HH LIBS) instrument was evaluated as a rapid method to qualitatively analyze rare earth elements in a uranium oxide matrix. This research is motivated by the need for development of a method to perform rapid, at-line chemical analysis in a nuclear facility, particularly to provide a rapid first pass analysis to determine if additional actions or measurements are warranted. This will result in the minimization of handling and transport of radiological and nuclear material and subsequent exposure to their associated hazards. In this work, rare earth elements (Eu, Nd, and Yb)more » were quantitatively spiked into a uranium oxide powder and analyzed by the HH LIBS instrumentation. This method demonstrates the ability to rapidly identify elemental constituents in sub-percent levels in a uranium matrix. Preliminary limits of detection (LODs) were determined with values on the order of hundredths of a percent. Validity of this methodology was explored by employing a National Institute of Standards and Technology (NIST) standard reference materials (SRM) 610 and 612 (Trace Elements in Glass). Finally, it was determined that the HH LIBS method was able to clearly discern the rare earths elements of interest in the glass or uranium matrices.« less

Analysis of Rare Earth Elements in Uranium Using Handheld Laser-Induced Breakdown Spectroscopy (HH LIBS).

PubMed

Manard, Benjamin T; Wylie, E Miller; Willson, Stephen P

2018-01-01

A portable handheld laser-induced breakdown spectroscopy (HH LIBS) instrument was evaluated as a rapid method to qualitatively analyze rare earth elements in a uranium oxide matrix. This research is motivated by the need for development of a method to perform rapid, at-line chemical analysis in a nuclear facility, particularly to provide a rapid first pass analysis to determine if additional actions or measurements are warranted. This will result in the minimization of handling and transport of radiological and nuclear material and subsequent exposure to their associated hazards. In this work, rare earth elements (Eu, Nd, and Yb) were quantitatively spiked into a uranium oxide powder and analyzed by the HH LIBS instrumentation. This method demonstrates the ability to rapidly identify elemental constituents in sub-percent levels in a uranium matrix. Preliminary limits of detection (LODs) were determined with values on the order of hundredths of a percent. Validity of this methodology was explored by employing a National Institute of Standards and Technology (NIST) standard reference materials (SRM) 610 and 612 (Trace Elements in Glass). It was determined that the HH LIBS method was able to clearly discern the rare earths elements of interest in the glass or uranium matrices.

Analysis of characteristics of Si in blast furnace pig iron and calibration methods in the detection by laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Mei, Yaguang; Cheng, Yuxin; Cheng, Shusen; Hao, Zhongqi; Guo, Lianbo; Li, Xiangyou; Zeng, Xiaoyan

2017-10-01

During the iron-making process in blast furnace, the Si content in liquid pig iron was usually used to evaluate the quality of liquid iron and thermal state of blast furnace. None effective method was found for rapid detecting the Si concentration of liquid iron. Laser-induced breakdown spectroscopy (LIBS) is a kind of atomic emission spectrometry technology based on laser ablation. Its obvious advantage is realizing rapid, in-situ, online analysis of element concentration in open air without sample pretreatment. The characteristics of Si in liquid iron were analyzed from the aspect of thermodynamic theory and metallurgical technology. The relationship between Si and C, Mn, S, P or other alloy elements were revealed based on thermodynamic calculation. Subsequently, LIBS was applied on rapid detection of Si of pig iron in this work. During LIBS detection process, several groups of standard pig iron samples were employed in this work to calibrate the Si content in pig iron. The calibration methods including linear, quadratic and cubic internal standard calibration, multivariate linear calibration and partial least squares (PLS) were compared with each other. It revealed that the PLS improved by normalization was the best calibration method for Si detection by LIBS.

Evaluation of elemental profiling methods, including laser-induced breakdown spectroscopy (LIBS), for the differentiation of Cannabis plant material grown in different nutrient solutions.

PubMed

El-Deftar, Moteaa M; Robertson, James; Foster, Simon; Lennard, Chris

2015-06-01

Laser-induced breakdown spectroscopy (LIBS) is an emerging atomic emission based solid sampling technique that has many potential forensic applications. In this study, the analytical performance of LIBS, as well as that of inductively coupled plasma mass spectrometry (ICP-MS), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and X-ray microfluorescence (μXRF), was evaluated for the ability to conduct elemental analyses on Cannabis plant material, with a specific investigation of the possible links between hydroponic nutrients and elemental profiles from associated plant material. No such study has been previously published in the literature. Good correlation among the four techniques was observed when the concentrations or peak areas of the elements of interest were monitored. For Cannabis samples collected at the same growth time, the elemental profiles could be related to the use of particular commercial nutrients. In addition, the study demonstrated that ICP-MS, LA-ICP-MS and LIBS are suitable techniques for the comparison of Cannabis samples from different sources, with high discriminating powers being achieved. On the other hand, μXRF method was not suitable for the discrimination of Cannabis samples originating from different growth nutrients. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Classification of red wine based on its protected designation of origin (PDO) using Laser-induced Breakdown Spectroscopy (LIBS).

PubMed

Moncayo, S; Rosales, J D; Izquierdo-Hornillos, R; Anzano, J; Caceres, J O

2016-09-01

This work reports on a simple and fast classification procedure for the quality control of red wines with protected designation of origin (PDO) by means of Laser Induced Breakdown Spectroscopy (LIBS) technique combined with Neural Networks (NN) in order to increase the quality assurance and authenticity issues. A total of thirty-eight red wine samples from different PDO were analyzed to detect fake wines and to avoid unfair competition in the market. LIBS is well known for not requiring sample preparation, however, in order to increase its analytical performance a new sample preparation treatment by previous liquid-to-solid transformation of the wine using a dry collagen gel has been developed. The use of collagen pellets allowed achieving successful classification results, avoiding the limitations and difficulties of working with aqueous samples. The performance of the NN model was assessed by three validation procedures taking into account their sensitivity (internal validation), generalization ability and robustness (independent external validation). The results of the use of a spectroscopic technique coupled with a chemometric analysis (LIBS-NN) are discussed in terms of its potential use in the food industry, providing a methodology able to perform the quality control of alcoholic beverages. Copyright © 2016 Elsevier B.V. All rights reserved.

Qualitative Analysis of Dairy and Powder Milk Using Laser-Induced Breakdown Spectroscopy (LIBS).

PubMed

Alfarraj, Bader A; Sanghapi, Herve K; Bhatt, Chet R; Yueh, Fang Y; Singh, Jagdish P

2018-01-01

Laser-induced breakdown spectroscopy (LIBS) technique was used to compare various types of commercial milk products. Laser-induced breakdown spectroscopy spectra were investigated for the determination of the elemental composition of soy and rice milk powder, dairy milk, and lactose-free dairy milk. The analysis was performed using radiative transitions. Atomic emissions from Ca, K, Na, and Mg lines observed in LIBS spectra of dairy milk were compared. In addition, proteins and fat level in milks can be determined using molecular emissions such as CN bands. Ca concentrations were calculated to be 2.165 ± 0.203 g/L in 1% of dairy milk fat samples and 2.809 ± 0.172 g/L in 2% of dairy milk fat samples using the standard addition method (SAM) with LIBS spectra. Univariate and multivariate statistical analysis methods showed that the contents of major mineral elements were higher in lactose-free dairy milk than those in dairy milk. The principal component analysis (PCA) method was used to discriminate four milk samples depending on their mineral elements concentration. In addition, proteins and fat level in dairy milks were determined using molecular emissions such as CN band. We applied partial least squares regression (PLSR) and simple linear regression (SLR) models to predict levels of milk fat in dairy milk samples. The PLSR model was successfully used to predict levels of milk fat in dairy milk sample with the relative accuracy (RA%) less than 6.62% using CN (0,0) band.

Discrimination of lymphoma using laser-induced breakdown spectroscopy conducted on whole blood samples

PubMed Central

Chen, Xue; Li, Xiaohui; Yang, Sibo; Yu, Xin; Liu, Aichun

2018-01-01

Lymphoma is a significant cancer that affects the human lymphatic and hematopoietic systems. In this work, discrimination of lymphoma using laser-induced breakdown spectroscopy (LIBS) conducted on whole blood samples is presented. The whole blood samples collected from lymphoma patients and healthy controls are deposited onto standard quantitative filter papers and ablated with a 1064 nm Q-switched Nd:YAG laser. 16 atomic and ionic emission lines of calcium (Ca), iron (Fe), magnesium (Mg), potassium (K) and sodium (Na) are selected to discriminate the cancer disease. Chemometric methods, including principal component analysis (PCA), linear discriminant analysis (LDA) classification, and k nearest neighbor (kNN) classification are used to build the discrimination models. Both LDA and kNN models have achieved very good discrimination performances for lymphoma, with an accuracy of over 99.7%, a sensitivity of over 0.996, and a specificity of over 0.997. These results demonstrate that the whole-blood-based LIBS technique in combination with chemometric methods can serve as a fast, less invasive, and accurate method for detection and discrimination of human malignancies. PMID:29541503

Direct measurements of sample heating by a laser-induced air plasma in pre-ablation spark dual-pulse laser-induced breakdown spectroscopy (LIBS).

PubMed

Register, Janna; Scaffidi, Jonathan; Angel, S Michael

2012-08-01

Direct measurements of temperature changes were made using small thermocouples (TC), placed near a laser-induced air plasma. Temperature changes up to ~500 °C were observed. From the measured temperature changes, estimates were made of the amount of heat absorbed per unit area. This allowed calculations to be made of the surface temperature, as a function of time, of a sample heated by the air plasma that is generated during orthogonal pre-ablation spark dual-pulse (DP) LIBS measurements. In separate experiments, single-pulse (SP) LIBS emission and sample ablation rate measurements were performed on nickel at sample temperatures ranging from room temperature to the maximum surface temperature that was calculated using the TC measurement results (500 °C). A small, but real sample temperature-dependent increase in both SP LIBS emission and the rate of sample ablation was found for nickel samples heated up to 500 °C. Comparison of DP LIBS emission enhancement values for bulk nickel samples at room temperature versus the enhanced SP LIBS emission and sample ablation rates observed as a function of increasing sample temperature suggests that sample heating by the laser-induced air plasma plays only a minor role in DP LIBS emission enhancement.

Measurement of Eu and Yb in aqueous solutions by underwater laser induced breakdown spectroscopy

DOE PAGES

Bhatt, Chet R.; Jain, Jinesh C.; Goueguel, Christian L.; ...

2017-09-13

In this paper, we report the use of laser induced breakdown spectroscopy (LIBS) to detect dissolved Eu and Yb in bulk aqueous solutions. Ten strong emission lines of Eu and one strong emission line of Yb were identified in the underwater LIBS spectra obtained by using Czerny–Turner spectrometer within the wavelength range of 375–515 nm. Temporal evolution of plasma and the effect of laser pulse energy on the spectral emission were studied. Finally, calibration curves using the concentration range from 500 to 10,000 ppm were developed and limits of detection for Eu and Yb were estimated to be 209 andmore » 156 ppm, respectively.« less

Measurement of Eu and Yb in aqueous solutions by underwater laser induced breakdown spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhatt, Chet R.; Jain, Jinesh C.; Goueguel, Christian L.

In this paper, we report the use of laser induced breakdown spectroscopy (LIBS) to detect dissolved Eu and Yb in bulk aqueous solutions. Ten strong emission lines of Eu and one strong emission line of Yb were identified in the underwater LIBS spectra obtained by using Czerny–Turner spectrometer within the wavelength range of 375–515 nm. Temporal evolution of plasma and the effect of laser pulse energy on the spectral emission were studied. Finally, calibration curves using the concentration range from 500 to 10,000 ppm were developed and limits of detection for Eu and Yb were estimated to be 209 andmore » 156 ppm, respectively.« less

Digital barcodes of suspension array using laser induced breakdown spectroscopy

PubMed Central

He, Qinghua; Liu, Yixi; He, Yonghong; Zhu, Liang; Zhang, Yilong; Shen, Zhiyuan

2016-01-01

We show a coding method of suspension array based on the laser induced breakdown spectroscopy (LIBS), which promotes the barcodes from analog to digital. As the foundation of digital optical barcodes, nanocrystals encoded microspheres are prepared with self-assembly encapsulation method. We confirm that digital multiplexing of LIBS-based coding method becomes feasible since the microsphere can be coded with direct read-out data of wavelengths, and the method can avoid fluorescence signal crosstalk between barcodes and analyte tags, which lead to overall advantages in accuracy and stability to current fluorescent multicolor coding method. This demonstration increases the capability of multiplexed detection and accurate filtrating, expanding more extensive applications of suspension array in life science. PMID:27808270

Laser Induced Breakdown Spectroscopy of Metals

NASA Astrophysics Data System (ADS)

Palmer, Andria; Lawhead, Carlos; Ujj, Laszlo

2015-03-01

Laser Induced Breakdown Spectroscopy (LIBS) is a very practical spectroscopy to determine the chemical composition of materials. Recent technical developments resulted in equipment used on the MARS Rover by NASA. It is capable of measuring the emission spectra of laser induced plasma created by energetic laser pulses focused on the sample (rocks, metals, etc.). We have develop a Laser Induced Breakdown Spectroscopy setup and investigated the necessary experimental and methodological challenges needed to make such material identification measurements. 355 and 532 nm laser pulses with 5 ns temporal duration was used to generate micro-plasma from which compositions can be determined based on known elemental and molecular emission intensities and wavelengths. The performance of LIBS depends on several parameters including laser wavelength, pulse energy, pulse duration, time interval of observation, geometrical configuration of collecting optics, and the properties of ambient medium. Spectra recorded from alloys (e.g. US penny coin) and pure metals will be presented. Special thanks for the financial support of the Office of Undergraduate Research of UWF.

Impact of oxygen chemistry on the emission and fluorescence spectroscopy of laser ablation plumes

NASA Astrophysics Data System (ADS)

Hartig, K. C.; Brumfield, B. E.; Phillips, M. C.; Harilal, S. S.

2017-09-01

Oxygen present in the ambient gas medium may affect both laser-induced breakdown spectroscopy (LIBS) and laser-induced fluorescence (LIF) emission through a reduction of emission intensity and persistence. In this study, an evaluation is made on the role of oxygen in the ambient environment under atmospheric pressure conditions in LIBS and laser ablation (LA)-LIF emission. To generate plasmas, 1064 nm, 10 ns pulses were focused on an aluminum alloy sample. LIF was performed by frequency scanning a CW laser over the 396.15 nm (3s24s 2S1/2 → 3s23p 2P°3/2) Al I transition. Time-resolved emission and fluorescence signals were recorded to evaluate the variation in emission intensity caused by the presence of oxygen. The oxygen partial pressure (po) in the atmospheric pressure environment using N2 as the makeup gas was varied from 0 to 400 Torr O2. 2D-fluorescence spectroscopy images were obtained for various oxygen concentrations for simultaneous evaluation of the emission and excitation spectral features. Results showed that the presence of oxygen in the ambient environment reduces the persistence of the LIBS and LIF emission through an oxidation process that depletes the density of atomic species within the resulting laser-produced plasma (LPP) plume.

Recognition of explosives fingerprints on objects for courier services using machine learning methods and laser-induced breakdown spectroscopy.

PubMed

Moros, J; Serrano, J; Gallego, F J; Macías, J; Laserna, J J

2013-06-15

During recent years laser-induced breakdown spectroscopy (LIBS) has been considered one of the techniques with larger ability for trace detection of explosives. However, despite of the high sensitivity exhibited for this application, LIBS suffers from a limited selectivity due to difficulties in assigning the molecular origin of the spectral emissions observed. This circumstance makes the recognition of fingerprints a latent challenging problem. In the present manuscript the sorting of six explosives (chloratite, ammonal, DNT, TNT, RDX and PETN) against a broad list of potential harmless interferents (butter, fuel oil, hand cream, olive oil, …), all of them in the form of fingerprints deposited on the surfaces of objects for courier services, has been carried out. When LIBS information is processed through a multi-stage architecture algorithm built from a suitable combination of 3 learning classifiers, an unknown fingerprint may be labeled into a particular class. Neural network classifiers trained by the Levenberg-Marquardt rule were decided within 3D scatter plots projected onto the subspace of the most useful features extracted from the LIBS spectra. Experimental results demonstrate that the presented algorithm sorts fingerprints according to their hazardous character, although its spectral information is virtually identical in appearance, with rates of false negatives and false positives not beyond of 10%. These reported achievements mean a step forward in the technology readiness level of LIBS for this complex application related to defense, homeland security and force protection. Copyright © 2013 Elsevier B.V. All rights reserved.

Surface characterization of carbon fiber reinforced polymers by picosecond laser induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Ledesma, Rodolfo; Palmieri, Frank; Connell, John; Yost, William; Fitz-Gerald, James

2018-02-01

Adhesive bonding of composite materials requires reliable monitoring and detection of surface contaminants as part of a vigorous quality control process to assure robust and durable bonded structures. Surface treatment and effective monitoring prior to bonding are essential in order to obtain a surface which is free from contaminants that may lead to inferior bond quality. In this study, the focus is to advance the laser induced breakdown spectroscopy (LIBS) technique by using pulse energies below 100 μJ (μLIBS) for the detection of low levels of silicone contaminants in carbon fiber reinforced polymer (CFRP) composites. Various CFRP surface conditions were investigated by LIBS using ∼10 ps, 355 nm laser pulses with pulse energies below 30 μJ. Time-resolved analysis was conducted to optimize the gate delay and gate width for the detection of the C I emission line at 247.9 nm to monitor the epoxy resin matrix of CFRP composites and the Si I emission line at 288.2 nm for detection of silicone contaminants in CFRP. To study the surface sensitivity to silicone contamination, CFRP surfaces were coated with polydimethylsiloxane (PDMS), the active ingredient in many mold release agents. The presence of PDMS was studied by inspecting the Si I emission lines at 251.6 nm and 288.2 nm. The measured PDMS areal densities ranged from 0.15 to 2 μg/cm2. LIBS measurements were performed before and after laser surface ablation. The results demonstrate the successful detection of PDMS thin layers on CFRP using picosecond μLIBS.

Evaluation of laser-induced breakdown spectroscopy analysis potential for addressing radiological threats from a distance

NASA Astrophysics Data System (ADS)

Gaona, I.; Serrano, J.; Moros, J.; Laserna, J. J.

2014-06-01

Although radioactive materials are nowadays valuable tools in nearly all fields of modern science and technology, the dangers stemming from the uncontrolled use of ionizing radiation are more than evident. Since preparedness is a key issue to face the risks of a radiation dispersal event, development of rapid and efficient monitoring technologies to control the contamination caused by radioactive materials is of crucial interest. Laser-induced breakdown spectroscopy (LIBS) exhibits appealing features for this application. This research focuses on the assessment of LIBS potential for the in-situ fingerprinting and identification of radioactive material surrogates from a safe distance. LIBS selectivity and sensitivity to detect a variety of radioactive surrogates, namely 59Co, 88Sr, 130Ba, 133Cs, 193Ir and 238U, on the surface of common urban materials at a distance of 30 m have been evaluated. The performance of the technique for nuclear forensics has been also studied on different model scenarios. Findings have revealed the difficulties to detect and to identify the analytes depending on the surface being interrogated. However, as demonstrated, LIBS shows potential enough for prompt and accurate gathering of essential evidence at a number of sites after the release, either accidental or intentional, of radioactive material. The capability of standoff analysis confers to LIBS unique advantages in terms of fast and safe inspection of forensic scenarios. The identity of the radioactive surrogates is easily assigned from a distance and the sensitivity to their detection is in the range of a few hundreds of ng per square centimeter.

Detection of uranium using laser-induced breakdown spectroscopy.

PubMed

Chinni, Rosemarie C; Cremers, David A; Radziemski, Leon J; Bostian, Melissa; Navarro-Northrup, Claudia

2009-11-01

The goal of this work is a detailed study of uranium detection by laser-induced breakdown spectroscopy (LIBS) for application to activities associated with environmental surveillance and detecting weapons of mass destruction (WMD). The study was used to assist development of LIBS instruments for standoff detection of bulk radiological and nuclear materials and these materials distributed as contaminants on surfaces. Uranium spectra were analyzed under a variety of different conditions at room pressure, reduced pressures, and in an argon atmosphere. All spectra displayed a high apparent background due to the high density of uranium lines. Time decay curves of selected uranium lines were monitored and compared to other elements in an attempt to maximize detection capabilities for each species in the complicated uranium spectrum. A survey of the LIBS uranium spectra was conducted and relative emission line strengths were determined over the range of 260 to 800 nm. These spectra provide a guide for selection of the strongest LIBS analytical lines for uranium detection in different spectral regions. A detection limit for uranium in soil of 0.26% w/w was obtained at close range and 0.5% w/w was achieved at a distance of 30 m. Surface detection limits were substrate dependent and ranged from 13 to 150 microg/cm2. Double-pulse experiments (both collinear and orthogonal arrangements) were shown to enhance the uranium signal in some cases. Based on the results of this work, a short critique is given of the applicability of LIBS for the detection of uranium residues on surfaces for environmental monitoring and WMD surveillance.

Rapid Analysis of Inorganic Species in Herbaceous Materials Using Laser-Induced Breakdown Spectroscopy

PubMed Central

Emerson, Rachel M.

2015-01-01

Abstract Inorganic compounds in biomass, often referred to as ash, are known to be problematic in the thermochemical conversion of biomass to bio-oil or syngas and, ultimately, hydrocarbon fuels because they negatively influence reaction pathways, contribute to fouling and corrosion, poison catalysts, and impact waste streams. The most common ash-analysis methods, such as inductively coupled plasma-optical emission spectrometry/mass spectrometry (ICP-OES/MS), require considerable time and expensive reagents. Laser-induced breakdown spectroscopy (LIBS) is emerging as a technique for rapid analysis of the inorganic constituents in a wide range of biomass materials. This study compares analytical results using LIBS data to results obtained from three separate ICP-OES/MS methods for 12 samples, including six standard reference materials. Analyzed elements include aluminum, calcium, iron, magnesium, manganese, phosphorus, potassium, sodium, and silicon, and results show that concentrations can be measured with an uncertainty of approximately 100 parts per million using univariate calibration models and relatively few calibration samples. These results indicate that the accuracy of LIBS is comparable to that of ICP-OES methods and indicate that some acid-digestion methods for ICP-OES may not be reliable for Na and Al. These results also demonstrate that germanium can be used as an internal standard to improve the reliability and accuracy of measuring many elements of interest, and that LIBS can be used for rapid determination of total ash in biomass samples. Key benefits of LIBS include little sample preparation, no reagent consumption, and the generation of meaningful analytical data instantaneously. PMID:26733765

Qualitative evaluation of maternal milk and commercial infant formulas via LIBS.

PubMed

Abdel-Salam, Z; Al Sharnoubi, J; Harith, M A

2013-10-15

This study focuses on the use of laser-induced breakdown spectroscopy (LIBS) for the evaluation of the nutrients in maternal milk and some commercially available infant formulas. The results of such evaluation are vital for adequate and healthy feeding for babies during lactation period. Laser-induced breakdown spectroscopy offers special advantages in comparison to the other conventional analytical techniques. Specifically, LIBS is a straightforward technique that can be used in situ to provide qualitative analytical information in few minutes for the samples under investigation without preparation processes. The samples studied in the current work were maternal milk samples collected during the first 3 months of lactation (not colostrum milk) and samples from six different types of commercially available infant formulas. The samples' elemental composition has been compared with respect to the relative abundance of the elements of nutrition importance, namely Mg, Ca, Na, and Fe using their spectral emission lines in the relevant LIBS spectra. In addition, CN and C2 molecular emission bands in the same spectra have been studied as indicators of proteins content in the samples. The obtained analytical results demonstrate the higher elemental contents of the maternal milk compared with the commercial formulas samples. Similar results have been obtained as for the proteins content. It has been also shown that calcium and proteins have similar relative concentration trends in the studied samples. This work demonstrates the feasibility of adopting LIBS as a fast, safe, less costly technique evaluating qualitatively the nutrients content of both maternal and commercial milk samples. Copyright © 2013 Elsevier B.V. All rights reserved.

Laser-induced breakdown spectroscopy (LIBS) analysis of calcium ions dissolved in water using filter paper substrates: an ideal internal standard for precision improvement.

PubMed

Choi, Daewoong; Gong, Yongdeuk; Nam, Sang-Ho; Han, Song-Hee; Yoo, Jonghyun; Lee, Yonghoon

2014-01-01

We report an approach for selecting an internal standard to improve the precision of laser-induced breakdown spectroscopy (LIBS) analysis for determining calcium (Ca) concentration in water. The dissolved Ca(2+) ions were pre-concentrated on filter paper by evaporating water. The filter paper was dried and analyzed using LIBS. By adding strontium chloride to sample solutions and using a Sr II line at 407.771 nm for the intensity normalization of Ca II lines at 393.366 or 396.847 nm, the analysis precision could be significantly improved. The Ca II and Sr II line intensities were mapped across the filter paper, and they showed a strong positive shot-to-shot correlation with the same spatial distribution on the filter paper surface. We applied this analysis approach for the measurement of Ca(2+) in tap, bottled, and ground water samples. The Ca(2+) concentrations determined using LIBS are in good agreement with those obtained from flame atomic absorption spectrometry. Finally, we suggest a homologous relation of the strongest emission lines of period 4 and 5 elements in groups IA and IIA based on their similar electronic structures. Our results indicate that the LIBS can be effectively applied for liquid analysis at the sub-parts per million level with high precision using a simple drying of liquid solutions on filter paper and the use of the correct internal standard elements with the similar valence electronic structure with respect to the analytes of interest.

Enhancement of laser-induced breakdown spectroscopy (LIBS) Detection limit using a low-pressure and short-pulse laser-induced plasma process.

PubMed

Wang, Zhen Zhen; Deguchi, Yoshihiro; Kuwahara, Masakazu; Yan, Jun Jie; Liu, Ji Ping

2013-11-01

Laser-induced breakdown spectroscopy (LIBS) technology is an appealing technique compared with many other types of elemental analysis because of the fast response, high sensitivity, real-time, and noncontact features. One of the challenging targets of LIBS is the enhancement of the detection limit. In this study, the detection limit of gas-phase LIBS analysis has been improved by controlling the pressure and laser pulse width. In order to verify this method, low-pressure gas plasma was induced using nanosecond and picosecond lasers. The method was applied to the detection of Hg. The emission intensity ratio of the Hg atom to NO (IHg/INO) was analyzed to evaluate the LIBS detection limit because the NO emission (interference signal) was formed during the plasma generation and cooling process of N2 and O2 in the air. It was demonstrated that the enhancement of IHg/INO arose by decreasing the pressure to a few kilopascals, and the IHg/INO of the picosecond breakdown was always much higher than that of the nanosecond breakdown at low buffer gas pressure. Enhancement of IHg/INO increased more than 10 times at 700 Pa using picosecond laser with 35 ps pulse width. The detection limit was enhanced to 0.03 ppm (parts per million). We also saw that the spectra from the center and edge parts of plasma showed different features. Comparing the central spectra with the edge spectra, IHg/INO of the edge spectra was higher than that of the central spectra using the picosecond laser breakdown process.

Application of LIBS and TMA for the determination of combustion predictive indices of coals and coal blends

NASA Astrophysics Data System (ADS)

Ctvrtnickova, T.; Mateo, M. P.; Yañez, A.; Nicolas, G.

2011-04-01

Presented work brings results of Laser-Induced Breakdown Spectroscopy (LIBS) and Thermo-Mechanical Analysis (TMA) of coals and coal blends used in coal fired power plants all over Spain. Several coal specimens, its blends and corresponding laboratory ash were analyzed by mentioned techniques and results were compared to standard laboratory methods. The indices of slagging, which predict the tendency of coal ash deposition on the boiler walls, were determined by means of standard chemical analysis, LIBS and TMA. The optimal coal suitable to be blended with the problematic national lignite coal was suggested in order to diminish the slagging problems. Used techniques were evaluated based on the precision, acquisition time, extension and quality of information they could provide. Finally, the applicability of LIBS and TMA to the successful calculation of slagging indices is discussed and their substitution of time-consuming and instrumentally difficult standard methods is considered.

Optimized LWIR enhancement of nanosecond and femtosecond LIBS uranium emission

NASA Astrophysics Data System (ADS)

Akpovo, Codjo A.; Ford, Alan; Johnson, Lewis

2016-05-01

A carbon dioxide (CO2) transverse electrical breakdown in atmosphere (TEA), pulsed laser was used to enhance the laser-induced breakdown spectroscopy (LIBS) spectral signatures of uranium under nanosecond (ns) and femtosecond (fs) ablation. The peak areas of both ionic and neutral species increased by one order of magnitude for ns-ablation and two orders of magnitude for fs-ablation over LIBS when the CO2 TEA laser was used with samples of dried solutions of uranyl nitrate hexahydrate (UO2(NO3)2·6H2O) on silicon wafers. Electron temperature and density measurements show that the spectral emission improvement from using the TEA laser comes from plasma reheating.

Detecting salt deposition on a wind turbine blade using laser induced breakdown spectroscopy technique

NASA Astrophysics Data System (ADS)

Sathiesh Kumar, V.; Vasa, Nilesh J.; Sarathi, R.

2013-07-01

The study of pollution performance on a wind turbine blade due to lightning is important, as it can cause major damage to wind turbine blades. In the present work, optical emission spectroscopy (OES) technique is used to understand the influence of pollutant deposited on a wind turbine blade in an off-shore environment. A methodical experimental study was carried out by adopting IEC 60507 standards, and it was observed that the lightning discharge propagates at the interface between the pollutant and the glass fiber reinforced plastic (Material used in manufacturing of wind turbine blades). In addition, as a diagnostic condition monitoring technique, laser-induced breakdown spectroscopy (LIBS) is proposed and demonstrated to rank the severity of pollutant on the wind turbine blades from a remote area. Optical emission spectra observed during surface discharge process induced by lightning impulse voltage is in agreement with the spectra observed during LIBS.

Laser induced breakdown spectroscopy on meteorites

NASA Astrophysics Data System (ADS)

de Giacomo, A.; Dell'Aglio, M.; de Pascale, O.; Longo, S.; Capitelli, M.

2007-12-01

The classification of meteorites when geological analysis is unfeasible is generally made by the spectral line emission ratio of some characteristic elements. Indeed when a meteorite impacts Earth's atmosphere, hot plasma is generated, as a consequence of the braking effect of air, with the consequent ablation of the falling body. Usually, by the plasma emission spectrum, the meteorite composition is determined, assuming the Boltzmann equilibrium. The plasma generated during Laser Induced Breakdown Spectroscopy (LIBS) experiment shows similar characteristics and allows one to verify the mentioned method with higher accuracy. On the other hand the study of Laser Induced Breakdown Spectroscopy on meteorite can be useful for both improving meteorite classification methods and developing on-flight techniques for asteroid investigation. In this paper certified meteorites belonging to different typologies have been investigated by LIBS: Dofhar 461 (lunar meteorite), Chondrite L6 (stony meteorite), Dofhar 019 (Mars meteorite) and Sikhote Alin (irony meteorite).

LIBS data analysis using a predictor-corrector based digital signal processor algorithm

NASA Astrophysics Data System (ADS)

Sanders, Alex; Griffin, Steven T.; Robinson, Aaron

2012-06-01

There are many accepted sensor technologies for generating spectra for material classification. Once the spectra are generated, communication bandwidth limitations favor local material classification with its attendant reduction in data transfer rates and power consumption. Transferring sensor technologies such as Cavity Ring-Down Spectroscopy (CRDS) and Laser Induced Breakdown Spectroscopy (LIBS) require effective material classifiers. A result of recent efforts has been emphasis on Partial Least Squares - Discriminant Analysis (PLS-DA) and Principle Component Analysis (PCA). Implementation of these via general purpose computers is difficult in small portable sensor configurations. This paper addresses the creation of a low mass, low power, robust hardware spectra classifier for a limited set of predetermined materials in an atmospheric matrix. Crucial to this is the incorporation of PCA or PLS-DA classifiers into a predictor-corrector style implementation. The system configuration guarantees rapid convergence. Software running on multi-core Digital Signal Processor (DSPs) simulates a stream-lined plasma physics model estimator, reducing Analog-to-Digital (ADC) power requirements. This paper presents the results of a predictorcorrector model implemented on a low power multi-core DSP to perform substance classification. This configuration emphasizes the hardware system and software design via a predictor corrector model that simultaneously decreases the sample rate while performing the classification.

Quantitative analysis of lead in aqueous solutions by ultrasonic nebulizer assisted laser induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Zhong, Shi-Lei; Lu, Yuan; Kong, Wei-Jin; Cheng, Kai; Zheng, Ronger

2016-08-01

In this study, an ultrasonic nebulizer unit was established to improve the quantitative analysis ability of laser-induced breakdown spectroscopy (LIBS) for liquid samples detection, using solutions of the heavy metal element Pb as an example. An analytical procedure was designed to guarantee the stability and repeatability of the LIBS signal. A series of experiments were carried out strictly according to the procedure. The experimental parameters were optimized based on studies of the pulse energy influence and temporal evolution of the emission features. The plasma temperature and electron density were calculated to confirm the LTE state of the plasma. Normalizing the intensities by background was demonstrated to be an appropriate method in this work. The linear range of this system for Pb analysis was confirmed over a concentration range of 0-4,150ppm by measuring 12 samples with different concentrations. The correlation coefficient of the fitted calibration curve was as high as 99.94% in the linear range, and the LOD of Pb was confirmed as 2.93ppm. Concentration prediction experiments were performed on a further six samples. The excellent quantitative ability of the system was demonstrated by comparison of the real and predicted concentrations of the samples. The lowest relative error was 0.043% and the highest was no more than 7.1%.

Detection of toxic elements using laser-induced breakdown spectroscopy in smokers' and nonsmokers' teeth and investigation of periodontal parameters.

PubMed

Alhasmi, Abdul M; Gondal, Mohammed A; Nasr, Mohamed M; Shafik, Sami; Habibullah, Yusuf B

2015-08-20

A laser-induced breakdown spectrometer (LIBS) was built and optimized to detect levels of toxic elements such as lead, cadmium, and arsenic present in the roots of extracted teeth of smokers and nonsmokers. Sixty extracted teeth from patients having a history of chronic periodontitis were divided into two groups of 30 teeth each for smoker and nonsmoker patients and, as controls, a third group of 30 patients who did not have a history of chronic periodontitis. The respective elemental concentration (Pb, Cd, and As) 23-29, 0.26-0. 31, and 0.64-11 ppm are for nonsmokers, 35-55, 0.33-0.51, and 0.91-1.5 ppm are for smokers, and lastly 0.17-0.31, 0.01-0.05, and 0.05-0.09 ppm are for control group. In order to test the validity of the results achieved using our LIBS system, a standard inductively coupled plasma (ICP) technique was also applied for the analysis of the same teeth samples, and ICP results were found to be in excellent agreement with our LIBS results. In addition to this, the gingival index, plaque index, clinical attachment loss (CAL) and probing pocket depth were also recorded. Our LIBS spectroscopic analysis showed high levels of lead, cadmium, and arsenic concentration on root surfaces of teeth, which may be due to CAL.

Performance evaluation of laser induced breakdown spectroscopy in the measurement of liquid and solid samples

NASA Astrophysics Data System (ADS)

Bilge, Gonca; Sezer, Banu; Boyaci, Ismail Hakki; Eseller, Kemal Efe; Berberoglu, Halil

2018-07-01

Liquid analysis by using LIBS is a complicated process due to difficulties encountered during the collection of light and formation of plasma in liquid. To avoid these, some applications are performed such as aerosol formation and transforming liquid into solid state. However, performance of LIBS in liquid samples still remains a challenging issue. In this study, performance evaluation of LIBS and parameter optimizations in liquid and solid phase samples were performed. For this purpose, milk was chosen as model sample; milk powder was used as solid sample, and milk was used as liquid sample in the experiments. Different experimental setups have been constructed for each sampling technique, and optimizations were performed to determine suitable parameters such as delay time, laser energy, repetition rate and speed of rotary table for solid sampling technique, and flow rate of carrier gas for liquid sampling technique. Target element was determined as Ca, which is a critically important element in milk for determining its nutritional value and Ca addition. In optimum parameters, limit of detection (LOD), limit of quantification (LOQ) and relative standard deviation (RSD) values were calculated as 0.11%, 0.36% and 8.29% respectively for milk powders samples; while LOD, LOQ and RSD values were calculated as 0.24%, 0.81%, and 10.93% respectively for milk samples. It can be said that LIBS is an applicable method in both liquid and solid samples with suitable systems and parameters. However, liquid analysis requires much more developed systems for more accurate results.

Rapid and Portable Methods for Identification of Bacterially Influenced Calcite: Application of Laser-Induced Breakdown Spectroscopy and AOTF Reflectance Spectroscopy, Fort Stanton Cave, New Mexico

NASA Astrophysics Data System (ADS)

McMillan, N. J.; Chavez, A.; Chanover, N.; Voelz, D.; Uckert, K.; Tawalbeh, R.; Gariano, J.; Dragulin, I.; Xiao, X.; Hull, R.

2014-12-01

Rapid, in-situ methods for identification of biologic and non-biologic mineral precipitation sites permit mapping of biological hot spots. Two portable spectrometers, Laser-Induced Breakdown Spectroscopy (LIBS) and Acoustic-Optic Tunable Filter Reflectance Spectroscopy (AOTFRS) were used to differentiate between bacterially influenced and inorganically precipitated calcite specimens from Fort Stanton Cave, NM, USA. LIBS collects light emitted from the decay of excited electrons in a laser ablation plasma; the spectrum is a chemical fingerprint of the analyte. AOTFRS collects light reflected from the surface of a specimen and provides structural information about the material (i.e., the presence of O-H bonds). These orthogonal data sets provide a rigorous method to determine the origin of calcite in cave deposits. This study used a set of 48 calcite samples collected from Fort Stanton cave. Samples were examined in SEM for the presence of biologic markers; these data were used to separate the samples into biologic and non-biologic groups. Spectra were modeled using the multivariate technique Partial Least Squares Regression (PLSR). Half of the spectra were used to train a PLSR model, in which biologic samples were assigned to the independent variable "0" and non-biologic samples were assigned the variable "1". Values of the independent variable were calculated for each of the training samples, which were close to 0 for the biologic samples (-0.09 - 0.23) and close to 1 for the non-biologic samples (0.57 - 1.14). A Value of Apparent Distinction (VAD) of 0.55 was used to numerically distinguish between the two groups; any sample with an independent variable value < 0.55 was classified as having a biologic origin; a sample with a value > 0.55 was determined to be non-biologic in origin. After the model was trained, independent variable values for the remaining half of the samples were calculated. Biologic or non-biologic origin was assigned by comparison to the VAD. Using LIBS data alone, the model has a 92% success rate, correctly identifying 23 of 25 samples. Modeling of AOTFRS spectra and the combined LIBS-AOTFRS data set have similar success rates. This study demonstrates that rapid, portable LIBS and AOTFRS instruments can be used to map the spatial distribution of biologic precipitation in caves.

Laser Induced Breakdown Spectroscopy (LIBS)

DTIC Science & Technology

2010-03-31

mass spectrometry and laser induced breakdown spectroscopy, Spe T Trejos, A Flores and JR. Almirall, Micro-spectrochemical analysis of document paper...and gel inks by laser ablation inductively coupled plasma mass spectrometry and laser induced breakdown spectroscopy, Spectrochimica Acta Part B...abstracts): 1. *Schenk, E.R. “Elemental analysis of unprocessed cotton by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and laser

Theoretical modeling of laser-induced plasmas using the ATOMIC code

NASA Astrophysics Data System (ADS)

Colgan, James; Johns, Heather; Kilcrease, David; Judge, Elizabeth; Barefield, James, II; Clegg, Samuel; Hartig, Kyle

2014-10-01

We report on efforts to model the emission spectra generated from laser-induced breakdown spectroscopy (LIBS). LIBS is a popular and powerful method of quickly and accurately characterizing unknown samples in a remote manner. In particular, LIBS is utilized by the ChemCam instrument on the Mars Science Laboratory. We model the LIBS plasma using the Los Alamos suite of atomic physics codes. Since LIBS plasmas generally have temperatures of somewhere between 3000 K and 12000 K, the emission spectra typically result from the neutral and singly ionized stages of the target atoms. We use the Los Alamos atomic structure and collision codes to generate sets of atomic data and use the plasma kinetics code ATOMIC to perform LTE or non-LTE calculations that generate level populations and an emission spectrum for the element of interest. In this presentation we compare the emission spectrum from ATOMIC with an Fe LIBS laboratory-generated plasma as well as spectra from the ChemCam instrument. We also discuss various physics aspects of the modeling of LIBS plasmas that are necessary for accurate characterization of the plasma, such as multi-element target composition effects, radiation transport effects, and accurate line shape treatments. The Los Alamos National Laboratory is operated by Los Alamos National Security, LLC for the National Nuclear Security Administration of the U.S. Department of Energy under Contract No. DE-AC5206NA25396.

Fire debris analysis for forensic fire investigation using laser induced breakdown spectroscopy (LIBS)

NASA Astrophysics Data System (ADS)

Choi, Soojin; Yoh, Jack J.

2017-08-01

The possibility verification of the first attempt to apply LIBS to arson investigation was performed. LIBS has capabilities for real time in-situ analysis and depth profiling. It can provide valuable information about the fire debris that are complementary to the classification of original sample components and combustion residues. In this study, fire debris was analyzed to determine the ignition source and existence of a fire accelerant using LIBS spectra and depth profiling analysis. Fire debris chemical composition and carbon layer thickness determines the possible ignition source while the carbon layer thickness of combusted samples represents the degree of sample carbonization. When a sample is combusted with fire accelerants, a thicker carbon layer is formed because the burning rate is increased. Therefore, depth profiling can confirm the existence of combustion accelerants, which is evidence of arson. Also investigation of fire debris by depth profiling is still possible when a fire is extinguished with water from fire hose. Such data analysis and in-situ detection of forensic signals via the LIBS may assist fire investigation at crime scenes.

Applications of High Resolution Laser Induced Breakdown Spectroscopy for Environmental and Biological Samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Madhavi Z; Labbe, Nicole; Wagner, Rebekah J.

2013-01-01

This chapter details the application of LIBS in a number of environmental areas of research such as carbon sequestration and climate change. LIBS has also been shown to be useful in other high resolution environmental applications for example, elemental mapping and detection of metals in plant materials. LIBS has also been used in phytoremediation applications. Other biological research involves a detailed understanding of wood chemistry response to precipitation variations and also to forest fires. A cross-section of Mountain pine (pinceae Pinus pungen Lamb.) was scanned using a translational stage to determine the differences in the chemical features both before andmore » after a fire event. Consequently, by monitoring the elemental composition pattern of a tree and by looking for abrupt changes, one can reconstruct the disturbance history of a tree and a forest. Lastly we have shown that multivariate analysis of the LIBS data is necessary to standardize the analysis and correlate to other standard laboratory techniques. LIBS along with multivariate statistical analysis makes it a very powerful technology that can be transferred from laboratory to field applications with ease.« less

A Comparison of Multivariate and Pre-Processing Methods for Quantitative Laser-Induced Breakdown Spectroscopy of Geologic Samples

NASA Technical Reports Server (NTRS)

Anderson, R. B.; Morris, R. V.; Clegg, S. M.; Bell, J. F., III; Humphries, S. D.; Wiens, R. C.

2011-01-01

The ChemCam instrument selected for the Curiosity rover is capable of remote laser-induced breakdown spectroscopy (LIBS).[1] We used a remote LIBS instrument similar to ChemCam to analyze 197 geologic slab samples and 32 pressed-powder geostandards. The slab samples are well-characterized and have been used to validate the calibration of previous instruments on Mars missions, including CRISM [2], OMEGA [3], the MER Pancam [4], Mini-TES [5], and Moessbauer [6] instruments and the Phoenix SSI [7]. The resulting dataset was used to compare multivariate methods for quantitative LIBS and to determine the effect of grain size on calculations. Three multivariate methods - partial least squares (PLS), multilayer perceptron artificial neural networks (MLP ANNs) and cascade correlation (CC) ANNs - were used to generate models and extract the quantitative composition of unknown samples. PLS can be used to predict one element (PLS1) or multiple elements (PLS2) at a time, as can the neural network methods. Although MLP and CC ANNs were successful in some cases, PLS generally produced the most accurate and precise results.

Analysis of carbon and nitrogen signatures with laser-induced breakdown spectroscopy; the quest for organics under Mars-like conditions

NASA Astrophysics Data System (ADS)

Dequaire, T.; Meslin, P.-Y.; Beck, P.; Jaber, M.; Cousin, A.; Rapin, W.; Lasne, J.; Gasnault, O.; Maurice, S.; Buch, A.; Szopa, C.; Coll, P.

2017-05-01

Organic matter has been continuously delivered by meteorites and comets to Mars since its formation, and possibly formed in situ by abiogenic and/or biogenic processes. This organic matter may be preserved from the harsh oxidizing environment of Mars in specific locations. Together with water, organic molecules are necessary to the emergence of life as we know it. Since the first martian landers, scientists have been searching for organics and until today, only one positive detection has been made by a Gas Chromatography Mass Spectrometer (GCMS) instrument onboard the Curiosity rover. In this article we investigate a complementary approach to guide the search for organic matter using ChemCam, the first Laser-Induced Breakdown Spectroscopy (LIBS) instrument on Mars. This experimental study focuses on the analysis of carbon and nitrogen LIBS signatures in organoclay samples and allows the determination of the critical level (Lc) and limit of detection (LoD) of these elements with LIBS under Mars-like conditions, giving new insights into the search of organic matter on Mars.

Quantification of water content by laser induced breakdown spectroscopy on Mars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rapin, W.; Meslin, P. -Y.; Maurice, S.

Laser induced breakdown spectroscopy (LIBS), as performed by the ChemCam instrument, provides a new technique to measure hydrogen at the surface of Mars. Using a laboratory replica of the LIBS instrument onboard the Curiosity rover, different types of hydrated samples (basalts, calcium and magnesium sulfates, opals and apatites) covering a range of targets observed on Mars have been characterized and analyzed in this paper. A number of factors related to laser parameters, atmospheric conditions and differences in targets properties can affect the standoff LIBS signal, and in particular the hydrogen emission peak. Dedicated laboratory tests were run to identify amore » normalization of the hydrogen signal which could best compensate for these effects and enable the application of the laboratory calibration to Mars data. We check that the hydrogen signal increases linearly with water content; and normalization of the hydrogen emission peak using to oxygen and carbon emission peaks (related to the breakdown of atmospheric carbon dioxide) constitutes a robust approach. Finally, moreover, the calibration curve obtained is relatively independent of the samples types.« less

Quantification of water content by laser induced breakdown spectroscopy on Mars

DOE PAGES

Rapin, W.; Meslin, P. -Y.; Maurice, S.; ...

2017-02-12

Laser induced breakdown spectroscopy (LIBS), as performed by the ChemCam instrument, provides a new technique to measure hydrogen at the surface of Mars. Using a laboratory replica of the LIBS instrument onboard the Curiosity rover, different types of hydrated samples (basalts, calcium and magnesium sulfates, opals and apatites) covering a range of targets observed on Mars have been characterized and analyzed in this paper. A number of factors related to laser parameters, atmospheric conditions and differences in targets properties can affect the standoff LIBS signal, and in particular the hydrogen emission peak. Dedicated laboratory tests were run to identify amore » normalization of the hydrogen signal which could best compensate for these effects and enable the application of the laboratory calibration to Mars data. We check that the hydrogen signal increases linearly with water content; and normalization of the hydrogen emission peak using to oxygen and carbon emission peaks (related to the breakdown of atmospheric carbon dioxide) constitutes a robust approach. Finally, moreover, the calibration curve obtained is relatively independent of the samples types.« less

Towards reconstruction of overlapping fingerprints using plasma spectroscopy

NASA Astrophysics Data System (ADS)

Yang, Jun-Ho; Choi, Soo-Jin; Yoh, Jack J.

2017-08-01

Chemical analysis is commonly used in the field of forensic science where the precise discrimination of primary evidence is of significant importance. Laser-Induced Breakdown Spectroscopy (LIBS) exceeds other spectroscopic methods in terms of the time required for pre- and post-sample preparation, the insensitivity to sample phase state be it solid, liquid, or gas, and the detection of two-dimensional spectral mapping from real time point measurements. In this research, fingerprint samples on various surface materials are considered in the chemical detection and reconstruction of fingerprints using the two-dimensional LIBS technique. Strong and distinct intensities of specific wavelengths represent visible ink, natural secretion of sweat, and contaminants from the environment, all of which can be present in latent fingerprints. The particular aim of the work presented here is to enhance the precision of the two-dimensional recreation of the fingerprints present on metal, plastic, and artificially prepared soil surface using LIBS with principal component analysis. By applying a distinct wavelength discrimination for two overlapping fingerprint samples, separation into two non-identical chemical fingerprints was successfully performed.

Investigation of the wavelength dependence of laser stratigraphy on Cu and Ni coatings using LIBS compared to a pure thermal ablation model

NASA Astrophysics Data System (ADS)

Paulis, Evgeniya; Pacher, Ulrich; Weimerskirch, Morris J. J.; Nagy, Tristan O.; Kautek, Wolfgang

2017-12-01

In this study, galvanic coatings of Cu and Ni, typically applied in industrial standard routines, were investigated. Ablation experiments were carried out using the first two harmonic wavelengths of a pulsed Nd:YAG laser and the resulting plasma spectra were analysed using a linear Pearson correlation method. For both wavelengths the absorption/ablation behaviour as well as laser-induced breakdown spectroscopy (LIBS) depth profiles were studied varying laser fluences between 4.3-17.2 J/cm^2 at 532 nm and 2.9-11.7 J/cm^2 at 1064 nm. The LIBS-stratigrams were compared with energy-dispersive X-ray spectroscopy of cross-sections. The ablation rates were calculated and compared to theoretical values originating from a thermal ablation model. Generally, higher ablation rates were obtained with 532 nm light for both materials. The light-plasma interaction is suggested as possible cause of the lower ablation rates in the infrared regime. Neither clear evidence of the pure thermal ablation, nor correlation with optical properties of investigated materials was obtained.

Applications of laser-induced breakdown spectroscopy in the aluminum electrolysis industry

NASA Astrophysics Data System (ADS)

Sun, Lanxiang; Yu, Haibin; Cong, Zhibo; Lu, Hui; Cao, Bin; Zeng, Peng; Dong, Wei; Li, Yang

2018-04-01

The industrial aluminum reduction cell is an electrochemistry reactor that operates under high temperatures and corrosive conditions. Monitoring the molten aluminum and electrolyte components is very important for controlling the chemical reaction process. Due to the lack of fast methods to monitor the components, controlling aluminum reduction cells is difficult. In this work, laser-induced breakdown spectroscopy (LIBS) was applied to aluminum electrolysis. A new method for calculating the molecular ratio, which is an important control parameter that represents the acidity of the electrolyte, was proposed. Experiments were first performed on solid electrolyte samples to test the performance of the proposed method. Using this method, the average relative standard deviation (RSD) of the molecular ratio measurement was 0.39%, and the average root mean square error (RMSE) was 0.0236. These results prove that LIBS can accurately measure the molecular ratio. Then, in situ measurements of the molten aluminum and electrolyte were performed in industrial aluminum induction cells using the developed LIBS equipment. The spectra of the molten electrolyte were successfully obtained and were consistent with the spectra of the solid electrolyte.

Application of picosecond laser-induced breakdown spectroscopy to quantitative analysis of boron in meatballs and other biological samples.

PubMed

Hedwig, Rinda; Lahna, Kurnia; Lie, Zener Sukra; Pardede, Marincan; Kurniawan, Koo Hendrik; Tjia, May On; Kagawa, Kiichiro

2016-11-10

This report presents the results of laser-induced breakdown spectroscopy (LIBS) study on biological and food samples of high water content using a picosecond (ps) laser at low output energy of 10 mJ and low-pressure helium ambient gas at 2 kPa. Evidence of excellent emission spectra of various analyte elements with very low background is demonstrated for a variety of samples without the need of sample pretreatment. Specifically, limits of detection in the range of sub-ppm are obtained for hazardous Pb and B impurities in carrots and meatballs. This study also shows the inferior performance of LIBS using a nanosecond laser and atmospheric ambient air for a soft sample of high water content and thereby explains its less successful applications in previous attempts. The present result has instead demonstrated the feasibility and favorable results of employing LIBS with a ps laser and low-pressure helium ambient gas as a less costly and more practical alternative to inductively coupled plasma for regular high sensitive inspection of harmful food preservatives and environmental pollutants.

Pulsations in the atmosphere of the rapidly oscillating star 33 Lib

NASA Astrophysics Data System (ADS)

Sachkov, M.; Hareter, M.; Ryabchikova, T.; Wade, G.; Kochukhov, O.; Shulyak, D.; Weiss, W. W.

2011-10-01

In 2009, the rapidly oscillating peculiar A-type (roAp) star 33 Lib was the target of an intense observing campaign, combining ground-based spectroscopy with space photometry obtained with the Microvariability and Oscillation of STars (MOST) satellite. We collected 780 spectra using the Echelle Spectro Polarimetric Device for the Observation of Stars (ESPaDOnS) spectrograph attached at the 3.6-m Canada-France-Hawaii Telescope and 374 spectra with the Fibre-fed Echelle Spectrograph attached at the 2.56-m Nordic Optical Telescope to perform time-resolved spectroscopy of 33 Lib. In addition, we used 111 Ultraviolet and Visual Echelle Spectrograph (UVES) spectra (2004) from the European Southern Observatory archive to check mode stability. Frequency analysis of the new radial velocity (RV) measurements confirms the previously reported frequency pattern (two frequencies and the first harmonic of the main one) and reveals an additional frequency at 1.991 mHz. The new frequency solution perfectly reproduces the RV variations from the 2004 and 2009 observational sets, providing strong support for p mode stability in this roAp star over at least 5 years.

Recent advances in the use of laser-induced breakdown spectroscopy (LIBS) as a rapid point-of-care pathogen diagnostic

NASA Astrophysics Data System (ADS)

Rehse, Steven J.; Miziolek, Andrzej W.

2012-06-01

Laser-induced breakdown spectroscopy (LIBS) has made tremendous progress in becoming a viable technology for rapid bacterial pathogen detection and identification. The significant advantages of LIBS include speed (< 1 sec analysis), portability, robustness, lack of consumables, little to no need for sample preparation, lack of genetic amplification, and the ability to identify all bacterial pathogens without bias (including spore-forms and viable but nonculturable specimens). In this manuscript, we present the latest advances achieved in LIBS-based bacterial sensing including the ability to uniquely identify species from more than five bacterial genera with high-sensitivity and specificity. Bacterial identifications are completely unaffected by environment, nutrition media, or state of growth and accurate diagnoses can be made on autoclaved or UV-irradiated specimens. Efficient discrimination of bacteria at the strain level has been demonstrated. A rapid urinary tract infection diagnosis has been simulated with no sample preparation and a one second diagnosis of a pathogen surrogate has been demonstrated using advanced chemometric analysis with a simple "stop-light" user interface. Stand-off bacterial identification at a 20-m distance has been demonstrated on a field-portable instrument. This technology could be implemented in doctors' offices, clinics, or hospital laboratories for point-of-care medical specimen analysis; mounted on military medical robotic platforms for in-the- field diagnostics; or used in stand-off configuration for remote sensing and detection.

Laser-induced breakdown spectroscopy for elemental characterization of calcitic alterations on cave walls.

PubMed

Bassel, Léna; Motto-Ros, Vincent; Trichard, Florian; Pelascini, Frédéric; Ammari, Faten; Chapoulie, Rémy; Ferrier, Catherine; Lacanette, Delphine; Bousquet, Bruno

2017-01-01

Cave walls are affected by different kinds of alterations involving preservative issues in the case of ornate caves, in particular regarding the rock art covering the walls. In this context, coralloids correspond to a facies with popcorn-like aspect belonging to the speleothem family, mostly composed of calcium carbonate. The elemental characterization indicates the presence of elements that might be linked to the diagenesis and the expansion of the alterations as demonstrated by prior analyses on stalagmites. In this study, we report the use of laser-induced breakdown spectroscopy (LIBS) to characterize the elemental composition of one coralloid sample with a portable instrument allowing punctual measurements and a laboratory mapping setup delivering elemental images with spatial resolution at the micrometric scale, being particularly attentive to Mg, Sr, and Si identified as elements of interest. The complementarity of both instruments allows the determination of the internal structure of the coralloid. Although a validation based on a reference technique is necessary, LIBS data reveal that the external layer of the coralloid is composed of laminations correlated to variations of the LIBS signal of Si. In addition, an interstitial layer showing high LIBS signals for Fe, Al, and Si is interpreted to be a detrital clay interface between the external and the internal part of the coralloid. These preliminary results sustain a possible formation scenario of the coralloid by migration of the elements from the bedrock.

A Comparative Study of Single-pulse and Double-pulse Laser-Induced Breakdown Spectroscopy with Uranium-containing Samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skrodzki, P. J.; Becker, J. R.; Diwakar, P. K.

Laser-induced breakdown spectroscopy (LIBS) holds potential advantages in special nuclear material (SNM) sensing and nuclear forensics which require rapid analysis, minimal sample preparation and stand-off distance capability. SNM, such as U, however, result in crowded emission spectra with LIBS, and characteristic emission lines are challenging to discern. It is well-known that double-pulse LIBS (DPLIBS) improves the signal intensity for analytes over conventional single-pulse LIBS (SPLIBS). This study investigates U signal in a glass matrix using DPLIBS and compares to signal features obtained using SPLIBS. DPLIBS involves sequential firing of 1.06 µm Nd:YAG pre-pulse and 10.6 µm TEA CO2 heating pulsemore » in near collinear geometry. Optimization of experimental parameters including inter-pulse delay and energy follows identification of characteristic lines and signals for bulk analyte Ca and minor constituent analyte U for both DPLIBS and SPLIBS. Spatial and temporal coupling of the two pulses in the proposed DPLIBS technique yields improvements in analytical merits with negligible further damage to the sample compared to SPLIBS. Subsequently, the study discusses optimum plasma emission conditions of U lines and relative figures of merit in both SPLIBS and DPLIBS. Investigation into plasma characteristics also addresses plausible mechanisms related to observed U analyte signal variation between SPLIBS and DPLIBS.« less

Highly concentrated, ring-shaped phase conversion laser-induced breakdown spectroscopy technology for liquid sample analysis.

PubMed

Lin, Qingyu; Wei, Zhimei; Guo, Hongli; Wang, Shuai; Guo, Guangmeng; Zhang, Zhi; Duan, Yixiang

2017-06-10

A highly concentrated, ring-shaped phase conversion (RSPC) method was developed for liquid sample analysis using the laser-induced breakdown spectroscopy (LIBS) technique. In this work, test samples were prepared by mixing the metal particles with polyvinyl alcohol (PVA) supporter in liquid phase. With heat, the PVA solution solidified inside a modified glass petri dish, forming a metal-enriched polymer ring film. Distinguished from other traditional liquid-to-solid conversing methods, the proposed new method takes advantage of enhanced homogeneity for the target elements inside the ring film. The modified glass petri dish was used to control the ring-shaped concentration. Due to the specially designed circular groove at the bottom of this dish, where the PVA solution and liquid sample mixture accumulated, the target elements were concentrated in this small ring, which is beneficial for enhancing and stabilizing the plasma signals compared to the direct liquid sample analysis using LIBS. The limits of detection for Ag, Cu, Cr, and Ba obtained with the RSPC-LIBS technology were 0.098  μg·mL -1 , 0.18  μg·mL -1 , 0.83  μg·mL -1 , and 0.046  μg·mL -1 , respectively, which provided greater improvement than the direct bulk liquid analysis using LIBS.

Rapid Analysis of Ash Composition Using Laser-Induced Breakdown Spectroscopy (LIBS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tyler L. Westover

2013-01-01

Inorganic compounds are known to be problematic in the thermochemical conversion of biomass to syngas and ultimately hydrocarbon fuels. The elements Si, K, Ca, Na, S, P, Cl, Mg, Fe, and Al are particularly problematic and are known to influence reaction pathways, contribute to fouling and corrosion, poison catalysts, and impact waste streams. Substantial quantities of inorganic species can be entrained in the bark of trees during harvest operations. Herbaceous feedstocks often have even greater quantities of inorganic constituents, which can account for as much as one-fifth of the total dry matter. Current methodologies to measure the concentrations of thesemore » elements, such as inductively coupled plasma-optical emission spectrometry/mass spectrometry (ICP-OES/MS) are expensive in time and reagents. This study demonstrates that a new methodology employing laser-induced breakdown spectroscopy (LIBS) can rapidly and accurately analyze the inorganic constituents in a wide range of biomass materials, including both woody and herbaceous examples. This technique requires little or no sample preparation, does not consume any reagents, and the analytical data is available immediately. In addition to comparing LIBS data with the results from ICP-OES methods, this work also includes discussions of sample preparation techniques, calibration curves for interpreting LIBS spectra, minimum detection limits, and the use of internal standards and standard reference materials.« less

Improved accuracy in quantitative laser-induced breakdown spectroscopy using sub-models

USGS Publications Warehouse

Anderson, Ryan; Clegg, Samuel M.; Frydenvang, Jens; Wiens, Roger C.; McLennan, Scott M.; Morris, Richard V.; Ehlmann, Bethany L.; Dyar, M. Darby

2017-01-01

Accurate quantitative analysis of diverse geologic materials is one of the primary challenges faced by the Laser-Induced Breakdown Spectroscopy (LIBS)-based ChemCam instrument on the Mars Science Laboratory (MSL) rover. The SuperCam instrument on the Mars 2020 rover, as well as other LIBS instruments developed for geochemical analysis on Earth or other planets, will face the same challenge. Consequently, part of the ChemCam science team has focused on the development of improved multivariate analysis calibrations methods. Developing a single regression model capable of accurately determining the composition of very different target materials is difficult because the response of an element’s emission lines in LIBS spectra can vary with the concentration of other elements. We demonstrate a conceptually simple “sub-model” method for improving the accuracy of quantitative LIBS analysis of diverse target materials. The method is based on training several regression models on sets of targets with limited composition ranges and then “blending” these “sub-models” into a single final result. Tests of the sub-model method show improvement in test set root mean squared error of prediction (RMSEP) for almost all cases. The sub-model method, using partial least squares regression (PLS), is being used as part of the current ChemCam quantitative calibration, but the sub-model method is applicable to any multivariate regression method and may yield similar improvements.

Mapping of lead, magnesium and copper accumulation in plant tissues by laser-induced breakdown spectroscopy and laser-ablation inductively coupled plasma mass spectrometry

NASA Astrophysics Data System (ADS)

Kaiser, J.; Galiová, M.; Novotný, K.; Červenka, R.; Reale, L.; Novotný, J.; Liška, M.; Samek, O.; Kanický, V.; Hrdlička, A.; Stejskal, K.; Adam, V.; Kizek, R.

2009-01-01

Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) were utilized for mapping the accumulation of Pb, Mg and Cu with a resolution up to 200 μm in a up to cm × cm area of sunflower ( Helianthus annuus L.) leaves. The results obtained by LIBS and LA-ICP-MS are compared with the outcomes from Atomic Absorption Spectrometry (AAS) and Thin-Layer Chromatography (TLC). It is shown that laser-ablation based analytical methods can substitute or supplement these techniques mainly in the cases when a fast multi-elemental mapping of a large sample area is needed.

Analysis of charcoal blast furnace slags by laser-induced breakdown spectroscopy

DOE PAGES

Bhatt, Chet R.; Goueguel, Christian L.; Jain, Jinesh C.; ...

2017-09-22

Laser-induced breakdown spectroscopy (LIBS) was used for the analysis of charcoal blast furnace slags. Plasma was generated by an application of a 1064 nm wavelength Nd:YAG laser beam to the surface of pellets created from the slags. The presence of Al, Ca, Fe, K, Mg, Mn, and Si was determined by identifying their characteristic spectral signatures. Multivariate analysis was performed for the quantification of these elements. The predicted LIBS results were found in agreement with the inductively coupled plasma optical emission spectrometry analysis. The limit of detection for Al, Ca, Fe, K, Mg, Mn, and Si was calculated to bemore » 0.10%, 0.22%, 0.02%, 0.01%, 0.01%, 0.005%, and 0.18%, respectively.« less

Location and detection of explosive-contaminated human fingerprints on distant targets using standoff laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Lucena, P.; Gaona, I.; Moros, J.; Laserna, J. J.

2013-07-01

Detection of explosive-contaminated human fingerprints constitutes an analytical challenge of high significance in security issues and in forensic sciences. The use of a laser-induced breakdown spectroscopy (LIBS) sensor working at 31 m distance to the target, fitted with 2D scanning capabilities and designed for capturing spectral information from laser-induced plasmas of fingerprints is presented. Distribution chemical maps based on Na and CN emissions are used to locate and detect chloratite, DNT, TNT, RDX and PETN residues that have been deposited on the surface of aluminum and glass substrates. An effectiveness of 100% on fingerprints detection, regardless the substrate scanned, is reached. Environmental factors that affect the prevalence of the fingerprint LIBS response are discussed.

Analysis of charcoal blast furnace slags by laser-induced breakdown spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhatt, Chet R.; Goueguel, Christian L.; Jain, Jinesh C.

Laser-induced breakdown spectroscopy (LIBS) was used for the analysis of charcoal blast furnace slags. Plasma was generated by an application of a 1064 nm wavelength Nd:YAG laser beam to the surface of pellets created from the slags. The presence of Al, Ca, Fe, K, Mg, Mn, and Si was determined by identifying their characteristic spectral signatures. Multivariate analysis was performed for the quantification of these elements. The predicted LIBS results were found in agreement with the inductively coupled plasma optical emission spectrometry analysis. The limit of detection for Al, Ca, Fe, K, Mg, Mn, and Si was calculated to bemore » 0.10%, 0.22%, 0.02%, 0.01%, 0.01%, 0.005%, and 0.18%, respectively.« less

Modeling of low-temperature plasmas generated using laser-induced breakdown spectroscopy: the ChemCam diagnostic tool on the Mars Science Laboratory Rover

NASA Astrophysics Data System (ADS)

Colgan, James

2016-05-01

We report on efforts to model the low-temperature plasmas generated using laser-induced breakdown spectroscopy (LIBS). LIBS is a minimally invasive technique that can quickly and efficiently determine the elemental composition of a target and is employed in an extremely wide range of applications due to its ease of use and fast turnaround. In particular, LIBS is the diagnostic tool used by the ChemCam instrument on the Mars Science Laboratory rover Curiosity. In this talk, we report on the use of the Los Alamos plasma modeling code ATOMIC to simulate LIBS plasmas, which are typically at temperatures of order 1 eV and electron densities of order 10 16 - 17 cm-3. At such conditions, these plasmas are usually in local-thermodynamic equilibrium (LTE) and normally contain neutral and singly ionized species only, which then requires that modeling must use accurate atomic structure data for the element under investigation. Since LIBS devices are often employed in a very wide range of applications, it is therefore desirable to have accurate data for most of the elements in the periodic table, ideally including actinides. Here, we discuss some recent applications of our modeling using ATOMIC that have explored the plasma physics aspects of LIBS generated plasmas, and in particular discuss the modeling of a plasma formed from a basalt sample used as a ChemCam standard1. We also highlight some of the more general atomic physics challenges that are encountered when attempting to model low-temperature plasmas. The Los Alamos National Laboratory is operated by Los Alamos National Security, LLC for the National Nuclear Security Administration of the U.S. Department of Energy under Contract No. DE-AC5206NA25396. Work performed in conjunction with D. P. Kilcrease, H. M. Johns, E. J. Judge, J. E. Barefield, R. C. Wiens, S. M. Clegg.

Monitoring uranium, hydrogen, and lithium and their isotopes using a compact laser-induced breakdown spectroscopy (LIBS) probe and high-resolution spectrometer.

PubMed

Cremers, David A; Beddingfield, Alan; Smithwick, Robert; Chinni, Rosemarie C; Jones, C Randy; Beardsley, Burt; Karch, Larry

2012-03-01

The development of field-deployable instruments to monitor radiological, nuclear, and explosive (RNE) threats is of current interest for a number of assessment needs such as the on-site screening of suspect facilities and nuclear forensics. The presence of uranium and plutonium and radiological materials can be determined through monitoring the elemental emission spectrum using relatively low-resolution spectrometers. In addition, uranium compounds, explosives, and chemicals used in nuclear fuel processing (e.g., tributyl-phosphate) can be identified by applying chemometric analysis to the laser-induced breakdown (LIBS) spectrum recorded by these spectrometers. For nuclear forensic applications, however, isotopes of U and Pu and other elements (e.g., H and Li) must also be determined, requiring higher resolution spectrometers given the small magnitude of the isotope shifts for some of these elements (e.g., 25 pm for U and 13 pm for Pu). High-resolution spectrometers will be preferred for several reasons but these must fit into realistic field-based analysis scenarios. To address the need for field instrumentation, we evaluated a previously developed field-deployable hand-held LIBS interrogation probe combined with two relatively new high-resolution spectrometers (λ/Δλ ~75,000 and ~44,000) that have the potential to meet field-based analysis needs. These spectrometers are significantly smaller and lighter in weight than those previously used for isotopic analysis and one unit can provide simultaneous wide spectral coverage and high resolution in a relatively small package. The LIBS interrogation probe was developed initially for use with low resolution compact spectrometers in a person-portable backpack LIBS instrument. Here we present the results of an evaluation of the LIBS probe combined with a high-resolution spectrometer and demonstrate rapid detection of isotopes of uranium and hydrogen and highly enriched samples of (6)Li and (7)Li. © 2012 Society for Applied Spectroscopy

Fast detection and characterization of organic and inorganic gunshot residues on the hands of suspects by CMV-GC-MS and LIBS.

PubMed

Tarifa, Anamary; Almirall, José R

2015-05-01

A rapid method for the characterization of both organic and inorganic components of gunshot residues (GSR) is proposed as an alternative tool to facilitate the identification of a suspected shooter. In this study, two fast screening methods were developed and optimized for the detection of organic compounds and inorganic components indicative of GSR presence on the hands of shooters and non-shooters. The proposed methods consist of headspace extraction of volatile organic compounds using a capillary microextraction of volatiles (CMV) device previously reported as a high-efficiency sampler followed by detection by GC-MS. This novel sampling technique has the potential to yield fast results (<2min sampling) and high sensitivity capable of detecting 3ng of diphenylamine (DPA) and 8ng of nitroglycerine (NG). Direct analysis of the headspace of over 50 swabs collected from the hands of suspected shooters (and non-shooters) provides information regarding VOCs present on their hands. In addition, a fast laser induced breakdown spectroscopy (LIBS) screening method for the detection of the inorganic components indicative of the presence of GSR (Sb, Pb and Ba) is described. The sampling method for the inorganics consists of liquid extraction of the target elements from the same cotton swabs (previously analyzed for VOCs) and an additional 30 swab samples followed by spiking 1μL of the extract solution onto a Teflon disk and then analyzed by LIBS. Advantages of LIBS include fast analysis (~12s per sample) and high selectivity and sensitivity, with expected LODs 0.1-18ng for each of the target elements after sampling. The analytical performance of the LIBS method is also compared to previously reported methods (inductively coupled plasma-optical emission spectroscopy). The combination of fast CMV sampling, unambiguous organic compound identification with GC-MS and fast LIBS analysis provides the basis for a new comprehensive screening method for GSR. Copyright © 2015 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

Effect of Sample Preparation on the Discrimination of Bacterial Isolates Cultured in Liquid Nutrient Media Using Laser-Induced Breakdown Spectroscopy (LIBS).

PubMed

Gamble, Gary R; Park, Bosoon; Yoon, Seung-Chul; Lawrence, Kurt C

2016-03-01

Laser-induced breakdown spectroscopy (LIBS) is used as the basis for discrimination between two genera of gram-negative bacteria and two genera of gram-positive bacteria representing pathogenic threats commonly found in poultry processing rinse waters. Because LIBS-based discrimination relies primarily upon the relative proportions of inorganic cell components including Na, K, Mg, and Ca, this study aims to determine the effects of trace mineral content and pH found in the water source used to isolate the bacteria upon the reliability of the resulting discriminant analysis. All four genera were cultured using tryptic soy agar (TSA) as the nutrient medium, and were grown under identical environmental conditions. The only variable introduced is the source water used to isolate the cultured bacteria. Cultures of each bacterium were produced using deionized (DI) water under two atmosphere conditions, reverse osmosis (RO) water, tap water, phosphate buffered saline (PBS) water, and TRIS buffered water. After 3 days of culture growth, the bacteria were centrifuged and washed three times in the same water source. Bacteria were then freeze dried, mixed with microcrystalline cellulose, and a pellet was made for LIBS analysis. Principal component analysis (PCA) was used to extract related variations in LIBS spectral data among the four bacteria genera and six water types used to isolate the bacteria, and Mahalanobis discriminant analysis (MDA) was used for classification. Results indicate not only that the four genera can be discriminated from each other in each water type, but that each genus can be discriminated by water type used for isolation. It is concluded that in order for LIBS to be a reliable and repeatable method for discrimination of bacteria grown in liquid nutrient media, care must be taken to insure that the water source used in purification of the culture be precisely controlled regarding pH, ionic strength, and proportionate amounts of mineral cations present. © The Author(s) 2016.

[Time-evolution study on the cation exchange in the process of reinforcing slip soil by laser-induced breakdown spectroscopy].

PubMed

Liu, Lu-Wen; Zeng, Wei-Li; Zhu, Xiang-Fei; Wu, Jin-Quan; Lin, Zhao-Xiang

2014-03-01

In the present paper, the time evolution study on slip soils treated by different proportions of ionic soil stabilizer (ISS) water solution was conducted by the LIBS system and the relationship between the cation exchange and such engineering properties of reinforcing soil as plasticity index, cohesive force and coefficient of compressibility were analyzed. The results showed that the cation exchange velocity of the proportion of 1:200 ISS reinforcing soil is the fastest among the three proportions (1:100, 1:200 and 1:300) and the modification effect of engineering performance index is quite obvious. These studies provide an experimental basis for the ISS applied to curing project, and monitoring geotechnical engineering performance by LIBS technology also provides a new way of thinking for the curing project monitoring.

Direct spectral analysis of tea samples using 266 nm UV pulsed laser-induced breakdown spectroscopy and cross validation of LIBS results with ICP-MS.

PubMed

Gondal, M A; Habibullah, Y B; Baig, Umair; Oloore, L E

2016-05-15

Tea is one of the most common and popular beverages spanning vast array of cultures all over the world. The main nutritional benefits of drinking tea are its anti-oxidant properties, presumed protection against certain cancers, inhibition of inflammation and possible protective effects against diabetes. Laser induced breakdown spectrometer (LIBS) was assembled as a powerful tool for qualitative and quantitative analysis of various brands of tea samples using 266 nm pulsed UV laser. LIBS spectra for six brands of tea samples in the wavelength range of 200-900 nm was recorded and all elements present in our tea samples were identified. The major toxic elements detected in several brands of tea samples were bromine, chromium and minerals like iron, calcium, potassium and silicon. The spectral assignment was conducted prior to the determination of concentration of each element. For quantitative analysis, calibration curves were drawn for each element using standard samples prepared in known concentration in the tea matrix. The plasma parameters (electron temperature and electron density) were also determined prior to the tea samples spectroscopic analysis. The concentration of iron, chromium, potassium, bromine, copper, silicon and calcium detected in all tea samples was between 378-656, 96-124, 1421-6785, 99-1476, 17-36, 2-11 and 92-130 mg L(-1) respectively. The limits of detection estimated for Fe, Cr, K, Br, Cu, Si, Ca in tea samples were 22, 12, 14, 11, 6, 1 and 12 mg L(-1) respectively. To further confirm the accuracy of our LIBS results, we determined the concentration of each element present in tea samples by using standard analytical technique like ICP-MS. The concentrations detected with our LIBS system are in excellent agreement with ICP-MS results. The system assembled for spectral analysis in this work could be highly applicable for testing the quality and purity of food and also pharmaceuticals products. Copyright © 2016 Elsevier B.V. All rights reserved.

Quantitative methods for compensation of matrix effects and self-absorption in Laser Induced Breakdown Spectroscopy signals of solids

NASA Astrophysics Data System (ADS)

Takahashi, Tomoko; Thornton, Blair

2017-12-01

This paper reviews methods to compensate for matrix effects and self-absorption during quantitative analysis of compositions of solids measured using Laser Induced Breakdown Spectroscopy (LIBS) and their applications to in-situ analysis. Methods to reduce matrix and self-absorption effects on calibration curves are first introduced. The conditions where calibration curves are applicable to quantification of compositions of solid samples and their limitations are discussed. While calibration-free LIBS (CF-LIBS), which corrects matrix effects theoretically based on the Boltzmann distribution law and Saha equation, has been applied in a number of studies, requirements need to be satisfied for the calculation of chemical compositions to be valid. Also, peaks of all elements contained in the target need to be detected, which is a bottleneck for in-situ analysis of unknown materials. Multivariate analysis techniques are gaining momentum in LIBS analysis. Among the available techniques, principal component regression (PCR) analysis and partial least squares (PLS) regression analysis, which can extract related information to compositions from all spectral data, are widely established methods and have been applied to various fields including in-situ applications in air and for planetary explorations. Artificial neural networks (ANNs), where non-linear effects can be modelled, have also been investigated as a quantitative method and their applications are introduced. The ability to make quantitative estimates based on LIBS signals is seen as a key element for the technique to gain wider acceptance as an analytical method, especially in in-situ applications. In order to accelerate this process, it is recommended that the accuracy should be described using common figures of merit which express the overall normalised accuracy, such as the normalised root mean square errors (NRMSEs), when comparing the accuracy obtained from different setups and analytical methods.

Determination of Cd, Cr and Pb in phosphate fertilizers by laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Nunes, Lidiane Cristina; de Carvalho, Gabriel Gustinelli Arantes; Santos, Dario; Krug, Francisco José

2014-07-01

A validated method for quantitative determination of Cd, Cr, and Pb in phosphate fertilizers by laser-induced breakdown spectroscopy (LIBS) is presented. Laboratory samples were comminuted and homogenized by cryogenic or planetary ball milling, pressed into pellets and analyzed by LIBS. The experimental setup was designed by using a Q-switched Nd:YAG at 1064 nm with 10 Hz repetition rate, and the intensity signals from Cd II 214.441 nm, Cr II 267.716 nm and Pb II 220.353 nm emission lines were measured by using a spectrometer furnished with an intensified charge-coupled device. LIBS parameters (laser fluence, lens-to-sample distance, delay time, integration time gate, number of sites and number of laser pulses per site) were chosen after univariate experiments with a pellet of NIST SRM 695 (Trace Elements in Multi-Nutrient Fertilizer). Calibration and validation were carried out with 30 fertilizer samples from single superphosphate, triple superphosphate, monoammonium phosphate, and NPK mixtures. Good results were obtained by using 30 pulses of 50 J cm- 2 (750 μm spot size), 2.0 μs delay time and 5.0 μs integration time gate. No significant differences between Cd, Cr, and Pb mass fractions determined by the proposed LIBS method and by ICP OES after microwave-assisted acid digestion (AOAC 2006.03 Official Method) were found at 95% confidence level. The limits of detection of 1 mg kg- 1 Cd, 2 mg kg- 1 Cr and 15 mg kg- 1 Pb and the precision (coefficients of variation of results ranging from 2% to 15%) indicate that the proposed LIBS method can be recommended for the determination of these analytes in phosphate fertilizers.

[High Precision Identification of Igneous Rock Lithology by Laser Induced Breakdown Spectroscopy].

PubMed

Wang, Chao; Zhang, Wei-gang; Yan, Zhi-quan

2015-09-01

In the field of petroleum exploration, lithology identification of finely cuttings sample, especially high precision identification of igneous rock with similar property, has become one of the geological problems. In order to solve this problem, a new method is proposed based on element analysis of Laser-Induced Breakdown Spectroscopy (LIBS) and Total Alkali versus Silica (TAS) diagram. Using independent LIBS system, factors influencing spectral signal, such as pulse energy, acquisition time delay, spectrum acquisition method and pre-ablation are researched through contrast experiments systematically. The best analysis conditions of igneous rock are determined: pulse energy is 50 mJ, acquisition time delay is 2 μs, the analysis result is integral average of 20 different points of sample's surface, and pre-ablation has been proved not suitable for igneous rock sample by experiment. The repeatability of spectral data is improved effectively. Characteristic lines of 7 elements (Na, Mg, Al, Si, K, Ca, Fe) commonly used for lithology identification of igneous rock are determined, and igneous rock samples of different lithology are analyzed and compared. Calibration curves of Na, K, Si are generated by using national standard series of rock samples, and all the linearly dependent coefficients are greater than 0.9. The accuracy of quantitative analysis is investigated by national standard samples. Element content of igneous rock is analyzed quantitatively by calibration curve, and its lithology is identified accurately by the method of TAS diagram, whose accuracy rate is 90.7%. The study indicates that LIBS can effectively achieve the high precision identification of the lithology of igneous rock.

A comparative study of highly-ionized Al plasma based on dual pulse laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Khalil, A. A. I.; Younis, W. O.; Gandol, M. A.

2017-03-01

We built a collinear dual-pulse laser-induced breakdown spectroscopy (DP-LIBS) system to study the aluminum (Al) plasma emission by installing a pair of Nd: YAG lasers operating at 266 and 1064 nm. The spectral intensities of selected aluminum doubly-ionized lines were employed to evaluate the optical emission spectra. The influences of the energy ratio of two pulsed lasers on the LIBS intensity for different Al doubly-ionized spectral lines were investigated. The de-excitation rate parameters of the excited ion and the electron impact excitation were computed using the analytical formulas proposed by Smeets and Vriens. The transition probabilities and energy states were computed using Hibbert's configuration interaction, computer package (CIV3). By solving the coupled rate equations including 1 s 22 s 22 p 6n s (2S), 1 s 22 s 22 p 6n p (2P), 1 s 22 s 22 p 6n d (2D) (n = 3-5) and 1 s 22 s 22 p 6n f (2F) (n = 4, 5) states, the level population densities were computed. We also proposed a theoretical population model in order to investigate the effectiveness of the various processes that might affect the population of the upper levels in Al plasma by using the rate coefficients. In addition, the population densities for the 19 upper levels were also computed. Good compatibility between the experimental and the theoretical model data had been observed. Our results might be significant as reference data for the optimization of the DP-LIBS spectrometry and diagnostics of laser produced plasmas.

Tuning excitation laser wavelength for secondary resonance in low-intensity phase-selective laser-induced breakdown spectroscopy for in-situ analytical measurement of nanoaerosols

NASA Astrophysics Data System (ADS)

Xiong, Gang; Li, Shuiqing; Tse, Stephen D.

2018-02-01

In recent years, a novel low-intensity phase-selective laser-induced breakdown spectroscopy (PS-LIBS) technique has been developed for unique elemental-composition identification of aerosolized nanoparticles, where only the solid-phase nanoparticles break down, forming nanoplasmas, without any surrounding gas-phase breakdown. Additional work has demonstrated that PS-LIBS emissions can be greatly enhanced with secondary resonant excitation by matching the excitation laser wavelength with an atomic transition line in the formed nanoplasma, thereby achieving low limits of detection. In this work, a tunable dye laser is employed to investigate the effects of excitation wavelength and irradiance on in-situ PS-LIBS measurements of TiO2 nanoaerosols. The enhancement factor by resonant excitation can be 220 times greater than that for non-resonant cases under similar conditions. Moreover, the emitted spectra are unique for the selected resonant transition lines for a given element, suggesting the potential to make precise phase-selective and analyte-selective measurements of nanoparticles in a multicomponent multiphase system. The enhancement factor by resonant excitation is highly sensitive to excitation laser wavelength, with narrow excitation spectral windows, i.e., 0.012 to 0.023 nm (FWHM, full width at half maximum) for Ti (I) neutral atomic lines, and 0.051 to 0.139 nm (FWHM) for Ti (II) single-ionized atomic lines. Boltzmann analysis of the emission intensities, temporal response of emissions, and emission dependence on excitation irradiance are investigated to understand aspects of the generated nanoplasmas such as temperature, local thermodynamic equilibrium (LTE), and excitation mechanism.

Characterization of cinematographic films by Laser Induced Breakdown Spectroscopy

NASA Astrophysics Data System (ADS)

Gaspard, S.; Oujja, M.; Rebollar, E.; Abrusci, C.; Catalina, F.; Castillejo, M.

2007-12-01

The emulsion-coated transparent plastic-base film has been the main carrier for production and preservation of motion picture contents since the 19th century. The knowledge of the composition of black and white silver gelatine cinematographic films is of great importance for the characterization of the photographic process and for identifying the optimum conditions for conservation. A cinematographic film is a multi-component system that consists of a layer of photographic emulsion overcoating a polymeric support (plasticized cellulose triacetate) and a protective transparent cross-linked gelatine layer coating the emulsion. In the present work, Laser Induced Breakdown Spectroscopy (LIBS) is used to characterize the composition of the materials of cinematographic films. LIB spectra of film samples and of different individual film components, polymeric support and reference gelatines, were acquired in vacuum by excitation at 266 nm (Q-switched Nd:YAG laser, 6 ns, 10 Hz). In the cinematographic film, silver lines from the light-sensitive silver halide salts of the photographic emulsion are accompanied by iron, lead, chrome and phosphorus lines. Iron and lead are constituents of film developers, chrome is included in the composition of the hardening agents and phosphorus has its origin in the plasticizer used in the polymeric support. By applying successive pulses on the same spot of the film sample, it was possible to observe through stratigraphic analysis the different layers composition. Additionally, the results obtained reveal the analytical capacity of LIBS for the study and classification of the different gelatine types and qualities used for the protecting layer and the photographic emulsion.

Comparison of laser-induced breakdown spectra of organic compounds with irradiation at 1.5 and 1.064 {mu}m

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wong, Diane M.; Dagdigian, Paul J

2008-11-01

A comprehensive investigation of laser-induced breakdown spectroscopy (LIBS) at 1.500 {mu}m of residues of six organic compounds (anthracene, caffeine, glucose, 1,3-dinitrobenzene, 2,4-dinitrophenol, and 2,4-dinitrotoluene) on aluminum substrates is presented and compared with LIBS at the Nd:YAG fundamental wavelength of 1.064 {mu}m. The overall emission intensities were found to be smaller at 1.500 {mu}m than at 1.064 {mu}m, and the ratios of C2 and CN molecular emissions to the H atomic emissions were observed to be less. Possible reasons for the observed differences in LIBS at 1.064 {mu}m versus 1.500 {mu}m are discussed.

Improved LIBS limit of detection of Be, Mg, Si, Mn, Fe and Cu in aluminum alloy samples using a portable Echelle spectrometer with ICCD camera

NASA Astrophysics Data System (ADS)

Mohamed, Walid Tawfik Y.

2008-02-01

Laser-induced breakdown spectroscopy (LIBS) is a laser-based technique that can provide non-intrusive, qualitative and quantitative measurement of metals in various environments. LIBS uses the plasma generated by a high-energy laser beam to prepare and excite the sample in one step. In the present work, LIBS has been applied to perform elemental analysis of six trace elements simultaneously in aluminum alloy targets. The plasma is generated by focusing a pulsed Nd:YAG laser on the target in air at atmospheric pressure. LIBS limit of detection (LOD) is affected by many experimental parameters such as interferences, self-absorption, spectral overlap and matrix effect. We aimed to improve the LIBS LOD by optimizing these experimental parameters as possible. In doing so, a portable Echelle spectrometer with intensified CCD camera was used to detect the LIBS plasma emission. This advanced Echelle spectrometer provides a constant spectral resolution (CSR) of 7500 corresponding to 4 pixels FWHM over a wavelength range 200-1000 nm displayable in a single spectrum. Then, the calibration curves for iron, beryllium, magnesium, silicon, manganese and copper as minor elements were achieved with linear regression coefficients between 98-99% on average in aluminum standard sample alloys. New LOD values were achieved in the ppm range with high precision (RSD 3-8%). From the application view point, improving LIBS LOD is very important in the on-line industrial process control to follow-up multi-elements for the correct alloying in metals.

Investigation of historical metal objects using Laser Induced Breakdown Spectroscopy (LIBS) technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdel-Kareem, O.; Ghoneim, M.; Harith, M. A.

2011-09-22

Analysis of metal objects is a necessary step for establishing an appropriate conservation treatment of an object or to follow up the application's result of the suggested treatments. The main considerations on selecting a method that can be used in investigation and analysis of metal objects are based on the diagnostic power, representative sampling, reproducibility, destructive nature/invasiveness of analysis and accessibility to the appropriate instrument. This study aims at evaluating the usefulness of the use of Laser Induced Breakdown Spectroscopy (LIBS) Technique for analysis of historical metal objects. In this study various historical metal objects collected from different museums andmore » excavations in Egypt were investigated using (LIBS) technique. For evaluating usefulness of the suggested analytical protocol of this technique, the same investigated metal objects were investigated by other methods such as Scanning Electron Microscope with energy-dispersive x-ray analyzer (SEM-EDX) and X-ray Diffraction (XRD). This study confirms that Laser Induced Breakdown Spectroscopy (LIBS) Technique is considered very useful technique that can be used safely for investigating historical metal objects. LIBS analysis can quickly provide information on the qualitative and semi-quantitative elemental content of different metal objects and their characterization and classification. It is practically non-destructive technique with the critical advantage of being applicable in situ, thereby avoiding sampling and sample preparations. It is can be dependable, satisfactory and effective method for low cost study of archaeological and historical metals. But we have to take into consideration that the corrosion of metal leads to material alteration and possible loss of certain metals in the form of soluble salts. Certain corrosion products are known to leach out of the object and therefore, their low content does not necessarily reflect the composition of the metal at the time of the object manufacture. Another point should be taken into consideration that the heterogeneity of a metal alloy object that often result from poor mixing of the different metal alloy composition.There is a necessity to carry out further research to investigate and determine the most appropriate and effective approaches and methods for conservation of these metal objects.« less

Contributions to process monitoring by laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Rusak, David Alexander

1998-12-01

When a pulsed laser of sufficient energy and pulse duration is brought to a focus, multi-photon ionization creates free electrons in the focal volume. These electrons are accelerated in a process known as inverse Bremsstrahlung and cause collisional ionization of species in the focal volume. More charge carriers are produced and the process continues for the duration of the laser pulse. The manifestation of this process is a visible spark or plasma which typically lasts for tens of microseconds. This laser-induced plasma can serve as a source in an atomic emission experiment. Because the composition of the plasma is determined in large part by the environment in which it forms, elements in the laser target can be determined spectroscopically. The goal of a laser-induced breakdown spectroscopy (LIBS) experiment is to establish a relationship between the concentration of an element of interest in the target and the intensity of light emitted from the laser-induced plasma at a wavelength characteristic of that element. Because LIBS requires only optical access to the sample and can perform elemental determinations in solids, liquids, or gases with little sample preparation, there is interest in using it as an on-line technique for process monitoring in a number of industrial applications. However, before the technique becomes useful in industrial applications, many issues regarding instrumentation and data analysis need to be addressed in the lab. The first two chapters of this dissertation provide, respectively, the basics of the atomic emission experiment and a background of laser-induced breakdown spectroscopy. The next two chapters examine the effect of target water content on the laser-induced plasma and the use of LIBS for analysis of aqueous samples. Chapter 5 describes construction of a fiber optic LIBS probe and its use to study temporal electron number density evolution in plasmas formed on different metals. Chapter 6 is a study of excitation, vibrational, and rotational temperatures in plasmas formed by ultraviolet and infrared laser beams. The last chapter is a brief assessment of classification software for analysis of LIBS data and a discussion of future work.

[Analysis of software for identifying spectral line of laser-induced breakdown spectroscopy based on LabVIEW].

PubMed

Hu, Zhi-yu; Zhang, Lei; Ma, Wei-guang; Yan, Xiao-juan; Li, Zhi-xin; Zhang, Yong-zhi; Wang, Le; Dong, Lei; Yin, Wang-bao; Jia, Suo-tang

2012-03-01

Self-designed identifying software for LIBS spectral line was introduced. Being integrated with LabVIEW, the soft ware can smooth spectral lines and pick peaks. The second difference and threshold methods were employed. Characteristic spectrum of several elements matches the NIST database, and realizes automatic spectral line identification and qualitative analysis of the basic composition of sample. This software can analyze spectrum handily and rapidly. It will be a useful tool for LIBS.

Evaluation of the laser-induced breakdown spectroscopy technique for determination of the chemical composition of copper concentrates

NASA Astrophysics Data System (ADS)

Łazarek, Łukasz; Antończak, Arkadiusz J.; Wójcik, Michał R.; Drzymała, Jan; Abramski, Krzysztof M.

2014-07-01

Laser-induced breakdown spectroscopy (LIBS), like many other spectroscopic techniques, is a comparative method. Typically, in qualitative analysis, synthetic certified standard with a well-known elemental composition is used to calibrate the system. Nevertheless, in all laser-induced techniques, such calibration can affect the accuracy through differences in the overall composition of the chosen standard. There are also some intermediate factors, which can cause imprecision in measurements, such as optical absorption, surface structure and thermal conductivity. In this work the calibration performed for the LIBS technique utilizes pellets made directly from the tested materials (old well-characterized samples). This choice produces a considerable improvement in the accuracy of the method. This technique was adopted for the determination of trace elements in industrial copper concentrates, standardized by conventional atomic absorption spectroscopy with a flame atomizer. A series of copper flotation concentrate samples was analyzed for three elements: silver, cobalt and vanadium. We also proposed a method of post-processing the measurement data to minimize matrix effects and permit reliable analysis. It has been shown that the described technique can be used in qualitative and quantitative analyses of complex inorganic materials, such as copper flotation concentrates. It was noted that the final validation of such methodology is limited mainly by the accuracy of the characterization of the standards.

Forensic analysis of printing inks using tandem Laser Induced Breakdown Spectroscopy and Laser Ablation Inductively Coupled Plasma Mass Spectrometry

NASA Astrophysics Data System (ADS)

Subedi, Kiran; Trejos, Tatiana; Almirall, José

2015-01-01

Elemental analysis, using either LA-ICP-MS or LIBS, can be used for the chemical characterization of materials of forensic interest to discriminate between source materials originating from different sources and also for the association of materials known to originate from the same source. In this study, a tandem LIBS/LA-ICP-MS system that combines the benefits of both LIBS and LA-ICP-MS was evaluated for the characterization of samples of printing inks (toners, inkjets, intaglio and offset.). The performance of both laser sampling methods is presented. A subset of 9 black laser toners, 10 colored (CMYK) inkjet samples, 12 colored (CMYK) offset samples and 12 intaglio inks originating from different manufacturing sources were analyzed to evaluate the discrimination capability of the tandem method. These samples were selected because they presented a very similar elemental profile by LA-ICP-MS. Although typical discrimination between different ink sources is found to be > 99% for a variety of inks when only LA-ICP-MS was used for the analysis, additional discrimination was achieved by combining the elemental results from the LIBS analysis to the LA-ICP-MS analysis in the tandem technique, enhancing the overall discrimination capability of the individual laser ablation methods. The LIBS measurements of the Ca, Fe, K and Si signals, in particular, improved the discrimination for this specific set of different ink samples previously shown to exhibit very similar LA-ICP-MS elemental profiles. The combination of these two techniques in a single setup resulted in better discrimination of the printing inks with two distinct fingerprint spectra, providing information from atomic/ionic emissions and isotopic composition (m/z) for each ink sample.

Laser-Induced Breakdown Spectroscopy of Trace Metals

NASA Technical Reports Server (NTRS)

Simons, Stephen (Technical Monitor); VanderWal, Randall L.; Ticich, Thomas M.; West, Joseph R., Jr.

2004-01-01

An alternative approach for laser-induced breakdown spectroscopy (LIBS) determination of trace metal determination in liquids is demonstrated. The limits of detection (LOD) for the technique ranged from 10 ppb to 10 ppm for 15 metals metals (Mg, Al, Si, Ca, Ti, Cr, Fe, Co, Ni, Cu, Zn, As, Cd, Hg, Pb) tested.

LIBS: a potential tool for industrial/agricultural waste water analysis

NASA Astrophysics Data System (ADS)

Karpate, Tanvi; K. M., Muhammed Shameem; Nayak, Rajesh; V. K., Unnikrishnan; Santhosh, C.

2016-04-01

Laser Induced Breakdown Spectroscopy (LIBS) is a multi-elemental analysis technique with various advantages and has the ability to detect any element in real time. This technique holds a potential for environmental monitoring and various such analysis has been done in soil, glass, paint, water, plastic etc confirms the robustness of this technique for such applications. Compared to the currently available water quality monitoring methods and techniques, LIBS has several advantages, viz. no need for sample preparation, fast and easy operation, and chemical free during the process. In LIBS, powerful pulsed laser generates plasma which is then analyzed to get quantitative and qualitative details of the elements present in the sample. Another main advantage of LIBS technique is that it can perform in standoff mode for real time analysis. Water samples from industries and agricultural strata tend to have a lot of pollutants making it harmful for consumption. The emphasis of this project is to determine such harmful pollutants present in trace amounts in industrial and agricultural wastewater. When high intensity laser is made incident on the sample, a plasma is generated which gives a multielemental emission spectra. LIBS analysis has shown outstanding success for solids samples. For liquid samples, the analysis is challenging as the liquid sample has the chances of splashing due to the high energy of laser and thus making it difficult to generate plasma. This project also deals with determining the most efficient method for testing of water sample for qualitative as well as quantitative analysis using LIBS.

Polarization mechanism in a ns laser-induced plasma spectroscopy of Al alloy

NASA Astrophysics Data System (ADS)

Aghababaei Nejad, Mahboobeh; Soltanolkotabi, Mahmood; Eslami Majd, Abdollah

2018-01-01

Polarization emission from aluminum alloy by ns laser-induced breakdown spectroscopy (LIBS) is carefully investigated in air using a non-gated CCD camera at integration time of 100 ms. First, the analysis reveals that the small polarization degree is the same for both continuum and discrete line emission spectra which also increases slowly with wavelength growth; second, laser fluence in the range of 347.81-550.10 J/cm2 has no significant changes in plasma polarization; and third, larger polarization in comparison with polarization introduced by preferential reflection of emission from the target surface (Fresnel reflectivity) is observed. The residual fluctuations of the anisotropic recombining plasma and the dynamic polarization of an ion's core are suggested as the possible main sources for observed polarized radiation in ns-LIBS.

Investigation of heavy-metal accumulation in selected plant samples using laser induced breakdown spectroscopy and laser ablation inductively coupled plasma mass spectrometry

NASA Astrophysics Data System (ADS)

Galiová, M.; Kaiser, J.; Novotný, K.; Novotný, J.; Vaculovič, T.; Liška, M.; Malina, R.; Stejskal, K.; Adam, V.; Kizek, R.

2008-12-01

Single-pulse Laser-Induced Breakdown Spectroscopy (LIBS) and Laser-Ablation Inductively Coupled Plasma Mass-Spectrometry (LA-ICP-MS) were applied for mapping the silver and copper distribution in Helianthus Annuus L. samples treated with contaminant in controlled conditions. For Ag and Cu detection the 328.07 nm Ag(I) and 324.75 nm Cu(I) lines were used, respectively. The LIBS experimental conditions (mainly the laser energy and the observation window) were optimized in order to avoid self-absorption effect in the measured spectra. In the LA-ICP-MS analysis the Ag 107 and Cu 63 isotopes were detected. The capability of these two analytical techniques for high-resolution mapping of selected trace chemical elements was demonstrated.

Analysis of organic vapors with laser induced breakdown spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nozari, Hadi; Tavassoli, Seyed Hassan; Rezaei, Fatemeh, E-mail: fatemehrezaei@kntu.ac.ir

2015-09-15

In this paper, laser induced breakdown spectroscopy (LIBS) is utilized in the study of acetone, ethanol, methanol, cyclohexane, and nonane vapors. Carbon, hydrogen, oxygen, and nitrogen atomic emission spectra have been recorded following laser-induced breakdown of the organic vapors that are mixed with air inside a quartz chamber at atmospheric pressure. The plasma is generated with focused, Q-switched Nd:YAG radiation at the wavelength of 1064 nm. The effects of ignition and vapor pressure are discussed in view of the appearance of the emission spectra. The recorded spectra are proportional to the vapor pressure in air. The hydrogen and oxygen contributions diminishmore » gradually with consecutive laser-plasma events without gas flow. The results show that LIBS can be used to characterize organic vapor.« less

Analyzing silver concentration in soil using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Prasetyo, S.; Isnaeni; Zaitun; Mitchell, K.; Suliyanti, M. M.; Herbani, Y.

2018-03-01

Determination of concentration of heavy metal ions in soil, such as silver, is very important to study soil pollution levels. Several techniques have been developed to determine silver ion concentration in soil. In this paper, we utilized laser-induced breakdown spectroscopy (LIBS) to study silver concentration in soil. We used four different data analysis methods to calculate silver concentration. In this case, we prepared soil samples with different silver ion concentrations from 400 ppm to 1000 ppm. Our analysis was focused on the 843.15 nm silver atomic absorption line. We found that plasma intensity increased as silver concentration increased. Our findings were based on our analysis using four different analysis methods. We believe that these analysis methods are able to calculate silver concentration in soil using LIBS.

Development of a LIBS assay for the detection of Salmonella enterica serovar Typhimurium from food.

PubMed

Barnett, Cleon; Bell, Courtneé; Vig, Komal; Akpovo, A C; Johnson, Lewis; Pillai, Shreekumar; Singh, Shree

2011-07-01

Laser-induced breakdown spectroscopy (LIBS) is used for the identification of the presence of hazardous bacteria in food. In this study, our main focus was centered on the identification of S. enterica serovar Typhimurium, a Gram-negative foodborne pathogen, in various liquids such as milk, chicken broth, and brain heart infusion due to the infection being most prevalent in raw meat and dairy products. A Nd:YAG laser of operating wavelength 266 nm was used to obtain the spectra from the artificially inoculated liquid samples. A series of experiments were performed to determine the effectiveness of LIBS to discriminate the bacteria from the background liquids. These results are compared with competing modern molecular methods of detection which include polymerase chain reaction (PCR) and quantitative real-time PCR. In addition to analyzing S. enterica serovar Typhimurium, another common Gram-negative, Escherichia coli, as well as Gram-positive pathogen, Staphlycoccus auerus, were used to determine the specificity of the LIBS technique.

The feasibility of TEA CO2 laser-induced plasma for spectrochemical analysis of geological samples in simulated Martian conditions

NASA Astrophysics Data System (ADS)

Savovic, Jelena; Stoiljkovic, Milovan; Kuzmanovic, Miroslav; Momcilovic, Milos; Ciganovic, Jovan; Rankovic, Dragan; Zivkovic, Sanja; Trtica, Milan

2016-04-01

The present work studies the possibility of using pulsed Transversely Excited Atmospheric (TEA) carbon dioxide laser as an energy source for laser-induced breakdown spectroscopy (LIBS) analysis of rocks under simulated Martian atmospheric conditions. Irradiation of a basaltic rock sample with the laser intensity of 56 MW cm- 2, in carbon-dioxide gas at a pressure of 9 mbar, created target plasma with favorable conditions for excitation of all elements usually found in geological samples. Detection limits of minor constituents (Ba, Cr, Cu, Mn, Ni, Sr, V, and Zr) were in the 3 ppm-30 ppm range depending on the element. The precision varied between 5% and 25% for concentration levels of 1% to 10 ppm, respectively. Generally, the proposed relatively simple TEA CO2 laser-LIBS system provides good sensitivity for geological studies under reduced CO2 pressure.

[Rapid multi-elemental analysis on four precious Tibetan medicines based on LIBS technique].

PubMed

Liu, Xiao-na; Shi, Xin-yuan; Jia, Shuai-yun; Zhao, Na; Wu, Zhi-sheng; Qiao, Yan-jiang

2015-06-01

The laser-induced breakdown spectroscopy (LIBS) was applied to perform a qualitative elementary analysis on four precious Tibetan medicines, i. e. Renqing Mangjue, Renqing Changjue, 25-herb coral pills and 25-herb pearl pills. The specific spectra of the four Tibetan medicines were established. In the experiment, Nd: YAG and 1 064 nm-baseband pulse laser were adopted to collect the spectra. A laser beam focused on the surface of the samples to generate plasma. Its spectral signal was detected by using spectrograph. Based on the National Institute of Standard and Technology (NIST) database, LIBS spectral lines were indentified. The four Tibetan medicines mainly included Ca, Na, K, Mg and other elements and C-N molecular band. Specifically, Fe was detected in Renqing Changjue and 25-herb pearl pills; heavy mental elements Hg and Cu were shown in Renqing Mangjue and Renqing Changjue; Ag was found in Renqing Changjue. The results demonstrated that LIBS is a reliable and rapid multi-element analysis on the four Tibetan medicines. With Real-time, rapid and nondestructive advantages, LIBS has a wide application prospect in the element analysis on ethnic medicines.

Quantitative estimation of carbonation and chloride penetration in reinforced concrete by laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Eto, Shuzo; Matsuo, Toyofumi; Matsumura, Takuro; Fujii, Takashi; Tanaka, Masayoshi Y.

2014-11-01

The penetration profile of chlorine in a reinforced concrete (RC) specimen was determined by laser-induced breakdown spectroscopy (LIBS). The concrete core was prepared from RC beams with cracking damage induced by bending load and salt water spraying. LIBS was performed using a specimen that was obtained by splitting the concrete core, and the line scan of laser pulses gave the two-dimensional emission intensity profiles of 100 × 80 mm2 within one hour. The two-dimensional profile of the emission intensity suggests that the presence of the crack had less effect on the emission intensity when the measurement interval was larger than the crack width. The chlorine emission spectrum was measured without using the buffer gas, which is usually used for chlorine measurement, by collinear double-pulse LIBS. The apparent diffusion coefficient, which is one of the most important parameters for chloride penetration in concrete, was estimated using the depth profile of chlorine emission intensity and Fick's law. The carbonation depth was estimated on the basis of the relationship between carbon and calcium emission intensities. When the carbon emission intensity was statistically higher than the calcium emission intensity at the measurement point, we determined that the point was carbonated. The estimation results were consistent with the spraying test results using phenolphthalein solution. These results suggest that the quantitative estimation by LIBS of carbonation depth and chloride penetration can be performed simultaneously.

Improved accuracy in quantitative laser-induced breakdown spectroscopy using sub-models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, Ryan B.; Clegg, Samuel M.; Frydenvang, Jens

We report that accurate quantitative analysis of diverse geologic materials is one of the primary challenges faced by the Laser-Induced Breakdown Spectroscopy (LIBS)-based ChemCam instrument on the Mars Science Laboratory (MSL) rover. The SuperCam instrument on the Mars 2020 rover, as well as other LIBS instruments developed for geochemical analysis on Earth or other planets, will face the same challenge. Consequently, part of the ChemCam science team has focused on the development of improved multivariate analysis calibrations methods. Developing a single regression model capable of accurately determining the composition of very different target materials is difficult because the response ofmore » an element’s emission lines in LIBS spectra can vary with the concentration of other elements. We demonstrate a conceptually simple “submodel” method for improving the accuracy of quantitative LIBS analysis of diverse target materials. The method is based on training several regression models on sets of targets with limited composition ranges and then “blending” these “sub-models” into a single final result. Tests of the sub-model method show improvement in test set root mean squared error of prediction (RMSEP) for almost all cases. Lastly, the sub-model method, using partial least squares regression (PLS), is being used as part of the current ChemCam quantitative calibration, but the sub-model method is applicable to any multivariate regression method and may yield similar improvements.« less

Signal processing for the detection of explosive residues on varying substrates using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Morton, Kenneth D., Jr.; Torrione, Peter A.; Collins, Leslie

2011-05-01

Laser induced breakdown spectroscopy (LIBS) can provide rapid, minimally destructive, chemical analysis of substances with the benefit of little to no sample preparation. Therefore, LIBS is a viable technology for the detection of substances of interest in near real-time fielded remote sensing scenarios. Of particular interest to military and security operations is the detection of explosive residues on various surfaces. It has been demonstrated that LIBS is capable of detecting such residues, however, the surface or substrate on which the residue is present can alter the observed spectra. Standard chemometric techniques such as principal components analysis and partial least squares discriminant analysis have previously been applied to explosive residue detection, however, the classification techniques developed on such data perform best against residue/substrate pairs that were included in model training but do not perform well when the residue/substrate pairs are not in the training set. Specifically residues in the training set may not be correctly detected if they are presented on a previously unseen substrate. In this work, we explicitly model LIBS spectra resulting from the residue and substrate to attempt to separate the response from each of the two components. This separation process is performed jointly with classifier design to ensure that the classifier that is developed is able to detect residues of interest without being confused by variations in the substrates. We demonstrate that the proposed classification algorithm provides improved robustness to variations in substrate compared to standard chemometric techniques for residue detection.

Improved accuracy in quantitative laser-induced breakdown spectroscopy using sub-models

DOE PAGES

Anderson, Ryan B.; Clegg, Samuel M.; Frydenvang, Jens; ...

2016-12-15

We report that accurate quantitative analysis of diverse geologic materials is one of the primary challenges faced by the Laser-Induced Breakdown Spectroscopy (LIBS)-based ChemCam instrument on the Mars Science Laboratory (MSL) rover. The SuperCam instrument on the Mars 2020 rover, as well as other LIBS instruments developed for geochemical analysis on Earth or other planets, will face the same challenge. Consequently, part of the ChemCam science team has focused on the development of improved multivariate analysis calibrations methods. Developing a single regression model capable of accurately determining the composition of very different target materials is difficult because the response ofmore » an element’s emission lines in LIBS spectra can vary with the concentration of other elements. We demonstrate a conceptually simple “submodel” method for improving the accuracy of quantitative LIBS analysis of diverse target materials. The method is based on training several regression models on sets of targets with limited composition ranges and then “blending” these “sub-models” into a single final result. Tests of the sub-model method show improvement in test set root mean squared error of prediction (RMSEP) for almost all cases. Lastly, the sub-model method, using partial least squares regression (PLS), is being used as part of the current ChemCam quantitative calibration, but the sub-model method is applicable to any multivariate regression method and may yield similar improvements.« less

A novel baseline correction method using convex optimization framework in laser-induced breakdown spectroscopy quantitative analysis

NASA Astrophysics Data System (ADS)

Yi, Cancan; Lv, Yong; Xiao, Han; Ke, Ke; Yu, Xun

2017-12-01

For laser-induced breakdown spectroscopy (LIBS) quantitative analysis technique, baseline correction is an essential part for the LIBS data preprocessing. As the widely existing cases, the phenomenon of baseline drift is generated by the fluctuation of laser energy, inhomogeneity of sample surfaces and the background noise, which has aroused the interest of many researchers. Most of the prevalent algorithms usually need to preset some key parameters, such as the suitable spline function and the fitting order, thus do not have adaptability. Based on the characteristics of LIBS, such as the sparsity of spectral peaks and the low-pass filtered feature of baseline, a novel baseline correction and spectral data denoising method is studied in this paper. The improved technology utilizes convex optimization scheme to form a non-parametric baseline correction model. Meanwhile, asymmetric punish function is conducted to enhance signal-noise ratio (SNR) of the LIBS signal and improve reconstruction precision. Furthermore, an efficient iterative algorithm is applied to the optimization process, so as to ensure the convergence of this algorithm. To validate the proposed method, the concentration analysis of Chromium (Cr),Manganese (Mn) and Nickel (Ni) contained in 23 certified high alloy steel samples is assessed by using quantitative models with Partial Least Squares (PLS) and Support Vector Machine (SVM). Because there is no prior knowledge of sample composition and mathematical hypothesis, compared with other methods, the method proposed in this paper has better accuracy in quantitative analysis, and fully reflects its adaptive ability.

Temporal and modal characterization of DoD source air toxic ...

EPA Pesticide Factsheets

This project tested three, real-/near real-time monitoring techniques to develop air toxic emission factors for Department of Defense (DoD) platform sources. These techniques included: resonance enhanced multi photon ionization time of flight mass spectrometry (REMPI-TOFMS) for organic air toxics, laser induced breakdown spectroscopy (LIBS) for metallic air toxics, and optical remote sensing (ORS) methods for measurement of criteria pollutants and other hazardous air pollutants (HAPs). Conventional emission measurements were used for verification of the real-time monitoring results. The REMPI-TOFMS system was demonstrated on the following: --a United States U.S. Marine Corps (USMC) diesel generator, --a U.S. Air Force auxiliary power unit (APU), --the waste combustor at the Portsmouth Naval Shipyard, during a multi-monitor environmental technology verification (ETV) test for dioxin monitoring systems, --two dynamometer-driven high mobility multi-purpose wheeled vehicles (HMMWVs), --an idling Abrams battle tank, --a Bradley infantry fighting vehicle (IFV), and --an F-15 and multiple F-22 U.S. Air Force aircraft engines. LIBS was tested and applied solely to the U.S. Marine Corps diesel generator. The high detection limits of LIBS for toxic metals limited its usefulness as a real time analyzer for most DoD sources. ORS was tested only on the APU with satisfactory results for non-condensable combustion products (carbon monoxide [CO], carbon dioxide

Evaluation of the Nutritional Changes Caused by Huanglongbing (HLB) to Citrus Plants Using Laser-Induced Breakdown Spectroscopy.

PubMed

Ranulfi, Anielle Coelho; Romano, Renan Arnon; Bebeachibuli Magalhães, Aida; Ferreira, Ednaldo José; Ribeiro Villas-Boas, Paulino; Marcondes Bastos Pereira Milori, Débora

2017-07-01

Huanglongbing (HLB) is the most recent and destructive bacterial disease of citrus and has no cure yet. A promising alternative to conventional methods is to use laser-induced breakdown spectroscopy (LIBS), a multi-elemental analytical technique, to identify the nutritional changes provoked by the disease to the citrus leaves and associate the mineral composition profile with its health status. The leaves were collected from adult citrus trees and identified by visual inspection as healthy, HLB-symptomatic, and HLB-asymptomatic. Laser-induced breakdown spectroscopy measurements were done in fresh leaves without sample preparation. Nutritional variations were evaluated using statistical tools, such as Student's t-test and analysis of variance applied to LIBS spectra, and the largest were found for Ca, Mg, and K. Considering the nutritional profile changes, a classifier induced by classification via regression combined with partial least squares regression was built resulting in an accuracy of 73% for distinguishing the three categories of leaves.

Microanalysis of tool steel and glass with laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Loebe, Klaus; Uhl, Arnold; Lucht, Hartmut

2003-10-01

A laser microscope system for the microanalytical characterization of complex materials is described. The universal measuring principle of laser-induced breakdown spectroscopy (LIBS) in combination with echelle optics permits a fast simultaneous multielement analysis with a possible spatial resolution below 10 pm. The developed system features completely UV-transparent optics for the laser-microscope coupling and the emission beam path and enables parallel signal detection within the wavelength range of 200-800 nm with a spectral resolution of a few picometers. Investigations of glass defects and tool steels were performed. The characterization of a glass defect in a tumbler by a micro-LIBS line scan, with use of a 266-nm diode-pumped Nd:YAG laser for excitation, is possible by simple comparison of plasma spectra of the defect and the surrounding area. Variations in the main elemental composition as well as impurities by trace elements are detected at the same time. Through measurement of the calibration samples with the known concentration of the corresponding element, a correlation between the intensity of spectral lines and the element concentration was also achieved. The change of elemental composition at the transient stellite solder of tool steels has been determined by an area scan. The two-dimensional pictures show abrupt changes of the element distribution along the solder edge and allow fundamental researches of dynamic modifications (e.g., diffusion) in steel.

Detecteur multibandes libs a base de reseaux holographiques epais: Conception optomecanique et gestion de l'innovation

NASA Astrophysics Data System (ADS)

Gagnon, Daniel

Detection of sulfur by optical emission spectroscopy generally presents difficulties because the strongest lines are in the vacuum ultraviolet and therefore are readily absorbed by oxygen molecules in air. A novel concept for a low cost and efficient system to detect sulfur using near infrared lines by Laser-Induced Breakdown Spectroscopy is proposed in this thesis. The concept proposes to use customized thick holographic gratings, also referred as Volume Bragg Grating, for spectral filtering of the plasma light, and built-in custom electronics that amplify and integrate photodiodes output signals. In this work, the optomechanical design, manufacturing and trials of a multiband sensor's prototype is reviewed. Preliminary results has been presented at NASLIBS 2011 and showed a limit of detection comparable to that of a conventional high-end system. An article describing the concept and results has been published in a special issue of the Applied Optics journal. To turn this newly patented concept into commercial success, the management of the innovation has been performed by proposing strategic and tactic alliances for commercialisation purposes applied to strategic business positioning structured along the 3 axis Technology -- Product -- Market. Open innovation is here acting as the paradigm to efficiently reach the market. Discussion relative to strategic and tactic alliance is actually taking place for deployment of the LIBS multiband sensor in the mining industry.

Detection of lead in brass by laser-induced breakdown spectroscopy combined with laser-induced fluorescence

NASA Astrophysics Data System (ADS)

Goueguel, Christian; Laville, Stéphane; Loudyi, Hakim; Chaker, Mohamed; Sabsabi, Mohamad; Vidal, François

2008-06-01

Laser-Induced Breakdown Spectroscopy (LIBS) technique combined with Laser-Induced Fluorescence (LIF) is known to be a high sensitivity and high selectivity analytical technique. Although sub-ppm limits of detection (LoD) have already been demonstrated, there is still a constant and urgent need to reach lower LoDs. Here, we report results obtained for the detection of lead trace in brass samples. The plasma was produced by a Q-switched Nd:YAG laser at 1064 nm and then re-excited by a nanosecond optical parametric oscillator (OPO) laser tuned at 283.31 nm. Emission from Pb atoms was then observed at 405.78 nm. The experiments were performed in air at atmospheric pressure. We found out that the optimal conditions were obtained for an ablation fluence of 2-3 J/cm2 and inter-pulse delay of 8-10 μs. Also, excitation energy of about 200 μJ was required to maximize the Pb(I) 405.78 nm emission. Using the LIBS-LIFS technique, the LoD was estimated to be about 180 ppb over 100 laser shots, which corresponds to an improvement of about two orders of magnitude with that obtained using conventional LIBS.

Qualitative and quantitative analysis of an additive element in metal oxide nanometer film using laser induced breakdown spectroscopy.

PubMed

Xiu, Junshan; Liu, Shiming; Sun, Meiling; Dong, Lili

2018-01-20

The photoelectric performance of metal ion-doped TiO 2 film will be improved with the changing of the compositions and concentrations of additive elements. In this work, the TiO 2 films doped with different Sn concentrations were obtained with the hydrothermal method. Qualitative and quantitative analysis of the Sn element in TiO 2 film was achieved with laser induced breakdown spectroscopy (LIBS) with the calibration curves plotted accordingly. The photoelectric characteristics of TiO 2 films doped with different Sn content were observed with UV visible absorption spectra and J-V curves. All results showed that Sn doping could improve the optical absorption to be red-shifted and advance the photoelectric properties of the TiO 2 films. We had obtained that when the concentration of Sn doping in TiO 2 films was 11.89  mmol/L, which was calculated by the LIBS calibration curves, the current density of the film was the largest, which indicated the best photoelectric performance. It indicated that LIBS was a potential and feasible measured method, which was applied to qualitative and quantitative analysis of the additive element in metal oxide nanometer film.

Understanding the signature of rock coatings in laser-induced breakdown spectroscopy data

USGS Publications Warehouse

Lanza, Nina L.; Ollila, Ann M.; Cousin, Agnes; Wiens, Roger C.; Clegg, Samuel M.; Mangold, Nicolas; Bridges, Nathan; Cooper, Daniel; Schmidt, Mariek E.; Berger, Jeffrey; Arvidson, Raymond E.; Melikechi, Noureddine; Newsom, Horton E.; Tokar, Robert; Hardgrove, Craig; Mezzacappa, Alissa; Jackson, Ryan S.; Clark, Benton C.; Forni, Olivier; Maurice, Sylvestre; Nachon, Marion; Anderson, Ryan B.; Blank, Jennifer; Deans, Matthew; Delapp, Dorothea; Léveillé, Richard; McInroy, Rhonda; Martinez, Ronald; Meslin, Pierre-Yves; Pinet, Patrick

2015-01-01

Surface compositional features on rocks such as coatings and weathering rinds provide important information about past aqueous environments and water–rock interactions. The search for these features represents an important aspect of the Curiosity rover mission. With its unique ability to do fine-scale chemical depth profiling, the ChemCam laser-induced breakdown spectroscopy instrument (LIBS) onboard Curiosity can be used to both identify and analyze rock surface alteration features. In this study we analyze a terrestrial manganese-rich rock varnish coating on a basalt rock in the laboratory with the ChemCam engineering model to determine the LIBS signature of a natural rock coating. Results show that there is a systematic decrease in peak heights for elements such as Mn that are abundant in the coating but not the rock. There is significant spatial variation in the relative abundance of coating elements detected by LIBS depending on where on the rock surface sampled; this is due to the variability in thickness and spatial discontinuities in the coating. Similar trends have been identified in some martian rock targets in ChemCam data, suggesting that these rocks may have coatings or weathering rinds on their surfaces.

Matrix Effects on Boron Containing Materials due to Laser Ablation Molecular Isotopic Spectrometry (LAMIS)

NASA Astrophysics Data System (ADS)

Brown, Staci R.; Akpovo, Charlemagne A.; Martinez, Jorge; Ford, Alan; Herbert, Kenley; Johnson, Lewis

2014-03-01

Laser Induced Breakdown Spectroscopy (LIBS) is a spectroscopic technique that is used for the qualitative and quantitative analysis of materials in the liquid, solid, or gas phase. LIBS can also be used for the detection of isotopic shifts in atomic and diatomic species via Laser-Ablation Molecular Isotopic Spectroscopy (LAMIS). However, any additional elements that are entrained into the plasma other than the element of interest, can affect the extent of ablation and quality of spectra and hence, potentially obscure or aid in the relative abundance assessment for a given element. To address the importance of matrix effects, the isotopic analysis of boron obtained from boron oxide (BO) emission originating from different boron-containing compounds, such as boron nitride (BN), boric acid (H3BO3) , and borax (Na2B4O710H2O), via LIBS has been performed here. Each of these materials has different physical properties and elemental composition in order to illustrate possible challenges for the LAMIS method. A calibration-free model similar to that for the original LAMIS work is used to determine properties of the plasma as the matrix is changed. DTRA

Pulsed—Laser Deposition Of Oxide Thin Films And Laser—Induced Breakdown Spectroscopy Of Multi—Element Materials

NASA Astrophysics Data System (ADS)

Pedarnig, Johannes D.

2010-10-01

New results of the Linz group on pulsed—laser deposition (PLD) of oxide thin films and on laser—induced breakdown spectroscopy (LIBS) of multi-element materials are reported. High-Tc superconducting (HTS) films with enhanced critical current density Jc are produced by laser ablation of novel nano-composite ceramic targets. The targets contain insulating nano-particles that are embedded into the YBa2Cu3O7 matrix. Epitaxial double-layers of lithium-doped and aluminum-doped ZnO are deposited on r-cut sapphire substrates. Acoustic over-modes in the GHz range are excited by piezoelectric actuation of layers. Smooth films of rare-earth doped glass are produced by F2—laser ablation. The transport properties of HTS thin films are modified by light—ion irradiation. Thin film nano—patterning is achieved by masked ion beam irradiation. LIBS is employed to analyze trace elements in industrial iron oxide powder and reference polymer materials. Various trace elements of ppm concentration are measured in the UV/VIS and vacuum-UV spectral range. Quantitative LIBS analysis of major components in oxide materials is performed by calibration-free methods.

Laser-induced breakdown spectroscopy measurement of a small fraction of rhenium in bulk tungsten

NASA Astrophysics Data System (ADS)

Nishijima, D.; Ueda, Y.; Doerner, R. P.; Baldwin, M. J.; Ibano, K.

2018-03-01

Laser-induced breakdown spectroscopy (LIBS) of bulk rhenium (Re) and tungsten (W)-Re alloy has been performed using a Q-switched Nd:YAG laser (wavelength = 1064 nm, pulse width ∼4-6 ns, laser energy = 115 mJ). It is found that the electron temperature, Te, of laser-induced Re plasma is lower than that of W plasma, and that Te of W-Re plasma is in between Re and W plasmas. This indicates that material properties affect Te in a laser-induced plasma. For analysis of W-3.3%Re alloy, only the strongest visible Re I 488.9 nm line is found to be used because of the strong enough intensity without contamination with W lines. Using the calibration-free LIBS method, the atomic fraction of Re, cRe, is evaluated as a function of the ambient Ar gas pressure, PAr. At PAr < 10 Torr, LIBS-measured cRe agrees well with that from EDX (energy-dispersive X-ray micro-analysis), while cRe increases with an increase in PAr at >10 Torr due to spectral overlapping of the Re I 488.9 nm line by an Ar II 488.9 nm line.

A study of association between fingernail elements and osteoporosis by laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Bahreini, Maryam; Hosseinimakarem, Zahra; Hassan Tavassoli, Seyed

2012-09-01

Laser induced breakdown spectroscopy (LIBS) is used to investigate the possible effect of osteoporosis on the elemental composition of fingernails. Also, the ability to classify healthy, osteopenic, and osteoporotic subjects based on their fingernail spectra has been examined. 46 atomic and ionic emission lines belonging to 13 elements, which are dominated by calcium and magnesium, have been identified. Measurements are carried out on fingernail clippings of 99 subjects including 27 healthy, 47 osteopenic, and 25 osteoporotic subjects. The Pearson correlations between spectral intensities of different elements of fingernail and age and bone mineral densities (BMDs) in nail samples are calculated. Correlations between line intensities of some elements such as sodium and potassium, calcium and iron, magnesium and silicon and also between some fingernail elements, BMD, and age are observed. Although some of these correlations are weak, some information about mineral metabolism can be deduced from them. Discrimination between nail samples of healthy, osteopenic, and osteoporotic subjects is shown to be somehow possible by a discriminant function analysis using 46 atomic emission lines of the LIBS spectra as input variables. The results of this study provide some evidences for association between osteoporosis and elemental composition of fingernails measured by LIBS.

Inverse Calibration Free fs-LIBS of Copper-Based Alloys

NASA Astrophysics Data System (ADS)

Smaldone, Antonella; De Bonis, Angela; Galasso, Agostino; Guarnaccio, Ambra; Santagata, Antonio; Teghil, Roberto

2016-09-01

In this work the analysis by Laser Induced Breakdown Spectroscopy (LIBS) technique of copper-based alloys having different composition and performed with fs laser pulses is presented. A Nd:Glass laser (Twinkle Light Conversion, λ = 527 nm at 250 fs) and a set of bronze and brass certified standards were used. The inverse Calibration-Free method (inverse CF-LIBS) was applied for estimating the temperature of the fs laser induced plasma in order to achieve quantitative elemental analysis of such materials. This approach strengthens the hypothesis that, through the assessment of the plasma temperature occurring in fs-LIBS, straightforward and reliable analytical data can be provided. With this aim the capability of the here adopted inverse CF-LIBS method, which is based on the fulfilment of the Local Thermodynamic Equilibrium (LTE) condition, for an indirect determination of the species excitation temperature, is shown. It is reported that the estimated temperatures occurring during the process provide a good figure of merit between the certified and the experimentally determined composition of the bronze and brass materials, here employed, although further correction procedure, like the use of calibration curves, can be demanded. The reported results demonstrate that the inverse CF-LIBS method can be applied when fs laser pulses are used even though the plasma properties could be affected by the matrix effects restricting its full employment to unknown samples provided that a certified standard having similar composition is available.

Application of LIBS to the in-line process control of liquid high-alloy steel under pressure.

PubMed

Hubmer, Gerhard; Kitzberger, Reinhard; Mörwald, Karl

2006-05-01

A process optimization and control system called VAI-CON Chem has been developed that uses laser-induced breakdown spectroscopy (LIBS) to quasi-continuously chemically analyze liquid high-alloy steel under pressure. The beam from a Nd:YAG laser, located on safe ground and operating at its fundamental wavelength, is guided by a mirror system to a process tuyere below bath level. Passing through the approximately 1.5 m long tuyere, the beam is then focused onto the steel bath. Light emitted from the induced plasma passes back through the tuyere, which is coupled to a fiber optic cable that carries the information over a distance of approximately 10 m back to an Echelle spectrometer located beside the laser. Calibrations were performed using the complete system, located in a laboratory, during system testing. An induction furnace was used to simulate the AOD converter, wherein the samples were molten and superheated to a temperature of approximately 1600 degrees C and kept at a pressure of approximately 1.7 bar under an argon atmosphere. Twelve different high alloyed reference samples taken from normal AOD production with Fe concentrations of >48 wt.% and non-Fe element concentrations of up to 25 wt.% were available for calibration. The mean residual deviations (defined as the square root of the variance of the concentration ratios determined by LIBS and the reference element concentration ratios) obtained were close to those reported for other comparable high-alloy samples that were investigated at room temperature under normal atmospheric pressure.

Elemental analysis of soils using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and laser-induced breakdown spectroscopy (LIBS) with multivariate discrimination: tape mounting as an alternative to pellets for small forensic transfer specimens.

PubMed

Jantzi, Sarah C; Almirall, José R

2014-01-01

Elemental analysis of soil is a useful application of both laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and laser-induced breakdown spectroscopy (LIBS) in geological, agricultural, environmental, archeological, planetary, and forensic sciences. In forensic science, the question to be answered is often whether soil specimens found on objects (e.g., shoes, tires, or tools) originated from the crime scene or other location of interest. Elemental analysis of the soil from the object and the locations of interest results in a characteristic elemental profile of each specimen, consisting of the amount of each element present. Because multiple elements are measured, multivariate statistics can be used to compare the elemental profiles in order to determine whether the specimen from the object is similar to one of the locations of interest. Previous work involved milling and pressing 0.5 g of soil into pellets before analysis using LA-ICP-MS and LIBS. However, forensic examiners prefer techniques that require smaller samples, are less time consuming, and are less destructive, allowing for future analysis by other techniques. An alternative sample introduction method was developed to meet these needs while still providing quantitative results suitable for multivariate comparisons. The tape-mounting method involved deposition of a thin layer of soil onto double-sided adhesive tape. A comparison of tape-mounting and pellet method performance is reported for both LA-ICP-MS and LIBS. Calibration standards and reference materials, prepared using the tape method, were analyzed by LA-ICP-MS and LIBS. As with the pellet method, linear calibration curves were achieved with the tape method, as well as good precision and low bias. Soil specimens from Miami-Dade County were prepared by both the pellet and tape methods and analyzed by LA-ICP-MS and LIBS. Principal components analysis and linear discriminant analysis were applied to the multivariate data. Results from both the tape method and the pellet method were nearly identical, with clear groupings and correct classification rates of >94%.

Effect of laser irradiance and wavelength on the analysis of gold- and silver-bearing minerals with laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Díaz, Daniel; Molina, Alejandro; Hahn, David

2018-07-01

The influence of laser irradiance and wavelength on the analysis of gold and silver in ore and surrogate samples with laser-induced breakdown spectroscopy (LIBS) was evaluated. Gold-doped mineral samples (surrogates) and ore samples containing naturally-occurring gold and silver were analyzed with LIBS using 1064 and 355 nm laser wavelengths at irradiances from 0.36 × 109 to 19.9 × 109 W/cm2 and 0.97 × 109 to 4.3 × 109 W/cm2, respectively. The LIBS net, background and signal-to-background signals were analyzed. For all irradiances, wavelengths, samples and analytes the calibration curves behaved linearly for concentrations from 1 to 9 μg/g gold (surrogate samples) and 0.7 to 47.0 μg/g silver (ore samples). However, it was not possible to prepare calibration curves for gold-bearing ore samples (at any concentration) nor for gold-doped surrogate samples with gold concentrations below 1 μg/g. Calibration curve parameters for gold-doped surrogate samples were statistically invariant at 1064 and 355 nm. Contrary, the Ag-ore analyte showed higher emission intensity at 1064 nm, but the signal-to-background normalization reduced the effect of laser wavelength of silver calibration plots. The gold-doped calibration curve metrics improved at higher laser irradiance, but that did not translate into lower limits of detection. While coefficients of determination (R2) and limits of detection did not vary significantly with laser wavelength, the LIBS repeatability at 355 nm improved up to a 50% with respect to that at 1064 nm. Plasma diagnostics by the Boltzmann and Stark broadening methods showed that the plasma temperature and electron density did not follow a specific trend as the wavelength changed for the delay and gate times used. This research presents supporting evidence that the LIBS discrete sampling features combined with the discrete and random distribution of gold in minerals hinder gold analysis by LIBS in ore samples; however, the use of higher laser irradiances at 1064 nm increased the probability of sampling and detecting naturally-occurring gold.

Fiber optic laser-induced breakdown spectroscopy sensor for molten material analysis

DOEpatents

Zhang, Hansheng; Rai, Awadesh K.; Singh, Jagdish P.; Yueh, Fang-Yu

2004-07-13

A fiber optic laser-induced breakdown spectroscopy (LIBS) sensor, including a laser light source, a harmonic separator for directing the laser light, a dichroic mirror for reflecting the laser light, a coupling lens for coupling the laser light at an input of a multimode optical fiber, a connector for coupling the laser light from an output of the multimode optical fiber to an input of a high temperature holder, such as a holder made of stainless steel, and a detector portion for receiving emission signal and analyzing LIBS intensities. In one variation, the multimode optical fiber has silica core and silica cladding. The holder includes optical lenses for collimating and focusing the laser light in a molten alloy to produce a plasma, and for collecting and transmitting an emission signal to the multimode optical fiber.

Determination of Trace Available Heavy Metals in Soil Using Laser-Induced Breakdown Spectroscopy Assisted with Phase Transformation Method.

PubMed

Yi, Rongxing; Yang, Xinyan; Zhou, Ran; Li, Jiaming; Yu, Huiwu; Hao, Zhongqi; Guo, Lianbo; Li, Xiangyou; Lu, Yongfeng; Zeng, Xiaoyan

2018-05-18

To detect available heavy metals in soil using laser-induced breakdown spectroscopy (LIBS) and improve its poor detection sensitivity, a simple and low cost sample pretreatment method named solid-liquid-solid transformation was proposed. By this method, available heavy metals were extracted from soil through ultrasonic vibration and centrifuging and then deposited on a glass slide. Utilization of this solid-liquid-solid transformation method, available Cd and Pb elements in soil were detected successfully. The results show that the regression coefficients of calibration curves for soil analyses reach to more than 0.98. The limits of detection could reach to 0.067 and 0.94 ppm for available Cd and Pb elements in soil under optimized conditions, respectively, which are much better than those obtained by conventional LIBS.

[INVITED] Signal and noise in Laser Induced Breakdown Spectroscopy: An introductory review

NASA Astrophysics Data System (ADS)

Tognoni, Elisabetta; Cristoforetti, Gabriele

2016-05-01

Laser Induced Breakdown Spectroscopy (LIBS) has become a very popular technique for elemental analysis thanks to its ease of use. However, LIBS users often report poor repeatability of the signal, due to shot-to-shot fluctuations, and consequent not satisfactory limits of detection. In many practical cases, these shortcomings are difficult to control because the signal is affected by several noise sources that cannot be reduced simultaneously. Hopefully, there is a large amount of knowledge, accumulated during several decades, that can provide guidelines to reduce the effect of the single sources of fluctuations. Experimental setup and measurement settings can be optimized on purpose. Spectral data can be processed in order to better exploit the information contained. In the current paper several approaches to improve the analytical figures-of-merit are reviewed and the respective advantages and drawbacks are discussed.

Laser-induced breakdown spectroscopy used to detect endophyte-mediated accumulation of metals by tall fescue

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Madhavi Z.; Stewart, Arthur J.; Gwinn, Kimberley D.

Laser-induced breakdown spectroscopy (LIBS) was used to determine the impact of endophyte (Neotyphodium sp.) infection on elemental composition of tall fescue (Festuca arundinacea). Leaf material from endophyte-infected (E+) and endophyte-free (E-) tall fescue populations in established plots was examined. Leaf-tissue digestates were also tested for metals, by inductively coupled plasma (ICP) mass spectrometry (MS). Seven of eleven metals (Ca, Mg, Fe, Mn, Cu, Ni, and Zn) were measured by both techniques at concentrations great enough for a reliable comparison. Mg, Zn, and Cd, a toxic metal that can be present in forage, were readily detected by LIBS, even though Cdmore » concentrations in the plants were below levels typically achieved using ICP MS detection. Implications of these results for research on forage analysis and phytoremediation are discussed.« less

Online monitoring of corrosion behavior in molten metal using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Zeng, Qiang; Pan, Congyuan; Li, Chaoyang; Fei, Teng; Ding, Xiaokang; Du, Xuewei; Wang, Qiuping

2018-04-01

The corrosion behavior of structure materials in direct contact with molten metals is widespread in metallurgical industry. The corrosion of casting equipment by molten metals is detrimental to the production process, and the corroded materials can also contaminate the metals being produced. Conventional methods for studying the corrosion behavior by molten metal are offline. This work explored the application of laser-induced breakdown spectroscopy (LIBS) for online monitoring of the corrosion behavior of molten metal. The compositional changes of molten aluminum in crucibles made of 304 stainless steel were obtained online at 1000 °C. Several offline techniques were combined to determine the corrosion mechanism, which was highly consistent with previous studies. Results proved that LIBS was an efficient method to study the corrosion mechanism of solid materials in molten metal.

Stark width and shift for electron number density diagnostics of low temperature plasma: Application to silicon Laser Induced Breakdown Spectroscopy

NASA Astrophysics Data System (ADS)

Ivković, M.; Konjević, N.

2017-05-01

In this work we summarize, analyze and critically evaluate experimental procedures and results of LIBS electron number density plasma characterization using as examples Stark broadened Si I and Si II line profiles. Selected publications are covering the time period from very beginning of silicon LIBS studies until the end of the year 2015. To perform the analysis of experimental LIBS data, the testing of available semiclassical theoretical Stark broadening parameters for Si I and Si II lines was accomplished first. This is followed by the description of experimental setups, results and details of experimental procedure relevant for the line shape analysis of spectral lines used for plasma characterization. Although most of results and conclusions of this analysis are related to the application of silicon lines for LIBS characterization they are of general importance and may be applied to other elements and different low-temperature plasma sources. The analysis of experimental procedures used for LIBS diagnostics from emission profiles of non-hydrogenic spectral lines is carried out in the following order: the influence of laser ablation and crater formation, spatial and temporal plasma observation, line self-absorption and experimental profile deconvolution, the contribution of ion broadening in comparison with electron impacts contributions to the line width in case of neutral atom line and some other aspects of line shape analysis are considered. The application of Stark shift for LIBS diagnostics is demonstrated and discussed. Finally, the recommendations for an improvement of experimental procedures for LIBS electron number density plasma characterization are offered.

Recognition of spectral identifier from green coffee beans of arabica and robusta varieties using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Anggraeni, Karina; Nasution, Aulia; Suyanto, Hery

2016-11-01

Coffee is one of the world's commodity that is cultivated in more than 50 countries. Production of coffee in Indonesia is positioned of fourth rank in the world, after Brazil, Vietnam, and Colombia. There are two varieties of coffee grown in Indonesia, i.e. the arabica and robusta. The chemical compositions between arabica and robusta are different each other. A trained coffee tester can distinguish these differences from its taste, but it is very subjective. Laser-Induced Breakdown Spectroscopy (LIBS) is a spectroscopic technique based on the analysis of micro-plasma induced on the surface sample after being shot with a laser pulse. In this study, elemental spectra acquired using Laser-Induced Breakdown Spectroscopy (LIBS) technique were analysed to differentate between green coffee beans of arabica and robusta, which are collected from plantations in Malang, Bondowoso, Prigen, and Pasuruan. Results show that optimum conditions for acquiring spectra from green coffee beans using LIBS are at 120 mJ of laser energy and 1,0 μs of delay time. Green coffee beans of arabica and robusta contain some elements such as Ca, W, Sr, Mg, Be, Na, H, N, K, Rb, and O. Discriminant analysis method was then applied to distinguish the green beans of arabica and robusta coffee. Element identifiers of green coffee beans are Ca, W, Mg, Be, Na, and Sr. The abundant element in green coffee beans is Calcium (Ca), and depth-profile testing shows that Ca is homogeneous inside the beans.

Calibration strategies for the direct determination of Ca, K, and Mg in commercial samples of powdered milk and solid dietary supplements using laser-induced breakdown spectroscopy (LIBS).

PubMed

Dos Santos Augusto, Amanda; Barsanelli, Paulo Lopes; Pereira, Fabiola Manhas Verbi; Pereira-Filho, Edenir Rodrigues

2017-04-01

This study describes the application of laser-induced breakdown spectroscopy (LIBS) for the direct determination of Ca, K and Mg in powdered milk and solid dietary supplements. The following two calibration strategies were applied: (i) use of the samples to calculate calibration models (milk) and (ii) use of sample mixtures (supplements) to obtain a calibration curve. In both cases, reference values obtained from inductively coupled plasma optical emission spectroscopy (ICP OES) after acid digestion were used. The emission line selection from LIBS spectra was accomplished by analysing the regression coefficients of partial least squares (PLS) regression models, and wavelengths of 534.947, 766.490 and 285.213nm were chosen for Ca, K and Mg, respectively. In the case of the determination of Ca in supplements, it was necessary to perform a dilution (10-fold) of the standards and samples to minimize matrix interference. The average accuracy for powdered milk ranged from 60% to 168% for Ca, 77% to 152% for K and 76% to 131% for Mg. In the case of dietary supplements, standard error of prediction (SEP) varied from 295 (Mg) to 3782mgkg -1 (Ca). The proposed method presented an analytical frequency of around 60 samples per hour and the step of sample manipulation was drastically reduced, with no generation of toxic chemical residues. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of laser induced breakdown plasmas used for measurements of arsenic, antimony and selenium hydrides

NASA Astrophysics Data System (ADS)

Simeonsson, J. B.; Williamson, L. J.

2011-09-01

Studies have been performed to characterize laser induced breakdown spectroscopy (LIBS) plasmas formed in Ar/H 2 gas mixtures that are used for hydride generation (HG) LIBS measurements of arsenic (As), antimony (Sb) and selenium (Se) hydrides. The plasma electron density and plasma excitation temperature have been determined through hydrogen, argon and arsenic emission measurements. The electron density ranges from 4.5 × 10 17 to 8.3 × 10 15 cm -3 over time delays of 0.2 to 15 μs. The plasma temperatures range from 8800 to 7700 K for Ar and from 8800 to 6500 K for As in the HG LIBS plasmas. Evaluation of the plasma properties leads to the conclusion that partial local thermodynamic equilibrium conditions are present in the HG LIBS plasmas. Comparison measurements in LIBS plasmas formed in Ar gas only indicate that the temperatures are similar in both plasmas. However it is also observed that the electron density is higher in the Ar only plasmas and that the emission intensities of Ar are higher and decay more slowly in the Ar only plasmas. These differences are attributed to the presence of H 2 which has a higher thermal conductivity and provides additional dissociation, excitation and ionization processes in the HG LIBS plasma environment. Based on the observed results, it is anticipated that changes to the HG conditions that change the amount of H 2 in the plasma will have a significant effect on analyte emission in the HG LIBS plasmas that is independent of changes in the HG efficiency. The HG LIBS plasmas have been evaluated for measurements of elements hydrides using a constant set of HG LIBS plasma conditions. Linear responses are observed and limits of detection of 0.7, 0.2 and 0.6 mg/L are reported for As, Sb and Se, respectively.

photonic sensors review progress of optical fiber sensors and its application in harsh environment

NASA Astrophysics Data System (ADS)

Zhang, Min; Ma, Xiaohong; Wang, Liwei; Lai, Shurong; Zhou, Hongpu; Zhao, Huafeng; Liao, Yanbiao

2011-03-01

Fiber sensors have been developed for industry application with significant advantages. In this paper, Fiber sensors for oil field service and harsh environment monitoring which have been investigated in Tsinghua University are demonstrated. By discussing the requirements of practical applications, the key technologies of long-period fiber grating (LPFG) based fiber sensor, optical spectrum analyzer for oil detection, laser induced breakdown spectroscopy (LIBS) system for soil contamination monitoring, and seismic sensor arrays are described.

Determination of chlorine, sulfur and carbon in reinforced concrete structures by double-pulse laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Labutin, Timur A.; Popov, Andrey M.; Zaytsev, Sergey M.; Zorov, Nikita B.; Belkov, Mikhail V.; Kiris, Vasilii V.; Raikov, Sergey N.

2014-09-01

Accurate and reliable quantitative determination of non-metal corrosion agents in concrete is still an actual task of analytical use of LIBS. Two double-pulse LIBS systems were tested as a tool for the determination of chlorine, sulfur and carbon in concretes. Both systems had collinear configuration; a laboratory setup was equipped with an ICCD and two lasers (355/532 nm + 540 nm), but a CCD was a detector for a mobile system with one laser (1064 nm). Analytical lines of Cl I at 837.59 nm, S I at 921 nm and C I at 247.86 nm were used to plot calibration curves. Optimal interpulse delays for the laboratory setup were 4 μs for chlorine and 2.8 μs for carbon, while an interpulse delay of 2 μs was optimal for chlorine and sulfur determination with the mobile system. We suggested the normalization of the Cl I line at 837.59 nm to the Mg II line at 279.08 nm (visible at 837.23 nm in the third order) to compensate for pulse-to-pulse fluctuations of chlorine lines. It provided the decrease of the detection limit of chlorine from 400 ppm to 50 ppm. Therefore, we reported that LIBS can be used to determine main corrosive active substances under ambient conditions in concrete below critical threshold values. Moreover, the application of the mobile system for in-situ qualitative assessment of corrosion way of a steel cage of a swimming pool dome was also demonstrated. It was found that chloride corrosion due to the disinfection of water was the main way for corrosion of the open part steel and the steel rebar inside the concrete.

Secondary plasma formation after single pulse laser ablation underwater and its advantages for laser induced breakdown spectroscopy (LIBS).

PubMed

Gavrilović, M R; Cvejić, M; Lazic, V; Jovićević, S

2016-06-07

In this work we present studies of spatial and temporal plasma evolution after single pulse ablation of an aluminium target in water. The laser ablation was performed using 20 ns long pulses emitted at 1064 nm. The plasma characterization was performed by fast photography, the Schlieren technique, shadowgraphy and optical emission spectroscopy. The experimental results indicate the existence of two distinct plasma stages: the first stage has a duration of approximately 500 ns from the laser pulse, and is followed by a new plasma growth starting from the crater center. The secondary plasma slowly evolves inside the growing vapor bubble, and its optical emission lasts over several tens of microseconds. Later, the hot glowing particles, trapped inside the vapor cavity, were detected during the whole cycle of the bubble, where the first collapse occurs after 475 μs from the laser pulse. Differences in the plasma properties during the two evolution phases are discussed, with an accent on the optical emission since its detection is of primary importance for LIBS. Here we demonstrate that the LIBS signal quality in single pulse excitation underwater can be greatly enhanced by detecting only the secondary plasma emission, and also by applying long acquisition gates (in the order of 10-100 μs). The presented results are of great importance for LIBS measurements inside a liquid environment, since they prove that a good analytical signal can be obtained by using nanosecond pulses from a single commercial laser source and by employing cost effective, not gated detectors.

Less is more: Avoiding the LIBS dimensionality curse through judicious feature selection for explosive detection.

PubMed

Kumar Myakalwar, Ashwin; Spegazzini, Nicolas; Zhang, Chi; Kumar Anubham, Siva; Dasari, Ramachandra R; Barman, Ishan; Kumar Gundawar, Manoj

2015-08-19

Despite its intrinsic advantages, translation of laser induced breakdown spectroscopy for material identification has been often impeded by the lack of robustness of developed classification models, often due to the presence of spurious correlations. While a number of classifiers exhibiting high discriminatory power have been reported, efforts in establishing the subset of relevant spectral features that enable a fundamental interpretation of the segmentation capability and avoid the 'curse of dimensionality' have been lacking. Using LIBS data acquired from a set of secondary explosives, we investigate judicious feature selection approaches and architect two different chemometrics classifiers -based on feature selection through prerequisite knowledge of the sample composition and genetic algorithm, respectively. While the full spectral input results in classification rate of ca.92%, selection of only carbon to hydrogen spectral window results in near identical performance. Importantly, the genetic algorithm-derived classifier shows a statistically significant improvement to ca. 94% accuracy for prospective classification, even though the number of features used is an order of magnitude smaller. Our findings demonstrate the impact of rigorous feature selection in LIBS and also hint at the feasibility of using a discrete filter based detector thereby enabling a cheaper and compact system more amenable to field operations.

Less is more: Avoiding the LIBS dimensionality curse through judicious feature selection for explosive detection

PubMed Central

Kumar Myakalwar, Ashwin; Spegazzini, Nicolas; Zhang, Chi; Kumar Anubham, Siva; Dasari, Ramachandra R.; Barman, Ishan; Kumar Gundawar, Manoj

2015-01-01

Despite its intrinsic advantages, translation of laser induced breakdown spectroscopy for material identification has been often impeded by the lack of robustness of developed classification models, often due to the presence of spurious correlations. While a number of classifiers exhibiting high discriminatory power have been reported, efforts in establishing the subset of relevant spectral features that enable a fundamental interpretation of the segmentation capability and avoid the ‘curse of dimensionality’ have been lacking. Using LIBS data acquired from a set of secondary explosives, we investigate judicious feature selection approaches and architect two different chemometrics classifiers –based on feature selection through prerequisite knowledge of the sample composition and genetic algorithm, respectively. While the full spectral input results in classification rate of ca.92%, selection of only carbon to hydrogen spectral window results in near identical performance. Importantly, the genetic algorithm-derived classifier shows a statistically significant improvement to ca. 94% accuracy for prospective classification, even though the number of features used is an order of magnitude smaller. Our findings demonstrate the impact of rigorous feature selection in LIBS and also hint at the feasibility of using a discrete filter based detector thereby enabling a cheaper and compact system more amenable to field operations. PMID:26286630

Spatial investigation of plasma emission from laminar diffusion methanol, ethanol, and n-propanol alcohol flames using LIBS method

NASA Astrophysics Data System (ADS)

Ghezelbash, Mahsa; Majd, Abdollah Eslami; Darbani, Seyyed Mohammad Reza; Mousavi, Seyyed Jabbar; Ghasemi, Ali; Tehrani, Masoud Kavosh

2017-01-01

Laser-induced breakdown spectroscopy (LIBS) technique is used to record some plasma emissions of different laminar diffusion methanol, ethanol, and n-propanol alcohol flames, to investigate the shapes, structures (i.e., reactants and products zones), kind, and quality of burning in different areas. For this purpose, molecular bands of CH, CH*, C2, CN, and CO as well as atomic and ionic lines of C, H, N, and O are identified, simultaneously. Experimental results indicate that the CN and C2 emissions have highest intensity in LIBS spectrum of n-propanol flame and the lowest in methanol. In addition, lowest content of CO pollution and better quality of burning process in n-propanol fuel flame toward ethanol and methanol are confirmed by comparison between their CO molecular band intensities. Moreover, variation of the signal intensity from these three flames with that from a known area of burner plate is compared. Our findings in this research advance the prior results in time-integrated LIBS combustion application and suggesting that LIBS can be used successfully with the CCD detector as a non-gated analytical tool, given its simple instrumentation needs, real-time capability applications of molecular detection in laminar diffusion flame samples, requirements.

Decomposition and correction overlapping peaks of LIBS using an error compensation method combined with curve fitting.

PubMed

Tan, Bing; Huang, Min; Zhu, Qibing; Guo, Ya; Qin, Jianwei

2017-09-01

The laser induced breakdown spectroscopy (LIBS) technique is an effective method to detect material composition by obtaining the plasma emission spectrum. The overlapping peaks in the spectrum are a fundamental problem in the qualitative and quantitative analysis of LIBS. Based on a curve fitting method, this paper studies an error compensation method to achieve the decomposition and correction of overlapping peaks. The vital step is that the fitting residual is fed back to the overlapping peaks and performs multiple curve fitting processes to obtain a lower residual result. For the quantitative experiments of Cu, the Cu-Fe overlapping peaks in the range of 321-327 nm obtained from the LIBS spectrum of five different concentrations of CuSO 4 ·5H 2 O solution were decomposed and corrected using curve fitting and error compensation methods. Compared with the curve fitting method, the error compensation reduced the fitting residual about 18.12-32.64% and improved the correlation about 0.86-1.82%. Then, the calibration curve between the intensity and concentration of the Cu was established. It can be seen that the error compensation method exhibits a higher linear correlation between the intensity and concentration of Cu, which can be applied to the decomposition and correction of overlapping peaks in the LIBS spectrum.

Advanced recognition of explosives in traces on polymer surfaces using LIBS and supervised learning classifiers.

PubMed

Serrano, Jorge; Moros, Javier; Sánchez, Carlos; Macías, Jorge; Laserna, J Javier

2014-01-02

The large similarity existing in the spectral emissions collected from organic compounds by laser-induced breakdown spectroscopy (LIBS) is a limiting factor for the use of this technology in the real world. Specifically, among the most ambitious challenges of today's LIBS involves the recognition of an organic residue when neglected on the surface of an object of identical nature. Under these circumstances, the development of an efficient algorithm to disclose the minute differences within this highly complex spectral information is crucial for a realistic application of LIBS in countering explosive threats. An approach cemented on scatter plots of characteristic emission features has been developed to identify organic explosives when located on polymeric surfaces (teflon, nylon and polyethylene). By using selected spectral variables, the approach allows to design a concise classifier for alerting when one of four explosives (DNT, TNT, RDX and PETN) is present on the surface of the polymer. Ordinary products (butter, fuel oil, hand cream, olive oil and motor oil) cause no confusion in the decisions taken by the classifier. With rates of false negatives and false positives below 5%, results demonstrate that the classification algorithm enables to label residues according to their harmful nature in the most demanding scenario for a LIBS sensor. Copyright © 2013 Elsevier B.V. All rights reserved.

Nondestructive Determination of Cu Residue in Orange Peel by Laser Induced Breakdown Spectroscopy

NASA Astrophysics Data System (ADS)

Hu, Huiqin; Huang, Lin; Liu, Muhua; Chen, Tianbing; Yang, Ping; Yao, Mingyin

2015-08-01

Laser induced breakdown spectroscopy (LIBS) is an emerging tool with rapid, nondestructive, green characteristics in qualitative or quantitative analyses of composition in materials. But LIBS has its shortcomings in detect limit and sensitivity. In this work, heavy metal Cu in Gannan Navel Orange, which is one of famous fruits from Jiangxi of China, was analyzed. In view of LIBS's limit, it is difficult to determinate heavy metals in natural fruits. In this work, nine orange samples were pretreated in 50-500 μg/mL Cu solution, respectively. Another one orange sample was chosen as a control group without any pollution treatment. Previous researchers observed that the content of heavy metals is much higher in peel than in pulp. So, the content in pulp can be reflected by detecting peel. The real concentrations of Cu in peels were acquired by atomic absorption spectrophotometer (AAS). A calibration model of Cu I 324.7 and Cu I 327.4 was constructed between LIBS intensity and AAS concentration by six samples. The correlation coefficient of the two models is also 0.95. All of the samples were used to verify the accuracy of the model. The results show that the relative error (RE) between predicted and real concentration is less than 6.5%, and Cu I 324.7 line has smaller RE than Cu I 327.4. The analysis demonstrated that different characteristic lines decided different accuracy. The results prove the feasibility of detecting heavy metals in fruits by LIBS. But the results are limited in treated samples. The next work will focus on direct analysis of heavy metals in natural fruits without any pretreatment. This work is helpful to explore the distribution of heavy metals between pulp and peel. supported by National Natural Science Foundation of China (No. 31460419) and Major Project of Science and Technology of Jiangxi, China (No. 20143ACB21013)

Onboard calibration igneous targets for the Mars Science Laboratory Curiosity rover and the Chemistry Camera laser induced breakdown spectroscopy instrument

NASA Astrophysics Data System (ADS)

Fabre, C.; Maurice, S.; Cousin, A.; Wiens, R. C.; Forni, O.; Sautter, V.; Guillaume, D.

2011-03-01

Accurate characterization of the Chemistry Camera (ChemCam) laser-induced breakdown spectroscopy (LIBS) on-board composition targets is of prime importance for the ChemCam instrument. The Mars Science Laboratory (MSL) science and operations teams expect ChemCam to provide the first compositional results at remote distances (1.5-7 m) during the in situ analyses of the Martian surface starting in 2012. Thus, establishing LIBS reference spectra from appropriate calibration standards must be undertaken diligently. Considering the global mineralogy of the Martian surface, and the possible landing sites, three specific compositions of igneous targets have been determined. Picritic, noritic, and shergottic glasses have been produced, along with a Macusanite natural glass. A sample of each target will fly on the MSL Curiosity rover deck, 1.56 m from the ChemCam instrument, and duplicates are available on the ground. Duplicates are considered to be identical, as the relative standard deviation (RSD) of the composition dispersion is around 8%. Electronic microprobe and laser ablation inductively coupled plasma mass spectrometry (LA ICP-MS) analyses give evidence that the chemical composition of the four silicate targets is very homogeneous at microscopic scales larger than the instrument spot size, with RSD < 5% for concentration variations > 0.1 wt.% using electronic microprobe, and < 10% for concentration variations > 0.01 wt.% using LA ICP-MS. The LIBS campaign on the igneous targets performed under flight-like Mars conditions establishes reference spectra for the entire mission. The LIBS spectra between 240 and 900 nm are extremely rich, hundreds of lines with high signal-to-noise, and a dynamical range sufficient to identify unambiguously major, minor and trace elements. For instance, a first LIBS calibration curve has been established for strontium from [Sr] = 284 ppm to [Sr] = 1480 ppm, showing the potential for the future calibrations for other major or minor elements.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shaw, Guinevere C.; Bannister, Mark E.; Biewer, Theodore M.

Laser-induced breakdown spectroscopy (LIBS) results are presented that provide depth-resolved identification of He implanted in polycrystalline tungsten (PC-W) targets by a 200 keV He+ ion beam, with a surface temperature of approximately 900 °C and a peak fluence of 10 23 m –2. He retention, and the influence of He on deuterium and tritium recycling, permeation, and retention in PC-W plasma facing components are important questions for the divertor and plasma facing components in a fusion reactor, yet are difficult to quantify. The purpose of this work is to demonstrate the ability of LIBS to identify helium in tungsten; tomore » investigate the sensitivity of laser parameters including, laser energy and gate delay, that directly influence the sensitivity and depth resolution of LIBS; and to perform a proof-of-principle experiment using LIBS to measure relative He intensities as a function of depth. In conclusion, the results presented demonstrate the potential not only to identify helium but also to develop a methodology to quantify gaseous impurity concentration in PC-W as a function of depth.« less

Sensitivity, stability, and precision of quantitative Ns-LIBS-based fuel-air-ratio measurements for methane-air flames at 1-11 bar.

PubMed

Hsu, Paul S; Gragston, Mark; Wu, Yue; Zhang, Zhili; Patnaik, Anil K; Kiefer, Johannes; Roy, Sukesh; Gord, James R

2016-10-01

Nanosecond laser-induced breakdown spectroscopy (ns-LIBS) is employed for quantitative local fuel-air (F/A) ratio (i.e., ratio of actual fuel-to-oxidizer mass over ratio of fuel-to-oxidizer mass at stoichiometry, measurements in well-characterized methane-air flames at pressures of 1-11 bar). We selected nitrogen and hydrogen atomic-emission lines at 568 nm and 656 nm, respectively, to establish a correlation between the line intensities and the F/A ratio. We have investigated the effects of laser-pulse energy, camera gate delay, and pressure on the sensitivity, stability, and precision of the quantitative ns-LIBS F/A ratio measurements. We determined the optimal laser energy and camera gate delay for each pressure condition and found that measurement stability and precision are degraded with an increase in pressure. We have identified primary limitations of the F/A ratio measurement employing ns-LIBS at elevated pressures as instabilities caused by the higher density laser-induced plasma and the presence of the higher level of soot. Potential improvements are suggested.

Rapid test for the detection of hazardous microbiological material

NASA Astrophysics Data System (ADS)

Mordmueller, Mario; Bohling, Christian; John, Andreas; Schade, Wolfgang

2009-09-01

After attacks with anthrax pathogens have been committed since 2001 all over the world the fast detection and determination of biological samples has attracted interest. A very promising method for a rapid test is Laser Induced Breakdown Spectroscopy (LIBS). LIBS is an optical method which uses time-resolved or time-integrated spectral analysis of optical plasma emission after pulsed laser excitation. Even though LIBS is well established for the determination of metals and other inorganic materials the analysis of microbiological organisms is difficult due to their very similar stoichiometric composition. To analyze similar LIBS-spectra computer assisted chemometrics is a very useful approach. In this paper we report on first results of developing a compact and fully automated rapid test for the detection of hazardous microbiological material. Experiments have been carried out with two setups: A bulky one which is composed of standard laboratory components and a compact one consisting of miniaturized industrial components. Both setups work at an excitation wavelength of λ=1064nm (Nd:YAG). Data analysis is done by Principal Component Analysis (PCA) with an adjacent neural network for fully automated sample identification.

Laser induced breakdown spectroscopy (LIBS) applied to stratigrafic elemental analysis and optical coherence tomography (OCT) to damage determination of cultural heritage Brazilian coins

NASA Astrophysics Data System (ADS)

M. Amaral, Marcello; Raele, Marcus P.; Z. de Freitas, Anderson; Zahn, Guilherme S.; Samad, Ricardo E.; D. Vieira, Nilson, Jr.; G. Tarelho, Luiz V.

2009-07-01

This work presents a compositional characterization of 1939's Thousand "Réis" and 1945's One "Cruzeiro" Brazilian coins, forged on aluminum bronze alloy. The coins were irradiated by a Q-switched Nd:YAG laser with 4 ns pulse width and energy of 25mJ emitting at 1064nm reaching 3.1010Wcm-2 (assured condition for stoichiometric ablation), forming a plasma in a small fraction of the coin. Plasma emission was collected by an optical fiber system connected to an Echelle spectrometer. The capability of LIBS to remove small fraction of material was exploited and the coins were analyzed ablating layer by layer from patina to the bulk. The experimental conditions to assure reproductivity were determined by evaluation of three plasma paramethers: ionization temperature using Saha-Boltzmann plot, excitation temperature using Boltzmann plot, plasma density using Saha-Boltzmann plot and Stark broadening. The Calibration-Free LIBS technique was applied to both coins and the analytical determination of elemental composition was employed. In order to confirm the Edict Law elemental composition the results were corroborated by Neutron Activation Analysis (NAA). In both cases the results determined by CF-LIBS agreed to with the Edict Law and NAA determination. Besides the major components for the bronze alloy some other impurities were observed. Finally, in order to determine the coin damage made by the laser, the OCT (Optical Coherence Tomography) technique was used. After tree pulses of laser 54μg of coin material were removed reaching 120μm in depth.

A novel specimen-preparing method using epoxy resin as binding material for LIBS analysis of powder samples.

PubMed

Shi, Linli; Lin, Qingyu; Duan, Yixiang

2015-11-01

In view of the inevitable preprocessing of powder samples for LIBS detection, epoxy resin glue was investigated for the first time as a binder of powder samples due to its superior property of improved performance in laser induced breakdown spectroscopy (LIBS) technique as a quantitative analytical tool. For comparative studies of the epoxy resin and traditional polyethylene (PE) pellets in soil, sample detection, the signal intensities of Fe (I) at 404.58 nm, Ca (I) at 443.57 nm, and Cr (I) at 453.52 nm, were studied and subsequently, the calibration curves for these elements were constructed using the standard samples with variable concentrations. The signal intensities of epoxy resin samples were, on average, about 2 times greater than those obtained with the traditional PE pellet samples. Meanwhile, the resin samples showed better R square values of 0.981, 0.985 and 0.979 for curves of Fe (I) 404.58 nm, Ca (I) 443.57 nm, and Cr (I) 453.52 nm, compared to the 0.974, 0.950 and 0.934, of the PE pellet samples. Furthermore, the former represented lower limits of detection (LOD) for Fe, Ca and Cr. These experimental results indicated that this proposed novel method based on epoxy resin can attach samples of properties of high homogeneity, cohesiveness, smoothness and hardness, which are conducive to system stability, testing accuracy and signal enhancement. This method can make LIBS more practical in powder sample analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

Detection of early caries by laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Sasazawa, Shuhei; Kakino, Satoko; Matsuura, Yuji

2015-07-01

To improve sensitivity of dental caries detection by laser-induced breakdown spectroscopy (LIBS) analysis, it is proposed to utilize emission peaks in the ultraviolet. We newly focused on zinc whose emission peaks exist in ultraviolet because zinc exists at high concentration in the outer layer of enamel. It was shown that by using ratios between heights of an emission peak of Zn and that of Ca, the detection sensitivity and stability are largely improved. It was also shown that early caries are differentiated from healthy part by properly setting a threshold in the detected ratios. The proposed caries detection system can be applied to dental laser systems such as ones based on Er:YAG-lasers. When ablating early caries part by laser light, the system notices the dentist that the ablation of caries part is finished. We also show the intensity of emission peaks of zinc decreased with ablation with Er:YAG laser light.

Evaluation of the potential of laser-induced breakdown spectroscopy for detection of trace element in liquid.

PubMed

Yueh, Fang-Yu; Sharma, Ramesh C; Singh, Jagdish P; Zhang, Hansheng; Spencer, William A

2002-11-01

The analytical figure of merit of the potential of laser-induced breakdown spectroscopy (LIBS) has been evaluated for detection of trace element in liquid. LIBS data of Mg, Cr, Mn, and Re were studied. Various optical geometries, which produce the laser spark in and at the liquid sample, were tested. The calibration curves for Mg, Cr, Mn, and Re were obtained at the optimized experimental conditions with bulk liquid and in liquid jet. It was found that measurements using a liquid jet provide better detection limits than bulk liquid measurements. The limits of detection (LOD) of Mg, Cr, Mn, and Re in the present liquid jet measurement are found to be 0.1, 0.4, 0.7, and 8 ppm, respectively. The LOD of Mg using Mg 279.55 nm was compared with the values found in other liquid work.

Analysis of fresco by laser induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Caneve, L.; Diamanti, A.; Grimaldi, F.; Palleschi, G.; Spizzichino, V.; Valentini, F.

2010-08-01

The laser-based techniques have been shown to be a very powerful tool for artworks characterization and are used in the field of cultural heritage for the offered advantages of minimum invasiveness, in situ applicability and high sensitivity. Laser induced breakdown spectroscopy, in particular, has been applied in this field to many different kinds of ancient materials with successful results. In this work, a fragment of a Roman wall painting from the archaeological area of Pompeii has been investigated by LIBS. The sample elemental composition resulting from LIBS measurements suggested the presence of certain pigments. The ratio of the intensities of different lines related to some characteristic elements is proposed as an indicator for pigment recognition. The depth profiling permitted to put in evidence the presence of successive paint layers with different compositions. A comparison with the results obtained by the microscopy inspection of the sample has been done.

Validation of the solidifying soil process using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Lin, Zhao-Xiang; Liu, Lin-Mei; Liu, Lu-Wen

2016-09-01

Although an Ionic Soil Stabilizer (ISS) has been widely used in landslide control, it is desirable to effectively monitor the stabilization process. With the application of laser-induced breakdown spectroscopy (LIBS), the ion contents of K, Ca, Na, Mg, Al, and Si in the permeable fluid are detected after the solidified soil samples have been permeated. The processes of the Ca ion exchange are analyzed at pressures of 2 and 3 atm, and it was determined that the cation exchanged faster as the pressure increased. The Ca ion exchanges were monitored for different stabilizer mixtures, and it was found that a ratio of 1:200 of ISS to soil is most effective. The investigated plasticity and liquidity indexes also showed that the 1:200 ratio delivers the best performance. The research work indicates that it is possible to evaluate the engineering performances of soil solidified by ISS in real time and online by LIBS.

Analyses of IR-Stealthy and Coated Surface Materials: A Comparison of LIBS and Reflectance Spectra and Their Application to Mars Surface Exploration

NASA Technical Reports Server (NTRS)

Wiens, R. C.; Kirkland, L. E.; McKay, C. P.; Cremers, D. A.; Thompson, J.; Maurice, S.; Pinet, P. C.

2004-01-01

Identification of non-silicate samples on Mars, such as carbonates, sulfates, nitrates, or evaporites in general, is important because of their association with aqueous processes and their potential as exobiology sites. Infrared (IR) and thermal emission (TE) spectroscopy have been considered the primary tools for remote identification of these minerals. This includes current and future orbital assets such as TES on MGS, THEMIS on Mars Odyssey, OMEGA on Mars Express, CRISM on MRO, and now the Mini-TES on the MER rovers. While reflectance and emission spectroscopy have clearly been the method of choice for these missions, the technique is not always successful in mineral identifications due to dust, surface weathering chemistry, coatings, or surface texture. Here we describe and show IR spectra of several such samples, and then report on the relative success of LIBS analyses in determining the rock type.

A comparison of different strategies in multivariate regression models for the direct determination of Mn, Cr, and Ni in steel samples using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Luna, Aderval S.; Gonzaga, Fabiano B.; da Rocha, Werickson F. C.; Lima, Igor C. A.

2018-01-01

Laser-induced breakdown spectroscopy (LIBS) analysis was carried out on eleven steel samples to quantify the concentrations of chromium, nickel, and manganese. LIBS spectral data were correlated to known concentrations of the samples using different strategies in partial least squares (PLS) regression models. For the PLS analysis, one predictive model was separately generated for each element, while different approaches were used for the selection of variables (VIP: variable importance in projection and iPLS: interval partial least squares) in the PLS model to quantify the contents of the elements. The comparison of the performance of the models showed that there was no significant statistical difference using the Wilcoxon signed rank test. The elliptical joint confidence region (EJCR) did not detect systematic errors in these proposed methodologies for each metal.

Comparative Study of Elemental Nutrients in Organic and Conventional Vegetables Using Laser-Induced Breakdown Spectroscopy (LIBS).

PubMed

Bhatt, Chet R; Alfarraj, Bader; Ghany, Charles T; Yueh, Fang Y; Singh, Jagdish P

2017-04-01

In this study, the laser-induced breakdown spectroscopy (LIBS) technique was used to identify and compare the presence of major nutrient elements in organic and conventional vegetables. Different parts of cauliflowers and broccolis were used as working samples. Laser-induced breakdown spectra from these samples were acquired at optimum values of laser energy, gate delay, and gate width. Both univariate and multivariate analyses were performed for the comparison of these organic and conventional vegetable flowers. Principal component analysis (PCA) was taken into account for multivariate analysis while for univariate analysis, the intensity of selected atomic lines of different elements and their intensity ratio with some reference lines of organic cauliflower and broccoli samples were compared with those of conventional ones. In addition, different parts of the cauliflower and broccoli were compared in terms of intensity and intensity ratio of elemental lines.

Estimation of Soil Nitrate (NO3) Level Using Laser-Induced Breakdown Spectroscopy (LIBS)

NASA Astrophysics Data System (ADS)

Angkat, A. R.; Seminar, K. B.; Rahmat, M.; Sutandi, A.

2018-05-01

Laser-Induced Breakdown Spectroscopy (LIBS) is a method for measuring level of nitrogen (N) in the soil in the form of N-nitrate (NO3) rapidly without going through the process of sieving and drying. The sample soil in the form of pellets subjected to laser pulses using a wavelength of 532 nm, pulse duration 5.5 ns, repetition rate of 10 Hz, and Q-switch delay of 150 μs. Emissions are captured by the spectrometer with the wavelength range of 190-1130 nm. Spectrum characterization was processed through the second derivative in order to obtain a wavelength identity that could be rapidly used to estimate the nitrate content of the soil with a determination coefficient of (R2) 0.9254 and a coefficient of variation (CV) of 8.41%. The results of this study are very potential to be applied for rapid measurement of soil nitrate.

Application of laser-induced breakdown spectroscopy to the analysis of algal biomass for industrial biotechnology

NASA Astrophysics Data System (ADS)

Pořízka, P.; Prochazka, D.; Pilát, Z.; Krajcarová, L.; Kaiser, J.; Malina, R.; Novotný, J.; Zemánek, P.; Ježek, J.; Šerý, M.; Bernatová, S.; Krzyžánek, V.; Dobranská, K.; Novotný, K.; Trtílek, M.; Samek, O.

2012-08-01

We report on the application of laser-induced breakdown spectroscopy (LIBS) to the determination of elements distinctive in terms of their biological significance (such as potassium, magnesium, calcium, and sodium) and to the monitoring of accumulation of potentially toxic heavy metal ions in living microorganisms (algae), in order to trace e.g. the influence of environmental exposure and other cultivation and biological factors having an impact on them. Algae cells were suspended in liquid media or presented in a form of adherent cell mass on a surface (biofilm) and, consequently, characterized using their spectra. In our feasibility study we used three different experimental arrangements employing double-pulse LIBS technique in order to improve on analytical selectivity and sensitivity for potential industrial biotechnology applications, e.g. for monitoring of mass production of commercial biofuels, utilization in the food industry and control of the removal of heavy metal ions from industrial waste waters.

Recent advances in the use of laser-induced breakdown spectroscopy (LIBS) as a rapid point-of-care pathogen diagnostic

NASA Astrophysics Data System (ADS)

Rehse, Steven; Trojand, Daniel; Putnam, Russell; Gillies, Derek; Woodman, Ryan; Sheikh, Khadija; Daabous, Andrew

2013-05-01

There is a well-known and urgent need in the fields of medicine, environmental health and safety, food-processing, and defense/security to develop new 21st Century technologies for the rapid and sensitive identification of bacterial pathogens. In only the last five years, the use of a real-time elemental (atomic) analysis performed with laser-induced breakdown spectroscopy (LIBS) has made tremendous progress in becoming a viable technology for rapid bacterial pathogen detection and identification. In this talk we will show how this laser-based optical emission spectroscopic technique is able to sensitively assay the elemental composition of bacterial cells in situ. We will also present the latest achievements of our lab to fully develop LIBS-based bacterial sensing including simulation of a rapid urinary tract infection diagnosis and investigation of a variety of autonomous multivariate analysis algorithms. Lastly, we will show how this technology is now ready to be transitioned from the laboratory to field-portable and potentially man-portable instrumentation. The introduction of such a technology into popular use could very well transform the field of bacterial biosensing - a market valued at approximately 10 billion/year world-wide. Funding for this project was provided in part by a Natural Sciences and Engineering Research Council of Canada Discovery Grant.

Laser-induced breakdown spectroscopy-based investigation and classification of pharmaceutical tablets using multivariate chemometric analysis

PubMed Central

Myakalwar, Ashwin Kumar; Sreedhar, S.; Barman, Ishan; Dingari, Narahara Chari; Rao, S. Venugopal; Kiran, P. Prem; Tewari, Surya P.; Kumar, G. Manoj

2012-01-01

We report the effectiveness of laser-induced breakdown spectroscopy (LIBS) in probing the content of pharmaceutical tablets and also investigate its feasibility for routine classification. This method is particularly beneficial in applications where its exquisite chemical specificity and suitability for remote and on site characterization significantly improves the speed and accuracy of quality control and assurance process. Our experiments reveal that in addition to the presence of carbon, hydrogen, nitrogen and oxygen, which can be primarily attributed to the active pharmaceutical ingredients, specific inorganic atoms were also present in all the tablets. Initial attempts at classification by a ratiometric approach using oxygen to nitrogen compositional values yielded an optimal value (at 746.83 nm) with the least relative standard deviation but nevertheless failed to provide an acceptable classification. To overcome this bottleneck in the detection process, two chemometric algorithms, i.e. principal component analysis (PCA) and soft independent modeling of class analogy (SIMCA), were implemented to exploit the multivariate nature of the LIBS data demonstrating that LIBS has the potential to differentiate and discriminate among pharmaceutical tablets. We report excellent prospective classification accuracy using supervised classification via the SIMCA algorithm, demonstrating its potential for future applications in process analytical technology, especially for fast on-line process control monitoring applications in the pharmaceutical industry. PMID:22099648

Identification and discrimination of Pseudomonas aeruginosa bacteria grown in blood and bile by laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Rehse, Steven J.; Diedrich, Jonathan; Palchaudhuri, Sunil

2007-10-01

Pseudomonas aeruginosa bacteria colonies have been analyzed by laser-induced breakdown spectroscopy using nanosecond laser pulses. LIBS spectra were obtained after transferring the bacteria from a nutrient-rich culture medium to a nutrient-free agar plate for laser ablation. To study the dependence of the LIBS spectrum on growth and environmental conditions, colonies were cultured on three different nutrient media: a trypticase soy agar (TSA) plate, a blood agar plate, and a medium chosen deliberately to induce bacteria membrane changes, a MacConkey agar plate containing bile salts. Nineteen atomic and ionic emission lines in the LIBS spectrum, which was dominated by inorganic elements such as calcium, magnesium and sodium, were used to identify and classify the bacteria. A discriminant function analysis was used to discriminate between the P. aeruginosa bacteria and two strains of E. coli: a non-pathogenic environmental strain and the pathogenic strain enterohemorrhagic E. coli 0157:H7 (EHEC). Nearly identical spectra were obtained from P. aeruginosa grown on the TSA plate and the blood agar plate, while the bacteria grown on the MacConkey plate exhibited easily distinguishable differences from the other two. All P. aeruginosa samples, independent of initial growth conditions, were readily discriminated from the two E. coli strains.

Quantitative analysis for the determination of aluminum percentage and detonation performance of aluminized plastic bonded explosives by laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Rezaei, A. H.; Keshavarz, M. H.; Kavosh Tehrani, M.; Darbani, S. M. R.

2018-06-01

The aluminized plastic-bonded explosive (PBX) is a composite material in which solid explosive particles are dispersed in a polymer matrix, which includes three major components, i.e. polymeric binder, metal fuel (aluminum) and nitramine explosive. This work introduces a new method on the basis of the laser-induced breakdown spectroscopy (LIBS) technique in air and argon atmospheres to investigate the determination of aluminum content and detonation performance of aluminized PBXs. Plasma emissions of aluminized PBXs are recorded where atomic lines of Al, C and H as well as molecular bands of AlO and CN are identified. The experimental results demonstrate that a good discrimination and separation between the aluminized PBXs is possible using LIBS and principle component analysis, although they have similar atomic composition. Relative intensity of the AlO/Al is used to determine aluminum percentage of the aluminized PBXs. The obtained quantitative calibration curve using the relative intensity of the AlO/Al is better than the resulting calibration curve using only the intensity of Al. By using the LIBS method and the measured intensity ratio of CN/C, an Al content of 15% is found to be the optimum value in terms of velocity of detonation of the RDX/Al/HTPB standard samples.

Laser-Induced Breakdown Spectroscopy Based Protein Assay for Cereal Samples.

PubMed

Sezer, Banu; Bilge, Gonca; Boyaci, Ismail Hakki

2016-12-14

Protein content is an important quality parameter in terms of price, nutritional value, and labeling of various cereal samples. However, conventional analysis methods, namely, Kjeldahl and Dumas, have major drawbacks such as long analysis time, titration mistakes, and carrier gas dependence with high purity. For this reason, there is an urgent need for rapid, reliable, and environmentally friendly technologies for protein analysis. The present study aims to develop a new method for protein analysis in wheat flour and whole meal by using laser-induced breakdown spectroscopy (LIBS), which is a multielemental, fast, and simple spectroscopic method. Unlike the Kjeldahl and Dumas methods, it has potential to analyze a high number of samples in considerably short time. In the study, nitrogen peaks in LIBS spectra of wheat flour and whole meal samples with different protein contents were correlated with results of the standard Dumas method with the aid of chemometric methods. A calibration graph showed good linearity with the protein content between 7.9 and 20.9% and a 0.992 coefficient of determination (R 2 ). The limit of detection was calculated as 0.26%. The results indicated that LIBS is a promising and reliable method with its high sensitivity for routine protein analysis in wheat flour and whole meal samples.

Unreported Emission Lines of Rb, Ce, La, Sr, Y, Zr, Pb and Se Detected Using Laser-Induced Breakdown Spectroscopy

NASA Technical Reports Server (NTRS)

Lepore, K. H.; Mackie, J.; Dyar, M. D.; Fassett, C. I.

2017-01-01

Information on emission lines for major and minor elements is readily available from the National Institute of Standards and Technology (NIST) as part of the Atomic Spectra Database. However, tabulated emission lines are scarce for some minor elements and the wavelength ranges presented on the NIST database are limited to those included in existing studies. Previous work concerning minor element calibration curves measured using laser-induced break-down spectroscopy found evidence of Zn emission lines that were not documented on the NIST database. In this study, rock powders were doped with Rb, Ce, La, Sr, Y, Zr, Pb and Se in concentrations ranging from 10 percent to 10 parts per million. The difference between normalized spectra collected on samples containing 10 percent dopant and those containing only 10 parts per million were used to identify all emission lines that can be detected using LIBS (Laser-Induced Breakdown Spectroscopy) in a ChemCam-like configuration at the Mount Holyoke College LIBS facility. These emission spectra provide evidence of many previously undocumented emission lines for the elements measured here.

Laser-induced Breakdown Spectroscopy: A New Approach for Nanoparticle's Mapping and Quantification in Organ Tissue

PubMed Central

Sancey, Lucie; Motto-Ros, Vincent; Kotb, Shady; Wang, Xiaochun; Lux, François; Panczer, Gérard; Yu, Jin; Tillement, Olivier

2014-01-01

Emission spectroscopy of laser-induced plasma was applied to elemental analysis of biological samples. Laser-induced breakdown spectroscopy (LIBS) performed on thin sections of rodent tissues: kidneys and tumor, allows the detection of inorganic elements such as (i) Na, Ca, Cu, Mg, P, and Fe, naturally present in the body and (ii) Si and Gd, detected after the injection of gadolinium-based nanoparticles. The animals were euthanized 1 to 24 hr after intravenous injection of particles. A two-dimensional scan of the sample, performed using a motorized micrometric 3D-stage, allowed the infrared laser beam exploring the surface with a lateral resolution less than 100 μm. Quantitative chemical images of Gd element inside the organ were obtained with sub-mM sensitivity. LIBS offers a simple and robust method to study the distribution of inorganic materials without any specific labeling. Moreover, the compatibility of the setup with standard optical microscopy emphasizes its potential to provide multiple images of the same biological tissue with different types of response: elemental, molecular, or cellular. PMID:24962015

Portable laser-induced breakdown spectroscopy/diffuse reflectance hybrid spectrometer for analysis of inorganic pigments

NASA Astrophysics Data System (ADS)

Siozos, Panagiotis; Philippidis, Aggelos; Anglos, Demetrios

2017-11-01

A novel, portable spectrometer, combining two analytical techniques, laser-induced breakdown spectroscopy (LIBS) and diffuse reflectance spectroscopy, was developed with the aim to provide an enhanced instrumental and methodological approach with regard to the analysis of pigments in objects of cultural heritage. Technical details about the hybrid spectrometer and its operation are presented and examples are given relevant to the analysis of paint materials. Both LIBS and diffuse reflectance spectra in the visible and part of the near infrared, corresponding to several neat mineral pigment samples, were recorded and the complementary information was used to effectively distinguish different types of pigments even if they had similar colour or elemental composition. The spectrometer was also employed in the analysis of different paints on the surface of an ancient pottery sherd demonstrating the capabilities of the proposed hybrid diagnostic approach. Despite its instrumental simplicity and compact size, the spectrometer is capable of supporting analytical campaigns relevant to archaeological, historical or art historical investigations, particularly when quick data acquisition is required in the context of surveys of large numbers of objects and samples.

Realization of a collection of reference minerals to develop a technique for in situ dating of the Martian rocks

NASA Astrophysics Data System (ADS)

Cattani, F.; Gillot, P. Y.; Hildenbrand, A.; Quidelleur, X.; Courtade, F.; Boukari, C.; Lefevre, J. C.

2017-12-01

Absolute dating within ± 20% is needed to check and to calibrate the relative Martian chronology presently available. For that purpose, a K-Ar dating system has been developed to experiment the feasibility of such dating in future landing planetary missions. It consists in a laser ablation-based system built to vaporize a reproducible volume of rock. Potassium content is measured by laser-induced breakdown spectroscopy (LIBS) and argon by quadrupole mass spectrometry (QMS). Improvements of LIBS acquisition (optimization of optics part and normalization by total intensity spectrum) and QMS calibration (by reproducible known amount of argon) have been achieved. In addition, we have test the determination of ablated mass from volume measurement performed by profilometry technique. Instrument calibration for Martian analyses requires terrestrial analogues to determine the most suitable analytical conditions. For that purpose, total chemistry, electron microprobe analyses, flame absorption spectrometry and mass spectrometry have been performed in order to qualify stoichiometry, mineralogy, K concentration and Ar content from a collection of old terrestrial rocks. These analyses coupled with those published have helped to select 14 mineral phases (e.g. feldspars) showing a large range of K content (0.15 - 11%). The objective is to calibrate the LIBS on different geological material with Mars-like %K values ( 0.4%), and assess the detection limit of the LIBS with extreme %K values. All these mineral phases display a K-Ar age older than 260 Ma. Hence, the content of radiogenic Ar atoms per gram is within the range of Martian samples (on the order of 1 Ga for 0.4 %K). Furthermore, the ablated mass is estimated by measurement of Ar extracted from an analogue mineral of known amount of radiogenic Ar content per gram. This quantification is then compared with the mass estimated from the volume measured by profilometry technique. Finally, it provides a well-defined relationship between the ablation time and the type of ablated mineral. Experiments have been conducted to test our dating system for rocks with similar features than those from the Martian surface. Our preliminary results show that our QMS and LIBS instruments are suitable for in-situ K-Ar analyses with an uncertainty for K-Ar age much better than 15%.

Detection of visually unrecognizable braking tracks using Laser-Induced Breakdown Spectroscopy, a feasibility study

NASA Astrophysics Data System (ADS)

Prochazka, David; Bilík, Martin; Prochazková, Petra; Brada, Michal; Klus, Jakub; Pořízka, Pavel; Novotný, Jan; Novotný, Karel; Ticová, Barbora; Bradáč, Albert; Semela, Marek; Kaiser, Jozef

2016-04-01

Identification of the position, length and mainly beginning of a braking track has proven to be essential for determination of causes of a road traffic accident. With the introduction of modern safety braking systems and assistance systems such as the Anti-lock Braking System (ABS) or Electronic Stability Control (ESC), the visual identification of braking tracks that has been used up until the present is proving to be rather complicated or even impossible. This paper focuses on identification of braking tracks using a spectrochemical analysis of the road surface. Laser-Induced Breakdown Spectroscopy (LIBS) was selected as a method suitable for fast in-situ element detection. In the course of detailed observations of braking tracks it was determined that they consist of small particles of tire treads that are caught in intrusions in the road surface. As regards detection of the "dust" resulting from wear and tear of tire treads in the environment, organic zinc was selected as the identification element in the past. The content of zinc in tire treads has been seen to differ with regard to various sources and tire types; however, the arithmetic mean and modus of these values are approximately 1% by weight. For in-situ measurements of actual braking tracks a mobile LIBS device equipped with a special module was used. Several measurements were performed for 3 different cars and tire types respectively which slowed down with full braking power. Moreover, the influence of different initial speed, vehicle mass and braking track length on detected signal is discussed here.

In situ laser-induced breakdown spectroscopy measurements of chemical compositions in stainless steels during tungsten inert gas welding

NASA Astrophysics Data System (ADS)

Taparli, Ugur Alp; Jacobsen, Lars; Griesche, Axel; Michalik, Katarzyna; Mory, David; Kannengiesser, Thomas

2018-01-01

A laser-induced breakdown spectroscopy (LIBS) system was combined with a bead-on-plate Tungsten Inert Gas (TIG) welding process for the in situ measurement of chemical compositions in austenitic stainless steels during welding. Monitoring the weld pool's chemical composition allows governing the weld pool solidification behavior, and thus enables the reduction of susceptibility to weld defects. Conventional inspection methods for weld seams (e.g. ultrasonic inspection) cannot be performed during the welding process. The analysis system also allows in situ study of the correlation between the occurrence of weld defects and changes in the chemical composition in the weld pool or in the two-phase region where solid and liquid phase coexist. First experiments showed that both the shielding Ar gas and the welding arc plasma have a significant effect on the selected Cr II, Ni II and Mn II characteristic emissions, namely an artificial increase of intensity values via unspecific emission in the spectra. In situ investigations showed that this artificial intensity increase reached a maximum in presence of weld plume. Moreover, an explicit decay has been observed with the termination of the welding plume due to infrared radiation during sample cooling. Furthermore, LIBS can be used after welding to map element distribution. For austenitic stainless steels, Mn accumulations on both sides of the weld could be detected between the heat affected zone (HAZ) and the base material.

System Concept for Remote Measurement of Asteroid Molecular Composition

NASA Astrophysics Data System (ADS)

Hughes, G. B.; Lubin, P. M.; Zhang, Q.; Brashears, T.; Cohen, A. N.; Madajian, J.

2016-12-01

We propose a method for probing the molecular composition of cold solar system targets (asteroids, comets, planets, moons) from a distant vantage, such as from a spacecraft orbiting the object. A directed energy beam is focused on the target. With sufficient flux, the spot temperature rises rapidly, and evaporation of surface materials occurs. The melted spot creates a high-temperature blackbody source, and ejected material creates a plume of surface materials in front of the spot. Molecular and atomic absorption of the blackbody radiation occurs within the ejected plume. Bulk composition of the surface material is investigated by using a spectrometer to view the heated spot through the ejected material. Our proposed method differs from technologies such as Laser-Induced Breakdown Spectroscopy (LIBS), which atomizes and ionizes materials in the target; scattered ions emit characteristic radiation, and the LIBS detector performs atomic composition analysis by observing emission spectra. Standoff distance for LIBS is limited by the strength of characteristic emission, and distances greater than 10 m are problematic. Our proposed method detects atomic and molecular absorption spectra in the plume; standoff distance is limited by the size of heated spot, and the plume opacity; distances on the order of tens of kilometers are immediately feasible. Simulations have been developed for laser heating of a rocky target, with concomitant evaporation. Evaporation rates lead to determination of plume density and opacity. Absorption profiles for selected materials are estimated from plume properties. Initial simulations of absorption profiles with laser heating show great promise for molecular composition analysis from tens of kilometers distance. This paper explores the feasibility a hypothetical mission that seeks to perform surface molecular composition analysis of a near-earth asteroid while the craft orbits the asteroid. Such a system has compelling potential benefit for solar system exploration.

Nd:YAG-CO2 double-pulse laser induced breakdown spectroscopy of organic films

DTIC Science & Technology

2010-01-05

Thermodynamic and spectroscopic properties of Nd:YAG-CO2 Double-Pulse Laser-Induced Iron Plasma,” Spectrochimica Acta Part B: Atomic Spectroscopy (2009...absorption in the plume of an aluminum alloy,” Anal. Chem. 41(6), 700–707 (1969). 15. D. N. Stratis, K. L. Eland, and S. M. Angel, “Dual-pulse LIBS using a...and S. Pershin, “A comparison of single and double pulse laser-induced breakdown spectroscopy of aluminum samples,” Spectrochim. Acta, B At

Detection of salts in soil using transversely excited atmospheric (TEA) carbon dioxide (CO2) laser-induced breakdown spectroscopy (LIBS) by the aid of a metal mesh

NASA Astrophysics Data System (ADS)

Idris, N.; Ramli, M.; Khumaeni, A.; Kurihara, K.

2018-04-01

In this work, a nickel metal mesh was used to allow a direct detection of salt in soil sample by LIBS utilizing unique characteristics of a TEA CO2. The metal mesh is placed in the front of the soil sample to prevent the soil sample from blowing off upon focusing the high pulsed laser beam irradiation. LIBS apparatus used in this work is a TEA CO2 laser operated at wavelength of 10.6 μm with pulse energy and duration of 3J and 200 ns, respectively. The laser beam was focused using a ZnSe lens (f = 200 mm) onto soil sample after passing through the metal mesh. The emission spectrum from the induced plasma was detected using an optical multichannel analyzer (OMA) system consisting of a 0.32-m-focal length spectrograph with a grating of 1200 graves/mm and a 1024-channel photodiode detector array with a micro-channel plate intensifier. The soil sample used is a standard soil and ordinary soil containing several salts such as Ca, Mg at high concentration. The LIBS experiment was carried out at high pressure surrounding gas of 1 atmosphere. It was observed that by the aid of the metal mesh, strong breakdown gas plasma can be produced just after TEA CO2 laser irradiation on soil sample without significant sample blowing off. It was found that emission lines from salts, Ca (Ca II 393. 3 nm, Ca II 396.3 nm, Ca I 422.5 nm), and also other salts including Mg and Na can clearly be detected with strong emission intensity and narrow spectral width. This result implies that a TEA CO2 LIBS assisted by the metal mesh (metal mesh method) can be used for direct analysis several salts such as Ca, Mg, and Na in soil sample.

Unveiling the identity of distant targets through advanced Raman-laser-induced breakdown spectroscopy data fusion strategies.

PubMed

Moros, Javier; Javier Laserna, J

2015-03-01

Data fusion is the process of combining data gathered from two or more sensors to produce a more specific, comprehensive and unified dataset of the inspected target. On this basis, much has been said about the possible benefits resulting from the use of molecular and atomic information for the detection of explosives. The orthogonal nature of the spectral and compositional information provided by Raman spectroscopy and laser-induced breakdown spectroscopy (LIBS) makes them suitable candidates for an optimal combination of their data, thus achieving inferences that are not feasible using a single sensor. The present manuscript evaluates several architectures for the combination of spectral outputs from these two sensors in order to compare the benefits and drawbacks of data fusion for improving the overall identification performance. From the simple assembling (concatenation or addition) of Raman and LIBS spectra to signals' processing on the basis of linear algebra (either the outer product or the outer sum), different identification patterns of several compounds (explosives, potential confusants and supports) have been built. The efficiency on target differentiation by using each of the architectures has been evaluated by comparing the identification yield obtained for all the inspected targets from correlation and similarity measurements. Additionally, a specific code integrated by several of these patterns to identify each compound has also been evaluated. This approach permits to obtain a better knowledge about the identity of an interrogated target, mainly in those decisive cases in which LIBS or Raman cannot be effective separately to reach a decision. Copyright © 2014 Elsevier B.V. All rights reserved.

Optical and laser spectroscopic diagnostics for energy applications

NASA Astrophysics Data System (ADS)

Tripathi, Markandey Mani

The continuing need for greater energy security and energy independence has motivated researchers to develop new energy technologies for better energy resource management and efficient energy usage. The focus of this dissertation is the development of optical (spectroscopic) sensing methodologies for various fuels, and energy applications. A fiber-optic NIR sensing methodology was developed for predicting water content in bio-oil. The feasibility of using the designed near infrared (NIR) system for estimating water content in bio-oil was tested by applying multivariate analysis to NIR spectral data. The calibration results demonstrated that the spectral information can successfully predict the bio-oil water content (from 16% to 36%). The effect of ultraviolet (UV) light on the chemical stability of bio-oil was studied by employing laser-induced fluorescence (LIF) spectroscopy. To simulate the UV light exposure, a laser in the UV region (325 nm) was employed for bio-oil excitation. The LIF, as a signature of chemical change, was recorded from bio-oil. From this study, it was concluded that phenols present in the bio-oil show chemical instability, when exposed to UV light. A laser-induced breakdown spectroscopy (LIBS)-based optical sensor was designed, developed, and tested for detection of four important trace impurities in rocket fuel (hydrogen). The sensor can simultaneously measure the concentrations of nitrogen, argon, oxygen, and helium in hydrogen from storage tanks and supply lines. The sensor had estimated lower detection limits of 80 ppm for nitrogen, 97 ppm for argon, 10 ppm for oxygen, and 25 ppm for helium. A chemiluminescence-based spectroscopic diagnostics were performed to measure equivalence ratios in methane-air premixed flames. A partial least-squares regression (PLS-R)-based multivariate sensing methodology was investigated. It was found that the equivalence ratios predicted with the PLS-R-based multivariate calibration model matched with the experimentally measured equivalence ratios within 7 %. A comparative study was performed for equivalence ratios measurement in atmospheric premixed methane-air flames with ungated LIBS and chemiluminescence spectroscopy. It was reported that LIBS-based calibration, which carries spectroscopic information from a "point-like-volume," provides better predictions of equivalence ratios compared to chemiluminescence-based calibration, which is essentially a "line-of-sight" measurement.

Rapid analysis of pharmaceutical drugs using LIBS coupled with multivariate analysis.

PubMed

Tiwari, P K; Awasthi, S; Kumar, R; Anand, R K; Rai, P K; Rai, A K

2018-02-01

Type 2 diabetes drug tablets containing voglibose having dose strengths of 0.2 and 0.3 mg of various brands have been examined, using laser-induced breakdown spectroscopy (LIBS) technique. The statistical methods such as the principal component analysis (PCA) and the partial least square regression analysis (PLSR) have been employed on LIBS spectral data for classifying and developing the calibration models of drug samples. We have developed the ratio-based calibration model applying PLSR in which relative spectral intensity ratios H/C, H/N and O/N are used. Further, the developed model has been employed to predict the relative concentration of element in unknown drug samples. The experiment has been performed in air and argon atmosphere, respectively, and the obtained results have been compared. The present model provides rapid spectroscopic method for drug analysis with high statistical significance for online control and measurement process in a wide variety of pharmaceutical industrial applications.

Accurate quantitative CF-LIBS analysis of both major and minor elements in alloys via iterative correction of plasma temperature and spectral intensity

NASA Astrophysics Data System (ADS)

Shuxia, ZHAO; Lei, ZHANG; Jiajia, HOU; Yang, ZHAO; Wangbao, YIN; Weiguang, MA; Lei, DONG; Liantuan, XIAO; Suotang, JIA

2018-03-01

The chemical composition of alloys directly determines their mechanical behaviors and application fields. Accurate and rapid analysis of both major and minor elements in alloys plays a key role in metallurgy quality control and material classification processes. A quantitative calibration-free laser-induced breakdown spectroscopy (CF-LIBS) analysis method, which carries out combined correction of plasma temperature and spectral intensity by using a second-order iterative algorithm and two boundary standard samples, is proposed to realize accurate composition measurements. Experimental results show that, compared to conventional CF-LIBS analysis, the relative errors for major elements Cu and Zn and minor element Pb in the copper-lead alloys has been reduced from 12%, 26% and 32% to 1.8%, 2.7% and 13.4%, respectively. The measurement accuracy for all elements has been improved substantially.

Mineralogy and Astrobiology Detection Using Laser Remote Sensing Instrument

NASA Technical Reports Server (NTRS)

Abedin, M. Nurul; Bradley, Arthur T.; Sharma, Shiv K.; Misra, Anupam K.; Lucey, Paul G.; Mckay, Chistopher P.; Ismail, Syed; Sandford, Stephen P.

2015-01-01

A multispectral instrument based on Raman, laser-induced fluorescence (LIF), laser-induced breakdown spectroscopy (LIBS), and a lidar system provides high-fidelity scientific investigations, scientific input, and science operation constraints in the context of planetary field campaigns with the Jupiter Europa Robotic Lander and Mars Sample Return mission opportunities. This instrument conducts scientific investigations analogous to investigations anticipated for missions to Mars and Jupiter's icy moons. This combined multispectral instrument is capable of performing Raman and fluorescence spectroscopy out to a >100 m target distance from the rover system and provides single-wavelength atmospheric profiling over long ranges (>20 km). In this article, we will reveal integrated remote Raman, LIF, and lidar technologies for use in robotic and lander-based planetary remote sensing applications. Discussions are focused on recently developed Raman, LIF, and lidar systems in addition to emphasizing surface water ice, surface and subsurface minerals, organics, biogenic, biomarker identification, atmospheric aerosols and clouds distributions, i.e., near-field atmospheric thin layers detection for next robotic-lander based instruments to measure all the above-mentioned parameters. OCIS codes: (120.0280) Remote sensing and sensors; (130.0250) Optoelectronics; (280.3640) Lidar; (300.2530) Fluorescence, laser-induced; (300.6450) Spectroscopy, Raman; (300.6365) Spectroscopy, laser induced breakdown

Multi-mode optical fibers for connecting space-based spectrometers

NASA Astrophysics Data System (ADS)

Roberts, W. T.; Lindenmisth, C. A.; Bender, S.; Miller, E. A.; Motts, E.; Ott, M.; LaRocca, F.; Thomes, J.

2017-11-01

Laser spectral analysis systems are increasingly being considered for in situ analysis of the atomic and molecular composition of selected rock and soil samples on other planets [1][2][3]. Both Laser Induced Breakdown Spectroscopy (LIBS) and Raman spectroscopy are used to identify the constituents of soil and rock samples in situ. LIBS instruments use a high peak-power laser to ablate a minute area of the surface of a sample. The resulting plasma is observed with an optical head, which collects the emitted light for analysis by one or more spectrometers. By identifying the ion emission lines observed in the plasma, the constituent elements and their abundance can be deduced. In Raman spectroscopy, laser photons incident on the sample surface are scattered and experience a Raman shift, exchanging small amounts of energy with the molecules scattering the light. By observing the spectrum of the scattered light, it is possible to determine the molecular composition of the sample. For both types of instruments, there are advantages to physically separating the light collecting optics from the spectroscopy optics. The light collection system will often have articulating or rotating elements to facilitate the interrogation of multiple samples with minimum expenditure of energy and motion. As such, the optical head is often placed on a boom or an appendage allowing it to be pointed in different directions or easily positioned in different locations. By contrast, the spectrometry portion of the instrument is often well-served by placing it in a more static location. The detectors often operate more consistently in a thermally-controlled environment. Placing them deep within the spacecraft structure also provides some shielding from ionizing radiation, extending the instrument's useful life. Finally, the spectrometry portion of the instrument often contains significant mass, such that keeping it off of the moving portion of the platform, allowing that portion to be significantly smaller, less massive and less robust. Large core multi-mode optical fibers are often used to accommodate the optical connection of the two separated portions of such instrumentation. In some cases, significant throughput efficiency improvement can be realized by judiciously orienting the strands of multi-fiber cable, close-bunching them to accommodate a tight focus of the optical system on the optical side of the connection, and splaying them out linearly along a spectrometer slit on the other end. For such instrumentation to work effectively in identifying elements and molecules, and especially to produce accurate quantitative results, the spectral throughput of the optical fiber connection must be consistent over varying temperatures, over the range of motion of the optical head (and it's implied optical cable stresses), and over angle-aperture invariant of the total system. While the first two of these conditions have been demonstrated[4], spectral observations of the latter present a cause for concern, and may have an impact on future design of fiber-connected LIBS and Raman spectroscopy instruments. In short, we have observed that the shape of the spectral efficiency curve of a large multi-mode core optical fiber changes as a function of input angle.

Using laser-induced breakdown spectroscopy on vacuum alloys-production process for elements concentration analysis

NASA Astrophysics Data System (ADS)

Zhao, Tianzhuo; Fan, Zhongwei; Lian, Fuqiang; Liu, Yang; Lin, Weiran; Mo, Zeqiang; Nie, Shuzhen; Wang, Pu; Xiao, Hong; Li, Xin; Zhong, Qixiu; Zhang, Hongbo

2017-11-01

Laser-induced breakdown spectroscopy (LIBS) utilizing an echelle spectrograph-ICCD system is employed for on-line analysis of elements concentration in a vacuum induction melting workshop. Active temperature stabilization of echelle spectrometer is implemented specially for industrial environment applications. The measurement precision is further improved by monitoring laser parameters, such as pulse energy, spatial and temporal profiles, in real time, and post-selecting laser pulses with specific pulse energies. Experimental results show that major components of nickel-based alloys are stable, and can be well detected. By using internal standard method, calibration curves for chromium and aluminum are obtained for quantitative determination, with determination coefficient (relative standard deviation) to be 0.9559 (< 2.2%) and 0.9723 (< 2.8%), respectively.

Improved Battery Performance of Nanocrystalline Si Anodes Utilized by Radio Frequency (RF) Sputtered Multifunctional Amorphous Si Coating Layers.

PubMed

Ahn, In-Kyoung; Lee, Young-Joo; Na, Sekwon; Lee, So-Yeon; Nam, Dae-Hyun; Lee, Ji-Hoon; Joo, Young-Chang

2018-01-24

Despite the high theoretical specific capacity of Si, commercial Li-ion batteries (LIBs) based on Si are still not feasible because of unsatisfactory cycling stability. Herein, amorphous Si (a-Si)-coated nanocrystalline Si (nc-Si) formed by versatile radio frequency (RF) sputtering systems is proposed as a promising anode material for LIBs. Compared to uncoated nc-Si (retention of 0.6% and Coulombic efficiency (CE) of 79.7%), the a-Si-coated nc-Si (nc-Si@a-Si) anodes show greatly improved cycling retention (C 50th /C first ) of ∼50% and a first CE of 86.6%. From the ex situ investigation with electrochemical impedance spectroscopy (EIS) and cracked morphology during cycling, the a-Si layer was found to be highly effective at protecting the surface of the nc-Si from the formation of solid-state electrolyte interphases (SEI) and to dissipate the mechanical stress upon de/lithiation due to the high fracture toughness.

Effect of sodium chloride concentration on elemental analysis of brines by laser-induced breakdown spectroscopy (LIBS).

PubMed

Goueguel, Christian; Singh, Jagdish P; McIntyre, Dustin L; Jain, Jinesh; Karamalidis, Athanasios K

2014-01-01

Leakage of injected carbon dioxide (CO2) or resident fluids, such as brine, is a major concern associated with the injection of large volumes of CO2 into deep saline formations. Migration of brine could contaminate drinking water resources by increasing their salinity or endanger vegetation and animal life as well as human health. The main objective of this study was to investigate the effect of sodium chloride (NaCl) concentration on the detection of calcium and potassium in brine samples using laser-induced breakdown spectroscopy (LIBS). The ultimate goals were to determine the suitability of the LIBS technique for in situ measurements of metal ion concentrations in NaCl-rich solution and to develop a chemical sensor that can provide the early detection of brine intrusion into formations used for domestic or agricultural water production. Several brine samples of NaCl-CaCl2 and NaCl-KCl were prepared at NaCl concentrations between 0.0 and 3.0 M. The effect of NaCl concentration on the signal-to-background ratio (SBR) and signal-to-noise ratio (SNR) for calcium (422.67 nm) and potassium (769.49 nm) emission lines was evaluated. Results show that, for a delay time of 300 ns and a gate width of 3 μs, the presence of and changes in NaCl concentration significantly affect the SBR and SNR for both emission lines. An increase in NaCl concentration from 0.0 to 3.0 M produced an increase in the SNR, whereas the SBR dropped continuously. The detection limits obtained for both elements were in the milligrams per liter range, suggesting that a NaCl-rich solution does not severely limit the ability of LIBS to detect trace amount of metal ions.

Novel approach of signal normalization for depth profile of cultural heritage materials

NASA Astrophysics Data System (ADS)

Syvilay, D.; Detalle, V.; Wilkie-Chancellier, N.; Texier, A.; Martinez, L.; Serfaty, S.

2017-01-01

The investigation of cultural heritage materials is always complex and specific because unique. Materials are most often heterogeneous and organized in several layers such as mural paintings or corrosion products. The characterization of a complete artwork's stratigraphy is actually one of the questions of science conservation. Indeed, the knowledge of these layers allows completing the history of the work of art and a better understanding of alteration processes in order to set up an appropriate conservation action. The LIBS technique has been employed to study the stratigraphy of an artwork thanks to the ablation laser. However, as we know, atomic information could be insufficient to characterize two materials composed by the same based elements. Therefore, an additional molecular analysis, like Raman spectroscopy; is sometimes necessary for a better identification of the material in particular for organic coatings in cultural heritage. We suggest in this study to use Standard Normal Variate (SNV) as a common normalization for different kinds of spectra (LIBS and Raman spectroscopy) combined with a 3D colour representation for stratigraphic identification of the different layers composing the complex material from artwork. So in this investigation, the SNV method will be applied on LIBS and Raman spectra but also on baseline Raman spectra often considering as nuisance. The aim of this study is to demonstrate the versatility of SNV applied on varied spectra like LIBS, Raman spectra as well as the luminescence background. This original work considers the SNV with a 3D colour representation as a probable new perspective for an easy recognition of a structure layered with a direct overview of the depth profile of the artwork.

Discrimination of biological and chemical threat simulants in residue mixtures on multiple substrates.

PubMed

Gottfried, Jennifer L

2011-07-01

The potential of laser-induced breakdown spectroscopy (LIBS) to discriminate biological and chemical threat simulant residues prepared on multiple substrates and in the presence of interferents has been explored. The simulant samples tested include Bacillus atrophaeus spores, Escherichia coli, MS-2 bacteriophage, α-hemolysin from Staphylococcus aureus, 2-chloroethyl ethyl sulfide, and dimethyl methylphosphonate. The residue samples were prepared on polycarbonate, stainless steel and aluminum foil substrates by Battelle Eastern Science and Technology Center. LIBS spectra were collected by Battelle on a portable LIBS instrument developed by A3 Technologies. This paper presents the chemometric analysis of the LIBS spectra using partial least-squares discriminant analysis (PLS-DA). The performance of PLS-DA models developed based on the full LIBS spectra, and selected emission intensities and ratios have been compared. The full-spectra models generally provided better classification results based on the inclusion of substrate emission features; however, the intensity/ratio models were able to correctly identify more types of simulant residues in the presence of interferents. The fusion of the two types of PLS-DA models resulted in a significant improvement in classification performance for models built using multiple substrates. In addition to identifying the major components of residue mixtures, minor components such as growth media and solvents can be identified with an appropriately designed PLS-DA model.

Ultrafast Laser Interaction Processes for LIBS and Other Sensing Technologies

DTIC Science & Technology

2013-04-05

Propagation of ultrashort pulses through water, Optics Express, (02 2007): . doi: 12/02/2009 8.00 Z. Chen, S. Mao. Femtosecond laser -induced electronic...CO2 double- pulse laser -induced breakdown spectroscopy for explosive residues detection" SPIE Defense, Security, Sensing; Orlando, FL, USA; 04/07...Matthieu Baudelet, Michael Sigman, Paul J Dagdigian, Martin C. Richardson, "Nd:YAG-CO2 Double- Pulse Laser Induced Breakdown Spectroscopy for Explosive

Correlation Between Early-Stage Expansion and Spectral Emission of a Nanosecond Laser-Induced Plasma from Organic Material

DTIC Science & Technology

2008-01-01

atmosphere like ours (mix of nitrogen and oxygen) implies a more complex plasma chemistry . For example, one of these difficulties is the interpretation of...due to LSDW have also been observed. KEYWORDS Polymer ablation, Shadowgraphy, Time-resolved laser induced breakdown spectroscopy, Plasma ... chemistry , Organic materials analysis, Expansion of laser-induced plasma 1 INTRODUCTION Laser-Induced Breakdown Spectroscopy (LIBS) traditionally

Using laser induced breakdown spectroscopy and acoustic radiation force elasticity microscope to measure the spatial distribution of corneal elasticity

NASA Astrophysics Data System (ADS)

Sun, Hui; Li, Xin; Fan, Zhongwei; Kurtz, Ron; Juhasz, Tibor

2017-02-01

Corneal biomechanics plays an important role in determining the eye's structural integrity, optical power and the overall quality of vision. It also plays an increasingly recognized role in corneal transplant and refractive surgery, affecting the predictability, quality and stability of final visual outcome [1]. A critical limitation to increasing our understanding of how corneal biomechanics controls corneal stability and refraction is the lack of non-invasive technologies that microscopically measure local biomechanical properties, such as corneal elasticity within the 3D space. Bubble based acoustic radiation force elastic microscopy (ARFEM) introduce the opportunity to measure the inhomogeneous elastic properties of the cornea by the movement of a micron size cavitation bubble generated by a low energy femtosecond laser pulse [2, 3]. Laser induced breakdown spectroscopy (LIBS) also known as laser induced plasma spectroscopy (LIPS) or laser spark spectrometry (LSS) is an atomic emission spectroscopy [4]. The LIBS principle of operation is quite simple, although the physical processes involved in the laser matter interaction are complex and still not completely understood. In one sentence for description, the laser pulses are focused down to a target so as to generate plasma that vaporizes a small amount of material which the emitted spectrum is measured to analysis the elements of the target.

Critical aspects of data analysis for quantification in laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Motto-Ros, V.; Syvilay, D.; Bassel, L.; Negre, E.; Trichard, F.; Pelascini, F.; El Haddad, J.; Harhira, A.; Moncayo, S.; Picard, J.; Devismes, D.; Bousquet, B.

2018-02-01

In this study, a collaborative contest focused on LIBS data processing has been conducted in an original way since the participants did not share the same samples to be analyzed on their own LIBS experiments but a set of LIBS spectra obtained from one single experiment. Each participant was asked to provide the predicted concentrations of several elements for two glass samples. The analytical contest revealed a wide diversity of results among participants, even when the same spectral lines were considered for the analysis. Then, a parametric study was conducted to investigate the influence of each step during the data processing. This study was based on several analytical figures of merit such as the determination coefficient, uncertainty, limit of quantification and prediction ability (i.e., trueness). Then, it was possible to interpret the results provided by the participants, emphasizing the fact that the type of data extraction, baseline modeling as well as the calibration model play key roles in the quantification performance of the technique. This work provides a set of recommendations based on a systematic evaluation of the quantification procedure with the aim of optimizing the methodological steps toward the standardization of LIBS.

Calibration Transfer in LIBS and Raman Spectroscopy for Planetary Applications

NASA Astrophysics Data System (ADS)

Dyar, M. D.; Thomas, B. F.; Parente, M.; Gemp, I.; Mullen, T. H.

2017-12-01

Planetary scientists rely on spectral libraries and instrument reproducibility to interpret results from missions. Major investments have been made into assembling libraries, but they often naively assume that spectra of single crystals versus powders and from varying instruments will be the same. Calibration transfer (CT) seeks to algorithmically resolve discrepancies among datasets from different instruments or conditions. It offers the ability to align suites of spectra with a small number of common samples, allowing better models to be built with combined data sets. LIBS and Raman data present different challenges for CT. Quantitative geochemical analyses by LIBS spectroscopy are limited by lack of consistency among repeated laser shots and across instruments. Many different factors affect the presence/absence of emission lines and their intensities, such as laser power/plasma temperature, angle of incidence, detector sensitivity/resolution. To overcome these, models in which disparate datasets are projected into a joint low-dimensional subspace where all data can be aligned before quantitative analysis, such as Correlation Analysis for Domain Adaptation (CADA), have proven very effective. They require some overlap between the populations of spectra to be aligned. For example, prediction of SiO2 on 80 samples from two different LIBS labs show errors of ±16-29 wt.% when the training and test sets have no overlap, and ±4.94 wt% SiO2 when CADA is used. Uncorrected Earth-Mars spectral differences are likely to cause errors with the same order of magnitude. As with other types of reflectance spectroscopy, Raman data are plagued by differences among single crystal/powder samples and laser wavelength that affect peak intensities, and by spectral offsets from instruments with varying resolution and wavenumber alignment schemes. These problems persist even within the archetypal RRUFF database. Pre-processing transformation functions such as optimized baseline removal, normalization, squashing, and smoothing improve mineral matching accuracy. Alignment methods can record shifts between corresponding peaks from the same mineral from pairs of instruments. By considering many pairs of minerals, corrections at each energy increment can be determined, creating a transfer function to align the data.

Application Of Laser Induced Breakdown Spectroscopy (LIBS) Technique In Investigation Of Historical Metal Threads

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdel-Kareem, O.; Khedr, A.; Abdelhamid, M.

Analysis of the composition of an object is a necessary step in the documentation of the properties of this object for estimating its condition. Also this is an important task for establishing an appropriate conservation treatment of an object or to follow up the result of the application of the suggested treatments. There has been an important evolution in the methods used for analysis of metal threads since the second half of the twentieth century. Today, the main considerations of selecting a method are based on the diagnostic power, representative sampling, reproducibility, destructive nature/invasiveness of analysis and accessibility to themore » appropriate instrument. This study aims at evaluating the usefulness of the use of Laser Induced Breakdown Spectroscopy (LIBS) Technique for analysis of historical metal threads. In this study various historical metal threads collected from different museums were investigated using (LIBS) technique. For evaluating usefulness of the suggested analytical protocol of this technique, the same investigated metal thread samples were investigated with Scanning Electron Microscope (SEM) with energy-dispersive x-ray analyzer (EDX) which is reported in conservation field as the best method, to determine the chemical composition, and corrosion of investigated metal threads. The results show that all investigated metal threads in the present study are too dirty, strongly damaged and corroded with different types of corrosion products. Laser Induced Breakdown Spectroscopy (LIBS) Technique is considered very useful technique that can be used safely for investigating historical metal threads. It is, in fact, very useful tool as a noninvasive method for analysis of historical metal threads. The first few laser shots are very useful for the investigation of the corrosion and dirt layer, while the following shots are very useful and effective for investigating the coating layer. Higher number of laser shots are very useful for the main composition of the metal thread. There is a necessity to carry out further research to investigate and determine the most appropriate and effective approaches and methods for conservation of these metal threads.« less

Mercury Amalgam Diffusion in Human Teeth Probed Using Femtosecond LIBS.

PubMed

Bello, Liciane Toledo; da Ana, Patricia Aparecida; Santos, Dário; Krug, Francisco José; Zezell, Denise Maria; Vieira, Nilson Dias; Samad, Ricardo Elgul

2017-04-01

In this work the diffusion of mercury and other elements from amalgam tooth restorations through the surrounding dental tissue (dentin) was evaluated using femtosecond laser-induced breakdown spectroscopy (fs-LIBS). To achieve this, seven deciduous and eight permanent extracted human molar teeth with occlusal amalgam restorations were half-sectioned and analyzed using pulses from a femtosecond laser. The measurements were performed from the amalgam restoration along the amalgam/dentin interface to the apical direction. It was possible to observe the presence of metallic elements (silver, mercury, copper and tin) emission lines, as well as dental constituent ones, providing fingerprints of each material and comparable data for checking the consistence of the results. It was also shown that the elements penetration depth values in each tooth are usually similar and consistent, for both deciduous and permanent teeth, indicating that all the metals diffuse into the dentin by the same mechanism. We propose that this diffusion mechanism is mainly through liquid dragging inside the dentin tubules. The mercury diffused further in permanent teeth than in deciduous teeth, probably due to the longer diffusion times due to the age of the restorations. It was possible to conclude that the proposed femtosecond-LIBS system can detect the presence of metals in the dental tissue, among the tooth constituent elements, and map the distribution of endogenous and exogenous chemical elements, with a spatial resolution that can be brought under 100 µm.

Remote Raman - laser induced breakdown spectroscopy (LIBS) geochemical investigation under Venus atmospheric conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clegg, Sanuel M; Barefield, James E; Humphries, Seth D

2010-12-13

The extreme Venus surface temperatures ({approx}740 K) and atmospheric pressures ({approx}93 atm) create a challenging environment for surface missions. Scientific investigations capable of Venus geochemical observations must be completed within hours of landing before the lander will be overcome by the harsh atmosphere. A combined remote Raman - LIBS (Laser Induced Breakdown Spectroscopy) instrument is capable of accomplishing the geochemical science goals without the risks associated with collecting samples and bringing them into the lander. Wiens et al. and Sharma et al. demonstrated that both analytical techniques can be integrated into a single instrument capable of planetary missions. The focusmore » of this paper is to explore the capability to probe geologic samples with Raman - LIBS and demonstrate quantitative analysis under Venus surface conditions. Raman and LIBS are highly complementary analytical techniques capable of detecting both the mineralogical and geochemical composition of Venus surface materials. These techniques have the potential to profoundly increase our knowledge of the Venus surface composition, which is currently limited to geochemical data from Soviet Venera and VEGA landers that collectively suggest a surface composition that is primarily tholeiitic basaltic with some potentially more evolved compositions and, in some locations, K-rich trachyandesite. These landers were not equipped to probe the surface mineralogy as can be accomplished with Raman spectroscopy. Based on the observed compositional differences and recognizing the imprecise nature of the existing data, 15 samples were chosen to constitute a Venus-analog suite for this study, including five basalts, two each of andesites, dacites, and sulfates, and single samples of a foidite, trachyandesite, rhyolite, and basaltic trachyandesite under Venus conditions. LIBS data reduction involved generating a partial least squares (PLS) model with a subset of the rock powder standards to quantitatively determine the major elemental abundance of the remaining samples. PLS analysis suggests that the major element compositions can be determined with root mean square errors ca. 5% (absolute) for SiO{sub 2}, Al{sub 2}O{sub 3}, Fe{sub 2}O{sub 3}(total), MgO, and CaO, and ca. 2% or less for TiO{sub 2}, Cr{sub 2}O{sub 3}, MnO, K{sub 2}O, and Na{sub 2}O. Finally, the Raman experiments have been conducted under supercritical CO{sub 2} involving single-mineral and mixed-mineral samples containing talc, olivine, pyroxenes, feldspars, anhydrite, barite, and siderite. The Raman data have shown that the individual minerals can easily be identified individually or in mixtures.« less

Measurement of Irradiated Pyroprocessing Samples via Laser Induced Breakdown Spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phongikaroon, Supathorn

The primary objective of this research is to develop an applied technology and provide an assessment to remotely measure and analyze the real time or near real time concentrations of used nuclear fuel (UNF) dissolute in electrorefiners. Here, Laser-Induced Breakdown Spectroscopy (LIBS), in UNF pyroprocessing facilities will be investigated. LIBS is an elemental analysis method, which is based on the emission from plasma generated by focusing a laser beam into the medium. This technology has been reported to be applicable in the media of solids, liquids (includes molten metals), and gases for detecting elements of special nuclear materials. The advantagesmore » of applying the technology for pyroprocessing facilities are: (i) Rapid real-time elemental analysis|one measurement/laser pulse, or average spectra from multiple laser pulses for greater accuracy in < 2 minutes; (ii) Direct detection of elements and impurities in the system with low detection limits|element specific, ranging from 2-1000 ppm for most elements; and (iii) Near non-destructive elemental analysis method (about 1 g material). One important challenge to overcome is achieving high-resolution spectral analysis to quantitatively analyze all important fission products and actinides. Another important challenge is related to accessibility of molten salt, which is heated in a heavily insulated, remotely operated furnace in a high radiation environment with an argon atmosphere.« less

Fast analysis of wood preservers using laser induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Uhl, A.; Loebe, K.; Kreuchwig, L.

2001-06-01

Laser-induced breakdown spectroscopy (LIBS) is used for the investigation of wood preservers in timber and in furniture. Both experiments in laboratory and practical applications in recycling facilities and on a building site prove the new possibilities for the fast detection of harmful agents in wood. A commercial system was developed for mobile laser-plasma-analysis as well as for industrial use in sorting plants. The universal measuring principle in combination with an Echelle optics permits real simultaneous multi-element-analysis in the range of 200-780 nm with a resolution of a few picometers. It enables the user to detect main and trace elements in wood within a few seconds, nearly independent of the matrix, knowing that different kinds of wood show an equal elemental composition. Sample preparation is not required. The quantitative analysis of inorganic wood preservers (containing, e.g. Cu, Cr, B, As, Pb, Hg) has been performed exactly using carbon as reference element. It can be shown that the detection limits for heavy metals in wood are in the ppm-range. Additional information is given concerning the quantitative analysis. Statistical data, e.g. the standard deviation (S.D.), were determined and calibration curves were used for each particular element. A comparison between ICP-AES and LIBS is given using depth profile correction factors regarding the different penetration depths with respect to the different volumes in wood analyzed by both analytical methods.

Calibration curves for commercial copper and aluminum alloys using handheld laser-induced breakdown spectroscopy

DOE PAGES

Bennett, B. N.; Martin, M. Z.; Leonard, D. N.; ...

2018-02-13

Handheld laser-induced breakdown spectroscopy (HH LIBS) was used to study the elemental composition of four copper alloys and four aluminum alloys to produce calibration curves. The HH LIBS instrument used is a SciAps Z-500, commercially available, that contains a class-1 solid-state laser with an output wavelength of 1532 nm, a laser energy of 5 mJ/pulse, and a pulse duration of 5 ns. Test samples were solid specimens comprising of copper and aluminum alloys and data were collected from the samples’ surface at three different locations, employing a 12-point-grid pattern for each data set. All three data sets of the spectramore » were averaged, and the intensity, corrected by subtraction of background, was used to produce the elemental calibration curves. Calibration curves are presented for the matrix elements, copper and aluminum, as well as several minor elements. The surface damage produced by the laser was examined by microscopy. The alloys were tested in air and in a glovebox to evaluate the instrument’s ability to identify the constituents within materials under different environmental conditions. The main objective of using this HH LIBS technology is to determine its capability to fingerprint the presence of certain elements related to subpercent level within materials in real time and in-situ, as a starting point for undertaking future complex material characterization work.« less

Identification of Coffee Varieties Using Laser-Induced Breakdown Spectroscopy and Chemometrics.

PubMed

Zhang, Chu; Shen, Tingting; Liu, Fei; He, Yong

2017-12-31

We linked coffee quality to its different varieties. This is of interest because the identification of coffee varieties should help coffee trading and consumption. Laser-induced breakdown spectroscopy (LIBS) combined with chemometric methods was used to identify coffee varieties. Wavelet transform (WT) was used to reduce LIBS spectra noise. Partial least squares-discriminant analysis (PLS-DA), radial basis function neural network (RBFNN), and support vector machine (SVM) were used to build classification models. Loadings of principal component analysis (PCA) were used to select the spectral variables contributing most to the identification of coffee varieties. Twenty wavelength variables corresponding to C I, Mg I, Mg II, Al II, CN, H, Ca II, Fe I, K I, Na I, N I, and O I were selected. PLS-DA, RBFNN, and SVM models on selected wavelength variables showed acceptable results. SVM and RBFNN models performed better with a classification accuracy of over 80% in the prediction set, for both full spectra and the selected variables. The overall results indicated that it was feasible to use LIBS and chemometric methods to identify coffee varieties. For further studies, more samples are needed to produce robust classification models, research should be conducted on which methods to use to select spectral peaks that correspond to the elements contributing most to identification, and the methods for acquiring stable spectra should also be studied.

The differentiation of oral soft- and hard tissues using laser induced breakdown spectroscopy - a prospect for tissue specific laser surgery.

PubMed

Rohde, Maximilian; Mehari, Fanuel; Klämpfl, Florian; Adler, Werner; Neukam, Friedrich-Wilhelm; Schmidt, Michael; Stelzle, Florian

2017-10-01

Compared to conventional techniques, Laser surgery procedures provide a number of advantages, but may be associated with an increased risk of iatrogenic damage to important anatomical structures. The type of tissue ablated in the focus spot is unknown. Laser-Induced Breakdown-Spectroscopy (LIBS) has the potential to gain information about the type of material that is being ablated by the laser beam. This may form the basis for tissue selective laser surgery. In the present study, 7 different porcine tissues (cortical and cancellous bone, nerve, mucosa, enamel, dentine and pulp) from 6 animals were analyzed for their qualitative and semiquantitative molecular composition using LIBS. The so gathered data was used to first differentiate between the soft- and hard-tissues using a Calcium-Carbon emission based classifier. The tissues were then further classified using emission-ratio based analysis, principal component analysis (PCA) and linear discriminant analysis (LDA). The relatively higher concentration of Calcium in the hard tissues allows for an accurate first differentiation of soft- and hard tissues (100% sensitivity and specificity). The ratio based statistical differentiation approach yields results in the range from 65% (enamel-dentine pair) to 100% (nerve-pulp, cancellous bone-dentine, cancellous bone-enamel pairs) sensitivity and specificity. Experimental LIBS measuring setup. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Calibration curves for commercial copper and aluminum alloys using handheld laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Bennett, B. N.; Martin, M. Z.; Leonard, D. N.; Garlea, E.

2018-03-01

Handheld laser-induced breakdown spectroscopy (HH LIBS) was used to study the elemental composition of four copper alloys and four aluminum alloys to produce calibration curves. The HH LIBS instrument used is a SciAps Z-500, commercially available, that contains a class-1 solid-state laser with an output wavelength of 1532 nm, laser energy of 5 mJ/pulse, and a pulse duration of 5 ns. Test samples were solid specimens comprising copper and aluminum alloys and data were collected from the samples' surface at three different locations, employing a 12-point-grid pattern for each data set. All three data sets of the spectra were averaged, and the intensity, corrected by subtraction of background, was used to produce the elemental calibration curves. Calibration curves are presented for the matrix elements, copper and aluminum, as well as several minor elements. The surface damage produced by the laser was examined by microscopy. The alloys were tested in air and in a glovebox to evaluate the instrument's ability to identify the constituents within materials under different environmental conditions. The main objective of using this HH LIBS technology is to determine its capability to fingerprint the presence of certain elements related to subpercent level within materials in real time and in situ, as a starting point for undertaking future complex material characterization work.

Calibration curves for commercial copper and aluminum alloys using handheld laser-induced breakdown spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bennett, B. N.; Martin, M. Z.; Leonard, D. N.

Handheld laser-induced breakdown spectroscopy (HH LIBS) was used to study the elemental composition of four copper alloys and four aluminum alloys to produce calibration curves. The HH LIBS instrument used is a SciAps Z-500, commercially available, that contains a class-1 solid-state laser with an output wavelength of 1532 nm, a laser energy of 5 mJ/pulse, and a pulse duration of 5 ns. Test samples were solid specimens comprising of copper and aluminum alloys and data were collected from the samples’ surface at three different locations, employing a 12-point-grid pattern for each data set. All three data sets of the spectramore » were averaged, and the intensity, corrected by subtraction of background, was used to produce the elemental calibration curves. Calibration curves are presented for the matrix elements, copper and aluminum, as well as several minor elements. The surface damage produced by the laser was examined by microscopy. The alloys were tested in air and in a glovebox to evaluate the instrument’s ability to identify the constituents within materials under different environmental conditions. The main objective of using this HH LIBS technology is to determine its capability to fingerprint the presence of certain elements related to subpercent level within materials in real time and in-situ, as a starting point for undertaking future complex material characterization work.« less

Identification of Coffee Varieties Using Laser-Induced Breakdown Spectroscopy and Chemometrics

PubMed Central

Zhang, Chu; Shen, Tingting

2017-01-01

We linked coffee quality to its different varieties. This is of interest because the identification of coffee varieties should help coffee trading and consumption. Laser-induced breakdown spectroscopy (LIBS) combined with chemometric methods was used to identify coffee varieties. Wavelet transform (WT) was used to reduce LIBS spectra noise. Partial least squares-discriminant analysis (PLS-DA), radial basis function neural network (RBFNN), and support vector machine (SVM) were used to build classification models. Loadings of principal component analysis (PCA) were used to select the spectral variables contributing most to the identification of coffee varieties. Twenty wavelength variables corresponding to C I, Mg I, Mg II, Al II, CN, H, Ca II, Fe I, K I, Na I, N I, and O I were selected. PLS-DA, RBFNN, and SVM models on selected wavelength variables showed acceptable results. SVM and RBFNN models performed better with a classification accuracy of over 80% in the prediction set, for both full spectra and the selected variables. The overall results indicated that it was feasible to use LIBS and chemometric methods to identify coffee varieties. For further studies, more samples are needed to produce robust classification models, research should be conducted on which methods to use to select spectral peaks that correspond to the elements contributing most to identification, and the methods for acquiring stable spectra should also be studied. PMID:29301228

Geometrical effects in data collection and processing for calibration-free laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Shabanov, S. V.; Gornushkin, I. B.

2018-01-01

Data processing in the calibration-free laser-induced breakdown spectroscopy (LIBS) is usually based on the solution of the radiative transfer equation along a particular line of sight through a plasma plume. The LIBS data processing is generalized to the case when the spectral data are collected from large portions of the plume. It is shown that by adjusting the optical depth and width of the lines the spectra obtained by collecting light from an entire spherical homogeneous plasma plume can be least-square fitted to a spectrum obtained by collecting the radiation just along a plume diameter with a relative error of 10-11 or smaller (for the optical depth not exceeding 0.3) so that a mismatch of geometries of data processing and data collection cannot be detected by fitting. Despite the existence of such a perfect least-square fit, the errors in the line optical depth and width found by a data processing with an inappropriate geometry can be large. It is shown with analytic and numerical examples that the corresponding relative errors in the found elemental number densities and concentrations may be as high as 50% and 20%, respectively. Safe for a few found exceptions, these errors are impossible to eliminate from LIBS data processing unless a proper solution of the radiative transfer equation corresponding to the ray tracing in the spectral data collection is used.

REVIEW ARTICLE: Industrial applications of temperature and species concentration monitoring using laser diagnostics

NASA Astrophysics Data System (ADS)

Deguchi, Y.; Noda, M.; Fukuda, Y.; Ichinose, Y.; Endo, Y.; Inada, M.; Abe, Y.; Iwasaki, S.

2002-10-01

Industrial applications of laser diagnostics have been demonstrated for the purpose of clarifying combustor chemical reaction mechanisms, as well as temperature and harmful substance monitoring in large-scale burners and commercial plant exhaust ducts, and the combustion control of commercial plants. Laser induced fluorescence (LIF), laser induced breakdown spectroscopy (LIBS), and tunable diode laser absorption spectroscopy (TDLAS) have accordingly been applied in various industrial fields. In this study, temperature and species concentration were measured inside gas turbine combustors, a diesel engine, and a large-scale industrial burner using LIF. This technique introduces a new tool with respect to practical combustors for the analysis of NO formation characteristics, turbulent flame front structure, and differences between standard and improved combustors. On-line monitoring of trace elements to the ppb level was also successfully demonstrated using LIBS. The automated LIBS unit was found to be capable of monitoring trace element concentration fluctuations at ppb levels with a 1 min detection time under actual plant conditions. In addition, real-time measurement of O2 and CO concentrations in a commercial incinerator furnace was performed using TDLAS to improve the combustion control. By using the multiple-point laser measurement results to control secondary air allocation, higher secondary combustion efficiency was achieved, and CO concentration (considered to be a substitute indicator for dioxins) was reduced from 11.9 to 8.0 ppm.

Simultaneous species concentration and temperature measurements using laser induced breakdown spectroscopy with direct spectrum matching

NASA Astrophysics Data System (ADS)

McGann, Brendan J.

Laser induced breakdown spectroscopy (LIBS) is used to simultaneously measure hydrocarbon fuel concentration and temperature in high temperature, high speed, compressible, and reacting flows, a regime in which LIBS has not been done previously. Emission spectra from the plasma produced from a focused laser pulse is correlated in the combustion region of a model scramjet operating in supersonic wind tunnel. A 532 nm Nd:YAG laser operating at 10 Hz is used to induce break-down. The emissions are captured during a 10 ns gate time approximately 75 ns after the first arrival of photons at the measurement location in order to minimize the measurement uncertainty in the turbulent, compressible, high-speed, and reacting environment. Three methods of emission detection are used and a new backward scattering direction method is developed that is beneficial in reducing the amount of optical access needed to perform LIBS measurements. Measurements are taken in the model supersonic combustion and the ignition process is shown to be highly dependent on fuel concentration and gas density as well as combustion surface temperature, concentration gradient, and flow field. Direct spectrum matching method is developed and used for quantitative measurements. In addition, a comprehensive database of spectra covering the fuel concentrations and gas densities found in the wind tunnel of Research Cell 19 at Wright Patterson Air Force Base is created which can be used for further work.

A flexible Li-ion battery with design towards electrodes electrical insulation

NASA Astrophysics Data System (ADS)

Vieira, E. M. F.; Ribeiro, J. F.; Sousa, R.; Correia, J. H.; Goncalves, L. M.

2016-08-01

The application of micro electromechanical systems (MEMS) technology in several consumer electronics leads to the development of micro/nano power sources with high power and MEMS integration possibility. This work presents the fabrication of a flexible solid-state Li-ion battery (LIB) (~2.1 μm thick) with a design towards electrodes electrical insulation, using conventional, low cost and compatible MEMS fabrication processes. Kapton® substrate provides flexibility to the battery. E-beam deposited 300 nm thick Ge anode was coupled with LiCoO2/LiPON (cathode/solid-state electrolyte) in a battery system. LiCoO2 and LiPON films were deposited by RF-sputtering with a power source of 120 W and 100 W, respectively. LiCoO2 film was annealed at 400 °C after deposition. The new design includes Si3N4 and LiPO thin-films, providing electrode electrical insulation and a battery chemical stability safeguard, respectively. Microstructure and battery performance were investigated by scanning electron microscopy, electric resistivity and electrochemical measurements (open circuit potential, charge/discharge cycles and electrochemical impedance spectroscopy). A rechargeable thin-film and lightweight flexible LIB using MEMS processing compatible materials and techniques is reported.

New insights on the Dronino iron meteorite by double-pulse micro-Laser-Induced Breakdown Spectroscopy

NASA Astrophysics Data System (ADS)

Tempesta, Gioacchino; Senesi, Giorgio S.; Manzari, Paola; Agrosì, Giovanna

2018-06-01

Two fragments of an iron meteorite shower named Dronino were characterized by a novel technique, i.e. Double-Pulse micro-Laser Induced Breakdown Spectroscopy (DP-μLIBS) combined with optical microscope. This technique allowed to perform a fast and detailed analysis of the chemical composition of the fragments and permitted to determine their composition, the alteration state differences and the cooling rate of the meteorite. Qualitative analysis indicated the presence of Fe, Ni and Co in both fragments, whereas the elements Al, Ca, Mg, Si and, for the first time Li, were detected only in one fragment and were related to its post-falling alteration and contamination by weathering processes. Quantitative analysis data obtained using the calibration-free (CF) - LIBS method showed a good agreement with those obtained by traditional methods generally applied to meteorite analysis, i.e. Electron Dispersion Spectroscopy - Scanning Electron Microscopy (EDS-SEM), also performed in this study, and Electron Probe Microanalysis (EMPA) (literature data). The local and coupled variability of Ni and Co (increase of Ni and decrease of Co) determined for the unaltered portions exhibiting plessite texture, suggested the occurrence of solid state diffusion processes under a slow cooling rate for the Dronino meteorite.