Patterns of Antimicrobial Resistance Observed in Escherichia coli Isolates Obtained from Domestic- and Wild-Animal Fecal Samples, Human Septage, and Surface Water

PubMed Central

Sayah, Raida S.; Kaneene, John B.; Johnson, Yvette; Miller, RoseAnn

2005-01-01

A repeated cross-sectional study was conducted to determine the patterns of antimicrobial resistance in 1,286 Escherichia coli strains isolated from human septage, wildlife, domestic animals, farm environments, and surface water in the Red Cedar watershed in Michigan. Isolation and identification of E. coli were done by using enrichment media, selective media, and biochemical tests. Antimicrobial susceptibility testing by the disk diffusion method was conducted for neomycin, gentamicin, streptomycin, chloramphenicol, ofloxacin, trimethoprim-sulfamethoxazole, tetracycline, ampicillin, nalidixic acid, nitrofurantoin, cephalothin, and sulfisoxazole. Resistance to at least one antimicrobial agent was demonstrated in isolates from livestock, companion animals, human septage, wildlife, and surface water. In general, E. coli isolates from domestic species showed resistance to the largest number of antimicrobial agents compared to isolates from human septage, wildlife, and surface water. The agents to which resistance was demonstrated most frequently were tetracycline, cephalothin, sulfisoxazole, and streptomycin. There were similarities in the patterns of resistance in fecal samples and farm environment samples by animal, and the levels of cephalothin-resistant isolates were higher in farm environment samples than in fecal samples. Multidrug resistance was seen in a variety of sources, and the highest levels of multidrug-resistant E. coli were observed for swine fecal samples. The fact that water sample isolates were resistant only to cephalothin may suggest that the resistance patterns for farm environment samples may be more representative of the risk of contamination of surface waters with antimicrobial agent-resistant bacteria. PMID:15746342

Strategies for Obtaining Probability Samples of Homeless Youth

ERIC Educational Resources Information Center

Golinelli, Daniela; Tucker, Joan S.; Ryan, Gery W.; Wenzel, Suzanne L.

2015-01-01

Studies of homeless individuals typically sample subjects from few types of sites or regions within a metropolitan area. This article focuses on the biases that can result from such a practice. We obtained a probability sample of 419 homeless youth from 41 sites (shelters, drop-in centers, and streets) in four regions of Los Angeles County (LAC).…

Using high frequency water quality data to assess sampling strategies for the EU Water Framework Directive

NASA Astrophysics Data System (ADS)

Skeffington, R. A.; Halliday, S. J.; Wade, A. J.; Bowes, M. J.; Loewenthal, M.

2015-01-01

The EU Water Framework Directive (WFD) requires that the ecological and chemical status of water bodies in Europe should be assessed, and action taken where possible to ensure that at least "good" quality is attained in each case by 2015. This paper is concerned with the accuracy and precision with which chemical status in rivers can be measured given certain sampling strategies, and how this can be improved. High frequency (hourly) chemical data from four rivers in southern England were subsampled to simulate different sampling strategies for four parameters used for WFD classification: dissolved phosphorus, dissolved oxygen, pH and water temperature. These data sub-sets were then used to calculate the WFD classification for each site. Monthly sampling was less precise than weekly sampling, but the effect on WFD classification depended on the closeness of the range of concentrations to the class boundaries. In some cases, monthly sampling for a year could result in the same water body being assigned to one of 3 or 4 WFD classes with 95% confidence, whereas with weekly sampling this was 1 or 2 classes for the same cases. In the most extreme case, random sampling effects could result in the same water body being assigned to any of the 5 WFD quality classes. The width of the weekly sampled confidence intervals was about 33% that of the monthly for P species and pH, about 50% for dissolved oxygen, and about 67% for water temperature. For water temperature, which is assessed as the 98th percentile in the UK, monthly sampling biases the mean downwards by about 1 °C compared to the true value, due to problems of assessing high percentiles with limited data. Confining sampling to the working week compared to all seven days made little difference, but a modest improvement in precision could be obtained by sampling at the same time of day within a 3 h time window, and this is recommended. For parameters with a strong diel variation, such as dissolved oxygen, the value

Using high-frequency water quality data to assess sampling strategies for the EU Water Framework Directive

NASA Astrophysics Data System (ADS)

Skeffington, R. A.; Halliday, S. J.; Wade, A. J.; Bowes, M. J.; Loewenthal, M.

2015-05-01

The EU Water Framework Directive (WFD) requires that the ecological and chemical status of water bodies in Europe should be assessed, and action taken where possible to ensure that at least "good" quality is attained in each case by 2015. This paper is concerned with the accuracy and precision with which chemical status in rivers can be measured given certain sampling strategies, and how this can be improved. High-frequency (hourly) chemical data from four rivers in southern England were subsampled to simulate different sampling strategies for four parameters used for WFD classification: dissolved phosphorus, dissolved oxygen, pH and water temperature. These data sub-sets were then used to calculate the WFD classification for each site. Monthly sampling was less precise than weekly sampling, but the effect on WFD classification depended on the closeness of the range of concentrations to the class boundaries. In some cases, monthly sampling for a year could result in the same water body being assigned to three or four of the WFD classes with 95% confidence, due to random sampling effects, whereas with weekly sampling this was one or two classes for the same cases. In the most extreme case, the same water body could have been assigned to any of the five WFD quality classes. Weekly sampling considerably reduces the uncertainties compared to monthly sampling. The width of the weekly sampled confidence intervals was about 33% that of the monthly for P species and pH, about 50% for dissolved oxygen, and about 67% for water temperature. For water temperature, which is assessed as the 98th percentile in the UK, monthly sampling biases the mean downwards by about 1 °C compared to the true value, due to problems of assessing high percentiles with limited data. Low-frequency measurements will generally be unsuitable for assessing standards expressed as high percentiles. Confining sampling to the working week compared to all 7 days made little difference, but a modest

Holding effects on coliform enumeration in drinking water samples.

PubMed Central

McDaniels, A E; Bordner, R H; Gartside, P S; Haines, J R; Brenner, K P; Rankin, C C

1985-01-01

Standard procedures for analyzing drinking water stress the need to adhere to the time and temperature conditions recommended for holding samples collected for microbiological testing. The National Drinking Water Laboratory Certification Program requires compliance with these holding limits, but some investigators have reported difficulties in meeting them. Research was conducted by standard analytical methods to determine if changes occurred when samples were held at 5 and 22 degrees C and analyzed at 0, 24, 30, and 48 h. Samples were analyzed for coliforms by the membrane filter and fermentation-tube procedures and for heterotrophs by the pour plate method. A total of 17 treated water samples were collected from a large municipal distribution system from August to December 1981, and 12 samples were collected from January to May 1983. The samples were dosed with coliforms previously isolated from the water system, Enterobacter cloacae in 1981 and Citrobacter freundii in 1983. The coliform counts declined linearly over time, and the rates of decline were significant at both 5 and 22 degrees C. Within 24 h at 22 degrees C, levels of E. cloacae and C. freundii decreased by 47 and 26%, respectively, and at 5 degrees C, E. cloacae numbers declined by 23%. Results from these representative laboratory-grown coliforms reinforced those previously obtained with naturally occurring coliforms under the same experimental conditions. Significantly, some samples with initially unacceptable counts (greater than 4/100 ml) met the safe drinking water limits after storage at 24 h at 5 and 22 degrees C and would have been classified as satisfactory.(ABSTRACT TRUNCATED AT 250 WORDS) Images PMID:4083877

GROUND WATER SAMPLING OF VOCS IN THE WATER/CAPILLARY FRINGE AREA FOR VAPOR INTRUSION ASSESSMENT

EPA Science Inventory

Vapor intrusion has recently been considered a major pathway for increased indoor air contamination from certain volatile organic contaminants (VOCs). The recent Draft EPA Subsurface Vapor Intrusion Guidance Document states that ground water samples should be obtained from the u...

Turbidimetric Analysis of Water and Wastewater Samples Using a Spectrofluorimeter

NASA Astrophysics Data System (ADS)

Evans, Jason J.

2000-12-01

As student interest in environmental science grows, many colleges and universities are developing new courses in environmental chemistry. Environmental analysis in the "real world" has become increasingly instrumental, and it is important to introduce students to the instruments and procedures that are commonly used in environmental laboratories. Turbidimetric analysis of water and wastewater is ordinarily performed in environmental laboratories using a nephelometer. This experiment illustrates that a spectrofluorimeter can be successfully employed for these types of analysis. Samples from various stages of the water and wastewater treatment processes were collected from the Carlisle Water and Wastewater Treatment Plants. The students in our Environmental Chemistry laboratory used the spectrofluorimeter to measure the scattering intensity from the samples and from a series of formazine standards. The standard curve produced from their data gave a correlation coefficient of .999, and the detection limit was 0.03 Standard Turbidity Units, which is sufficient to obtain meaningful data on most water samples. This experiment was an excellent supplement to lecture material covering water and wastewater treatment because the students were able to monitor the level of suspended particulates in the water as it makes its way through the treatment plants.

Remote measurement of water color in coastal waters. [spectral radiance data used to obtain quantitative values for chlorophyll and turbidity

NASA Technical Reports Server (NTRS)

Weldon, J. W.

1973-01-01

An investigation was conducted to develop procedure to obtain quantitative values for chlorophyll and turbidity in coastal waters by observing the changes in spectral radiance of the backscattered spectrum. The technique under consideration consists of Examining Exotech model 20-D spectral radiometer data and determining which radiance ratios best correlated with chlorophyll and turbidity measurements as obtained from analyses of water samples and sechi visibility readings. Preliminary results indicate that there is a correlation between backscattered light and chlorophyll concentration and secchi visibility. The tests were conducted with the spectrometer mounted in a light aircraft over the Mississippi Sound at altitudes of 2.5K, 2.8K and 10K feet.

GROUND WATER MONITORING AND SAMPLING: MULTI-LEVEL VERSUS TRADITIONAL METHODS WHATS WHAT?

EPA Science Inventory

After years of research and many publications, the question still remains: What is the best method to collect representative ground water samples from monitoring wells? Numerous systems and devices are currently available for obtaining both multi-level samples as well as traditi...

Quantitative Real-Time Legionella PCR for Environmental Water Samples: Data Interpretation

PubMed Central

Joly, Philippe; Falconnet, Pierre-Alain; André, Janine; Weill, Nicole; Reyrolle, Monique; Vandenesch, François; Maurin, Max; Etienne, Jerome; Jarraud, Sophie

2006-01-01

Quantitative Legionella PCRs targeting the 16S rRNA gene (specific for the genus Legionella) and the mip gene (specific for the species Legionella pneumophila) were applied to a total of 223 hot water system samples (131 in one laboratory and 92 in another laboratory) and 37 cooling tower samples (all in the same laboratory). The PCR results were compared with those of conventional culture. 16S rRNA gene PCR results were nonquantifiable for 2.8% of cooling tower samples and up to 39.1% of hot water system samples, and this was highly predictive of Legionella CFU counts below 250/liter. PCR cutoff values for identifying hot water system samples containing >103 CFU/liter legionellae were determined separately in each laboratory. The cutoffs differed widely between the laboratories and had sensitivities from 87.7 to 92.9% and specificities from 77.3 to 96.5%. The best specificity was obtained with mip PCR. PCR cutoffs could not be determined for cooling tower samples, as the results were highly variable and often high for culture-negative samples. Thus, quantitative Legionella PCR appears to be applicable to samples from hot water systems, but the positivity cutoff has to be determined in each laboratory. PMID:16597985

Nationwide Drinking Water Sampling Campaign for Exposure Assessments in Denmark

PubMed Central

Voutchkova, Denitza Dimitrova; Hansen, Birgitte; Ernstsen, Vibeke; Kristiansen, Søren Munch

2018-01-01

Nationwide sampling campaign of treated drinking water of groundwater origin was designed and implemented in Denmark in 2013. The main purpose of the sampling was to obtain data on the spatial variation of iodine concentration and speciation in treated drinking water, which was supplied to the majority of the Danish population. This data was to be used in future exposure and epidemiologic studies. The water supply sector (83 companies, owning 144 waterworks throughout Denmark) was involved actively in the planning and implementation process, which reduced significantly the cost and duration of data collection. The dataset resulting from this collaboration covers not only iodine species (I−, IO3−, TI), but also major elements and parameters (pH, electrical conductivity, DOC, TC, TN, F−, Cl−, NO3−, SO42−, Ca2+, Mg2+, K+, Na+) and a long list of trace elements (n = 66). The water samples represent 144 waterworks abstracting about 45% of the annual Danish groundwater abstraction for drinking water purposes, which supply about 2.5 million Danes (45% of all Danish residents). This technical note presents the design, implementation, and limitations of such a sampling design in detail in order (1) to facilitate the future use of this dataset, (2) to inform future replication studies, or (3) to provide an example for other researchers. PMID:29518987

Terahertz time-domain spectroscopy for non-invasive assessment of water content in biological samples.

PubMed

Borovkova, Mariia; Khodzitsky, Mikhail; Demchenko, Petr; Cherkasova, Olga; Popov, Alexey; Meglinski, Igor

2018-05-01

We apply terahertz time-domain spectroscopy for the quantitative non-invasive assessment of the water content in biological samples, such as Carpinus caroliniana tree leaves and pork muscles. The developed experimental terahertz time-domain spectroscopy system operates both in transmission and reflection modes. The Landau-Looyenga-Lifshitz-based model is used for the calculation of the water concentration within the samples. The results of the water concentration measurements are compared with the results of the gravimetric measurements. The obtained results show that the water content in biological samples can be measured non-invasively, with a high accuracy, utilizing terahertz waves in transmission and reflection modes.

Concentration of ions in selected bottled water samples sold in Malaysia

NASA Astrophysics Data System (ADS)

Aris, Ahmad Zaharin; Kam, Ryan Chuan Yang; Lim, Ai Phing; Praveena, Sarva Mangala

2013-03-01

Many consumers around the world, including Malaysians, have turned to bottled water as their main source of drinking water. The aim of this study is to determine the physical and chemical properties of bottled water samples sold in Selangor, Malaysia. A total of 20 bottled water brands consisting of `natural mineral (NM)' and `packaged drinking (PD)' types were randomly collected and analyzed for their physical-chemical characteristics: hydrogen ion concentration (pH), electrical conductivity (EC) and total dissolved solids (TDS), selected major ions: calcium (Ca), potassium (K), magnesium (Mg) and sodium (Na), and minor trace constituents: copper (Cu) and zinc (Zn) to ascertain their suitability for human consumption. The results obtained were compared with guideline values recommended by World Health Organization (WHO) and Malaysian Ministry of Health (MMOH), respectively. It was found that all bottled water samples were in accordance with the guidelines set by WHO and MMOH except for one sample (D3) which was below the pH limit of 6.5. Both NM and PD bottled water were dominated by Na + K > Ca > Mg. Low values for EC and TDS in the bottled water samples showed that water was deficient in essential elements, likely an indication that these were removed by water treatment. Minerals like major ions were present in very low concentrations which could pose a risk to individuals who consume this water on a regular basis. Generally, the overall quality of the supplied bottled water was in accordance to standards and guidelines set by WHO and MMOH and safe for consumption.

Stable Isotope Analysis of Precipitation Samples Obtained via Crowdsourcing Reveals the Spatiotemporal Evolution of Superstorm Sandy

PubMed Central

Good, Stephen P.; Mallia, Derek V.; Lin, John C.; Bowen, Gabriel J.

2014-01-01

Extra-tropical cyclones, such as 2012 Superstorm Sandy, pose a significant climatic threat to the northeastern United Sates, yet prediction of hydrologic and thermodynamic processes within such systems is complicated by their interaction with mid-latitude water patterns as they move poleward. Fortunately, the evolution of these systems is also recorded in the stable isotope ratios of storm-associated precipitation and water vapor, and isotopic analysis provides constraints on difficult-to-observe cyclone dynamics. During Superstorm Sandy, a unique crowdsourced approach enabled 685 precipitation samples to be obtained for oxygen and hydrogen isotopic analysis, constituting the largest isotopic sampling of a synoptic-scale system to date. Isotopically, these waters span an enormous range of values (21‰ for O, 160‰ for H) and exhibit strong spatiotemporal structure. Low isotope ratios occurred predominantly in the west and south quadrants of the storm, indicating robust isotopic distillation that tracked the intensity of the storm's warm core. Elevated values of deuterium-excess (25‰) were found primarily in the New England region after Sandy made landfall. Isotope mass balance calculations and Lagrangian back-trajectory analysis suggest that these samples reflect the moistening of dry continental air entrained from a mid-latitude trough. These results demonstrate the power of rapid-response isotope monitoring to elucidate the structure and dynamics of water cycling within synoptic-scale systems and improve our understanding of storm evolution, hydroclimatological impacts, and paleo-storm proxies. PMID:24618882

Water Sample Concentrator

ScienceCinema

Idaho National Laboratory

2017-12-09

Automated portable device that concentrates and packages a sample of suspected contaminated water for safe, efficient transport to a qualified analytical laboratory. This technology will help safeguard against pathogen contamination or chemical and biolog

Sampling trace organic compounds in water: a comparison of a continuous active sampler to continuous passive and discrete sampling methods

USGS Publications Warehouse

Coes, Alissa L.; Paretti, Nicholas V.; Foreman, William T.; Iverson, Jana L.; Alvarez, David A.

2014-01-01

A continuous active sampling method was compared to continuous passive and discrete sampling methods for the sampling of trace organic compounds (TOCs) in water. Results from each method are compared and contrasted in order to provide information for future investigators to use while selecting appropriate sampling methods for their research. The continuous low-level aquatic monitoring (CLAM) sampler (C.I.Agent® Storm-Water Solutions) is a submersible, low flow-rate sampler, that continuously draws water through solid-phase extraction media. CLAM samplers were deployed at two wastewater-dominated stream field sites in conjunction with the deployment of polar organic chemical integrative samplers (POCIS) and the collection of discrete (grab) water samples. All samples were analyzed for a suite of 69 TOCs. The CLAM and POCIS samples represent time-integrated samples that accumulate the TOCs present in the water over the deployment period (19–23 h for CLAM and 29 days for POCIS); the discrete samples represent only the TOCs present in the water at the time and place of sampling. Non-metric multi-dimensional scaling and cluster analysis were used to examine patterns in both TOC detections and relative concentrations between the three sampling methods. A greater number of TOCs were detected in the CLAM samples than in corresponding discrete and POCIS samples, but TOC concentrations in the CLAM samples were significantly lower than in the discrete and (or) POCIS samples. Thirteen TOCs of varying polarity were detected by all of the three methods. TOC detections and concentrations obtained by the three sampling methods, however, are dependent on multiple factors. This study found that stream discharge, constituent loading, and compound type all affected TOC concentrations detected by each method. In addition, TOC detections and concentrations were affected by the reporting limits, bias, recovery, and performance of each method.

Sampling trace organic compounds in water: a comparison of a continuous active sampler to continuous passive and discrete sampling methods.

PubMed

Coes, Alissa L; Paretti, Nicholas V; Foreman, William T; Iverson, Jana L; Alvarez, David A

2014-03-01

A continuous active sampling method was compared to continuous passive and discrete sampling methods for the sampling of trace organic compounds (TOCs) in water. Results from each method are compared and contrasted in order to provide information for future investigators to use while selecting appropriate sampling methods for their research. The continuous low-level aquatic monitoring (CLAM) sampler (C.I.Agent® Storm-Water Solutions) is a submersible, low flow-rate sampler, that continuously draws water through solid-phase extraction media. CLAM samplers were deployed at two wastewater-dominated stream field sites in conjunction with the deployment of polar organic chemical integrative samplers (POCIS) and the collection of discrete (grab) water samples. All samples were analyzed for a suite of 69 TOCs. The CLAM and POCIS samples represent time-integrated samples that accumulate the TOCs present in the water over the deployment period (19-23 h for CLAM and 29 days for POCIS); the discrete samples represent only the TOCs present in the water at the time and place of sampling. Non-metric multi-dimensional scaling and cluster analysis were used to examine patterns in both TOC detections and relative concentrations between the three sampling methods. A greater number of TOCs were detected in the CLAM samples than in corresponding discrete and POCIS samples, but TOC concentrations in the CLAM samples were significantly lower than in the discrete and (or) POCIS samples. Thirteen TOCs of varying polarity were detected by all of the three methods. TOC detections and concentrations obtained by the three sampling methods, however, are dependent on multiple factors. This study found that stream discharge, constituent loading, and compound type all affected TOC concentrations detected by each method. In addition, TOC detections and concentrations were affected by the reporting limits, bias, recovery, and performance of each method. Published by Elsevier B.V.

Direct sampling of chemical weapons in water by photoionization mass spectrometry.

PubMed

Syage, Jack A; Cai, Sheng-Suan; Li, Jianwei; Evans, Matthew D

2006-05-01

The vulnerability of water supplies to toxic contamination calls for fast and effective means for screening water samples for multiple threats. We describe the use of photoionization (PI) mass spectrometry (MS) for high-speed, high-throughput screening and molecular identification of chemical weapons (CW) threats and other hazardous compounds. The screening technology can detect a wide range of compounds at subacute concentrations with no sample preparation and a sampling cycle time of approximately 45 s. The technology was tested with CW agents VX, GA, GB, GD, GF, HD, HN1, and HN3, in addition to riot agents and precursors. All are sensitively detected and give simple PI mass spectra dominated by the parent ion. The target application of the PI MS method is as a routine, real-time early warning system for CW agents and other hazardous compounds in air and in water. In this work, we also present comprehensive measurements for water analysis and report on the system detection limits, linearity, quantitation accuracy, and false positive (FP) and false negative rates for concentrations at subacute levels. The latter data are presented in the form of receiver operating characteristic curves of the form of detection probability P(D) versus FP probability P(FP). These measurements were made using the CW surrogate compounds, DMMP, DEMP, DEEP, and DIMP. Method detection limits (3sigma) obtained using a capillary injection method yielded 1, 6, 3, and 2 ng/mL, respectively. These results were obtained using 1-microL injections of water samples without any preparation, corresponding to mass detection limits of 1, 6, 3, and 2 pg, respectively. The linear range was about 3-4 decades and the dynamic range about 4-5 decades. The relative standard deviations were generally <10% at CW subacute concentrations levels.

Rapid detection of Naegleria fowleri in water distribution pipeline biofilms and drinking water samples.

PubMed

Puzon, Geoffrey J; Lancaster, James A; Wylie, Jason T; Plumb, Iason J

2009-09-01

Rapid detection of pathogenic Naegleria fowler in water distribution networks is critical for water utilities. Current detection methods rely on sampling drinking water followed by culturing and molecular identification of purified strains. This culture-based method takes an extended amount of time (days), detects both nonpathogenic and pathogenic species, and does not account for N. fowleri cells associated with pipe wall biofilms. In this study, a total DNA extraction technique coupled with a real-time PCR method using primers specific for N. fowleri was developed and validated. The method readily detected N. fowleri without preculturing with the lowest detection limit for N. fowleri cells spiked in biofilm being one cell (66% detection rate) and five cells (100% detection rate). For drinking water, the detection limit was five cells (66% detection rate) and 10 cells (100% detection rate). By comparison, culture-based methods were less sensitive for detection of cells spiked into both biofilm (66% detection for <10 cells) and drinking water (0% detection for <10 cells). In mixed cultures of N. fowleri and nonpathogenic Naegleria, the method identified N. fowleri in 100% of all replicates, whereastests with the current consensus primers detected N. fowleri in only 5% of all replicates. Application of the new method to drinking water and pipe wall biofilm samples obtained from a distribution network enabled the detection of N. fowleri in under 6 h, versus 3+ daysforthe culture based method. Further, comparison of the real-time PCR data from the field samples and the standard curves enabled an approximation of N. fowleri cells in the biofilm and drinking water. The use of such a method will further aid water utilities in detecting and managing the persistence of N. fowleri in water distribution networks.

Approach for environmental baseline water sampling

USGS Publications Warehouse

Smith, K.S.

2011-01-01

Samples collected during the exploration phase of mining represent baseline conditions at the site. As such, they can be very important in forecasting potential environmental impacts should mining proceed, and can become measurements against which future changes are compared. Constituents in stream water draining mined and mineralized areas tend to be geochemically, spatially, and temporally variable, which presents challenges in collecting both exploration and baseline water-quality samples. Because short-term (daily) variations can complicate long-term trends, it is important to consider recent findings concerning geochemical variability of stream-water constituents at short-term timescales in designing sampling plans. Also, adequate water-quality information is key to forecasting potential ecological impacts from mining. Therefore, it is useful to collect baseline water samples adequate tor geochemical and toxicological modeling. This requires complete chemical analyses of dissolved constituents that include major and minor chemical elements as well as physicochemical properties (including pH, specific conductance, dissolved oxygen) and dissolved organic carbon. Applying chemical-equilibrium and appropriate toxicological models to water-quality information leads to an understanding of the speciation, transport, sequestration, bioavailability, and aquatic toxicity of potential contaminants. Insights gained from geochemical and toxicological modeling of water-quality data can be used to design appropriate mitigation and for economic planning for future mining activities.

Chapter A5. Processing of Water Samples

USGS Publications Warehouse

Wilde, Franceska D.; Radtke, Dean B.; Gibs, Jacob; Iwatsubo, Rick T.

1999-01-01

The National Field Manual for the Collection of Water-Quality Data (National Field Manual) describes protocols and provides guidelines for U.S. Geological Survey (USGS) personnel who collect data used to assess the quality of the Nation's surface-water and ground-water resources. This chapter addresses methods to be used in processing water samples to be analyzed for inorganic and organic chemical substances, including the bottling of composite, pumped, and bailed samples and subsamples; sample filtration; solid-phase extraction for pesticide analyses; sample preservation; and sample handling and shipping. Each chapter of the National Field Manual is published separately and revised periodically. Newly published and revised chapters will be announced on the USGS Home Page on the World Wide Web under 'New Publications of the U.S. Geological Survey.' The URL for this page is http:/ /water.usgs.gov/lookup/get?newpubs.

Robowell: An automated process for monitoring ground water quality using established sampling protocols

USGS Publications Warehouse

Granato, G.E.; Smith, K.P.

1999-01-01

Robowell is an automated process for monitoring selected ground water quality properties and constituents by pumping a well or multilevel sampler. Robowell was developed and tested to provide a cost-effective monitoring system that meets protocols expected for manual sampling. The process uses commercially available electronics, instrumentation, and hardware, so it can be configured to monitor ground water quality using the equipment, purge protocol, and monitoring well design most appropriate for the monitoring site and the contaminants of interest. A Robowell prototype was installed on a sewage treatment plant infiltration bed that overlies a well-studied unconfined sand and gravel aquifer at the Massachusetts Military Reservation, Cape Cod, Massachusetts, during a time when two distinct plumes of constituents were released. The prototype was operated from May 10 to November 13, 1996, and quality-assurance/quality-control measurements demonstrated that the data obtained by the automated method was equivalent to data obtained by manual sampling methods using the same sampling protocols. Water level, specific conductance, pH, water temperature, dissolved oxygen, and dissolved ammonium were monitored by the prototype as the wells were purged according to U.S Geological Survey (USGS) ground water sampling protocols. Remote access to the data record, via phone modem communications, indicated the arrival of each plume over a few days and the subsequent geochemical reactions over the following weeks. Real-time availability of the monitoring record provided the information needed to initiate manual sampling efforts in response to changes in measured ground water quality, which proved the method and characterized the screened portion of the plume in detail through time. The methods and the case study described are presented to document the process for future use.

Umbrella sampling of proton transfer in a creatine-water system

NASA Astrophysics Data System (ADS)

Ivchenko, Olga; Bachert, Peter; Imhof, Petra

2014-04-01

Proton transfer reactions are among the most common processes in chemistry and biology. Proton transfer between creatine and surrounding solvent water is underlying the chemical exchange saturation transfer used as a contrast in magnetic resonance imaging. The free energy barrier, determined by first-principles umbrella sampling simulations (EaDFT 3 kcal/mol) is in the same order of magnitude as the experimentally obtained activation energy. The underlying mechanism is a first proton transfer from the guanidinium group to the water pool, followed by a second transition where a proton is "transferred back" from the nearest water molecule to the deprotonated nitrogen atom of creatine.

Investigation of Properties of Nanocomposite Polyimide Samples Obtained by Fused Deposition Modeling

NASA Astrophysics Data System (ADS)

Polyakov, I. V.; Vaganov, G. V.; Yudin, V. E.; Ivan'kova, E. M.; Popova, E. N.; Elokhovskii, V. Yu.

2018-03-01

Nanomodified polyimide samples were obtained by fused deposition modeling (FDM) using an experimental setup for 3D printing of highly heat-resistant plastics. The mechanical properties and structure of these samples were studied by viscosimetry, differential scanning calorimetry, and scanning electron microscopy. A comparative estimation of the mechanical properties of laboratory samples obtained from a nanocomposite based on heat-resistant polyetherimide by FDM and injection molding is presented.

SUPERFUND GROUND WATER ISSUE: GROUND WATER SAMPLING FOR METALS ANALYSES

EPA Science Inventory

Filtration of ground-water samples for metals analysis is an issue identified by the Forum as a concern of Superfund decision-makers. Inconsistency in EPA Syperfund cleanup pracices occurs where one EPA Region implements a remedial action based on unfiltered ground-water samples,...

7 CFR 75.35 - Obtaining samples for lot inspections.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 3 2012-01-01 2012-01-01 false Obtaining samples for lot inspections. 75.35 Section 75.35 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING...

7 CFR 75.35 - Obtaining samples for lot inspections.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 3 2014-01-01 2014-01-01 false Obtaining samples for lot inspections. 75.35 Section 75.35 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING...

7 CFR 75.35 - Obtaining samples for lot inspections.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 3 2013-01-01 2013-01-01 false Obtaining samples for lot inspections. 75.35 Section 75.35 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING...

Stability of low levels of perchlorate in drinking water and natural water samples

USGS Publications Warehouse

Stetson, S.J.; Wanty, R.B.; Helsel, D.R.; Kalkhoff, S.J.; Macalady, D.L.

2006-01-01

Perchlorate ion (ClO4-) is an environmental contaminant of growing concern due to its potential human health effects, impact on aquatic and land animals, and widespread occurrence throughout the United States. The determination of perchlorate cannot normally be carried out in the field. As such, water samples for perchlorate analysis are often shipped to a central laboratory, where they may be stored for a significant period before analysis. The stability of perchlorate ion in various types of commonly encountered water samples has not been generally examined-the effect of such storage is thus not known. In the present study, the long-term stability of perchlorate ion in deionized water, tap water, ground water, and surface water was examined. Sample sets containing approximately 1000, 100, 1.0, and 0.5 ??g l-1 perchlorate ion in deionized water and also in local tap water were formulated. These samples were analyzed by ion chromatography for perchlorate ion concentration against freshly prepared standards every 24 h for the first 7 days, biweekly for the next 4 weeks, and periodically after that for a total of 400 or 610 days for the two lowest concentrations and a total of 428 or 638 days for the high concentrations. Ground and surface water samples containing perchlorate were collected, held and analyzed for perchlorate concentration periodically over at least 360 days. All samples except for the surface water samples were found to be stable for the duration of the study, allowing for holding times of at least 300 days for ground water samples and at least 90 days for surface water samples. ?? 2006 Elsevier B.V. All rights reserved.

Comparison of geochemical data obtained using four brine sampling methods at the SECARB Phase III Anthropogenic Test CO2 injection site, Citronelle Oil Field, Alabama

USGS Publications Warehouse

Conaway, Christopher; Thordsen, James J.; Manning, Michael A.; Cook, Paul J.; Trautz, Robert C.; Thomas, Burt; Kharaka, Yousif K.

2016-01-01

The chemical composition of formation water and associated gases from the lower Cretaceous Paluxy Formation was determined using four different sampling methods at a characterization well in the Citronelle Oil Field, Alabama, as part of the Southeast Regional Carbon Sequestration Partnership (SECARB) Phase III Anthropogenic Test, which is an integrated carbon capture and storage project. In this study, formation water and gas samples were obtained from well D-9-8 #2 at Citronelle using gas lift, electric submersible pump, U-tube, and a downhole vacuum sampler (VS) and subjected to both field and laboratory analyses. Field chemical analyses included electrical conductivity, dissolved sulfide concentration, alkalinity, and pH; laboratory analyses included major, minor and trace elements, dissolved carbon, volatile fatty acids, free and dissolved gas species. The formation water obtained from this well is a Na–Ca–Cl-type brine with a salinity of about 200,000 mg/L total dissolved solids. Differences were evident between sampling methodologies, particularly in pH, Fe and alkalinity. There was little gas in samples, and gas composition results were strongly influenced by sampling methods. The results of the comparison demonstrate the difficulty and importance of preserving volatile analytes in samples, with the VS and U-tube system performing most favorably in this aspect.

Kuipers performs Water Sample Analysis

NASA Image and Video Library

2012-05-15

ISS031-E-084619 (15 May 2012) --- After collecting samples from the Water Recovery System (WRS), European Space Agency astronaut Andre Kuipers, Expedition 31 flight engineer, processes the samples for chemical and microbial analysis in the Unity node of the International Space Station.

Fluoride concentration in drinking water samples in Fiji.

PubMed

Prasad, Neha; Pushpaangaeli, Bernadette; Ram, Anumala; Maimanuku, Leenu

2018-04-26

The main aim of this study was to determine the content of fluoride in drinking water from sources within the sampling areas for the National Oral Health Survey (NOHS) 2011 from the Central, Northern, Western and Eastern Divisions in the Fiji Islands. Drinking water samples were collected from taps, a waterfall, wells, creeks, streams, springs, rivers, boreholes and rain water tanks in a diverse range of rural and urban areas across the Fiji Islands. A total of 223 areas were sampled between December 2014 and June 2015. Samples were analysed for fluoride using a colorimetric assay with the Zirconyl-SPADNS Reagent. The samples were pre-treated with sodium arsenite solution prior to analysis to eliminate interference from chlorine. Measured fluoride concentrations ranged from 0.01 to 0.35 ppm, with a mean concentration across all samples of 0.03 + 0.04 ppm. No samples achieved the optimal level for caries prevention (0.7 ppm). The Western Division had the highest fluoride levels compared to the other Divisions. The highest single fluoride concentration was found in Valase. The drinking water for this rural area located in the Western Division is from a borehole. The lowest concentrations of fluoride were in reticulated water samples from rural areas in the Central Division, which were consistently less than those recorded in the Northern, Eastern and Western Divisions. All samples had fluoride concentrations below the optimum level required to prevent dental caries. Implications for public health: This research forms part of the objectives of the 2011 National Oral Health Survey in Fiji. At present, Fiji lacks water fluoridation and therefore a baseline of the fluoride content in drinking water supplies is essential before water fluoridation is implemented. The results from this study would be beneficial in designing caries-preventive strategies through water fluoridation and for comparing those strategies with caries prevalence overtime. © 2018 The Authors.

Magnificent Ground Water Connection. [Sample Activities].

ERIC Educational Resources Information Center

Environmental Protection Agency, Washington, DC.

Water conservation and usage is an important concept in science. This document, geared specifically to New England, provides many activities for protecting and discussing ground water situations. Sample activities for grades K-6 include: (1) All the Water in the World; (2) The Case of the Disappearing Water; (3) Deep Subjects--Wells and Ground…

Determination of natural radioactivity by gross alpha and beta measurements in ground water samples.

PubMed

Turhan, S; Ozçitak, E; Taşkin, H; Varinlioğlu, A

2013-06-01

In this study, the activity concentrations of the gross α and β in ground water samples collected from the different drilled wells in Nevşehir province were measured to assess annual effective dose due to the ingestion of the water samples. Nevşehir province is one of the major cities of Cappadocia Region which is a popular tourist destination as it has many areas with unique geological, historic, and cultural features. Sampling and measurements were carried out in the autumn of 2011 and the spring of 2012. The values of the activity concentrations of the gross α and β measured in the water samples ranged from 80 to 380 mBq L(-1) with a mean of 192 mBq L(-1) and 120-3470 mBq L(-1) with a mean of 579 mBq L(-1) respectively. All values of the gross α were lower than the limit value of 500 mBq L(-1) while two ground water samples were found to have gross β activity concentrations of greater than 1000 mBq L(-1). Therefore two water samples were the subject of further radioisotope-specific analysis. The obtained result indicated that the elevated activity concentrations of the gross β in these water samples are dominated by (40)K activity. Annual effective doses ranged from 0.04 to 0.20 mSv y(-1). Copyright © 2013 Elsevier Ltd. All rights reserved.

CRUMP 2003 Selected Water Sample Results

EPA Pesticide Factsheets

Point locations and water sampling results performed in 2003 by the Church Rock Uranium Monitoring Project (CRUMP) a consortium of organizations (Navajo Nation Environmental Protection Agency, US Environmental Protection Agency, New Mexico Scientific Laboratory Division, Navajo Tribal Utility Authority and NM Water Quality Control Commission). Samples include general description of the wells sampled, general chemistry, heavy metals and aestheic parameters, and selected radionuclides. Here only six sampling results are presented in this point shapefile, including: Gross Alpha (U-Nat Ref.) (pCi/L), Gross Beta (Sr/Y-90 Ref.) (pCi/L), Radium-226 (pCi/L), Radium-228 (pCi/L), Total Uranium (pCi/L), and Uranium mass (ug/L). The CRUMP samples were collected in the area of Churchrock, NM in the Eastern AUM Region of the Navajo Nation.

Catch me if you can: Comparing ballast water sampling skids to traditional net sampling

NASA Astrophysics Data System (ADS)

Bradie, Johanna; Gianoli, Claudio; Linley, Robert Dallas; Schillak, Lothar; Schneider, Gerd; Stehouwer, Peter; Bailey, Sarah

2018-03-01

With the recent ratification of the International Convention for the Control and Management of Ships' Ballast Water and Sediments, 2004, it will soon be necessary to assess ships for compliance with ballast water discharge standards. Sampling skids that allow the efficient collection of ballast water samples in a compact space have been developed for this purpose. We ran 22 trials on board the RV Meteor from June 4-15, 2015 to evaluate the performance of three ballast water sampling devices (traditional plankton net, Triton sampling skid, SGS sampling skid) for three organism size classes: ≥ 50 μm, ≥ 10 μm to < 50 μm, and < 10 μm. Natural sea water was run through the ballast water system and untreated samples were collected using paired sampling devices. Collected samples were analyzed in parallel by multiple analysts using several different analytic methods to quantify organism concentrations. To determine whether there were differences in the number of viable organisms collected across sampling devices, results were standardized and statistically treated to filter out other sources of variability, resulting in an outcome variable representing the mean difference in measurements that can be attributed to sampling devices. These results were tested for significance using pairwise Tukey contrasts. Differences in organism concentrations were found in 50% of comparisons between sampling skids and the plankton net for ≥ 50 μm, and ≥ 10 μm to < 50 μm size classes, with net samples containing either higher or lower densities. There were no differences for < 10 μm organisms. Future work will be required to explicitly examine the potential effects of flow velocity, sampling duration, sampled volume, and organism concentrations on sampling device performance.

Development and evaluation of a gas chromatographic method for the determination of triazine herbicides in natural water samples

USGS Publications Warehouse

Steinheimer, T.R.; Brooks, M.G.

1984-01-01

A multi-residue method is described for the determination of triazine herbicides in natural water samples. The technique uses solvent extraction followed by gas chromatographic separation and detection employing nitrogen-selective devices. Seven compounds can be determined simultaneously at a nominal detection limit of 0.1 ??g/L in a 1-litre sample. Three different natural water samples were used for error analysis via evaluation of recovery efficiencies and estimation of overall method precision. As an alternative to liquid-liquid partition (solvent extraction) for removal of compounds of interest from water, solid-phase extraction (SPE) techniques employing chromatographic grade silicas with chemically modified surfaces have been examined. SPE is found to provide rapid and efficient concentration with quantitative recovery of some triazine herbicides from natural water samples. Concentration factors of 500 to 1000 times are obtained readily by the SPE technique.A multi-residue method is described for the determination of triazine herbicides in natural water samples. The technique uses solvent extraction followed by gas chromatographic separation and detection employing nitrogen-selective devices. Seven compounds can be determined simultaneously at a nominal detection limit of 0. 1 mu g/L in a 1-litre sample. As an alternative to liquid-liquid partition (solvent extraction) for removal of compounds of interest from water, solid-phase extraction (SPE) techniques employing chromatographic grade silicas with chemically modified surfaces have been examined. SPE is found to provide rapid and efficient concentration with quantitative recovery of some triazine herbicides from natural water samples. Concentration factors of 500 to 1000 times are obtained readily by the SPE technique.

Adsorption of Water on JSC-1A Lunar Simulant Samples

NASA Technical Reports Server (NTRS)

Goering, John; Sah, Shweta; Burghaus, Uwe; Street, Kenneth W.

2008-01-01

Remote sensing probes sent to the moon in the 1990s indicated that water may exist in areas such as the bottoms of deep, permanently shadowed craters at the lunar poles, buried under regolith. Water is of paramount importance for any lunar exploration and colonization project which would require self-sustainable systems. Therefore, investigating the interaction of water with lunar regolith is pertinent to future exploration. The lunar environment can be approximated in ultra-high vacuum systems such as those used in thermal desorption spectroscopy (TDS). Questions about water dissociation, surface wetting, degree of crystallization, details of water-ice transitions, and cluster formation kinetics can be addressed by TDS. Lunar regolith specimens collected during the Apollo missions are still available though precious, so testing with simulant is required before applying to use lunar regolith samples. Hence, we used for these studies JSC-1a, mostly an aluminosilicate glass and basaltic material containing substantial amounts of plagioclase, some olivine and traces of other minerals. Objectives of this project include: 1) Manufacturing samples using as little raw material as possible, allowing the use of surface chemistry and kinetics tools to determine the feasibility of parallel studies on regolith, and 2) Characterizing the adsorption kinetics of water on the regolith simulant. This has implications for the probability of finding water on the moon and, if present, for recovery techniques. For condensed water films, complex TDS data were obtained containing multiple features, which are related to subtle rearrangements of the water adlayer. Results from JSC-1a TDS studies indicate: 1) Water dissociation on JSC-1a at low exposures, with features detected at temperatures as high as 450 K and 2) The formation of 3D water clusters and a rather porous condensed water film. It appears plausible that the sub- m sized particles act as nucleation centers.

Quality-control design for surface-water sampling in the National Water-Quality Network

USGS Publications Warehouse

Riskin, Melissa L.; Reutter, David C.; Martin, Jeffrey D.; Mueller, David K.

2018-04-10

The data-quality objectives for samples collected at surface-water sites in the National Water-Quality Network include estimating the extent to which contamination, matrix effects, and measurement variability affect interpretation of environmental conditions. Quality-control samples provide insight into how well the samples collected at surface-water sites represent the true environmental conditions. Quality-control samples used in this program include field blanks, replicates, and field matrix spikes. This report describes the design for collection of these quality-control samples and the data management needed to properly identify these samples in the U.S. Geological Survey’s national database.

Diallelic analysis to obtain cowpea (Vigna unguiculata L. Walp.) populations tolerant to water deficit.

PubMed

Rodrigues, E V; Damasceno-Silva, K J; Rocha, M M; Bastos, E A

2016-05-13

The purpose of this study was to identify parents and obtain segregating populations of cowpea (Vigna unguiculata L. Walp.) with the potential for tolerance to water deficit. A full diallel was performed with six cowpea genotypes, and two experiments were conducted in Teresina, PI, Brazil in 2011 to evaluate 30 F2 populations and their parents, one under water deficit and the other under full irrigation. A triple-lattice experimental design was used, with six 2-m-long rows in each plot. Sixteen plants were sampled per plot. The data were subjected to analysis of variance, and general and specific combining ability estimates were obtained based on the means. Additive effects were more important than non-additive effects, and maternal inheritance had occurred. The genotypes BRS Xiquexique, Pingo de Ouro-1-2, and MNC99-510F-16-1 were the most promising for use in selection programs aimed at water deficit tolerance. The hybrid combinations Pingo de Ouro-1-2 x BRS Xiquexique, BRS Xiquexique x Santo Inácio, CNCx 698-128G x MNC99-510F-16-1, Santo Inácio x CNCx 698-128G, MNC99-510F-16-1 x BRS Paraguaçu, MNC99- 510F-16-1 x Pingo de Ouro-1-2, and MNC99-510F-16-1 x BRS Xiquexique have the potential to increase grain production and tolerate water deficit.

Development of a novel method for simultaneous concentration of viruses and protozoa from a single water sample.

PubMed

Haramoto, Eiji; Katayama, Hiroyuki; Asami, Mari; Akiba, Michihiro

2012-06-01

A novel method, electronegative membrane-vortex (EMV) method, was developed for simultaneous concentration of viruses and protozoa from a single water sample. Viruses and protozoa in a water sample were mixed with a cation solution and adsorbed on an electronegative membrane. Concentrated virus and protozoa samples were obtained as supernatant and pellet fractions, respectively, by vigorous vortex mixing of the membrane and centrifugation of the eluted material. The highest recovery efficiencies of model microbes from river water and tap water by this EMV method were obtained using a mixed cellulose ester membrane with a pore size of 0.45 μm (Millipore) as the electronegative membrane and MgCl(2) as the cation solution. The recovery was 27.7-86.5% for poliovirus, 25.7-68.3% for coliphage Qβ, 28.0-60.0% for Cryptosporidium oocysts, and 35.0-53.0% for Giardia cysts. The EMV method detected successfully indigenous viruses and protozoa in wastewater and river water samples from the Kofu basin, Japan, showing an overall positive rate of 100% (43/43) for human adenovirus, 79% (34/43) for norovirus GI, 65% (28/43) for norovirus GII, 23% (10/43) for Cryptosporidium oocysts, and 60% (26/43) for Giardia cysts. By direct DNA sequencing, a total of four genotypes (AI, AII, B, and G) of Giardia intestinalis were identified in the water samples, indicating that the river water was contaminated with feces from various mammals, including humans. Copyright © 2012 Elsevier B.V. All rights reserved.

Nanometer-sized alumina packed microcolumn solid-phase extraction combined with field-amplified sample stacking-capillary electrophoresis for the speciation analysis of inorganic selenium in environmental water samples.

PubMed

Duan, Jiankuan; Hu, Bin; He, Man

2012-10-01

In this paper, a new method of nanometer-sized alumina packed microcolumn SPE combined with field-amplified sample stacking (FASS)-CE-UV detection was developed for the speciation analysis of inorganic selenium in environmental water samples. Self-synthesized nanometer-sized alumina was packed in a microcolumn as the SPE adsorbent to retain Se(IV) and Se(VI) simultaneously at pH 6 and the retained inorganic selenium was eluted by concentrated ammonia. The eluent was used for FASS-CE-UV analysis after NH₃ evaporation. The factors affecting the preconcentration of both Se(IV) and Se(VI) by SPE and FASS were studied and the optimal CE separation conditions for Se(IV) and Se(VI) were obtained. Under the optimal conditions, the LODs of 57 ng L⁻¹ (Se(IV)) and 71 ng L⁻¹ (Se(VI)) were obtained, respectively. The developed method was validated by the analysis of a certified reference material of GBW(E)080395 environmental water and the determined value was in a good agreement with the certified value. It was also successfully applied to the speciation analysis of inorganic selenium in environmental water samples, including Yangtze River water, spring water, and tap water. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Radiation hazard indices of soil and water samples in Northern Malaysian Peninsula.

PubMed

Almayahi, B A; Tajuddin, A A; Jaafar, M S

2012-11-01

The radioactivity quantity and quality were determined in soil and water samples in Northern Malaysian Peninsula (NMP) using HPGe spectroscopy and GR-135 spectrometer. The (226)Ra, (232)Th and (40)K concentrations in soil samples are 57±2, 68±4 and 427±17 Bq kg(-1), respectively, whereas in water samples were found to be 2.86±0.79, 3.78±1.73 and 152±12 Bq l(-1), respectively. These concentrations are within those reported from literature in other countries in the world. The radiological hazard indices of the samples were also calculated. The mean values obtained from soil samples are 186 Bq kg(-1), 88 nGy h(-1), 108 μSv y(-1), 0.50 and 0.65 for Radium Equivalent Activity (Ra(eq)), Absorbed Dose Rates (D(R)), Annual Effective Dose Rates (ED), External Hazard Index (H(ex)) and Internal Hazard Index (H(in)) respectively, whereas, for water samples were found to be 20, 10, 13, 0.05 and 0.06, respectively. All the health hazard indices are well below their recommended limits, except in two soil sampling sites which were found to be (*)025 (1.1 H(ex)) and (*)026 (1.1 H(ex), 1.6 H(in)). The calculated and the measured gamma dose rates had a good correlation coefficient, R=0.88. Moreover, the average value radon is 20 (in the range of 7-64) Bq m(-3), a positive correlation (R=0.81) was observed between the (222)Rn and (226)Ra concentrations in samples measured by the SNC continuous radon monitor (model 1029, Sun Nuclear Corporation) and HPGe detector, respectively. Some soils in this study with H(in) and H(ex)<1 are suitable for use in agriculture and as building materials. Also, in this study H(in) and H(ex)<1 for water samples, therefore, water after processing and filtration is safe and suitable for use in household and industrial purposes. Copyright © 2012 Elsevier Ltd. All rights reserved.

Soil Gas Sample Handling: Evaluation of Water Removal and Sample Ganging

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

Fritz, Brad G.; Abrecht, David G.; Hayes, James C.

2016-10-31

Soil gas sampling is currently conducted in support of Nuclear Test Ban treaty verification. Soil gas samples are collected and analyzed for isotopes of interest. Some issues that can impact sampling and analysis of these samples are excess moisture and sample processing time. Here we discuss three potential improvements to the current sampling protocol; a desiccant for water removal, use of molecular sieve to remove CO 2 from the sample during collection, and a ganging manifold to allow composite analysis of multiple samples.

Rapid determination of 210Po in water samples

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

Maxwell, Sherrod L.; Culligan, Brian K.; Hutchison, Jay B.

2013-08-02

A new rapid method for the determination of 210Po in water samples has been developed at the Savannah River National Laboratory (SRNL) that can be used for emergency response or routine water analyses. If a radiological dispersive device (RDD) event or a radiological attack associated with drinking water supplies occurs, there will be an urgent need for rapid analyses of water samples, including drinking water, ground water and other water effluents. Current analytical methods for the assay of 210Po in water samples have typically involved spontaneous auto-deposition of 210Po onto silver or other metal disks followed by counting by alphamore » spectrometry. The auto-deposition times range from 90 minutes to 24 hours or more, at times with yields that may be less than desirable. If sample interferences are present, decreased yields and degraded alpha spectrums can occur due to unpredictable thickening in the deposited layer. Separation methods have focused on the use of Sr Resin, often in combination with 210Pb analysis. A new rapid method for 210Po in water samples has been developed at the Savannah River National Laboratory (SRNL) that utilizes a rapid calcium phosphate co-precipitation method, separation using DGA Resin (N,N,N,N-tetraoctyldiglycolamide extractant-coated resin, Eichrom Technologies or Triskem-International), followed by rapid microprecipitation of 210Po using bismuth phosphate for counting by alpha spectrometry. This new method can be performed quickly with excellent removal of interferences, high chemical yields and very good alpha peak resolution, eliminating any potential problems with the alpha source preparation for emergency or routine samples. A rapid sequential separation method to separate 210Po and actinide isotopes was also developed. This new approach, rapid separation with DGA Resin plus microprecipitation for alpha source preparation, is a significant advance in radiochemistry for the rapid determination of 210Po.« less

Qualilty, isotopes, and radiochemistry of water sampled from the Upper Moenkopi Village water-supply wells, Coconino County, Arizona

USGS Publications Warehouse

Carruth, Rob; Beisner, Kimberly; Smith, Greg

2013-01-01

The Hopi Tribe Water Resources Program has granted contracts for studies to evaluate water supply conditions for the Moenkopi villages in Coconino County, Arizona. The Moenkopi villages include Upper Moenkopi Village and the village of Lower Moencopi, both on the Hopi Indian Reservation south of the Navajo community of Tuba City. These investigations have determined that water supplies are limited and vulnerable to several potential sources of contamination, including the Tuba City Landfill and a former uranium processing facility known as the Rare Metals Mill. Studies are ongoing to determine if uranium and other metals in groundwater beneath the landfill are greater than regional groundwater concentrations. The source of water supply for the Upper Moenkopi Village is three public-supply wells. The wells are referred to as MSW-1, MSW-2, and MSW-3 and all three wells obtain water from the regionally extensive N aquifer. The N aquifer is the principal aquifer in this region of northern Arizona and consists of thick beds of sandstone between less permeable layers of siltstone and mudstone. The relatively fine-grained character of the N aquifer inhibits rapid movement of water and large yields to wells. In recent years, water levels have declined in the three public-supply wells, causing concern that the current water supply will not be able to accommodate peak demand and allow for residential and economic growth. Analyses of major ions, nutrients, selected trace metals, stable and radioactive isotopes, and radiochemistry were performed on the groundwater samples from the three public-supply wells to describe general water-quality conditions and groundwater ages in and immediately surrounding the Upper Moenkopi Village area. None of the water samples collected from the public-supply wells exceeded the U.S. Environmental Protection Agency primary drinking water standards. The ratios of the major dissolved ions from the samples collected from MSW-1 and MSW-2 indicate

PCR detection of Burkholderia multivorans in water and soil samples.

PubMed

Peeters, Charlotte; Daenekindt, Stijn; Vandamme, Peter

2016-08-12

Although semi-selective growth media have been developed for the isolation of Burkholderia cepacia complex bacteria from the environment, thus far Burkholderia multivorans has rarely been isolated from such samples. Because environmental B. multivorans isolates mainly originate from water samples, we hypothesized that water rather than soil is its most likely environmental niche. The aim of the present study was to assess the occurrence of B. multivorans in water samples from Flanders (Belgium) using a fast, culture-independent PCR assay. A nested PCR approach was used to achieve high sensitivity, and specificity was confirmed by sequencing the resulting amplicons. B. multivorans was detected in 11 % of the water samples (n = 112) and 92 % of the soil samples (n = 25) tested. The percentage of false positives was higher for water samples compared to soil samples, showing that the presently available B. multivorans recA primers lack specificity when applied to the analysis of water samples. The results of the present study demonstrate that B. multivorans DNA is commonly present in soil samples and to a lesser extent in water samples in Flanders (Belgium).

A self-sampling method to obtain large volumes of undiluted cervicovaginal secretions.

PubMed

Boskey, Elizabeth R; Moench, Thomas R; Hees, Paul S; Cone, Richard A

2003-02-01

Studies of vaginal physiology and pathophysiology sometime require larger volumes of undiluted cervicovaginal secretions than can be obtained by current methods. A convenient method for self-sampling these secretions outside a clinical setting can facilitate such studies of reproductive health. The goal was to develop a vaginal self-sampling method for collecting large volumes of undiluted cervicovaginal secretions. A menstrual collection device (the Instead cup) was inserted briefly into the vagina to collect secretions that were then retrieved from the cup by centrifugation in a 50-ml conical tube. All 16 women asked to perform this procedure found it feasible and acceptable. Among 27 samples, an average of 0.5 g of secretions (range, 0.1-1.5 g) was collected. This is a rapid and convenient self-sampling method for obtaining relatively large volumes of undiluted cervicovaginal secretions. It should prove suitable for a wide range of assays, including those involving sexually transmitted diseases, microbicides, vaginal physiology, immunology, and pathophysiology.

Correlations of water quality parameters with mutagenicity of chlorinated drinking water samples.

PubMed

Schenck, Kathleen M; Sivaganesan, Mano; Rice, Glenn E

2009-01-01

Adverse health effects that may result from chronic exposure to mixtures of disinfection by-products (DBPs) present in drinking waters may be linked to both the types and concentrations of DBPs present. Depending on the characteristics of the source water and treatment processes used, both types and concentrations of DBPs found in drinking waters vary substantially. The composition of a drinking-water mixture also may change during distribution. This study evaluated the relationships between mutagenicity, using the Ames assay, and water quality parameters. The study included information on treatment, mutagenicity data, and water quality data for source waters, finished waters, and distribution samples collected from five full-scale drinking water treatment plants, which used chlorine exclusively for disinfection. Four of the plants used surface water sources and the fifth plant used groundwater. Correlations between mutagenicity and water quality parameters are presented. The highest correlation was observed between mutagenicity and the total organic halide concentrations in the treated samples.

Automated storm water sampling on small watersheds

USGS Publications Warehouse

Harmel, R.D.; King, K.W.; Slade, R.M.

2003-01-01

Few guidelines are currently available to assist in designing appropriate automated storm water sampling strategies for small watersheds. Therefore, guidance is needed to develop strategies that achieve an appropriate balance between accurate characterization of storm water quality and loads and limitations of budget, equipment, and personnel. In this article, we explore the important sampling strategy components (minimum flow threshold, sampling interval, and discrete versus composite sampling) and project-specific considerations (sampling goal, sampling and analysis resources, and watershed characteristics) based on personal experiences and pertinent field and analytical studies. These components and considerations are important in achieving the balance between sampling goals and limitations because they determine how and when samples are taken and the potential sampling error. Several general recommendations are made, including: setting low minimum flow thresholds, using flow-interval or variable time-interval sampling, and using composite sampling to limit the number of samples collected. Guidelines are presented to aid in selection of an appropriate sampling strategy based on user's project-specific considerations. Our experiences suggest these recommendations should allow implementation of a successful sampling strategy for most small watershed sampling projects with common sampling goals.

Genotoxicity assessment of raw and treated water samples using Allium cepa assay: evidence from Perak River, Malaysia.

PubMed

Malakahmad, Amirhossein; Manan, Teh Sabariah Binti Abd; Sivapalan, Subarna; Khan, Taimur

2018-02-01

Allium cepa assay was carried out in this study to evaluate genotoxic effects of raw and treated water samples from Perak River in Perak state, Malaysia. Samples were collected from three surface water treatment plants along the river, namely WTPP, WTPS, and WTPK. Initially, triplicates of equal size Allium cepa (onions) bulbs, 25-30 mm in diameter and average weight of 20 g, were set up in distilled water for 24 h at 20 ± 2 °C and protected from direct sunlight, to let the roots to grow. After germination of roots (0.5-1.0 cm in length), bulbs were transferred to collected water samples each for a 96-h period of exposure. The root physical deformations were observed. Genotoxicity quantification was based on mitotic index and genotoxicity level. Statistical analysis using cross-correlation function for replicates from treated water showed that root length has inverse correlation with mitotic indices (r = - 0.969) and frequencies of cell aberrations (r = - 0.976) at lag 1. Mitotic indices and cell aberrations of replicates from raw water have shown positive correlation at lag 1 (r = 0.946). Genotoxicity levels obtained were 23.4 ± 1.98 (WTPP), 26.68 ± 0.34 (WTPS), and 30.4 ± 1.13 (WTPK) for treated water and 17.8 ± 0.18 (WTPP), 37.15 ± 0.17 (WTPS), and 47.2 ± 0.48 (WTPK) for raw water. The observed cell aberrations were adherence, chromosome delay, C-metaphase, chromosome loss, chromosome bridge, chromosome breaks, binucleated cell, mini cell, and lobulated nuclei. The morphogenetic deformations obtained were likely due to genotoxic substances presence in collected water samples. Thus, water treatment in Malaysia does not remove genotoxic compounds.

A new method to obtain Fourier transform infrared spectra free from water vapor disturbance.

PubMed

Chen, Yujing; Wang, Hai-Shui; Umemura, Junzo

2010-10-01

Infrared absorption bands due to water vapor in the mid-infrared regions often obscure important spectral features of the sample. Here, we provide a novel method to collect a qualified infrared spectrum without any water vapor interference. The scanning procedure for a single-beam spectrum of the sample is divided into two stages under an atmosphere with fluctuating humidity. In the first stage, the sample spectrum is measured with approximately the same number of scans as the background. If the absorbance of water vapor in the spectrum is positive (or negative) at the end of the first stage, then the relative humidity in the sample compartment of the spectrometer is changed by a dry (or wet) air blow at the start of the second stage while the measurement of the sample spectrum continues. After the relative humidity changes to a lower (or higher) level than that of the previously collected background spectrum, water vapor peaks will become smaller and smaller with the increase in scanning number during the second stage. When the interfering water lines disappear from the spectrum, the acquisition of a sample spectrum is terminated. In this way, water vapor interference can finally be removed completely.

A rapid and sensitive analytical method for the determination of 14 pyrethroids in water samples.

PubMed

Feo, M L; Eljarrat, E; Barceló, D

2010-04-09

A simple, efficient and environmentally friendly analytical methodology is proposed for extracting and preconcentrating pyrethroids from water samples prior to gas chromatography-negative ion chemical ionization mass spectrometry (GC-NCI-MS) analysis. Fourteen pyrethroids were selected for this work: bifenthrin, cyfluthrin, lambda-cyhalothrin, cypermethrin, deltamethrin, esfenvalerate, fenvalerate, fenpropathrin, tau-fluvalinate, permethrin, phenothrin, resmethrin, tetramethrin and tralomethrin. The method is based on ultrasound-assisted emulsification-extraction (UAEE) of a water-immiscible solvent in an aqueous medium. Chloroform was used as extraction solvent in the UAEE technique. Target analytes were quantitatively extracted achieving an enrichment factor of 200 when 20 mL aliquot of pure water spiked with pyrethroid standards was extracted. The method was also evaluated with tap water and river water samples. Method detection limits (MDLs) ranged from 0.03 to 35.8 ng L(-1) with RSDs values < or =3-25% (n=5). The coefficients of estimation of the calibration curves obtained following the proposed methodology were > or =0.998. Recovery values were in the range of 45-106%, showing satisfactory robustness of the method for analyzing pyrethroids in water samples. The proposed methodology was applied for the analysis of river water samples. Cypermethrin was detected at concentration levels ranging from 4.94 to 30.5 ng L(-1). Copyright 2010 Elsevier B.V. All rights reserved.

Monitoring of uranium concentrations in water samples collected near potentially hazardous objects in North-West Tajikistan.

PubMed

Zoriy, P; Schläger, M; Murtazaev, K; Pillath, J; Zoriy, M; Heuel-Fabianek, B

2018-01-01

The water contamination near ecologically problematic objects was investigated between 2009 and 2014 in North-West Tajikistan as a part of a joint project between Forschungszentrum Jülich and Khujand State University. The main part of this work was the determination of uranium in water samples collected near the Degmay tailings dump, the Taboshar pit lake and the Syr Darya river. More than 130 water samples were collected and analyzed to monitor the uranium concentration near the investigated areas. Two different mass spectrometers and an ion chromatograph were used for element concentration measurements. Based on the results obtained, the uranium influence of the Degmay tailings on the rivers Khoja-Bakyrgan-Say and Syr Darya and surrounding water was not found. The uranium concentration in water samples was monitored for a lengthy period at seven locations Great differences in the uranium concentration in waters collected in 2010, 2011, 2012, 2013 for each location were not observed. Drinking water samples from the region of North-West Tajikistan were analyzed and compared with the World Health Organization's guidelines. Seven out of nine drinking water samples near Taboshar exceeded the WHO guideline value for uranium concentrations (30 μg/L). The average uranium concentration of water samples from Syr Darya for the period from 2009 to 2014 was determined to be 20.1 (±5.2) μg/L. The uranium contamination of the Syr Darya was determined from the western border to the eastern border and the results are shown in this paper. Copyright © 2017 Elsevier Ltd. All rights reserved.

On-line Determination of Zinc in Water and Biological Samples after Its Preconcentration onto Zincon Anchored Polyurethane Foam.

PubMed

Azeem, Sami M Abdel; Hanafi, Hassan A; El-Shahat, M F

2015-01-01

A fast and sensitive on-line procedure for the determination of zinc in water and biological samples was developed. Zinc was preconcentrated in a mini-column packed with polyurethane foam (PUF) chemically modified with zincon via -N=N- bonding. The optimal conditions for preconcentration were pH 8.5 and sample flow rate of 4.0 mL min(-1). Quantitative desorption of Zn(II) was obtained by 0.1 mol L(-1) hydrochloric acid and subsequent spectrophotmetric determination using 4-(2-pyridylazo)-resorcinol at 498 nm. The obtained detection limit was found to be 3.0 ng mL(-1), precision (RSD) was 4.8 and 6.7% at 20 and 110 ng mL(-1), respectively, for 60 s preconcentration time and enrichment factor was 31. The linearity range was from 10 to 120 ng mL(-1) and maximum sample throughput was 20 h(-1). Finally, the method was successfully applied to the determination of zinc in tap water, Nile River water and human urine samples with RSD in the range of 1.1 - 8.3%.

Landsat image and sample design for water reservoirs (Rapel dam Central Chile).

PubMed

Lavanderos, L; Pozo, M E; Pattillo, C; Miranda, H

1990-01-01

Spatial heterogeneity of the Rapel reservoir surface waters is analyzed through Landsat images. The image digital counts are used with the aim or developing an aprioristic quantitative sample design.Natural horizontal stratification of the Rapel Reservoir (Central Chile) is produced mainly by suspended solids. The spatial heterogeneity conditions of the reservoir for the Spring 86-Summer 87 period were determined by qualitative analysis and image processing of the MSS Landsat, bands 1 and 3. The space-time variations of the different observed strata obtained with multitemporal image analysis.A random stratified sample design (r.s.s.d) was developed, based on the digital counts statistical analysis. Strata population size as well as the average, variance and sampling size of the digital counts were obtained by the r.s.s.d method.Stratification determined by analysis of satellite images were later correlated with ground data. Though the stratification of the reservoir is constant over time, the shape and size of the strata varys.

Continuous water sampling and water analysis in estuaries

USGS Publications Warehouse

Schemel, L.E.; Dedini, L.A.

1982-01-01

Salinity, temperature, light transmission, oxygen saturation, pH, pCO2, chlorophyll a fluorescence, and the concentrations of nitrate, nitrite, dissolved silica, orthophosphate, and ammonia are continuously measured with a system designed primarily for estuarine studies. Near-surface water (2-m depth) is sampled continuously while the vessel is underway; on station, water to depths of 100 m is sampled with a submersible pump. The system is comprised of commercially available instruments, equipment, and components, and of specialized items designed and fabricated by the authors. Data are read from digital displays, analog strip-chart recorders, and a teletype printout, and can be logged in disc storage for subsequent plotting. Data records made in San Francisco Bay illustrate physical, biological, and chemical estuarine processes, such as mixing and phytoplankton net production. The system resolves large- and small-scale events, which contributes to its reliability and usefulness.

A new device for collecting time-integrated water samples from springs and surface water bodies

USGS Publications Warehouse

Panno, S.V.; Krapac, I.G.; Keefer, D.A.

1998-01-01

A new device termed the 'seepage sampler' was developed to collect representative water samples from springs, streams, and other surface-water bodies. The sampler collects composite, time-integrated water samples over short (hours) or extended (weeks) periods without causing significant changes to the chemical composition of the samples. The water sample within the sampler remains at the ambient temperature of the water body and does not need to be cooled. Seepage samplers are inexpensive to construct and easy to use. A sampling program of numerous springs and/or streams can be designed at a relatively low cost through the use of these samplers. Transient solutes migrating through such flow systems, potentially unnoticed by periodic sampling, may be detected. In addition, the mass loading of solutes (e.g., agrichemicals) may be determined when seepage samplers are used in conjunction with discharge measurements.

Triple Gene Analysis Using Samples Obtained by Endobronchial Ultrasound-guided Transbronchial Needle Aspiration

PubMed Central

Lee, Kyungjong; Um, Sang-Won; Jeong, Byeong-Ho; Yang, Jung Wook; Choi, Yoon-La; Han, Joungho; Kim, Hojoong; Kwon, O Jung

2016-01-01

Objective A mutational analysis of tumor tissue samples is an important part of advanced lung cancer treatment strategies. This study evaluated the efficacy of a triple gene analysis using samples obtained via endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). Methods Either metastatic lymph nodes or primary lung mass samples obtained by EBUS-TBNA were collected between May 2011 and May 2013. We consecutively analyzed epidermal growth factor receptor (EGFR), V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS), and anaplastic lymphoma kinase (ALK) fusion genes using remnant tissue samples. Results A total of 109 patients were diagnosed with non-small cell lung cancer (NSCLC). Of these, 70% were adenocarcinoma, 27% squamous cell carcinoma with NSCLC, and 3% were related to other types of lung cancer. EGFR mutations were detected in 23 cases (21.1%), KRAS mutations in 13 cases (11.9%), and ALK fusion genes in 5 cases (4.9%). The ALK fusion genes could not be analyzed in four cases because of insufficient tissue samples remaining after routine histochemistry and an EGFR/KRAS mutation analysis. We found that small biopsy samples from EBUS-TBNA were adequate for performing a triple gene analysis in 97 patients (96%). ALK fusion protein immunohistochemistry (IHC) was 100% consistent with fluorescence in situ hybridization (FISH). Conclusion Small samples obtained by EBUS-TBNA were found to be sufficient for performing a triple gene analysis following routine histology and IHC. ALK IHC showed a very good concordance with FISH for detecting ALK fusion genes. PMID:27803402

Metal-organic framework based in-syringe solid-phase extraction for the on-site sampling of polycyclic aromatic hydrocarbons from environmental water samples.

PubMed

Zhang, Xiaoqiong; Wang, Peiyi; Han, Qiang; Li, Hengzhen; Wang, Tong; Ding, Mingyu

2018-04-01

In-syringe solid-phase extraction is a promising sample pretreatment method for the on-site sampling of water samples because of its outstanding advantages of portability, simple operation, short extraction time, and low cost. In this work, a novel in-syringe solid-phase extraction device using metal-organic frameworks as the adsorbent was fabricated for the on-site sampling of polycyclic aromatic hydrocarbons from environmental waters. Trace polycyclic aromatic hydrocarbons were effectively extracted through the self-made device followed by gas chromatography with mass spectrometry analysis. Owing to the excellent adsorption performance of metal-organic frameworks, the analytes could be completely adsorbed during one adsorption cycle, thus effectively shortening the extraction time. Moreover, the adsorbed analytes could remain stable on the device for at least 7 days, revealing the potential of the self-made device for on-site sampling of degradable compounds in remote regions. The limit of detection ranged from 0.20 to 1.9 ng/L under the optimum conditions. Satisfactory recoveries varying from 84.4 to 104.5% and relative standard deviations below 9.7% were obtained in real samples analysis. The results of this study promote the application of metal-organic frameworks in sample preparation and demonstrate the great potential of in-syringe solid-phase extraction for the on-site sampling of trace contaminants in environmental waters. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Mutagenicity study of water samples from a waterworks taking Yangtze River as its water source in Jiangsu Province].

PubMed

Xiao, Sanhua; Luo, Lan; Qiao, Qian; Lü, Xuemin; Wang, Yanhui; Feng, Lin; Tang, Fei; Wang, Haiyong; Bie, Nana; Wang, Yuehong

2017-05-01

To understand the occurrence and change of mutagencity of water samples in the process of drinking water treatment and distribution in a waterworks taking Yangtze River as its water source in Jiangsu Province. Large volume of inlet water, finished water and tap water samples were extracted by XAD-2 resin. Mutagencities were assessed by Ames test and a mutation ratio( MR) of 2 or greater was judged as a positive result. Compared with the samples with S9, samples without S9 presented more positive results( P = 0. 005). That water treatment elevated MR values( P = 0. 007) while the pipe transport made MR values down( P = 0. 038) was observed in samples without S9. The tap water showed weaker mutagenicities than the raw water in samples with S9( P = 0. 008). Compared to the raw water samples, the finished water samples showed more positive results(-S9) and lower MR values( + S9, P =0. 002). Significant mutagenicities of water samples from the Yangtze Riverand its processed water were presented, and frame shit and direct mutagens deserved special concern.

Technical note: A device for obtaining time-integrated samples of ruminal fluid

USGS Publications Warehouse

Corley, R. N.; Murphy, M.R.; Lucena, J.; Panno, S.V.

1999-01-01

A device was adapted to allow for time-integrated sampling of fluid from the rumen via a cannula. The sampler consisted of a cup-shaped ceramic filter positioned in the ventral rumen of a cannulated cow and attached to a tube through which fluid entering the filter was removed continuously using a peristaltic pump. Rate of ruminal fluid removal using the device was monitored over two 36-h periods (at 6-h intervals) and was not affected (P > .05) by time, indicating that the system was not susceptible to clogging during this period. Two cows having ad libitum access to a totally mixed ration were used in a split-block design to evaluate the utility of the system for obtaining time-integrated samples of ruminal fluid. Ruminal fluid VFA concentration and pattern in samples collected in two replicated 8-h periods by the time-integrated sampler (at 1-h intervals) were compared with composite samples collected using a conventional suction-strainer device (at 30-min intervals). Each 8-h collection period started 2 h before or 6 h after feeding. Results indicated that total VFA concentration was not affected (P > .05) by the sampling method. Volatile fatty acid patterns were likewise unaffected (P > .05) except that acetate was 2.5% higher (P < .05) in samples collected 2 h before feeding and valerate was 5% higher (P < .05) in samples collected 6 h after feeding by the suction-strainer device. Although significant, these differences were not considered physiologically important. We concluded that use of the ceramic filter improved the sampling of ruminal fluid by simplifying the technique and allowing time-integrated samples to be obtained.

Ground Water Sampling at ISCO Sites - Residual Oxidant Impact on Sample Quality and Sample Preservation Guideline

EPA Science Inventory

In-situ chemical oxidation (ISCO) involves the delivery of a chemical oxidant into the subsurface where oxidative reactions transform ground water contaminants into less toxic or harmless byproducts. Due to oxidant persistence, ground water samples collected at hazardous waste si...

Determination of dissolved aluminum in water samples

USGS Publications Warehouse

Afifi, A.A.

1983-01-01

A technique has been modified for determination of a wide range of concentrations of dissolved aluminum (Al) in water and has been tested. In this technique, aluminum is complexed with 8-hydroxyquinoline at pH 8.3 to minimize interferences, then extracted with methyl isobutyl ketone (MIBK). The extract is analyzed colorimetrically at 395 nm. This technique is used to analyze two forms of monomeric Al, nonlabile (organic complexes) and labile (free, Al, Al sulfate, fluoride and hydroxide complexes). A detection limit 2 ug/L is possible with 25-ml samples and 10-ml extracts. The detection limit can be decreased by increasing the volume of the sample and (or) decreasing the volume of the methyl isobutyl ketone extract. The analytical uncertainty of this method is approximately + or - 5 percent. The standard addition technique provides a recovery test for this technique and ensures precision in samples of low Al concentrations. The average percentage recovery of the added Al plus the amount originally present was 99 percent. Data obtained from analyses of filtered standard solutions indicated that Al is adsorbed on various types of filters. However, the relationship between Al concentrations and adsorption remains linear. A test on standard solutions also indicated that Al is not adsorbed on nitric acid-washed polyethylene and polypropylene bottle wells. (USGS)

Water sample filtration unit

USGS Publications Warehouse

Skougstad, M.W.; Scarbro, G.F.

1968-01-01

A readily portable, all plastic, pressure filtration unit is described which greatly facilitates rapid micropore membrane field filtration of up to several liters of water with a minimum risk of inorganic chemical alteration or contamination of the sample. The unit accommodates standard 10.2-cm. (4-inch) diameter filters. The storage and carrying case serves as a convenient filter stand for both field and laboratory use.

Comparison of two filtration-elution procedures to improve the standard methods ISO 10705-1 & 2 for bacteriophage detection in groundwater, surface water and finished water samples.

PubMed

Helmi, K; Jacob, P; Charni-Ben-Tabassi, N; Delabre, K; Arnal, C

2011-09-01

To select a reliable method for bacteriophage concentration prior detection by culture from surface water, groundwater and drinking water to enhance the sensitivity of the standard methods ISO 10705-1 & 2. Artificially contaminated (groundwater and drinking water) and naturally contaminated (surface water) 1-litre samples were processed for bacteriophages detection. The spiked samples were inoculated with about 150 PFU of F-specific RNA bacteriophages and somatic coliphages using wastewater. Bacteriophage detection in the water samples was achieved using the standard method without and with a concentration step (electropositive Anodisc membrane or a pretreated electronegative Micro Filtration membrane, MF). For artificially contaminated matrices (drinking and ground waters), recovery rates using the concentration step were superior to 70% whilst analyses without concentration step mainly led to false negative results. Besides, the MF membrane presented higher performances compared with the Anodisc membrane. The concentration of a large volume of water (up to one litre) on a filter membrane avoids false negative results obtained by direct analysis as it allows detecting low number of bacteriophages in water samples. The addition of concentration step before applying the standard method could be useful to enhance the reliability of bacteriophages monitoring in water samples as bio-indicators to highlight faecal pollution. © No claim to French Government works. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

[Optimization of solid-phase extraction for enrichment of toxic organic compounds in water samples].

PubMed

Zhang, Ming-quan; Li, Feng-min; Wu, Qian-yuan; Hu, Hong-ying

2013-05-01

A concentration method for enrichment of toxic organic compounds in water samples has been developed based on combined solid-phase extraction (SPE) to reduce impurities and improve recoveries of target compounds. This SPE method was evaluated in every stage to identify the source of impurities. Based on the analysis of Waters Oasis HLB without water samples, the eluent of SPE sorbent after dichloromethane and acetone contributed 85% of impurities during SPE process. In order to reduce the impurities from SPE sorbent, soxhlet extraction of dichloromethane followed by acetone and lastly methanol was applied to the sorbents for 24 hours and the results had proven that impurities were reduced significantly. In addition to soxhlet extraction, six types of prevalent SPE sorbents were used to absorb 40 target compounds, the lgK(ow) values of which were within the range of 1.46 and 8.1, and recovery rates were compared. It was noticed and confirmed that Waters Oasis HLB had shown the best recovery results for most of the common testing samples among all three styrenedivinylbenzene (SDB) polymer sorbents, which were 77% on average. Furthermore, Waters SepPak AC-2 provided good recovery results for pesticides among three types of activated carbon sorbents and the average recovery rates reached 74%. Therefore, Waters Oasis HLB and Waters SepPak AC-2 were combined to obtain a better recovery and the average recovery rate for the tested 40 compounds of this new SPE method was 87%.

Immunomagnetic Separation of Cryptosporidium parvum from Source Water Samples of Various Turbidities

PubMed Central

Bukhari, Z.; McCuin, R. M.; Fricker, C. R.; Clancy, J. L.

1998-01-01

Immunomagnetic separation (IMS) procedures which specifically capture Cryptosporidium oocysts and have the potential to isolate oocysts from debris have become commercially available. We compared two IMS kits (kit DB [Dynabeads anti-Cryptosporidium; product no. 730.01; Dynal A.S., Oslo, Norway] and kit IC1 [Crypto Scan IMS; product no. R10; Clearwater Diagnostics Company, LLC, Portland, Maine]) and a modification of kit IC1 (kit IC2 [Crypto Scan IMS; product no. R10; Clearwater Diagnostics Company, LLC]) at three turbidity levels (50, 500, and 5,000 nephelometric turbidity units [ntu]) by using water matrices obtained from different geographical locations. In deionized water, kit DB yielded recoveries between 68 and 83%, whereas the recoveries obtained with kits IC1 and IC2 were more variable and ranged from 0.2 to 74.5%. In water matrices with turbidity levels up to 500 ntu, the oocyst recoveries were more variable with kit DB; however, the recoveries were similar to those obtained in deionized water. In contrast, there were notable reductions in oocyst recoveries in the turbid matrices with kits IC1 and IC2, and the highest recovery (8.3%) was obtained with a 50-ntu sample. An examination of the effects of age on oocyst recovery with kit DB revealed that oocysts up to 16 weeks old yielded recoveries similar to the recoveries observed with fresh oocysts. These data indicate that all IMS kits do not perform equally well, and it is important to conduct in-house quality assurance work before a commercially available IMS kit is selected to replace flotation procedures for recovery of Cryptosporidium oocysts. PMID:9797313

ISS Potable Water Sampling and Chemical Analysis Results for 2016

NASA Technical Reports Server (NTRS)

Straub, John E., II; Plumlee, Debrah K.; Wallace William T.; Alverson, James T.; Benoit, Mickie J.; Gillispie, Robert L.; Hunter, David; Kuo, Mike; Rutz, Jeffrey A.; Hudson, Edgar K.;

ISS Potable Water Sampling and Chemical Analysis Results for 2016

NASA Technical Reports Server (NTRS)

Straub, John E., II; Plumlee, Debrah K.; Wallace, William T.; Alverson, James T.; Benoit, Mickie J.; Gillispie, Robert L.; Hunter, David; Kuo, Mike; Rutz, Jeffrey A.; Hudson, Edgar K.;

A yeast bioassay for direct measurement of thyroid hormone disrupting effects in water without sample extraction, concentration, or sterilization.

PubMed

Li, Jian; Ren, Shujuan; Han, Shaolun; Li, Na

2014-04-01

The present study introduces an improved yeast bioassay for rapid yet sensitive evaluation of thyroid hormone disruption at the level of thyroid receptor (TR) in environmental water samples. This assay does not require water sample preparation and thus requires very little hands-on time. Based on different β-galactosidase substrates, two modified bioassays, a colorimetric bioassay and a chemiluminescent bioassay, were developed. The compounds tested included the known thyroid hormone 3,3',5-triiodo-l-thyronine (T3), the specific TR antagonist amiodarone hydrochloride (AH) and phthalate esters (PAEs), which potentially disrupt thyroid hormone signaling. The EC50 values for T3 were similar to those previously obtained using a 96-well plate bioassay. TR antagonism by AH was studied in the presence of 2.5 × 10(-7)M T3, and the concentration producing 20% of the maximum effect (RIC20) for AH was 3.1 × 10(-7)M and 7.8 × 10(-9)M for the colorimetric bioassay and chemiluminescent bioassay, respectively. None of the tested PAEs induced β-galactosidase expression, but diethylhexyl phthalate, benzyl butyl phthalate and dibutyl phthalate demonstrated TR antagonism. Furthermore, water samples collected from Guanting reservoir in Beijing were evaluated. Although TR agonism was not observed, antagonism was detected in all water samples and is expressed as AH equivalents. The toxicology equivalent quantity values obtained by the chemiluminescent bioassay ranged from 21.2 ± 1.6 to 313.9 ± 28.8 μg L(-1) AH, and similar values were obtained for the colorimetric bioassay. The present study shows that the modified yeast bioassay can be used as a valuable tool for quantification of thyroid hormone disrupting effects in environmental water samples. Copyright © 2013 Elsevier Ltd. All rights reserved.

Physiological response of wild dugongs (Dugong dugon) to out-of-water sampling for health assessment

USGS Publications Warehouse

Lanyon, Janet M.; Sneath, Helen L.; Long, Trevor; Bonde, Robert K.

2010-01-01

The dugong (Dugong dugon) is a vulnerable marine mammal with large populations living in urban Queensland waters. A mark-recapture program for wild dugongs has been ongoing in southern Queensland since 2001. This program has involved capture and in-water sampling of more than 700 dugongs where animals have been held at the water surface for 5 min to be gene-tagged, measured, and biopsied. In 2008, this program expanded to examine more comprehensively body condition, reproductive status, and the health of wild dugongs in Moreton Bay. Using Sea World's research vessel, captured dugongs were lifted onto a boat and sampled out-of-water to obtain accurate body weights and morphometrics, collect blood and urine samples for baseline health parameters and hormone profiles, and ultrasound females for pregnancy status. In all, 30 dugongs, including two pregnant females, were sampled over 10 d and restrained on deck for up to 55 min each while biological data were collected. Each of the dugongs had their basic temperature-heart rate-respiration (THR) monitored throughout their period of handling, following protocols developed for the West Indian manatee (Trichechus manatus). This paper reports on the physiological response of captured dugongs during this out-of-water operation as indicated by their vital signs and the suitability of the manatee monitoring protocols to this related sirenian species. A recommendation is made that the range of vital signs of these wild dugongs be used as benchmark criteria of normal parameters for other studies that intend to sample dugongs out-of-water.

[Detection of Cryptospordium spp. in environmental water samples by FTA-PCR].

PubMed

Zhang, Xiao-Ping; Zhu, Qian; He, Yan-Yan; Jiang, Li; Jiang, Shou-Fu

2011-02-01

To establish a FTA-polymeras chain reaction (FTA-PCR) method in detection of Cryptospordium spp. in different sources of water. The semi automated immunomagnetic separation (IMS) of Cryptospordium oocysts in environmental water samples was performed firstly, and then genomic DNA of Cryptospordium oocysts was extracted by FTA filters disk. Oligonucleotide primers were designed based on the DNA fragment of the 18 S rRNA gene from C. parvum. Plate DNA was amplified with primers in PCR. The control DNA samples from Toxoplasma gondii,Sarcocystis suihominis, Echinococcus granulosus, and Clonorchis sinensis were amplified simultaneously. All PCR products were detected by agar electrophoresis dyed with ethidium bromide. The 446 bp fragment of DNA was detected in all samples of C. parvum, C. andersoni, and C. baileyi, while it was not detected in control groups in laboratory. No positive samples were found from 10 samples collected from tape water in 5 districts of Shanghai City by FTA-PCR. Nine positive samples were detected totally from 70 different environmental water samples, there were 0 out of 15 samples from the source of tape water, 2 out of 25 from the Huangpu River, 5 out of 15 from rivers around the animal farmers, 1 out of 9 from output water of contaminating water treatment factory, 1 out of 6 from the out gate of living contaminating water. The 446 bp fragment was detected from all the amplified positive water samples. FTA-PCR is an efficient method for gene detection of Cryptospordium oocysts, which could be used in detection of environmental water samples. The contamination degree of Cryptospordium oocysts in the river water around animal farms is high.

Variation in aluminum, iron, and particle concentrations in oxic ground-water samples collected by use of tangential-flow ultrafiltration with low-flow sampling

USGS Publications Warehouse

Szabo, Z.; Oden, J.H.; Gibs, J.; Rice, D.E.; Ding, Y.; ,

2001-01-01

. Variations in concentrations aluminum and iron (1 -74 and 1-199 ug/L (micrograms per liter), respectively), common indicators of the presence of particulate-borne trace elements, were greatest in sample sets from individual wells with the greatest variations in turbidity and particle concentration. Differences in trace-element concentrations in sequentially collected unfiltered samples with variable turbidity were 5 to 10 times as great as those in concurrently collected samples that were passed through various filters. These results indicate that turbidity must be both reduced and stabilized even when low-flow sample-collection techniques are used in order to obtain water samples that do not contain considerable particulate artifacts. Currently (2001) available techniques need to be refined to ensure that the measured trace-element concentrations are representative of those that are mobile in the aquifer water.

Optimal approaches for inline sampling of organisms in ballast water: L-shaped vs. Straight sample probes

NASA Astrophysics Data System (ADS)

Wier, Timothy P.; Moser, Cameron S.; Grant, Jonathan F.; Riley, Scott C.; Robbins-Wamsley, Stephanie H.; First, Matthew R.; Drake, Lisa A.

2017-10-01

Both L-shaped ("L") and straight ("Straight") sample probes have been used to collect water samples from a main ballast line in land-based or shipboard verification testing of ballast water management systems (BWMS). A series of experiments was conducted to quantify and compare the sampling efficiencies of L and Straight sample probes. The findings from this research-that both L and Straight probes sample organisms with similar efficiencies-permit increased flexibility for positioning sample probes aboard ships.

Evaluation of wastewater contaminant transport in surface waters using verified Lagrangian sampling.

PubMed

Antweiler, Ronald C; Writer, Jeffrey H; Murphy, Sheila F

2014-02-01

Contaminants released from wastewater treatment plants can persist in surface waters for substantial distances. Much research has gone into evaluating the fate and transport of these contaminants, but this work has often assumed constant flow from wastewater treatment plants. However, effluent discharge commonly varies widely over a 24-hour period, and this variation controls contaminant loading and can profoundly influence interpretations of environmental data. We show that methodologies relying on the normalization of downstream data to conservative elements can give spurious results, and should not be used unless it can be verified that the same parcel of water was sampled. Lagrangian sampling, which in theory samples the same water parcel as it moves downstream (the Lagrangian parcel), links hydrologic and chemical transformation processes so that the in-stream fate of wastewater contaminants can be quantitatively evaluated. However, precise Lagrangian sampling is difficult, and small deviations - such as missing the Lagrangian parcel by less than 1h - can cause large differences in measured concentrations of all dissolved compounds at downstream sites, leading to erroneous conclusions regarding in-stream processes controlling the fate and transport of wastewater contaminants. Therefore, we have developed a method termed "verified Lagrangian" sampling, which can be used to determine if the Lagrangian parcel was actually sampled, and if it was not, a means for correcting the data to reflect the concentrations which would have been obtained had the Lagrangian parcel been sampled. To apply the method, it is necessary to have concentration data for a number of conservative constituents from the upstream, effluent, and downstream sites, along with upstream and effluent concentrations that are constant over the short-term (typically 2-4h). These corrections can subsequently be applied to all data, including non-conservative constituents. Finally, we show how data

Evaluation of wastewater contaminant transport in surface waters using verified Lagrangian sampling

USGS Publications Warehouse

Antweiler, Ronald C.; Writer, Jeffrey H.; Murphy, Sheila F.

2014-01-01

Contaminants released from wastewater treatment plants can persist in surface waters for substantial distances. Much research has gone into evaluating the fate and transport of these contaminants, but this work has often assumed constant flow from wastewater treatment plants. However, effluent discharge commonly varies widely over a 24-hour period, and this variation controls contaminant loading and can profoundly influence interpretations of environmental data. We show that methodologies relying on the normalization of downstream data to conservative elements can give spurious results, and should not be used unless it can be verified that the same parcel of water was sampled. Lagrangian sampling, which in theory samples the same water parcel as it moves downstream (the Lagrangian parcel), links hydrologic and chemical transformation processes so that the in-stream fate of wastewater contaminants can be quantitatively evaluated. However, precise Lagrangian sampling is difficult, and small deviations – such as missing the Lagrangian parcel by less than 1 h – can cause large differences in measured concentrations of all dissolved compounds at downstream sites, leading to erroneous conclusions regarding in-stream processes controlling the fate and transport of wastewater contaminants. Therefore, we have developed a method termed “verified Lagrangian” sampling, which can be used to determine if the Lagrangian parcel was actually sampled, and if it was not, a means for correcting the data to reflect the concentrations which would have been obtained had the Lagrangian parcel been sampled. To apply the method, it is necessary to have concentration data for a number of conservative constituents from the upstream, effluent, and downstream sites, along with upstream and effluent concentrations that are constant over the short-term (typically 2–4 h). These corrections can subsequently be applied to all data, including non-conservative constituents. Finally, we

Preliminary Investigation on the Effects of Shockwaves on Water Samples Using a Portable Semi-Automatic Shocktube

NASA Astrophysics Data System (ADS)

Wessley, G. Jims John

2017-10-01

The propagation of shock waves through any media results in an instantaneous increase in pressure and temperature behind the shockwave. The scope of utilizing this sudden rise in pressure and temperature in new industrial, biological and commercial areas has been explored and the opportunities are tremendous. This paper presents the design and testing of a portable semi-automatic shock tube on water samples mixed with salt. The preliminary analysis shows encouraging results as the salinity of water samples were reduced up to 5% when bombarded with 250 shocks generated using a pressure ratio of 2. 5. Paper used for normal printing is used as the diaphragm to generate the shocks. The impact of shocks of much higher intensity obtained using different diaphragms will lead to more reduction in the salinity of the sea water, thus leading to production of potable water from saline water, which is the need of the hour.

Reduction of hexavalent chromium in water samples acidified for preservation

USGS Publications Warehouse

Stollenwerk, K.G.; Grove, D.B.

1985-01-01

Reduction of hexavalent chromium, Cr(VI), in water samples, preserved by standard techniques, was investigated. The standard preservation technique for water samples that are to be analyzed for Cr(VI) consists of filtration through a 0.45-??m membrane, acidification to a pH < 2, and storage in plastic bottles. Batch experiments were conducted to evaluate the effect of H+ concentration, NO2, temperature, and dissolved organic carbon (DOC) on the reduction of Cr(VI) to Cr(III). The rate of reduction of Cr(VI) to Cr(III) increased with increasing NO2, DOC, H+, and temperature. Reduction of Cr(VI) by organic matter occurred in some samples even though the samples were unacidified. Reduction of Cr(VI) is inhibited to an extent by storing the sample at 4??C. Stability of Cr(VI) in water is variable and depends on the other constituents present in the sample. Water samples collected for the determination of Cr(VI) should be filtered (0.45-??m membrane), refrigerated, and analyzed as quickly as possible. Water samples should not be acidified. Measurement of total Cr in addition to Cr(VI) can serve as a check for Cr(VI) reduction. If total Cr is greater than Cr(VI), the possibility that Cr(VI) reduction has occurred needs to be considered.The rate of reduction of Cr(VI) to Cr(III) increased with increasing NO//2, DOC, H** plus , and temperature. Reduction of Cr(VI) by organic matter occurred in some samples even though the samples were unacidified. Reduction of Cr(VI) is inhibited to an extent by storing the sample at 4 degree C. Stability of Cr(VI) in water is variable and depends on the other constituents present in the sample. Water samples collected for the determination of Cr(VI) should be filtered (0. 45- mu m membrane), refrigerated, and analyzed as quickly as possible. Water samples should not be acidified. Measurement of total Cr in addition to Cr(VI) can serve as a check for Cr(VI) reduction. If total Cr is greater than Cr(VI), the possibility that Cr

Effects of Subsurface Sampling & Processing on Martian Simulant Containing Varying Quantities of Water

NASA Technical Reports Server (NTRS)

Menard, J.; Sangillo, J.; Savain, A.; McNamara, K. M.

2004-01-01

The presence of water-ice in the Martian subsurface is a subject of much debate and excited speculation. Recent results from the gammaray spectrometer (GRS) on board NASA's Mars Odyssey spacecraft indicate the presence of large amounts of hydrogen in regions of predicted ice stability. The combination of chemistry, low gravitational field (3.71 m/s(exp 2)) and a surface pressure of about 6.36 mbar at the mean radius, place limits on the stability of H2O on the surface, however, results from the GRS indicate that the hydrogen rich phase may be present at a depth as shallow as one meter in some locations on Mars. The potential for water on Mars leads directly to the speculation that life may once have existed there, since liquid water is the unifying factor for environments known to support life on Earth. Lubricant-free drilling has been considered as a means of obtaining water-rich subsurface samples on Mars, and two recent white papers sponsored by the Mars Program have attempted to identify the problems associated with this goal. The two major issues identified were: the engineering challenges of drilling into a water-soil mixture where phase changes may occur; and the potential to compromise the integrity of in-situ scientific analysis due to contamination, volatilization, and mineralogical or chemical changes as a result of processing. This study is a first attempt to simulate lubricantfree drilling into JSC Mars-1 simulant containing up to 50% water by weight. The goal is to address the following: 1) Does sample processing cause reactions or changes in mineralogy which will compromise the interpretation of scientific measurements conducted on the surface? 2) Does the presence of water-ice in the sample complicate (1)? 3) Do lubricant-free drilling and processing leave trace contaminants which may compromise our understanding of sample composition? 4) How does the torque/power required for drilling change as a function of water content and does this lead to

Sampling procedure for lake or stream surface water chemistry

Treesearch

Robert Musselman

2012-01-01

Surface waters collected in the field for chemical analyses are easily contaminated. This research note presents a step-by-step detailed description of how to avoid sample contamination when field collecting, processing, and transporting surface water samples for laboratory analysis.

Miniaturized and direct spectrophotometric multi-sample analysis of trace metals in natural waters.

PubMed

Albendín, Gemma; López-López, José A; Pinto, Juan J

2016-03-15

Trends in the analysis of trace metals in natural waters are mainly based on the development of sample treatment methods to isolate and pre-concentrate the metal from the matrix in a simpler extract for further instrumental analysis. However, direct analysis is often possible using more accessible techniques such as spectrophotometry. In this case a proper ligand is required to form a complex that absorbs radiation in the ultraviolet-visible (UV-Vis) spectrum. In this sense, the hydrazone derivative, di-2-pyridylketone benzoylhydrazone (dPKBH), forms complexes with copper (Cu) and vanadium (V) that absorb light at 370 and 395 nm, respectively. Although spectrophotometric methods are considered as time- and reagent-consuming, this work focused on its miniaturization by reducing the volume of sample as well as time and cost of analysis. In both methods, a micro-amount of sample is placed into a microplate reader with a capacity for 96 samples, which can be analyzed in times ranging from 5 to 10 min. The proposed methods have been optimized using a Box-Behnken design of experiments. For Cu determination, concentration of phosphate buffer solution at pH 8.33, masking agents (ammonium fluoride and sodium citrate), and dPKBH were optimized. For V analysis, sample (pH 4.5) was obtained using acetic acid/sodium acetate buffer, and masking agents were ammonium fluoride and 1,2-cyclohexanediaminetetraacetic acid. Under optimal conditions, both methods were applied to the analysis of certified reference materials TMDA-62 (lake water), LGC-6016 (estuarine water), and LGC-6019 (river water). In all cases, results proved the accuracy of the method. Copyright © 2015 Elsevier Inc. All rights reserved.

Discrimination of non-explosive and explosive samples through nitrocellulose fingerprints obtained by capillary electrophoresis.

PubMed

Fernández de la Ossa, Ma Ángeles; Ortega-Ojeda, Fernando; García-Ruiz, Carmen

2013-08-09

This work is focused on a novel procedure to discriminate nitrocellulose-based samples with non-explosive and explosive properties. The nitrocellulose study has been scarcely approached in the literature due to its special polymeric properties such as its high molar mass and complex chemical and structural characteristics. These properties require the nitrocellulose analysis to be performed by using a few organic solvents and in consequence, they limit the number of adequate analytical techniques for its study. In terms of identification of pre-blast explosives, mass spectrometry is one of the most preferred technique because it allows to obtain structural information. However, it has never been used to analyze polymeric nitrocellulose. In this study, the differentiation of non-explosive and explosive samples through nitrocellulose fingerprints obtained by capillary electrophoresis was investigated. A batch of 30 different smokeless gunpowders and 23 different everyday products were pulverized, derivatized with a fluorescent agent and analyzed by capillary electrophoresis with laser-induced fluorescence detection. Since this methodology is specific to d-glucopyranose derivatives (cellulosic and related compounds), and paper samples could be easily found in explosion scenes, 11 different paper samples were also included in the study as potential interference samples. In order to discriminate among samples, multivariate analysis (principal component analysis and soft independent modeling of class analogy) was applied to the obtained electrophoretic profiles. To the best of our knowledge, this represents the first study that achieve a successful discrimination between non-explosive and explosive nitrocellulose-based samples, as well as potential cellulose interference samples, and posterior classification of unknown samples into their corresponding groups using CE-LIF and chemometric tools. Copyright © 2013 Elsevier B.V. All rights reserved.

Analysis of DDT and its metabolites in soil and water samples obtained in the vicinity of a closed-down factory in Bangladesh using various extraction methods.

PubMed

Al Mahmud, M N U; Khalil, Farzana; Rahman, Md Musfiqur; Mamun, M I R; Shoeb, Mohammad; Abd El-Aty, A M; Park, Jong-Hyouk; Shin, Ho-Chul; Nahar, Nilufar; Shim, Jae-Han

2015-12-01

This study was conducted to monitor the spread of dichlorodiphenyltrichloroethane (DDT) and its metabolites (dichlorodiphenyldichloroethylene (DDE), dichlorodiphenyldichloroethane (DDD)) in soil and water to regions surrounding a closed DDT factory in Bangladesh. This fulfillment was accomplished using inter-method and inter-laboratory validation studies. DDTs (DDT and its metabolites) from soil samples were extracted using microwave-assisted extraction (MAE), supercritical fluid extraction (SFE), and solvent extraction (SE). Inter-laboratory calibration was assessed by SE, and all methods were validated by intra- and inter-day accuracy (expressed as recovery %) and precision (expressed as relative standard deviation (RSD)) in the same laboratory, at three fortified concentrations (n = 4). DDTs extracted from water samples by liquid-liquid partitioning and all samples were analyzed by gas chromatography (GC)-electron capture detector (ECD) and confirmed by GC/mass spectrometry (GC/MS). Linearities expressed as determination coefficients (R (2)) were ≥0.995 for matrix-matched calibrations. The recovery rate was in the range of 72-120 and 83-110%, with <15% RSD in soil and water, respectively. The limit of quantification (LOQ) was 0.0165 mg kg(-1) in soil and 0.132 μg L(-1) in water. Greater quantities of DDTs were extracted from soil using the MAE and SE techniques than with the SFE method. Higher amounts of DDTs were discovered in the southern (2.2-936 × 10(2) mg kg(-1)) or southwestern (86.3-2067 × 10(2) mg kg(-1)) direction from the factory than in the eastern direction (1.0-48.6 × 10(2) mg kg(-1)). An exception was the soil sample collected 50 ft (15.24 m) east (2904 × 10(2) mg kg(-1)) of the factory. The spread of DDTs in the water bodies (0.59-3.01 μg L(-1)) was approximately equal in all directions. We concluded that DDTs might have been dumped randomly around the warehouse after the closing of the factory.

Screen-printed electrode based electrochemical detector coupled with ionic liquid dispersive liquid-liquid microextraction and microvolume back-extraction for determination of mercury in water samples.

PubMed

Fernández, Elena; Vidal, Lorena; Martín-Yerga, Daniel; Blanco, María del Carmen; Canals, Antonio; Costa-García, Agustín

2015-04-01

A novel approach is presented, whereby gold nanostructured screen-printed carbon electrodes (SPCnAuEs) are combined with in-situ ionic liquid formation dispersive liquid-liquid microextraction (in-situ IL-DLLME) and microvolume back-extraction for the determination of mercury in water samples. In-situ IL-DLLME is based on a simple metathesis reaction between a water-miscible IL and a salt to form a water-immiscible IL into sample solution. Mercury complex with ammonium pyrrolidinedithiocarbamate is extracted from sample solution into the water-immiscible IL formed in-situ. Then, an ultrasound-assisted procedure is employed to back-extract the mercury into 10 µL of a 4 M HCl aqueous solution, which is finally analyzed using SPCnAuEs. Sample preparation methodology was optimized using a multivariate optimization strategy. Under optimized conditions, a linear range between 0.5 and 10 µg L(-1) was obtained with a correlation coefficient of 0.997 for six calibration points. The limit of detection obtained was 0.2 µg L(-1), which is lower than the threshold value established by the Environmental Protection Agency and European Union (i.e., 2 µg L(-1) and 1 µg L(-1), respectively). The repeatability of the proposed method was evaluated at two different spiking levels (3 and 10 µg L(-1)) and a coefficient of variation of 13% was obtained in both cases. The performance of the proposed methodology was evaluated in real-world water samples including tap water, bottled water, river water and industrial wastewater. Relative recoveries between 95% and 108% were obtained. Copyright © 2014 Elsevier B.V. All rights reserved.

40 CFR 2.302 - Special rules governing certain information obtained under the Clean Water Act.

Code of Federal Regulations, 2013 CFR

2013-07-01

... information obtained under the Clean Water Act. 2.302 Section 2.302 Protection of Environment ENVIRONMENTAL... governing certain information obtained under the Clean Water Act. (a) Definitions. For the purposes of this section: (1) Act means the Clean Water Act, as amended, 33 U.S.C. 1251 et seq. (2)(i) Effluent data means...

Identification and Genotyping of Mycobacterium tuberculosis Isolated From Water and Soil Samples of a Metropolitan City

PubMed Central

Velayati, Ali Akbar; Farnia, Parissa; Mozafari, Mohadese; Malekshahian, Donya; Farahbod, Amir Masoud; Seif, Shima; Rahideh, Snaz

2015-01-01

BACKGROUND: The potential role of environmental Mycobacterium tuberculosis in the epidemiology of TB remains unknown. We investigated the transmission of M tuberculosis from humans to the environment and the possible transmission of M tuberculosis from the environment to humans. METHODS: A total of 1,500 samples were collected from three counties of the Tehran, Iran metropolitan area from February 2012 to January 2014. A total of 700 water samples (47%) and 800 soil samples (53%) were collected. Spoligotyping and the mycobacterial interspersed repetitive units-variable number of tandem repeats typing method were performed on DNA extracted from single colonies. Genotypes of M tuberculosis strains isolated from the environment were compared with the genotypes obtained from 55 patients with confirmed pulmonary TB diagnosed during the study period in the same three counties. RESULTS: M tuberculosis was isolated from 11 of 800 soil samples (1%) and 71 of 700 water samples (10%). T family (56 of 82, 68%) followed by Delhi/CAS (11 of 82, 13.4%) were the most frequent M tuberculosis superfamilies in both water and soil samples. Overall, 27.7% of isolates in clusters were related. No related typing patterns were detected between soil, water, and clinical isolates. The most frequent superfamily of M tuberculosis in clinical isolates was Delhi/CAS (142, 30.3%) followed by NEW-1 (127, 27%). The bacilli in contaminated soil (36%) and damp water (8.4%) remained reculturable in some samples up to 9 months. CONCLUSIONS: Although the dominant M tuberculosis superfamilies in soil and water did not correspond to the dominant M tuberculosis family in patients, the presence of circulating genotypes of M tuberculosis in soil and water highlight the risk of transmission. PMID:25340935

High-resolution passive sampling of dissolved methane in the water column of lakes in Greenland

NASA Astrophysics Data System (ADS)

Goldman, A. E.; Cadieux, S. B.; White, J. R.; Pratt, L. M.

2013-12-01

Arctic lakes are important participants in the global carbon cycle, releasing methane in a warming climate and contributing to a positive feedback to climate change. In order to yield detailed methane budgets and understand the implications of warming on methane dynamics, high-resolution profiles revealing methane behavior within the water column need to be obtained. Single day sampling using disruptive techniques has the potential to result in biases. In order to obtain high-resolution, undisturbed profiles of methane concentration and isotopic composition, this study evaluates a passive sampling method over a multi-day equilibration period. Selected for this study were two small lakes (<1km2) within a narrow valley stretching between Russells Glacier and Søndre Strømfjord in southwestern Greenland, which are part of an ongoing study of a series of seven lakes. Commercially available, 150 mL, polyethylene Passive Diffusion Bags (PDB's) were deployed in July 2013 for five days at 0.5-meter depth intervals. PDB samples were compared to samples collected with a submersible, electric pump taken immediately before PBD deployment. Preliminary CH4 concentrations and carbon isotopes for one lake were obtained in the field using a Los Gatos Research Methane Carbon Isotope Analyzer. PDB sampling and pump sampling resulted in statistically similar concentrations (R2=0.89), ranging from 0.85 to 135 uM from PDB and 0.74 to 143 uM from pump sampling. In anoxic waters of the lake, where concentrations were high enough to yield robust isotopic results on the LGR MCIA, δ13C were also similar between the two methods, yielding -73‰ from PDB and -74‰ from pump sampling. Further investigation will produce results for a second lake and methane carbon and hydrogen isotopic composition for both lakes. Preliminary results for this passive sampling method are promising. We envision the use of this technique in future studies of dissolved methane and expect that it will provide a

Water stable isotope measurements of Antarctic samples by means of IRMS and WS-CRDS techniques

NASA Astrophysics Data System (ADS)

Michelini, Marzia; Bonazza, Mattia; Braida, Martina; Flora, Onelio; Dreossi, Giuliano; Stenni, Barbara

2010-05-01

In the last years in the scientific community there has been an increasing interest for the application of stable isotope techniques to several environmental problems such as drinking water safeguarding, groundwater management, climate change, soils and paleoclimate studies etc. For example, the water stable isotopes, being natural tracers of the hydrological cycle, have been extensively used as tools to characterize regional aquifers and to reconstruct past temperature changes from polar ice cores. Here the need for improvements in analytical techniques: the high request for information calls for technologies that can offer a great quantity of analyses in short times and with low costs. Furthermore, sometimes it is difficult to obtain big amount of samples (as is the case for Antarctic ice cores or interstitial water) preventing the possibility to replicate the analyses. Here, we present oxygen and hydrogen measurements performed on water samples covering a big range of isotopic values (from very negative antarctic precipitation to mid-latitude precipitation values) carried out with both the conventional Isotope Ratio Mass Spectrometry (IRMS) technique and with a new method based on laser absorption techniques, the Wavelenght Scanned Cavity Ringdown Spectroscopy (WS-CRDS). This study is focusing on improving the precision of the measurements carried out with WS-CRDS in order to extensively apply this method to Antarctic ice core paleoclimate studies. The WS-CRDS is a variation of the CRDS developed in 1988 by O'Keef and Deacon. In CRDS a pulse of light goes through a box with high reflective inner surfaces; when there is no sample in the box the light beam doesn't find any obstacle in its path, but the reflectivity of the walls is not perfect so eventually there will be an absorption of the light beam; when the sample is injected in the box there is absorption and the difference between the time of absorption without and with sample is proportional to the quantity

Microbial Condition of Water Samples from Foreign Fuel Storage Facilities

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

Berry, C.J.; Fliermans, C.B.; Santo Domingo, J.

1997-10-30

In order to assess the microbial condition of foreign nuclear fuel storage facilities, fourteen different water samples were received from facilities outside the United States that have sent spent nuclear fuel to SRS for wet storage. Each water sample was analyzed for microbial content and activity as determined by total bacteria, viable aerobic bacteria, viable anaerobic bacteria, viable sulfate- reducing bacteria, viable acid-producing bacteria and enzyme diversity. The results for each water sample were then compared to other foreign samples and to data from the receiving basin for off- site fuel (RBOF) at SRS.

Combined sample collection and gas extraction for the measurement of helium isotopes and neon in natural waters

NASA Astrophysics Data System (ADS)

Roether, Wolfgang; Vogt, Martin; Vogel, Sandra; Sültenfuß, Jürgen

2013-06-01

We present a new method to obtain samples for the measurement of helium isotopes and neon in water, to replace the classical sampling procedure using clamped-off Cu tubing containers that we have been using so far. The new method saves the gas extraction step prior to admission to the mass spectrometer, which the classical method requires. Water is drawn into evacuated glass ampoules with subsequent flame sealing. Approximately 50% headspace is left, from which admission into the mass spectrometer occurs without further treatment. Extensive testing has shown that, with due care and with small corrections applied, the samples represent the gas concentrations in the water within ±0.07% (95% confidence level; ±0.05% with special handling). Fast evacuation is achieved by pumping on a small charge of water placed in the ampoule. The new method was successfully tested at sea in comparison with Cu-tubing sampling. We found that the ampoule samples were superior in data precision and that a lower percentage of samples were lost prior to measurement. Further measurements revealed agreement between the two methods in helium, 3He and neon within ±0.1%. The new method facilitates the dealing with large sample sets and minimizes the delay between sampling and measurement. The method is applicable also for gases other than helium and neon.

Extractive procedure for uranium determination in water samples by liquid scintillation counting.

PubMed

Gomez Escobar, V; Vera Tomé, F; Lozano, J C; Martín Sánchez, A

1998-07-01

An extractive procedure for uranium determination using liquid scintillation counting with the URAEX cocktail is described. Interference from radon and a strong influence of nitrate ion were detected in this procedure. Interference from radium, thorium and polonium emissions were very low when optimal operating conditions were reached. Quenching effects were considered and the minimum detectable activity was evaluated for different sample volumes. Isotopic analysis of samples can be performed using the proposed method. Comparisons with the results obtained with the general procedure used in alpha spectrometry with passivated implanted planar silicon detectors showed good agreement. The proposed procedure is thus suitable for uranium determination in water samples and can be considered as an alternative to the laborious conventional chemical preparations needed for alpha spectrometry methods using semiconductor detectors.

Potential bias in TEOS10 density of sea water samples

NASA Astrophysics Data System (ADS)

Budéus, G. Th.

2018-04-01

Direct density measurements of ocean water samples are compared to TEOS10 derived densities. The water sample set includes waters from remote areas as Antarctic waters and the central Arctic, but also waters of regions that resemble closely the reference composition of TEOS10. With few exceptions, the measured densities are smaller than those derived according to TEOS10. The result suggests a potential systematic overestimation of density by TEOS10. For the majority of waters the deviations are about 10 g/m3.

Procedures for Obtaining and Analyzing Writing Samples of School-Age Children and Adolescents.

PubMed

Price, Johanna R; Jackson, Sandra C

2015-10-01

Many students' writing skills are below grade-level expectations, and students with oral language difficulties are at particular risk for writing difficulties. Speech-language pathologists' (SLPs') expertise in language applies to both the oral and written modalities, yet evidence suggests that SLPs' confidence regarding writing assessment is low. Writing samples are a clinically useful, criterion-referenced assessment technique that is relevant to helping students satisfy writing-related requirements of the Common Core State Standards (National Governors Association Center for Best Practices and Council of Chief State School Officers, 2010a). This article provides recommendations for obtaining and analyzing students' writing samples. In this tutorial, the authors provide a comprehensive literature review of methods regarding (a) collection of writing samples from narrative, expository (informational/explanatory), and persuasive (argument) genres; (b) variables of writing performance that are useful to assess; and (c) manual and computer-aided techniques for analyzing writing samples. The authors relate their findings to expectations for writing skills expressed in the Common Core State Standards (National Governors Association Center for Best Practices & Council of Chief State School Officers, 2010a). SLPs can readily implement many techniques for obtaining and analyzing writing samples. The information in this article provides SLPs with recommendations for the use of writing samples and may help increase SLPs' confidence regarding written language assessment.

Salting-out assisted liquid-liquid extraction combined with capillary HPLC for the determination of sulfonylurea herbicides in environmental water and banana juice samples.

PubMed

Gure, Abera; Lara, Francisco J; Moreno-González, David; Megersa, Negussie; del Olmo-Iruela, Monsalud; García-Campaña, Ana M

2014-09-01

A salting-out assisted liquid-liquid extraction (SALLE) combined with capillary high performance liquid chromatography with diode array detector (capillary HPLC-DAD) was proposed for extraction and determination of residues of nine sulfonylurea herbicides (SUHs) in environmental water and banana juice samples. Various parameters affecting the extraction process such as the type and volume of the organic solvent, sample volume, type and amount of salt, pH of the sample and vortex time were optimized. Under optimum conditions, matrix matched calibration curves were established using river water and banana juice samples. Good linear relationships as well as low limits of detection, LODs (0.4-1.3 and 3-13 µg/L) and quantification, LOQs (1.3-4.3 and 10-43 µg/L) were obtained in water and banana juice samples, respectively. The precision (intra- and inter-day) of the peak areas expressed as relative standard deviations (%, RSD), at two concentration levels were below 10 % in both matrices. Recoveries obtained from spiked environmental waters (river water and groundwater) and banana juice samples, at two concentration levels, ranged from 72 to 115%. The results of the analysis revealed that the proposed SALLE-capillary HPLC method is simple, rapid, cheap and environmentally friendly, being successfully applicable for the determination of SUH residues in waters and banana juices. Copyright © 2014 Elsevier B.V. All rights reserved.

Total Water Content Measurements with an Isokinetic Sampling Probe

NASA Technical Reports Server (NTRS)

Reehorst, Andrew L.; Miller, Dean R.; Bidwell, Colin S.

2010-01-01

The NASA Glenn Research Center has developed a Total Water Content (TWC) Isokinetic Sampling Probe. Since it is not sensitive to cloud water particle phase nor size, it is particularly attractive to support super-cooled large droplet and high ice water content aircraft icing studies. The instrument is comprised of the Sampling Probe, Sample Flow Control, and Water Vapor Measurement subsystems. Analysis and testing have been conducted on the subsystems to ensure their proper function and accuracy. End-to-end bench testing has also been conducted to ensure the reliability of the entire instrument system. A Stokes Number based collection efficiency correction was developed to correct for probe thickness effects. The authors further discuss the need to ensure that no condensation occurs within the instrument plumbing. Instrument measurements compared to facility calibrations from testing in the NASA Glenn Icing Research Tunnel are presented and discussed. There appears to be liquid water content and droplet size effects in the differences between the two measurement techniques.

Use of Cdse/ZnS quantum dots for sensitive detection and quantification of paraquat in water samples.

PubMed

Durán, Gema M; Contento, Ana M; Ríos, Ángel

2013-11-01

Based on the highly sensitive fluorescence change of water-soluble CdSe/ZnS core-shell quantum dots (QD) by paraquat herbicide, a simple, rapid and reproducible methodology was developed to selectively determine paraquat (PQ) in water samples. The methodology enabled the use of simple pretreatment procedure based on the simple water solubilization of CdSe/ZnS QDs with hydrophilic heterobifunctional thiol ligands, such as 3-mercaptopropionic acid (3-MPA), using microwave irradiation. The resulting water-soluble QDs exhibit a strong fluorescence emission at 596 nm with a high and reproducible photostability. The proposed analytical method thus satisfies the need for a simple, sensible and rapid methodology to determine residues of paraquat in water samples, as required by the increasingly strict regulations for health protection introduced in recent years. The sensitivity of the method, expressed as detection limits, was as low as 3.0 ng L(-1). The lineal range was between 10-5×10(3) ng L(-1). RSD values in the range of 71-102% were obtained. The analytical applicability of proposed method was demonstrated by analyzing water samples from different procedence. Copyright © 2013 Elsevier B.V. All rights reserved.

Composite Magnetic Nanoparticles (CuFe₂O₄) as a New Microsorbent for Extraction of Rhodamine B from Water Samples.

PubMed

Roostaie, Ali; Allahnoori, Farzad; Ehteshami, Shokooh

2017-09-01

In this work, novel composite magnetic nanoparticles (CuFe2O4) were synthesized based on sol-gel combustion in the laboratory. Next, a simple production method was optimized for the preparation of the copper nanoferrites (CuFe2O4), which are stable in water, magnetically active, and have a high specific area used as sorbent material for organic dye extraction in water solution. CuFe2O4 nanopowders were characterized by field-emission scanning electron microscopy (SEM), FTIR spectroscopy, and energy dispersive X-ray spectroscopy. The size range of the nanoparticles obtained in such conditions was estimated by SEM images to be 35-45 nm. The parameters influencing the extraction of CuFe2O4 nanoparticles, such as desorption solvent, amount of sorbent, desorption time, sample pH, ionic strength, and extraction time, were investigated and optimized. Under the optimum conditions, a linear calibration curve in the range of 0.75-5.00 μg/L with R2 = 0.9996 was obtained. The LOQ (10Sb) and LOD (3Sb) of the method were 0.75 and 0.25 μg/L (n = 3), respectively. The RSD for a water sample spiked with 1 μg/L rhodamine B was 3% (n = 5). The method was applied for the determination of rhodamine B in tap water, dishwashing foam, dishwashing liquid, and shampoo samples. The relative recovery percentages for these samples were in the range of 95-99%.

40 CFR 258.53 - Ground-water sampling and analysis requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Ground-water sampling and analysis requirements. 258.53 Section 258.53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Ground-Water Monitoring and Corrective Action § 258.53 Ground-water sampling and analysi...

40 CFR 258.53 - Ground-water sampling and analysis requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Ground-water sampling and analysis requirements. 258.53 Section 258.53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Ground-Water Monitoring and Corrective Action § 258.53 Ground-water sampling and analysi...

Preparation of water samples for carbon-14 dating

USGS Publications Warehouse

Feltz, H.R.; Hanshaw, Bruce B.

1963-01-01

For most natural water, a large sample is required to provide the 3 grams of carbon needed for a carbon-14 determination. A field procedure for isolating total dissolved-carbonate species is described. Carbon dioxide gas is evolved by adding sulfuric acid to the water sample; the gas is then collected in a sodium hydroxide trap by recycling in a closed system. The trap is then transported to the dating laboratory where the carbon-14 is counted.

Seasonal rationalization of river water quality sampling locations: a comparative study of the modified Sanders and multivariate statistical approaches.

PubMed

Varekar, Vikas; Karmakar, Subhankar; Jha, Ramakar

2016-02-01

The design of surface water quality sampling location is a crucial decision-making process for rationalization of monitoring network. The quantity, quality, and types of available dataset (watershed characteristics and water quality data) may affect the selection of appropriate design methodology. The modified Sanders approach and multivariate statistical techniques [particularly factor analysis (FA)/principal component analysis (PCA)] are well-accepted and widely used techniques for design of sampling locations. However, their performance may vary significantly with quantity, quality, and types of available dataset. In this paper, an attempt has been made to evaluate performance of these techniques by accounting the effect of seasonal variation, under a situation of limited water quality data but extensive watershed characteristics information, as continuous and consistent river water quality data is usually difficult to obtain, whereas watershed information may be made available through application of geospatial techniques. A case study of Kali River, Western Uttar Pradesh, India, is selected for the analysis. The monitoring was carried out at 16 sampling locations. The discrete and diffuse pollution loads at different sampling sites were estimated and accounted using modified Sanders approach, whereas the monitored physical and chemical water quality parameters were utilized as inputs for FA/PCA. The designed optimum number of sampling locations for monsoon and non-monsoon seasons by modified Sanders approach are eight and seven while that for FA/PCA are eleven and nine, respectively. Less variation in the number and locations of designed sampling sites were obtained by both techniques, which shows stability of results. A geospatial analysis has also been carried out to check the significance of designed sampling location with respect to river basin characteristics and land use of the study area. Both methods are equally efficient; however, modified Sanders

Perilymph sampling from the cochlear apex: a reliable method to obtain higher purity perilymph samples from scala tympani.

PubMed

Salt, Alec N; Hale, Shane A; Plonkte, Stefan K R

2006-05-15

Measurements of drug levels in the fluids of the inner ear are required to establish kinetic parameters and to determine the influence of specific local delivery protocols. For most substances, this requires cochlear fluids samples to be obtained for analysis. When auditory function is of primary interest, the drug level in the perilymph of scala tympani (ST) is most relevant, since drug in this scala has ready access to the auditory sensory cells. In many prior studies, ST perilymph samples have been obtained from the basal turn, either by aspiration through the round window membrane (RWM) or through an opening in the bony wall. A number of studies have demonstrated that such samples are likely to be contaminated with cerebrospinal fluid (CSF). CSF enters the basal turn of ST through the cochlear aqueduct when the bony capsule is perforated or when fluid is aspirated. The degree of sample contamination has, however, not been widely appreciated. Recent studies have shown that perilymph samples taken through the round window membrane are highly contaminated with CSF, with samples greater than 2microL in volume containing more CSF than perilymph. In spite of this knowledge, many groups continue to sample from the base of the cochlea, as it is a well-established method. We have developed an alternative, technically simple method to increase the proportion of ST perilymph in a fluid sample. The sample is taken from the apex of the cochlea, a site that is distant from the cochlear aqueduct. A previous problem with sampling through a perforation in the bone was that the native perilymph rapidly leaked out driven by CSF pressure and was lost to the middle ear space. We therefore developed a procedure to collect all the fluid that emerged from the perforated apex after perforation. We evaluated the method using a marker ion trimethylphenylammonium (TMPA). TMPA was applied to the perilymph of guinea pigs either by RW irrigation or by microinjection into the apical turn. The

Perilymph Sampling from the Cochlear Apex: A Reliable Method to Obtain Higher Purity Perilymph Samples from Scala Tympani

PubMed Central

Salt, Alec N.; Hale, Shane A.; Plontke, Stefan K. R.

2006-01-01

Measurements of drug levels in the fluids of the inner ear are required to establish kinetic parameters and to determine the influence of specific local delivery protocols. For most substances, this requires cochlear fluids samples to be obtained for analysis. When auditory function is of primary interest, the drug level in the perilymph of scala tympani (ST) is most relevant, since drug in this scala has ready access to the auditory sensory cells. In many prior studies, ST perilymph samples have been obtained from the basal turn, either by aspiration through the round window membrane (RWM) or through an opening in the bony wall. A number of studies have demonstrated that such samples are likely to be contaminated with cerebrospinal fluid (CSF). CSF enters the basal turn of ST through the cochlear aqueduct when the bony capsule is perforated or when fluid is aspirated. The degree of sample contamination has, however, not been widely appreciated. Recent studies have shown that perilymph samples taken through the round window membrane are highly contaminated with CSF, with samples greater than 2 μL in volume containing more CSF than perilymph. In spite of this knowledge, many groups continue to sample from the base of the cochlea, as it is a well-established method. We have developed an alternative, technically simple method to increase the proportion of ST perilymph in a fluid sample. The sample is taken from the apex of the cochlea, a site that is distant from the cochlear aqueduct. A previous problem with sampling through a perforation in the bone was that the native perilymph rapidly leaked out driven by CSF pressure and was lost to the middle ear space. We therefore developed a procedure to collect all the fluid that emerged from the perforated apex after perforation. We evaluated the method using a marker ion trimethylphenylammonium (TMPA). TMPA was applied to the perilymph of guinea pigs either by RW irrigation or by microinjection into the apical turn. The

Ground Water Sampling for Metal Analyses

EPA Pesticide Factsheets

Filtration of ground-water samples for metals analysis is an issue identified by the Forum as a concern of Superfund decision-makers. Inconsistency in EPA Superfund cleanup ractices occurs where one EPA Region implements a remedial action based on...

Applying multi-criteria analysis for preliminary assessment of the properties of alginate immobilized Myriophyllum spicatum in lake water samples.

PubMed

Milojković, Jelena V; Popović-Djordjević, Jelena B; Pezo, Lato L; Brčeski, Ilija D; Kostić, Aleksandar Ž; Milošević, Vladan D; Stojanović, Mirjana D

2018-05-11

The preliminary assessment of the properties of alginate immobilized aquatic weed Myriophyllum spicatum beads-MsAlg in a multi-element system of nine Serbian lakes water samples was done. Herein, the results obtained in the biosorption experiment with MsAlg contents of twenty-two elements analysed by inductively coupled plasma-optical emission spectrometry, biosorption capacity, element removal efficiency, total hardness (TH) and quality index of water (WQI) are presented. Scanning electron microscopy with energy dispersive X-ray spectroscopy was used for the characterization of M. spicatum and its beads. The study showed that aluminium, magnesium and strontium were adsorbed by MsAlg in the water samples from all examined lakes; barium and iron in the water samples from six lakes. The overall average efficiency of MsAlg in biosorption of elements was in the following order: Al > Ba > Sr > Fe > Mg (58.6, 51.7, 48.2, 23.9 and 17.7%, respectively). The increase of TH and WQI values after the biosorption was noticed in all studied lake water samples. The most significant correlations for pH were regarding the contents of B, Mg and Ca, whereas WQI was highly correlated to the contents of B and Mg, and pH. The complexity of the obtained data was explained by Cluster Analysis and Principal Component Analysis, which showed good discrimination capabilities between the water samples taken from different locations. Considering that the invasive M. spicatum is natural, widespread and that its immobilization is cheap and eco-friendly, presented findings could be helpful in further assessment of MsAlg beads for its potential use as biofilter. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ultrasensitive environmental assessment of xeno-estrogens in water samples using label-free graphene immunosensors.

PubMed

Barton, Huw; Berbel-Filho, Waldir M; Consuegra, Sofia; Francis, Lewis; Tizaoui, Chedly; Conlan, R Steven; Teixeira, Sofia Rodrigues

2018-05-01

There is a growing interest in the possible environmental health impact posed by endocrine-disrupting chemicals (EDCs). A challenge to the field of endocrine disruption is that these substances are diverse and may not appear to share any structural similarity other than usually being low molecular mass (<1000 Da) compounds. Here we demonstrate the effectiveness of sensor device for the detection of low molecular weight, poorly water soluble, estrogenic compounds E1, E2 and EE2, fabricated by electropolymerization over graphene screen printed electrode (SPE). The PANI/Gr-SPE-devices displayed linear responses to estrogenic substances, in EIS assays, from 0.0975 ng/L to 200 ng/L in water samples, with a detection limit of 0.043 pg/L for E1, 0.19 ng/L for E2 and 0.070 pg/L for EE2 which is lower than other current biosensing techniques. This portable, disposable immunosensor offers a solution for immediate measurement at sample collection sites, due to its excellent sensitivity and selectivity when testing water samples obtained directly from rivers and waste water treatment facilities. The simple screen printing production method will enable the low cost, high volume production required for this type of environmental analysis. Copyright © 2018 Elsevier Inc. All rights reserved.

Sampling for Lead in Drinking Water

EPA Science Inventory

Sampling protocols for lead in water can be broadly categorized based on their intended purpose of 1) Pb regulatory compliance/corrosion control efficacy, 2) Pb plumbing source determination or Pb type identification, and 3) Pb exposure assessment. Choosing the appropriate protoc...

Determination of volatile chlorinated hydrocarbons in water samples by static headspace gas chromatography with electron capture detection.

PubMed

Li, Tiejun; Guo, Yuanming; Hu, Hongmei; Zhang, Xiaoning; Jin, Yanjian; Zhang, Xiaojun; Zhang, Yurong

2016-01-01

A simple, efficient, solvent-free, and commercial readily available approach for determination of five volatile chlorinated hydrocarbons in water samples using the static headspace sampling and gas chromatography with electron capture detection has been described. The proposed static headspace sampling method was initially optimized and the optimum experimental conditions found were 10 mL water sample containing 20% w/v sodium chloride placed in a 20 mL vial and stirred at 50ºC for 20 min. The linearity of the method was in the range of 1.2-240 μg/L for dichloromethane, 0.2-40 μg/L for trichloromethane, 0.005-1 μg/L for perchloromethane, 0.025-5 μg/L for trichloroethylene, and 0.01-2 μg/L for perchloroethylene, with coefficients of determination ranging between 0.9979 and 0.9990. The limits of detection were in the low μg/L level, ranging between 0.001 and 0.3 μg/L. The relative recoveries of spiked five volatile chlorinated hydrocarbons with external calibration method at different concentration levels in pure, tap, sea water of Jiaojiang Estuary, and sea water of waters of Xiaomendao were in the range of 91-116, 96-105, 86-112, and 80-111%, respectively, and with relative standard deviations of 1.9-3.6, 2.3-3.5, 1.5-2.7, and 2.3-3.7% (n = 5), respectively. The performance of the proposed method was compared with traditional liquid-liquid extraction on the real water samples (i.e., pure, tap, and sea water, etc.) and comparable efficiencies were obtained. It is concluded that this method can be successfully applied for the determination of volatile chlorinated hydrocarbons in different water samples. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ion mobility mass spectrometry for ion recovery and clean-up of MS and MS/MS spectra obtained from low abundance viral samples

PubMed Central

Harvey, David J.; Crispin, Max; Bonomelli, Camille; Scrivens, Jim H.

2016-01-01

Graphical abstract Many samples of complex mixtures of N-glycans released from small amounts of material, such as glycoproteins from viruses, present problems for mass spectrometric analysis because of the presence of contaminating material that is difficult to remove by conventional methods without involving sample loss. This paper describes the use of ion mobility for extraction of glycan profiles from such samples and for obtaining clean CID spectra when targeted m/z values capture additional ions from those of the target compound. N-Glycans were released enzymatically from within SDS-PAGE gels, from the representative glycoprotein, gp120 of the human immunodeficiency virus, and examined by direct infusion electrospray in negative mode followed by ion mobility with a Waters Synapt G2 mass spectrometer. Clean profiles of singly, doubly and triply charged N-glycans were obtained from samples in cases where the raw electrospray spectra displayed only a few glycan ions as the result of low sample concentration or the presence of contamination. Ion mobility also enabled uncontaminated CID spectra to be obtained from glycans when their molecular ions displayed coincidence with ions from fragments or multiply charged ions with similar m/z values. This technique proved to be invaluable for removing extraneous ions from many CID spectra. The presence of such ions often produces spectra that are difficult to interpret. Most CID spectra, even those from abundant glycan constituents, benefited from such clean-up showing that the extra dimension provided by ion mobility was invaluable for studies of this type. PMID:26204966

40 CFR 2.304 - Special rules governing certain information obtained under the Safe Drinking Water Act.

Code of Federal Regulations, 2010 CFR

2010-07-01

... information obtained under the Safe Drinking Water Act. 2.304 Section 2.304 Protection of Environment... Special rules governing certain information obtained under the Safe Drinking Water Act. (a) Definitions. For the purposes of this section: (1) Act means the Safe Drinking Water Act, 42 U.S.C. 300f et seq. (2...

40 CFR 2.304 - Special rules governing certain information obtained under the Safe Drinking Water Act.

Code of Federal Regulations, 2011 CFR

2011-07-01

... information obtained under the Safe Drinking Water Act. 2.304 Section 2.304 Protection of Environment... Special rules governing certain information obtained under the Safe Drinking Water Act. (a) Definitions. For the purposes of this section: (1) Act means the Safe Drinking Water Act, 42 U.S.C. 300f et seq. (2...

USE OF NATURAL WATERS AS U. S. GEOLOGICAL SURVEY REFERENCE SAMPLES.

USGS Publications Warehouse

Janzer, Victor J.

1985-01-01

The U. S. Geological Survey conducts research and collects hydrologic data relating to the Nation's water resources. Seven types of natural matrix reference water samples are prepared for use in the Survey's quality assurance program. These include samples containing major constituents, trace metals, nutrients, herbicides, insecticides, trace metals in a water and suspended-sediment mixture, and precipitation (snowmelt). To prepare these reference samples, natural water is collected in plastic drums and the sediment is allowed to settle. The water is then filtered, selected constituents are added, and if necessary the water is acidified and sterilized by ultraviolet irradiation before bottling in plastic or glass. These reference samples are distributed twice yearly to more than 100 laboratories for chemical analysis. The most probable values for each constituent are determined by evaluating the data submitted by the laboratories using statistical techniques recommended by ASTM.

Pennsylvania StreamStats--A web-based application for obtaining water-resource-related information

USGS Publications Warehouse

Stuckey, Marla H.; Hoffman, Scott A.

2010-01-01

StreamStats is a national web-based Geographic Information System (GIS) application, developed by the U.S. Geological Survey (USGS), in cooperation with Environmental Systems Research Institute, Inc., to provide a variety of water-resource-related information. Users can easily obtain descriptive information, basin characteristics, and streamflow statistics for USGS streamgages and ungaged stream locations throughout Pennsylvania. StreamStats also allows users to search upstream and (or) downstream from user-selected points to identify locations of and obtain information for water-resource-related activities, such as dams and streamgages.

Determination of ammonium in river water and sewage samples by capillary zone electrophoresis with direct UV detection.

PubMed

Fukushi, Keiichi; Ito, Hideyuki; Kimura, Kenichi; Yokota, Kuriko; Saito, Keiitsu; Chayama, Kenji; Takeda, Sahori; Wakida, Shin-ichi

2006-02-17

We developed capillary zone electrophoresis (CZE) with direct UV detection for determination of ammonium in environmental water samples. Ammonium in the samples was partly converted into ammonia in the alkaline background electrolyte (BGE) during migration and was detected by molecular absorption of ammonia at 190 nm in approximately 7 min. The limit of detection (LOD) for ammonium was 0.24 mg/l (as nitrogen) at a signal-to-noise ratio of three. The respective values of the relative standard deviation (RSD) of peak area, peak height, and migration time for ammonium were 2.1, 1.8, and 0.46%. Major alkali and alkaline earth metal ions coexisting in the samples did not interfere with ammonium determination by the proposed method. The proposed method determined ammonium in surface water and sewage samples. The results were compared to those obtained using ion chromatography (IC).

Screening of pesticide residues in soil and water samples from agricultural settings

PubMed Central

Akogbéto, Martin C; Djouaka, Rousseau F; Kindé-Gazard, Dorothée A

2006-01-01

Background The role of agricultural practices in the selection of insecticide resistance in malaria vectors has so far been hypothesized without clear evidence. Many mosquito species, Anopheles gambiae in particular, lay their eggs in breeding sites located around agricultural settings. There is a probability that, as a result of farming activities, insecticide residues may be found in soil and water, where they exercise a selection pressure on the larval stage of various populations of mosquitoes. To confirm this hypothesis, a study was conducted in the Republic of Benin to assess the environmental hazards which can be generated from massive use of pesticides in agricultural settings. Methods Lacking an HPLC machine for direct quantification of insecticide residues in samples, this investigation was performed using indirect bioassays focussed on the study of factors inhibiting the normal growth of mosquito larvae in breeding sites. The speed of development was monitored as well as the yield of rearing An. gambiae larvae in breeding sites reconstituted with water and soil samples collected in agricultural areas known to be under pesticide pressure. Two strains of An. gambiae were used in this indirect bioassay: the pyrethroid-susceptible Kisumu strain and the resistant Ladji strain. The key approach in this methodology is based on comparison of the growth of larvae in test and in control breeding sites, the test samples having been collected from two vegetable farms. Results Results obtained clearly show the presence of inhibiting factors on test samples. A normal growth of larvae was observed in control samples. In breeding sites simulated by using a few grams of soil samples from the two vegetable farms under constant insecticide treatments (test samples), a poor hatching rate of Anopheles eggs coupled with a retarded growth of larvae and a low yield of adult mosquitoes from hatched eggs, was noticed. Conclusion Toxic factors inhibiting the hatching of anopheles

Chapter 5: Surface water quality sampling in streams and canals

USDA-ARS?s Scientific Manuscript database

Surface water sampling and water quality assessments have greatly evolved in the United States since the 1970s establishment of the Clean Water Act. Traditionally, water quality referred to only the chemical characteristics of the water and its toxicological properties related to drinking water or ...

Idaho's surface-water-quality monitoring program: results from five sites sampled during water years 1990-93

USGS Publications Warehouse

,

1994-01-01

In 1990, the U.S. Geological Survey (USGS), in cooperation with the Idaho Department of Health and Welfare, Division of Environmental Quality, implemented a statewide water-quality monitoring program in response to Idaho's antidegradation policy as required by the Clean Water Act. The program objective is to provide water-quality managers with a coordinated statewide network to detect trends in surface-water quality. The monitoring program includes the collection and analysis of samples from 56 sites on the Bear, Clearwater, Kootenai, Pend Oreille, Salmon, Snake, and Spokane Rivers and their tributaries (fig. 1). Samples are collected every year at 5 sites (annual sites) in drainage basins where long-term water-quality management is practiced, every other year at 19 sites (biennial sites) in basins where land and water uses change slowly, and every third year at 32 sites (triennial sites) where future development may affect water quality. Each year, 25 of the 56 sites are sampled. This report discusses results of sampling at five annual sites. During water years 1990-93 (October 1, 1989, through September 30, 1993), samples were collected six times per year at the five annual sites (fig. 1). Onsite analyses were made for discharge, specific conductance, pH, temperature, dissolved oxygen, bacteria (fecal coliform and fecal streptococci), and alkalinity. Laboratory analyses were made for major ions, nutrients, trace elements, and suspended sediment. Suspended sediment, nitrate, fecal coliform, trace elements, and specific conductance were used to characterize surface-water quality. Because concentrations of all trace elements except zinc were near detection limits, only zinc is discussed.

Detection of Small Numbers of Campylobacter jejuni and Campylobacter coli Cells in Environmental Water, Sewage, and Food Samples by a Seminested PCR Assay

PubMed Central

Waage, Astrid S.; Vardund, Traute; Lund, Vidar; Kapperud, Georg

1999-01-01

A rapid and sensitive assay was developed for detection of small numbers of Campylobacter jejuni and Campylobacter coli cells in environmental water, sewage, and food samples. Water and sewage samples were filtered, and the filters were enriched overnight in a nonselective medium. The enrichment cultures were prepared for PCR by a rapid and simple procedure consisting of centrifugation, proteinase K treatment, and boiling. A seminested PCR based on specific amplification of the intergenic sequence between the two Campylobacter flagellin genes, flaA and flaB, was performed, and the PCR products were visualized by agarose gel electrophoresis. The assay allowed us to detect 3 to 15 CFU of C. jejuni per 100 ml in water samples containing a background flora consisting of up to 8,700 heterotrophic organisms per ml and 10,000 CFU of coliform bacteria per 100 ml. Dilution of the enriched cultures 1:10 with sterile broth prior to the PCR was sometimes necessary to obtain positive results. The assay was also conducted with food samples analyzed with or without overnight enrichment. As few as ≤3 CFU per g of food could be detected with samples subjected to overnight enrichment, while variable results were obtained for samples analyzed without prior enrichment. This rapid and sensitive nested PCR assay provides a useful tool for specific detection of C. jejuni or C. coli in drinking water, as well as environmental water, sewage, and food samples containing high levels of background organisms. PMID:10103261

Installation of water and gas-sampling wells in low-level radioactive-waste burial trenches, West Valley, New York

USGS Publications Warehouse

Prudic, David E.

1978-01-01

A low-level radioactive-waste burial site, West Valley, N.Y., operated from 1963 to 1975, contains 12 refuse-filled trenches about 20 feet deep in till. Twenty-eight wells, 1.25 inch in diameter, were driven to selected depths in 11 of the 12 trenches to obtain gas and water samples for chemical and radiochemical analysis, water-level measurements for evaluation of trench-cover permeability. Gas from unsaturated refuse above the trench water level was detected in nearly all wells. Rapid water-level response in most wells to pumping of water from trench sumps 20 to 275 feet distant showed the refuse to be highly permeable. Described in detail are the methods and equipment used to (1) install the wells, (2) collect gas and water samples, and (3) monitor radiation and methane concentrations while driving wells into trenches. A record of each well driven into the burial trenches is included. (Woodard-USGS)

UMTRA Project water sampling and analysis plan, Durango, Colorado. Revision 1

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

NONE

1995-09-01

Planned, routine ground water sampling activities at the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project site in Durango, Colorado, are described in this water sampling and analysis plan. The plan identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequency for the routine monitoring stations at the site. The ground water data are used to characterize the site ground water compliance strategies and to monitor contaminants of potential concern identified in the baseline risk assessment (DOE, 1995a). Regulatory basis for routine ground water monitoring at UMTRA Project sites is derived from themore » US EPA regulations in 40 CFR Part 192 (1994) and EPA standards of 1995 (60 FR 2854). Sampling procedures are guided by the UMTRA Project standard operating procedures (SOP) (JEG, n.d.), the Technical Approach Document (TAD) (DOE, 1989), and the most effective technical approach for the site.« less

Determination of nitrite and nitrate in water samples by an automated hydrodynamic sequential injection method.

PubMed

Somnam, Sarawut; Jakmunee, Jaroon; Grudpan, Kate; Lenghor, Narong; Motomizu, Shoji

2008-12-01

An automated hydrodynamic sequential injection (HSI) system with spectrophotometric detection was developed. Thanks to the hydrodynamic injection principle, simple devices can be used for introducing reproducible microliter volumes of both sample and reagent into the flow channel to form stacked zones in a similar fashion to those in a sequential injection system. The zones were then pushed to the detector and a peak profile was recorded. The determination of nitrite and nitrate in water samples by employing the Griess reaction was chosen as a model. Calibration graphs with linearity in the range of 0.7 - 40 muM were obtained for both nitrite and nitrate. Detection limits were found to be 0.3 muM NO(2)(-) and 0.4 muM NO(3)(-), respectively, with a sample throughput of 20 h(-1) for consecutive determination of both the species. The developed system was successfully applied to the analysis of water samples, employing simple and cost-effective instrumentation and offering higher degrees of automation and low chemical consumption.

Quality of nutrient data from streams and ground water sampled during water years 1992-2001

USGS Publications Warehouse

Mueller, David K.; Titus, Cindy J.

2005-01-01

Proper interpretation of water-quality data requires consideration of the effects that bias and variability might have on measured constituent concentrations. In this report, methods are described to estimate the bias due to contamination of samples in the field or laboratory and the variability due to sample collection, processing, shipment, and analysis. Contamination can adversely affect interpretation of measured concentrations in comparison to standards or criteria. Variability can affect interpretation of small differences between individual measurements or mean concentrations. Contamination and variability are determined for nutrient data from quality-control samples (field blanks and replicates) collected as part of the National Water-Quality Assessment (NAWQA) Program during water years 1992-2001. Statistical methods are used to estimate the likelihood of contamination and variability in all samples. Results are presented for five nutrient analytes from stream samples and four nutrient analytes from ground-water samples. Ammonia contamination can add at least 0.04 milligram per liter in up to 5 percent of all samples. This could account for more than 22 percent of measured concentrations at the low range of aquatic-life criteria (0.18 milligram per liter). Orthophosphate contamination, at least 0.019 milligram per liter in up to 5 percent of all samples, could account for more than 38 percent of measured concentrations at the limit to avoid eutrophication (0.05 milligram per liter). Nitrite-plus-nitrate and Kjeldahl nitrogen contamination is less than 0.4 milligram per liter in 99 percent of all samples; thus there is no significant effect on measured concentrations of environmental significance. Sampling variability has little or no effect on reported concentrations of ammonia, nitrite-plus-nitrate, orthophosphate, or total phosphorus sampled after 1998. The potential errors due to sampling variability are greater for the Kjeldahl nitrogen analytes and

Evaluation of selected information on splitting devices for water samples

USGS Publications Warehouse

Capel, P.D.; Larson, S.J.

1996-01-01

Four devices for splitting water samples into representative aliquots are used by the U.S. Geological Survey's Water Resources Division. A thorough evaluation of these devices (14-liter churn, 8-liter churn, plastic cone, and Teflon cone) encompasses a wide variety of concerns, based on both chemical and physical considerations. This report surveys the existing data (as of April 1994) on cleaning efficiency and splitting capability of these devices and presents the data in a systematic framework for evaluation. From the existing data, some of these concerns are adequately or partially addressed, but the majority of concerns could not be addressed because of the lack of data. In general, the existing cleaning and transport protocols are adequate at the milligram per liter level, but the adequacy is largely unknown for trace elements and organic chemicals at lower concen- trations. The existing data indicate that better results are obtained when the splitters are cleaned in the laboratory rather than in the field. Two conclusions that can be reached on the splitting capability of solids are that more work must be done with all four devices to characterize and quantify their limitations and range of usefulness, and that the 14-liter churn (and by association, the 8-liter churn) is not useful in obtaining representative splits of sand-sized particles.

Pesticide residues analysis in water samples of Nagarpur and Saturia Upazila, Bangladesh

NASA Astrophysics Data System (ADS)

Hasanuzzaman, M.; Rahman, M. A.; Islam, M. S.; Salam, M. A.; Nabi, M. R.

2018-03-01

Pesticides used to protect the crops from pest attack in the agricultural fields pose harmful effect to the non-target organisms such as human and many other aquatic and terrestrial organisms either directly or indirectly through food chain. The present study was conducted to monitor a total of seven pesticide residues under organochlorine, organophosphorus and carbamate pesticides in three different sources of pond water, paddy field water and tube-well water from Nagarpur Upazila and paddy field water in the company of Dhaleshwari and Gazikhali river water from Saturia Upazila, Bangladesh. A total of 40 water samples were analyzed using high-performance liquid chromatography equipped with ultraviolet detector. Among the organophosphorus pesticides, diazinon was detected in eight water samples at a concentration ranging from 4.11 to 257.91 μg/l whereas, malathion was detected only in one water sample at a concentration of 84.64 μg/l and chlorpyrifos pesticide was also detected only in one water sample and the concentration was 37.3 μg/l. Trace amount of carbaryl was identified but it was below the detection limit. None of the tested water samples was found to be contaminated with DDT or its metabolites (DDE and DDD). The water samples contaminated with the suspected pesticides were above the acceptable limit except for the fish pond samples of Sahabatpur and Dubaria union. To control the misuse of pesticides and to reduce the possible health risk, appropriate control systems of pests such as integrated pest management system should be implemented immediately by the authorities of the country.

Comparison of antibiotic resistant Escherichia coli obtained from drinking water sources in northern Tanzania: a cross-sectional study.

PubMed

Lyimo, Beatus; Buza, Joram; Subbiah, Murugan; Smith, Woutrina; Call, Douglas R

2016-11-03

Antimicrobial resistance (AMR) is a growing and significant threat to public health on a global scale. Escherichia coli comprises Gram-negative, fecal-borne pathogenic and commensal bacteria that are frequently associated with antibiotic resistance. AMR E. coli can be ingested via food, water and direct contact with fecal contamination. We estimated the prevalence of AMR Escherichia coli from select drinking water sources in northern Tanzania. Water samples (n = 155) were collected and plated onto Hi-Crome E. coli and MacConkey agar. Presumptive E. coli were confirmed by using a uidA PCR assay. Antibiotic susceptibility breakpoint assays were used to determine the resistance patterns of each isolate for 10 antibiotics. Isolates were also characterized by select PCR genotyping and macro-restriction digest assays. E. coli was isolated from 71 % of the water samples, and of the 1819 E. coli tested, 46.9 % were resistant to one or more antibiotics. Resistance to ampicillin, streptomycin, sulfamethoxazole, tetracycline, and trimethoprim was significantly higher (15-30 %) compared to other tested antibiotics (0-6 %; P < 0.05). Of the β-lactam-resistant isolates, bla TEM-1 was predominant (67 %) followed by bla CTX-M (17.7 %) and bla SHV-1 (6.0 %). Among the tetracycline-resistant isolates, tet(A) was predominant (57.4 %) followed by tet(B) (24.0 %). E. coli isolates obtained from these water sources were genetically diverse with few matching macro-restriction digest patterns. Water supplies in northern Tanzania may be a source of AMR E. coli for people and animals. Further studies are needed to identify the source of these contaminants and devise effective intervention strategies.

ACQUISITION OF REPRESENTATIVE GROUND WATER QUALITY SAMPLES FOR METALS

EPA Science Inventory

R.S. Kerr Environmental Research Laboratory (RSKERL) personnel have evaluated sampling procedures for the collection of representative, accurate, and reproducible ground water quality samples for metals for the past four years. Intensive sampling research at three different field...

ENHANCED DAPI STAINING FOR CRYPTOSPORIDIUM IN WATER SAMPLES

EPA Science Inventory

The U.S. Environmental Protection Agency's Method 1623 is used to detect and quantify the presence of {ital Cryptosporidium} spp. oocysts in water. The protocol consists of concentrating a sample, staining this concentrate with a fluorescent antibody, and examining the sample mi...

Detection of protozoa in water samples by formalin/ether concentration method.

PubMed

Lora-Suarez, Fabiana; Rivera, Raul; Triviño-Valencia, Jessica; Gomez-Marin, Jorge E

2016-09-01

Methods to detect protozoa in water samples are expensive and laborious. We evaluated the formalin/ether concentration method to detect Giardia sp., Cryptosporidium sp. and Toxoplasma in water. In order to test the properties of the method, we spiked water samples with different amounts of each protozoa (0, 10 and 50 cysts or oocysts) in a volume of 10 L of water. Immunofluorescence assay was used for detection of Giardia and Cryptosporidium. Toxoplasma oocysts were identified by morphology. The mean percent of recovery in 10 repetitions of the entire method, in 10 samples spiked with ten parasites and read by three different observers, were for Cryptosporidium 71.3 ± 12, for Giardia 63 ± 10 and for Toxoplasma 91.6 ± 9 and the relative standard deviation of the method was of 17.5, 17.2 and 9.8, respectively. Intraobserver variation as measured by intraclass correlation coefficient, was fair for Toxoplasma, moderate for Cryptosporidium and almost perfect for Giardia. The method was then applied in 77 samples of raw and drinkable water in three different plant of water treatment. Cryptosporidium was found in 28 of 77 samples (36%) and Giardia in 31 of 77 samples (40%). Theses results identified significant differences in treatment process to reduce the presence of Giardia and Cryptosporidium. In conclusion, the formalin ether method to concentrate protozoa in water is a new alternative for low resources countries, where is urgently need to monitor and follow the presence of theses protozoa in drinkable water. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development and optimization of the determination of pharmaceuticals in water samples by SPE and HPLC with diode-array detection.

PubMed

Pavlović, Dragana Mutavdžić; Ašperger, Danijela; Tolić, Dijana; Babić, Sandra

2013-09-01

This paper describes the development, optimization, and validation of a method for the determination of five pharmaceuticals from different therapeutic classes (antibiotics, anthelmintics, glucocorticoides) in water samples. Water samples were prepared using SPE and extracts were analyzed by HPLC with diode-array detection. The efficiency of 11 different SPE cartridges to extract the investigated compounds from water was tested in preliminary experiments. Then, the pH of the water sample, elution solvent, and sorbent mass were optimized. Except for optimization of the SPE procedure, selection of the optimal HPLC column with different stationary phases from different manufacturers has been performed. The developed method was validated using spring water samples spiked with appropriate concentrations of pharmaceuticals. Good linearity was obtained in the range of 2.4-200 μg/L, depending on the pharmaceutical with the correlation coefficients >0.9930 in all cases, except for ciprofloxacin (0.9866). Also, the method has revealed that low LODs (0.7-3.9 μg/L), good precision (intra- and interday) with RSD below 17% and recoveries above 98% for all pharmaceuticals. The method has been successfully applied to the analysis of production wastewater samples from the pharmaceutical industry. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Minimum and Maximum Times Required to Obtain Representative Suspended Sediment Samples

NASA Astrophysics Data System (ADS)

Gitto, A.; Venditti, J. G.; Kostaschuk, R.; Church, M. A.

2014-12-01

Bottle sampling is a convenient method of obtaining suspended sediment measurements for the development of sediment budgets. While these methods are generally considered to be reliable, recent analysis of depth-integrated sampling has identified considerable uncertainty in measurements of grain-size concentration between grain-size classes of multiple samples. Point-integrated bottle sampling is assumed to represent the mean concentration of suspended sediment but the uncertainty surrounding this method is not well understood. Here we examine at-a-point variability in velocity, suspended sediment concentration, grain-size distribution, and grain-size moments to determine if traditional point-integrated methods provide a representative sample of suspended sediment. We present continuous hour-long observations of suspended sediment from the sand-bedded portion of the Fraser River at Mission, British Columbia, Canada, using a LISST laser-diffraction instrument. Spectral analysis suggests that there are no statistically significant peak in energy density, suggesting the absence of periodic fluctuations in flow and suspended sediment. However, a slope break in the spectra at 0.003 Hz corresponds to a period of 5.5 minutes. This coincides with the threshold between large-scale turbulent eddies that scale with channel width/mean velocity and hydraulic phenomena related to channel dynamics. This suggests that suspended sediment samples taken over a period longer than 5.5 minutes incorporate variability that is larger scale than turbulent phenomena in this channel. Examination of 5.5-minute periods of our time series indicate that ~20% of the time a stable mean value of volumetric concentration is reached within 30 seconds, a typical bottle sample duration. In ~12% of measurements a stable mean was not reached over the 5.5 minute sample duration. The remaining measurements achieve a stable mean in an even distribution over the intervening interval.

Filtration of water-sediment samples for the determination of organic compounds

USGS Publications Warehouse

Sandstrom, Mark W.

1995-01-01

This report describes the equipment and procedures used for on-site filtration of surface-water and ground-water samples for determination of organic compounds. Glass-fiber filters and a positive displacement pumping system are suitable for processing most samples for organic analyses. An optional system that uses disposable in-line membrane filters is suitable for a specific gas chromatography/mass spectrometry, selected-ion monitoring analytical method for determination of organonitrogen herbicides. General procedures to minimize contamination of the samples include preparing a clean workspace at the site, selecting appropriate sample-collection materials, and cleaning of the equipment with detergent, tap water, and methanol.

In-situ pre-concentration through repeated sampling and pyrolysis for ultrasensitive determination of thallium in drinking water by electrothermal atomic absorption spectrometry.

PubMed

Liu, Liwei; Zheng, Huaili; Xu, Bincheng; Xiao, Lang; Chigan, Yong; Zhangluo, Yilan

2018-03-01

In this paper, a procedure for in-situ pre-concentration in graphite furnace by repeated sampling and pyrolysis is proposed for the determination of ultra-trace thallium in drinking water by graphite furnace atomic absorption spectrometry (GF-AAS). Without any other laborious enrichment processes that routinely result in analyte loss and contamination, thallium was directly concentrated in the graphite furnace automatically and subsequently subject to analysis. The effects of several key factors, such as the temperature for pyrolysis and atomization, the chemical modifier, and the repeated sampling times were investigated. Under the optimized conditions, a limit of detection of 0.01µgL -1 was obtained, which fulfilled thallium determination in drinking water by GB 5749-2006 regulated by China. Successful analysis of thallium in certified water samples and drinking water samples was demonstrated, with analytical results in good agreement with the certified values and those by inductively coupled plasma mass spectrometry (ICP-MS), respectively. Routine spike-recovery tests with randomly selected drinking water samples showed satisfactory results of 80-96%. The proposed method is simple and sensitive for screening of ultra-trace thallium in drinking water samples. Copyright © 2017. Published by Elsevier B.V.

Comparison of Niskin vs. in situ approaches for analysis of gene expression in deep Mediterranean Sea water samples

NASA Astrophysics Data System (ADS)

Edgcomb, V. P.; Taylor, C.; Pachiadaki, M. G.; Honjo, S.; Engstrom, I.; Yakimov, M.

2016-07-01

Obtaining an accurate picture of microbial processes occurring in situ is essential for our understanding of marine biogeochemical cycles of global importance. Water samples are typically collected at depth and returned to the sea surface for processing and downstream experiments. Metatranscriptome analysis is one powerful approach for investigating metabolic activities of microorganisms in their habitat and which can be informative for determining responses of microbiota to disturbances such as the Deepwater Horizon oil spill. For studies of microbial processes occurring in the deep sea, however, sample handling, pressure, and other changes during sample recovery can subject microorganisms to physiological changes that alter the expression profile of labile messenger RNA. Here we report a comparison of gene expression profiles for whole microbial communities in a bathypelagic water column sample collected in the Eastern Mediterranean Sea using Niskin bottle sample collection and a new water column sampler for studies of marine microbial ecology, the Microbial Sampler - In Situ Incubation Device (MS-SID). For some taxa, gene expression profiles from samples collected and preserved in situ were significantly different from potentially more stressful Niskin sampling and preservation on deck. Some categories of transcribed genes also appear to be affected by sample handling more than others. This suggests that for future studies of marine microbial ecology, particularly targeting deep sea samples, an in situ sample collection and preservation approach should be considered.

Characterization of Water and CO2 Adsorption by Stores 3A Desiccant Samples Using Thermal Gravimetric Analysis and Fourier Transform Infrared Spectroscopy

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

RIVERA, DION A.; ALAM, M. KATHLEEN; MARTIN, LAURA

2003-02-01

Two lots of manufactured Type 3a zeolite samples were compared by TGA/IR analysis. The first lot, obtained from Davidson Chemical, a commercial vendor, was characterized during the previous study cycle for its water and water-plus-CO{sub 2} uptake in order to determine whether CO{sub 2} uptake prevented water adsorption by the zeolite. It was determined that CO{sub 2} did not hamper water adsorption using the Davidson zeolite. CO{sub 2} was found on the zeolite surface at dewpoints below -40 C, however it was found to be reversibly adsorbed. During the course of the previous studies, chemical analyses revealed that the Davidsonmore » 3a zeolite contained calcium in significant quantities, along with the traditional counterions potassium and sodium. Chemical analysis of a Type 3a zeolite sample retrieved from Kansas City (heretofore referred to as the ''Stores 3a'' sample) indicated that the Stores sample was a more traditional Type 3a zeolite, containing no calcium. TGA/IR studies this year focused on obtaining CO{sub 2} and water absorbance data from the Stores 3a zeolite. Within the Stores 3a sample, CO{sub 2} was found to be reversibly absorbed within the sample, but only at and below -60 C with 5% CO{sub 2} loading. The amount of CO{sub 2} observed eluting from the Stores zeolite at this condition was similar to what was observed from the Davidson zeolite sample but with a greater uncertainty in the measured value. The results of the Stores 3a studies are summarized within this report.« less

Fishing in the Water: Effect of Sampled Water Volume on Environmental DNA-Based Detection of Macroinvertebrates.

PubMed

Mächler, Elvira; Deiner, Kristy; Spahn, Fabienne; Altermatt, Florian

2016-01-05

Accurate detection of organisms is crucial for the effective management of threatened and invasive species because false detections directly affect the implementation of management actions. The use of environmental DNA (eDNA) as a species detection tool is in a rapid development stage; however, concerns about accurate detections using eDNA have been raised. We evaluated the effect of sampled water volume (0.25 to 2 L) on the detection rate for three macroinvertebrate species. Additionally, we tested (depending on the sampled water volume) what amount of total extracted DNA should be screened to reduce uncertainty in detections. We found that all three species were detected in all volumes of water. Surprisingly, however, only one species had a positive relationship between an increased sample volume and an increase in the detection rate. We conclude that the optimal sample volume might depend on the species-habitat combination and should be tested for the system where management actions are warranted. Nevertheless, we minimally recommend sampling water volumes of 1 L and screening at least 14 μL of extracted eDNA for each sample to reduce uncertainty in detections when studying macroinvertebrates in rivers and using our molecular workflow.

Time-weighted average water sampling with a solid-phase microextraction device.

PubMed

Ouyang, Gangfeng; Chen, Yong; Pawliszyn, Janusz

2005-11-15

A fiber-in-needle SPME device was developed and investigated for time-weighted average water sampling. The device was designed so that the overall mass-transfer resistance is contained within the static water inside the needle, which ensures that mass uptake could be predicted with Fick's first law of diffusion and the sampling rate is less affected by water turbulence. The device possesses all of the advantages of commercialized devices, in addition to needle filling and replacement ease. Laboratory calibration with deployment of the device to a flow-through system demonstrated that there was a linear mass uptake for up to 12 days, and the linear range could be longer. PDMS coating is assumed to be a perfect zero sink for most polycyclic aromatic hydrocarbons, except naphthalene. The effect of water temperature was also investigated. Under normal field conditions, the change of mass uptake rate with temperature was negligible. To facilitate the convenience for long-term water sampling, a new standard aqueous generator was introduced. This study extended the application of SPME technology for long-term water sampling.

Evaluation of the methods for enumerating coliform bacteria from water samples using precise reference standards.

PubMed

Wohlsen, T; Bates, J; Vesey, G; Robinson, W A; Katouli, M

2006-04-01

To use BioBall cultures as a precise reference standard to evaluate methods for enumeration of Escherichia coli and other coliform bacteria in water samples. Eight methods were evaluated including membrane filtration, standard plate count (pour and spread plate methods), defined substrate technology methods (Colilert and Colisure), the most probable number method and the Petrifilm disposable plate method. Escherichia coli and Enterobacter aerogenes BioBall cultures containing 30 organisms each were used. All tests were performed using 10 replicates. The mean recovery of both bacteria varied with the different methods employed. The best and most consistent results were obtained with Petrifilm and the pour plate method. Other methods either yielded a low recovery or showed significantly high variability between replicates. The BioBall is a very suitable quality control tool for evaluating the efficiency of methods for bacterial enumeration in water samples.

Arsenic-related water quality with depth and water quality of well-head samples from production wells, Oklahoma, 2008

USGS Publications Warehouse

Becker, Carol J.; Smith, S. Jerrod; Greer, James R.; Smith, Kevin A.

2010-01-01

The U.S. Geological Survey well profiler was used to describe arsenic-related water quality with well depth and identify zones yielding water with high arsenic concentrations in two production wells in central and western Oklahoma that yield water from the Permian-aged Garber-Wellington and Rush Springs aquifers, respectively. In addition, well-head samples were collected from 12 production wells yielding water with historically large concentrations of arsenic (greater than 10 micrograms per liter) from the Garber-Wellington aquifer, Rush Springs aquifer, and two minor aquifers: the Arbuckle-Timbered Hills aquifer in southern Oklahoma and a Permian-aged undefined aquifer in north-central Oklahoma. Three depth-dependent samples from a production well in the Rush Springs aquifer had similar water-quality characteristics to the well-head sample and did not show any substantial changes with depth. However, slightly larger arsenic concentrations in the two deepest depth-dependent samples indicate the zones yielding noncompliant arsenic concentrations are below the shallowest sampled depth. Five depth-dependent samples from a production well in the Garber-Wellington aquifer showed increases in arsenic concentrations with depth. Well-bore travel-time information and water-quality data from depth-dependent and well-head samples showed that most arsenic contaminated water (about 63 percent) was entering the borehole from perforations adjacent to or below the shroud that overlaid the pump. Arsenic concentrations ranged from 10.4 to 124 micrograms per liter in 11 of the 12 production wells sampled at the well head, exceeding the maximum contaminant level of 10 micrograms per liter for drinking water. pH values of the 12 well-head samples ranged from 6.9 to 9. Seven production wells in the Garber-Wellington aquifer had the largest arsenic concentrations ranging from 18.5 to 124 micrograms per liter. Large arsenic concentrations (10.4-18.5) and near neutral to slightly alkaline

Effect of water quality sampling time and frequency on storm load predictions of a prominent regression-based model

USDA-ARS?s Scientific Manuscript database

High frequency in situ measurements of nitrate can greatly reduce the uncertainty in nitrate flux estimates. Water quality databases maintained by various federal and state agencies often consist of pollutant concentration data obtained from periodic grab samples collected from gauged reaches of a s...

Presence of Cryptosporidium parvum and Giardia lamblia in water samples from Southeast Asia: towards an integrated water detection system.

PubMed

Kumar, Thulasi; Abd Majid, Mohamad Azlan; Onichandran, Subashini; Jaturas, Narong; Andiappan, Hemah; Salibay, Cristina C; Tabo, Hazel A L; Tabo, Norbel; Dungca, Julieta Z; Tangpong, Jitbanjong; Phiriyasamith, Sucheep; Yuttayong, Boonyaorn; Polseela, Raxsina; Do, Binh Nhu; Sawangjaroen, Nongyao; Tan, Tian-Chye; Lim, Yvonne A L; Nissapatorn, Veeranoot

2016-01-13

Access to clean and safe drinking water that is free from pathogenic protozoan parasites, especially Cryptosporidium parvum and Giardia lamblia that cause gastrointestinal illness in humans, is still an issue in Southeast Asia (SEA). This study is the first attempt to detect the aforementioned protozoan parasites in water samples from countries in SEA, using real-time polymerase chain reaction (qPCR) assays. A total of 221 water samples of 10 l each were collected between April and October 2013 from Malaysia (53), Thailand (120), the Philippines (33), and Vietnam (15). A physicochemical analysis was conducted. The water samples were processed in accordance with the US Environmental Protection Agency's methods 1622/1623.1, microscopically observed and subsequently screened using qPCR assays. Cryptosporidium oocysts were detected in treated water samples from the Philippines (1/10), with a concentration of 0.06 ± 0.19 oocyst/L, and untreated water samples from Thailand (25/93), Malaysia (17/44), and the Philippines (11/23), with concentrations ranging from 0.13 ± 0.18 to 0.57 ± 1.41 oocyst/L. Giardia cysts were found in treated water samples from the Philippines (1/10), with a concentration of 0.02 ± 0.06 cyst/L, and in untreated water samples from Thailand (20/93), Vietnam (5/10), Malaysia (22/44), and the Philippines (16/23), with concentrations ranging from 0.12 ± 0.3 to 8.90 ± 19.65 cyst/L. The pathogens C. parvum and G. lamblia were detected using using qPCR assays by targeting the 138-bp fragment and the small subunit gene, respectively. C. parvum was detected in untreated water samples from the Philippines (1/23) and Malaysia (2/44), whilst, G. lamblia detected was detected in treated water samples from the Philippines (1/10) and in untreated water samples from Thailand (21/93), Malaysia (12/44), and the Philippines (17/23). Nitrate concentration was found to have a high positive correlation with (oo)cyst (0.993). The presence of

Laser based water equilibration method for d18O determination of water samples

NASA Astrophysics Data System (ADS)

Mandic, Magda; Smajgl, Danijela; Stoebener, Nils

2017-04-01

Determination of d18O with water equilibration method using mass spectrometers equipped with equilibration unit or Gas Bench is known already for many years. Now, with development of laser spectrometers this extends methods and possibilities to apply different technologies in laboratory but also in the field. The Thermo Scientific™ Delta Ray™ Isotope Ratio Infrared Spectrometer (IRIS) analyzer with the Universal Reference Interface (URI) Connect and Teledyne Cetac ASX-7100 offers high precision and throughput of samples. It employs optical spectroscopy for continuous measurement of isotope ratio values and concentration of carbon dioxide in ambient air, and also for analysis of discrete samples from vials, syringes, bags, or other user-provided sample containers. Test measurements and conformation of precision and accuracy of method determination d18O in water samples were done in Thermo Fisher application laboratory with three lab standards, namely ANST, Ocean II and HBW. All laboratory standards were previously calibrated with international reference material VSMOW2 and SLAP2 to assure accuracy of the isotopic values of the water. With method that we present in this work achieved repeatability and accuracy are 0.16‰ and 0.71‰, respectively, which fulfill requirements of regulatory method for wine and must after equilibration with CO2.

Sampling and Chemical Analysis of Potable Water for ISS Expeditions 12 and 13

NASA Technical Reports Server (NTRS)

Straub, John E. II; Plumlee, Deborah K.; Schultz, John R.

2007-01-01

The crews of Expeditions 12 and 13 aboard the International Space Station (ISS) continued to rely on potable water from two different sources, regenerated humidity condensate and Russian ground-supplied water. The Space Shuttle launched twice during the 12- months spanning both expeditions and docked with the ISS for delivery of hardware and supplies. However, no Shuttle potable water was transferred to the station during either of these missions. The chemical quality of the ISS onboard potable water supplies was verified by performing ground analyses of archival water samples at the Johnson Space Center (JSC) Water and Food Analytical Laboratory (WAFAL). Since no Shuttle flights launched during Expedition 12 and there was restricted return volume on the Russian Soyuz vehicle, only one chemical archive potable water sample was collected with U.S. hardware and returned during Expedition 12. This sample was collected in March 2006 and returned on Soyuz 11. The number and sensitivity of the chemical analyses performed on this sample were limited due to low sample volume. Shuttle flights STS-121 (ULF1.1) and STS-115 (12A) docked with the ISS in July and September of 2006, respectively. These flights returned to Earth with eight chemical archive potable water samples that were collected with U.S. hardware during Expedition 13. The average collected volume increased for these samples, allowing full chemical characterization to be performed. This paper presents a discussion of the results from chemical analyses performed on Expeditions 12 and 13 archive potable water samples. In addition to the results from the U.S. samples analyzed, results from pre-flight samples of Russian potable water delivered to the ISS on Progress vehicles and in-flight samples collected with Russian hardware during Expeditions 12 and 13 and analyzed at JSC are also discussed.

Validation of internal controls for extraction and amplification of nucleic acids from enteric viruses in water samples.

PubMed

Hata, Akihiko; Katayama, Hiroyuki; Kitajima, Masaaki; Visvanathan, Chettiyappan; Nol, Chea; Furumai, Hiroaki

2011-07-01

Inhibitors that reduce viral nucleic acid extraction efficiency and interfere with cDNA synthesis and/or polymerase activity affect the molecular detection of viruses in aquatic environments. To overcome these significant problems, we developed a methodology for assessing nucleic acid yields and DNA amplification efficiencies for environmental water samples. This involved adding particles of adenovirus type 5 and murine norovirus and newly developed primer-sharing controls, which are amplified with the same primer pairs and result in the same amplicon sizes as the targets, to these samples. We found that nucleic acid loss during the extraction process, rather than reverse transcription-PCR (RT-PCR) inhibition, more significantly attributed to underestimation of the presence of viral genomes in the environmental water samples tested in this study. Our success rate for satisfactorily amplifying viral RNAs and DNAs by RT-PCR was higher than that for obtaining adequate nucleic acid preparations. We found that inhibitory properties were greatest when we used larger sample volumes. A magnetic silica bead-based RNA extraction method effectively removed inhibitors that interfere with viral nucleic acid extraction and RT-PCR. To our knowledge, this is the first study to assess the inhibitory properties of environmental water samples by using both control virus particles and primer-sharing controls.

Pesticide-sampling equipment, sample-collection and processing procedures, and water-quality data at Chicod Creek, North Carolina, 1992

USGS Publications Warehouse

Manning, T.K.; Smith, K.E.; Wood, C.D.; Williams, J.B.

1994-01-01

Water-quality samples were collected from Chicod Creek in the Coastal Plain Province of North Carolina during the summer of 1992 as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Chicod Creek is in the Albemarle-Pamlico drainage area, one of four study units designated to test equipment and procedures for collecting and processing samples for the solid-phase extraction of selected pesticides, The equipment and procedures were used to isolate 47 pesticides, including organonitrogen, carbamate, organochlorine, organophosphate, and other compounds, targeted to be analyzed by gas chromatography/mass spectrometry. Sample-collection and processing equipment equipment cleaning and set-up procedures, methods pertaining to collecting, splitting, and solid-phase extraction of samples, and water-quality data resulting from the field test are presented in this report Most problems encountered during this intensive sampling exercise were operational difficulties relating to equipment used to process samples.

A Small Diameter Rosette for Sampling Ice Covered Waters

NASA Astrophysics Data System (ADS)

Chayes, D. N.; Smethie, W. M.; Perry, R. S.; Schlosser, P.; Friedrich, R.

2011-12-01

A gas tight, small diameter, lightweight rosette, supporting equipment and an effective operational protocol has been developed for aircraft supported sampling of sea water across the Lincoln Sea. The system incorporates a commercial off the shelf CTD electronics (SBE19+ sensor package and SBE33 deck unit) to provide real-time measurement data at the surface. We designed and developed modular water sample units and custom electronics to decode the bottle firing commands and close the sample bottles. For a typical station, we land a ski-equipped deHaviland Twin Otter (DHC-6) aircraft on a suitable piece of sea-ice, drill a 12" diameter hole through the ice next to the cargo door and set up a tent to provide a reasonable working environment over the hole. A small winch with 0.1" diameter single conductor cable is mounted in the aircraft by the cargo door and a tripod supports a sheave above the hole. The CTD module is connected to the end of the wire and the water sampling modules are stacked on top as the system is lowered. For most stations, three sample modules are used to provide 12 four (4) liter sample bottles. Data collected during the down-cast is used to formulate the sampling plan which is executed on the up-cast. The system is powered by a 3,700 Watt, 120VAC gasoline generator. After collection, the sample modules are stored in passively temperature stabilized ice chests during the flight back to the logistics facility at Alert where a broad range of samples are drawn and stored for future analysis. The transport mechanism has a good track record of maintaining water samples within about two degrees of the original collection temperature which minimizes out-gassing. The system has been successfully deployed during a field program each spring starting in 2004 along a transect between the north end of Ellesmere Island (Alert, Nunavut) and the North Pole. During the eight field programs we have taken 48 stations with twelve bottles at most stations (eight at

Analytical techniques for steroid estrogens in water samples - A review.

PubMed

Fang, Ting Yien; Praveena, Sarva Mangala; deBurbure, Claire; Aris, Ahmad Zaharin; Ismail, Sharifah Norkhadijah Syed; Rasdi, Irniza

2016-12-01

In recent years, environmental concerns over ultra-trace levels of steroid estrogens concentrations in water samples have increased because of their adverse effects on human and animal life. Special attention to the analytical techniques used to quantify steroid estrogens in water samples is therefore increasingly important. The objective of this review was to present an overview of both instrumental and non-instrumental analytical techniques available for the determination of steroid estrogens in water samples, evidencing their respective potential advantages and limitations using the Need, Approach, Benefit, and Competition (NABC) approach. The analytical techniques highlighted in this review were instrumental and non-instrumental analytical techniques namely gas chromatography mass spectrometry (GC-MS), liquid chromatography mass spectrometry (LC-MS), enzyme-linked immuno sorbent assay (ELISA), radio immuno assay (RIA), yeast estrogen screen (YES) assay, and human breast cancer cell line proliferation (E-screen) assay. The complexity of water samples and their low estrogenic concentrations necessitates the use of highly sensitive instrumental analytical techniques (GC-MS and LC-MS) and non-instrumental analytical techniques (ELISA, RIA, YES assay and E-screen assay) to quantify steroid estrogens. Both instrumental and non-instrumental analytical techniques have their own advantages and limitations. However, the non-instrumental ELISA analytical techniques, thanks to its lower detection limit and simplicity, its rapidity and cost-effectiveness, currently appears to be the most reliable for determining steroid estrogens in water samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

New kinetic-spectrophotometric method for monitoring the concentration of iodine in river and city water samples.

PubMed

Farmany, A; Khosravi, A; Abbasi, S; Cheraghi, J; Hushmandfar, R; Sobhanardakani, S; Noorizadeh, H; Mortazavi, S S

2013-01-01

A new kinetic method has been developed for the determination of iodine in water samples. The method is based on the catalytic effect of I(-) with the oxidation of Indigo Carmine (IC) by KBrO(3) in the sulfuric acid medium. The optimum conditions obtained are 0.16 M sulfuric acid, 1 × 10(-3) M of IC, 1 × 10(-2) M KBrO(3), reaction temperature of 35°C, and reaction time of 80 s at 612 nm. Under the optimized conditions, the method allowed the quantification of I(-) in a range of 12-375 ng/mL with a detection limit of 0.46 ng/mL. The method was applied to the determination of iodine in river and city water samples with the satisfactorily results.

Polymeric ionic liquid-based portable tip microextraction device for on-site sample preparation of water samples.

PubMed

Chen, Lei; Pei, Junxian; Huang, Xiaojia; Lu, Min

2018-06-05

On-site sample preparation is highly desired because it avoids the transportation of large-volume samples and ensures the accuracy of the analytical results. In this work, a portable prototype of tip microextraction device (TMD) was designed and developed for on-site sample pretreatment. The assembly procedure of TMD is quite simple. Firstly, polymeric ionic liquid (PIL)-based adsorbent was in-situ prepared in a pipette tip. After that, the tip was connected with a syringe which was driven by a bidirectional motor. The flow rates in adsorption and desorption steps were controlled accurately by the motor. To evaluate the practicability of the developed device, the TMD was used to on-site sample preparation of waters and combined with high-performance liquid chromatography with diode array detection to measure trace estrogens in water samples. Under the most favorable conditions, the limits of detection (LODs, S/N = 3) for the target analytes were in the range of 4.9-22 ng/L, with good coefficients of determination. Confirmatory study well evidences that the extraction performance of TMD is comparable to that of the traditional laboratory solid-phase extraction process, but the proposed TMD is more simple and convenient. At the same time, the TMD avoids complicated sampling and transferring steps of large-volume water samples. Copyright © 2018 Elsevier B.V. All rights reserved.

Water-quality assessment of south-central Texas : comparison of water quality in surface-water samples collected manually and by automated samplers

USGS Publications Warehouse

Ging, Patricia B.

1999-01-01

Surface-water sampling protocols of the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program specify samples for most properties and constituents to be collected manually in equal-width increments across a stream channel and composited for analysis. Single-point sampling with an automated sampler (autosampler) during storms was proposed in the upper part of the South-Central Texas NAWQA study unit, raising the question of whether property and constituent concentrations from automatically collected samples differ significantly from those in samples collected manually. Statistical (Wilcoxon signed-rank test) analyses of 3 to 16 paired concentrations for each of 26 properties and constituents from water samples collected using both methods at eight sites in the upper part of the study unit indicated that there were no significant differences in concentrations for dissolved constituents, other than calcium and organic carbon.

Determination of Organothiophosphate Insecticides in Environmental Water Samples by a Very Simple and Sensitive Spectrofluorimetric Method.

PubMed

Bavili Tabrizi, Ahad; Abdollahi, Ali

2015-10-01

A simple, rapid and sensitive spectrofluorimetric method was developed for the determination of di-syston, ethion and phorate in environmental water samples. The procedure is based on the oxidation of these pesticides with cerium (IV) to produce cerium (III), and its fluorescence was monitored at 368 ± 3 nm after excitation at 257 ± 3 nm. The variables effecting oxidation of each pesticide were studied and optimized. Under the experimental conditions used, the calibration graphs were linear over the range 0.2-15, 0.1-13, 0.1-13 ng mL(-1) for di-syston, ethion and phorate, respectively. The limit of detection and quantification were in the range 0.034-0.096 and 0.112-0.316 ng mL(-1), respectively. Intra- and inter-day assay precisions, expressed as the relative standard deviation (RSD), were lower than 5.2 % and 6.7 %, respectively. Good recoveries in the range 86 %-108 % were obtained for spiked water samples. The proposed method was applied to the determination of studied pesticides in environmental water samples.

Process and apparatus for obtaining samples of liquid and gas from soil

DOEpatents

Rossabi, J.; May, C.P.; Pemberton, B.E.; Shinn, J.; Sprague, K.

1999-03-30

An apparatus and process for obtaining samples of liquid and gas from subsurface soil is provided having filter zone adjacent an external expander ring. The expander ring creates a void within the soil substrate which encourages the accumulation of soil-borne fluids. The fluids migrate along a pressure gradient through a plurality of filters before entering a first chamber. A one-way valve regulates the flow of fluid into a second chamber in further communication with a collection tube through which samples are collected at the surface. A second one-way valve having a reverse flow provides additional communication between the chambers for the pressurized cleaning and back-flushing of the apparatus. 8 figs.

Process and apparatus for obtaining samples of liquid and gas from soil

DOEpatents

Rossabi, Joseph; May, Christopher P.; Pemberton, Bradley E.; Shinn, Jim; Sprague, Keith

1999-01-01

An apparatus and process for obtaining samples of liquid and gas from subsurface soil is provided having filter zone adjacent an external expander ring. The expander ring creates a void within the soil substrate which encourages the accumulation of soil-borne fluids. The fluids migrate along a pressure gradient through a plurality of filters before entering a first chamber. A one-way valve regulates the flow of fluid into a second chamber in further communication with a collection tube through which samples are collected at the surface. A second one-way valve having a reverse flow provides additional communication between the chambers for the pressurized cleaning and back-flushing of the apparatus.

Adaptive Water Sampling based on Unsupervised Clustering

NASA Astrophysics Data System (ADS)

Py, F.; Ryan, J.; Rajan, K.; Sherman, A.; Bird, L.; Fox, M.; Long, D.

2007-12-01

Autonomous Underwater Vehicles (AUVs) are widely used for oceanographic surveys, during which data is collected from a number of on-board sensors. Engineers and scientists at MBARI have extended this approach by developing a water sampler specialy for the AUV, which can sample a specific patch of water at a specific time. The sampler, named the Gulper, captures 2 liters of seawater in less than 2 seconds on a 21" MBARI Odyssey AUV. Each sample chamber of the Gulper is filled with seawater through a one-way valve, which protrudes through the fairing of the AUV. This new kind of device raises a new problem: when to trigger the gulper autonomously? For example, scientists interested in studying the mobilization and transport of shelf sediments would like to detect intermediate nepheloïd layers (INLs). To be able to detect this phenomenon we need to extract a model based on AUV sensors that can detect this feature in-situ. The formation of such a model is not obvious as identification of this feature is generally based on data from multiple sensors. We have developed an unsupervised data clustering technique to extract the different features which will then be used for on-board classification and triggering of the Gulper. We use a three phase approach: 1) use data from past missions to learn the different classes of data from sensor inputs. The clustering algorithm will then extract the set of features that can be distinguished within this large data set. 2) Scientists on shore then identify these features and point out which correspond to those of interest (e.g. nepheloïd layer, upwelling material etc) 3) Embed the corresponding classifier into the AUV control system to indicate the most probable feature of the water depending on sensory input. The triggering algorithm looks to this result and triggers the Gulper if the classifier indicates that we are within the feature of interest with a predetermined threshold of confidence. We have deployed this method of online

Representation of solid and nutrient concentrations in irrigation water from tailwater recovery systems by surface water grab samples

USDA-ARS?s Scientific Manuscript database

Tailwater recovery (TWR) systems are being implemented on agricultural landscapes to create an additional source of irrigation water. Existing studies have sampled TWR systems using grab samples; however, the applicability of solids and nutrient concentrations in these samples to water being irrigat...

EPA GROUND WATER ISSUE: Ground Water Sample Preservation at ISCO Sites – Recommended Guidelines

EPA Science Inventory

In-situ chemical oxidation (ISCO) involves the introduction of a chemical oxidant into the subsurface for the purpose of transforming ground water contaminants into harmless byproducts. Due to oxidant persistence, ground water samples collected at hazardous waste sites may contai...

Bacterial contamination of water samples in Gabon, 2013.

PubMed

Ehrhardt, Jonas; Alabi, Abraham S; Kremsner, Peter G; Rabsch, Wolfgang; Becker, Karsten; Foguim, Francis Tsombeng; Kuczius, Thorsten; Esen, Meral; Schaumburg, Frieder

2017-10-01

Contamination of water is a major burden in the public health setting of developing countries. We therefore assessed the quality of water samples in Gabon in 2013. The main findings were a contamination rate with coliforms of 13.5% and the detection of a possible environmental reservoir for extended spectrum beta-lactamase-producing bacteria. Copyright © 2016. Published by Elsevier B.V.

Evaluation of various soil water samplers for virological sampling.

PubMed Central

Wang, D S; Lance, J C; Gerba, C P

1980-01-01

Two commercially available soil water samplers and a ceramic sampler constructed in our laboratories were evaluated for their ability to recover viruses from both tap water and secondary sewage effluent. The ceramic sampler consistently gave the best recoveries of viruses from water samples. Soil columns containing ceramic samplers at various depths provide a simple method for studying virus transport through sewage-contaminated soils. Images PMID:6247976

Well installation and documentation, and ground-water sampling protocols for the pilot National Water-Quality Assessment Program

USGS Publications Warehouse

Hardy, M.A.; Leahy, P.P.; Alley, W.M.

1989-01-01

Several pilot projects are being conducted as part of the National Water Quality Assessment (NAWQA) Program. The purpose of the pilot program is to test and refine concepts for a proposed full-scale program. Three of the pilot projects are specifically designed to assess groundwater. The purpose of this report is to describe the criteria that are being used in the NAWQA pilot projects for selecting and documenting wells, installing new wells, and sampling wells for different water quality constituents. Guidelines are presented for the selection of wells for sampling. Information needed to accurately document each well includes site characteristics related to the location of the well, land use near the well, and important well construction features. These guidelines ensure the consistency of the information collected and will provide comparable data for interpretive purposes. Guidelines for the installation of wells are presented and include procedures that need to be followed for preparations prior to drilling, the selection of the drilling technique and casing type, the grouting procedure, and the well-development technique. A major component of the protocols is related to water quality sampling. Tasks are identified that need to be completed prior to visiting the site for sampling. Guidelines are presented for purging the well prior t sampling, both in terms of the volume of water pumped and the chemical stability of field parameters. Guidelines are presented concerning sampler selection as related to both inorganic and organic constituents. Documentation needed to describe the measurements and observations related to sampling each well and treating and preserving the samples are also presented. Procedures are presented for the storage and shipping of water samples, equipment cleaning, and quality assurance. Quality assurance guidelines include the description of the general distribution of the various quality assurance samples (blanks, spikes, duplicates, and

Mutagenicity of drinking water sampled from the Yangtze River and Hanshui River (Wuhan section) and correlations with water quality parameters.

PubMed

Lv, Xuemin; Lu, Yi; Yang, Xiaoming; Dong, Xiaorong; Ma, Kunpeng; Xiao, Sanhua; Wang, Yazhou; Tang, Fei

2015-03-31

A total of 54 water samples were collected during three different hydrologic periods (level period, wet period, and dry period) from Plant A and Plant B (a source for Yangtze River and Hanshui River water, respectively), and several water parameters, such as chemical oxygen demand (COD), turbidity, and total organic carbon (TOC), were simultaneously analyzed. The mutagenicity of the water samples was evaluated using the Ames test with Salmonella typhimurium strains TA98 and TA100. According to the results, the organic compounds in the water were largely frame-shift mutagens, as positive results were found for most of the tests using TA98. All of the finished water samples exhibited stronger mutagenicity than the relative raw and distribution water samples, with water samples collected from Plant B presenting stronger mutagenic strength than those from Plant A. The finished water samples from Plant A displayed a seasonal-dependent variation. Water parameters including COD (r = 0.599, P = 0.009), TOC (r = 0.681, P = 0.02), UV254 (r = 0.711, P = 0.001), and total nitrogen (r = 0.570, P = 0.014) exhibited good correlations with mutagenicity (TA98), at 2.0 L/plate, which bolsters the argument of the importance of using mutagenicity as a new parameter to assess the quality of drinking water.

Mutagenicity of drinking water sampled from the Yangtze River and Hanshui River (Wuhan section) and correlations with water quality parameters

PubMed Central

Lv, Xuemin; Lu, Yi; Yang, Xiaoming; Dong, Xiaorong; Ma, Kunpeng; Xiao, Sanhua; Wang, Yazhou; Tang, Fei

2015-01-01

A total of 54 water samples were collected during three different hydrologic periods (level period, wet period, and dry period) from Plant A and Plant B (a source for Yangtze River and Hanshui River water, respectively), and several water parameters, such as chemical oxygen demand (COD), turbidity, and total organic carbon (TOC), were simultaneously analyzed. The mutagenicity of the water samples was evaluated using the Ames test with Salmonella typhimurium strains TA98 and TA100. According to the results, the organic compounds in the water were largely frame-shift mutagens, as positive results were found for most of the tests using TA98. All of the finished water samples exhibited stronger mutagenicity than the relative raw and distribution water samples, with water samples collected from Plant B presenting stronger mutagenic strength than those from Plant A. The finished water samples from Plant A displayed a seasonal-dependent variation. Water parameters including COD (r = 0.599, P = 0.009), TOC (r = 0.681, P = 0.02), UV254 (r = 0.711, P = 0.001), and total nitrogen (r = 0.570, P = 0.014) exhibited good correlations with mutagenicity (TA98), at 2.0 L/plate, which bolsters the argument of the importance of using mutagenicity as a new parameter to assess the quality of drinking water. PMID:25825837

Classification and authentication of unknown water samples using machine learning algorithms.

PubMed

Kundu, Palash K; Panchariya, P C; Kundu, Madhusree

2011-07-01

This paper proposes the development of water sample classification and authentication, in real life which is based on machine learning algorithms. The proposed techniques used experimental measurements from a pulse voltametry method which is based on an electronic tongue (E-tongue) instrumentation system with silver and platinum electrodes. E-tongue include arrays of solid state ion sensors, transducers even of different types, data collectors and data analysis tools, all oriented to the classification of liquid samples and authentication of unknown liquid samples. The time series signal and the corresponding raw data represent the measurement from a multi-sensor system. The E-tongue system, implemented in a laboratory environment for 6 numbers of different ISI (Bureau of Indian standard) certified water samples (Aquafina, Bisleri, Kingfisher, Oasis, Dolphin, and McDowell) was the data source for developing two types of machine learning algorithms like classification and regression. A water data set consisting of 6 numbers of sample classes containing 4402 numbers of features were considered. A PCA (principal component analysis) based classification and authentication tool was developed in this study as the machine learning component of the E-tongue system. A proposed partial least squares (PLS) based classifier, which was dedicated as well; to authenticate a specific category of water sample evolved out as an integral part of the E-tongue instrumentation system. The developed PCA and PLS based E-tongue system emancipated an overall encouraging authentication percentage accuracy with their excellent performances for the aforesaid categories of water samples. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

Gritty Surface Sample Holder Invented To Obtain Correct X-ray Absorption Fine Structure Spectra for Concentrated Materials by Fluorescence Yield.

PubMed

Abe, Hitoshi; Niwa, Yasuhiro; Kimura, Masao; Murakami, Youichi; Yokoyama, Toshiharu; Hosono, Hideo

2016-04-05

A gritty surface sample holder has been invented to obtain correct XAFS spectra for concentrated samples by fluorescence yield (FY). Materials are usually mixed with boron nitride (BN) to prepare proper concentrations to measure XAFS spectra. Some materials, however, could not be mixed with BN and would be measured in too concentrated conditions to obtain correct XAFS spectra. Consequently, XAFS spectra will be incorrect typically with decreased intensities of the peaks. We have invented the gritty surface sample holders to obtain correct XAFS spectra even for concentrated materials for FY measurements. Pure Cu and CuO powders were measured mounted on the sample holders, and the same spectra were obtained as transmission spectra of properly prepared samples. This sample holder is useful to measure XAFS for any concentrated materials.

Comparison of Barium and Arsenic Concentrations in Well Drinking Water and in Human Body Samples and a Novel Remediation System for These Elements in Well Drinking Water.

PubMed

Kato, Masashi; Kumasaka, Mayuko Y; Ohnuma, Shoko; Furuta, Akio; Kato, Yoko; Shekhar, Hossain U; Kojima, Michiyo; Koike, Yasuko; Dinh Thang, Nguyen; Ohgami, Nobutaka; Ly, Thuy Bich; Jia, Xiaofang; Yetti, Husna; Naito, Hisao; Ichihara, Gaku; Yajima, Ichiro

2013-01-01

Health risk for well drinking water is a worldwide problem. Our recent studies showed increased toxicity by exposure to barium alone (≤700 µg/L) and coexposure to barium (137 µg/L) and arsenic (225 µg/L). The present edition of WHO health-based guidelines for drinking water revised in 2011 has maintained the values of arsenic (10 µg/L) and barium (700 µg/L), but not elements such as manganese, iron and zinc. Nevertheless, there have been very few studies on barium in drinking water and human samples. This study showed significant correlations between levels of arsenic and barium, but not its homologous elements (magnesium, calcium and strontium), in urine, toenail and hair samples obtained from residents of Jessore, Bangladesh. Significant correlation between levels of arsenic and barium in well drinking water and levels in human urine, toenail and hair samples were also observed. Based on these results, a high-performance and low-cost adsorbent composed of a hydrotalcite-like compound for barium and arsenic was developed. The adsorbent reduced levels of barium and arsenic from well water in Bangladesh and Vietnam to <7 µg/L within 1 min. Thus, we have showed levels of arsenic and barium in humans and propose a novel remediation system.

Comparison of Barium and Arsenic Concentrations in Well Drinking Water and in Human Body Samples and a Novel Remediation System for These Elements in Well Drinking Water

PubMed Central

Kato, Masashi; Kumasaka, Mayuko Y.; Ohnuma, Shoko; Furuta, Akio; Kato, Yoko; Shekhar, Hossain U.; Kojima, Michiyo; Koike, Yasuko; Dinh Thang, Nguyen; Ohgami, Nobutaka; Ly, Thuy Bich; Jia, Xiaofang; Yetti, Husna; Naito, Hisao; Ichihara, Gaku; Yajima, Ichiro

2013-01-01

Health risk for well drinking water is a worldwide problem. Our recent studies showed increased toxicity by exposure to barium alone (≤700 µg/L) and coexposure to barium (137 µg/L) and arsenic (225 µg/L). The present edition of WHO health-based guidelines for drinking water revised in 2011 has maintained the values of arsenic (10 µg/L) and barium (700 µg/L), but not elements such as manganese, iron and zinc. Nevertheless, there have been very few studies on barium in drinking water and human samples. This study showed significant correlations between levels of arsenic and barium, but not its homologous elements (magnesium, calcium and strontium), in urine, toenail and hair samples obtained from residents of Jessore, Bangladesh. Significant correlation between levels of arsenic and barium in well drinking water and levels in human urine, toenail and hair samples were also observed. Based on these results, a high-performance and low-cost adsorbent composed of a hydrotalcite-like compound for barium and arsenic was developed. The adsorbent reduced levels of barium and arsenic from well water in Bangladesh and Vietnam to <7 µg/L within 1 min. Thus, we have showed levels of arsenic and barium in humans and propose a novel remediation system. PMID:23805262

New porous water ice metastable at atmospheric pressure obtained by emptying a hydrogen-filled ice

PubMed Central

del Rosso, Leonardo; Celli, Milva; Ulivi, Lorenzo

2016-01-01

The properties of some forms of water ice reserve still intriguing surprises. Besides the several stable or metastable phases of pure ice, solid mixtures of water with gases are precursors of other ices, as in some cases they may be emptied, leaving a metastable hydrogen-bound water structure. We present here the first characterization of a new form of ice, obtained from the crystalline solid compound of water and molecular hydrogen called C0-structure filled ice. By means of Raman spectroscopy, we measure the hydrogen release at different temperatures and succeed in rapidly removing all the hydrogen molecules, obtaining a new form of ice (ice XVII). Its structure is determined by means of neutron diffraction measurements. Of paramount interest is that the emptied crystal can adsorb again hydrogen and release it repeatedly, showing a temperature-dependent hysteresis. PMID:27819265

Impact of Oxidant Residuals on Ground Water Samples at ISCO Sites: Recommended Guidelines for Sample Preservation

EPA Science Inventory

In-situ chemical oxidation (ISCO) involves the introduction of a chemical oxidant into the subsurface for the purpose of transforming ground water contaminants into less toxic or harmless byproducts. Due to oxidant persistence, ground water samples collected at hazardous waste si...

Direct measurement of toxicants inhaled by water pipe users in the natural environment using a real-time in situ sampling technique.

PubMed

Katurji, M; Daher, N; Sheheitli, H; Saleh, R; Shihadeh, A

2010-11-01

While narghile water pipe smoking has become a global phenomenon, knowledge regarding its toxicant content and delivery, addictive properties, and health consequences is sorely lagging. One challenge in measuring toxicant content of the smoke in the laboratory is the large number of simplifying assumptions that must be made to model a "typical" smoking session using a smoking machine, resulting in uncertainty over the obtained toxicant yields. In this study, we develop an alternative approach in which smoke generated by a human water pipe user is sampled directly during the smoking session. The method, dubbed real-time in situ sampling (RINS), required developing a self-powered portable instrument capable of automatically sampling a fixed fraction of the smoke generated by the user. Instrument performance was validated in the laboratory, and the instrument was deployed in a field study involving 43 ad libitum water pipe use sessions in Beirut area cafés in which we measured inhaled nicotine, carbon monoxide (CO), and water pipe ma'ssel-derived "tar." We found that users drew a mean of 119 L of smoke containing 150 mg of CO, 4 mg of nicotine, and 602 mg of ma'ssel-derived "tar" during a single use session (mean duration = 61 min). These first direct measurements of toxicant delivery demonstrate that ordinary water pipe use involves inhaling large quantities of CO, nicotine, and dry particulate matter. Results are compared with those obtained using the Beirut method smoking machine protocol.

GROUND WATER PURGING AND SAMPLING METHODS: HISTORY VS. HYSTERIA

EPA Science Inventory

It has been over 10 years since the low-flow ground water purging and sampling method was initially reported in the literature. The method grew from the recognition that well purging was necessary to collect representative samples, bailers could not achieve well purging, and high...

Procedures for Handling and Chemical Analysis of Sediment and Water Samples,

DTIC Science & Technology

1981-05-01

silts. Particularly suitable for studies of the sediment/ water interface, for studies on depositonal sediment structures. Al pi ne- ravity Cores of 2 m...adverse water quality impacts would occur. Elemental partitioning or sedimentation fractionation studies are the most complex of the tests considered...8217 water %nd blend the core or dredge sample. Place a{js roximalel-i 00 cc of’ the blended sample in an oxygen-free, poly - ca rbor’~ [ ’-l centrifuge bottle

A new method of snowmelt sampling for water stable isotopes

USGS Publications Warehouse

Penna, D.; Ahmad, M.; Birks, S. J.; Bouchaou, L.; Brencic, M.; Butt, S.; Holko, L.; Jeelani, G.; Martinez, D. E.; Melikadze, G.; Shanley, J.B.; Sokratov, S. A.; Stadnyk, T.; Sugimoto, A.; Vreca, P.

2014-01-01

We modified a passive capillary sampler (PCS) to collect snowmelt water for isotopic analysis. Past applications of PCSs have been to sample soil water, but the novel aspect of this study was the placement of the PCSs at the ground-snowpack interface to collect snowmelt. We deployed arrays of PCSs at 11 sites in ten partner countries on five continents representing a range of climate and snow cover worldwide. The PCS reliably collected snowmelt at all sites and caused negligible evaporative fractionation effects in the samples. PCS is low-cost, easy to install, and collects a representative integrated snowmelt sample throughout the melt season or at the melt event scale. Unlike snow cores, the PCS collects the water that would actually infiltrate the soil; thus, its isotopic composition is appropriate to use for tracing snowmelt water through the hydrologic cycle. The purpose of this Briefing is to show the potential advantages of PCSs and recommend guidelines for constructing and installing them based on our preliminary results from two snowmelt seasons.

A Improved Seabed Surface Sand Sampling Device

NASA Astrophysics Data System (ADS)

Luo, X.

2017-12-01

In marine geology research it is necessary to obtain a suf fcient quantity of seabed surface samples, while also en- suring that the samples are in their original state. Currently,there are a number of seabed surface sampling devices available, but we fnd it is very diffcult to obtain sand samples using these devices, particularly when dealing with fne sand. Machine-controlled seabed surface sampling devices are also available, but generally unable to dive into deeper regions of water. To obtain larger quantities of seabed surface sand samples in their original states, many researchers have tried to improve upon sampling devices,but these efforts have generally produced ambiguous results, in our opinion.To resolve this issue, we have designed an improved andhighly effective seabed surface sand sampling device that incorporates the strengths of a variety of sampling devices. It is capable of diving into deepwater to obtain fne sand samples and is also suited for use in streams, rivers, lakes and seas with varying levels of depth (up to 100 m). This device can be used for geological mapping, underwater prospecting, geological engineering and ecological, environmental studies in both marine and terrestrial waters.

Two-step microextraction combined with high performance liquid chromatographic analysis of pyrethroids in water and vegetable samples.

PubMed

Mukdasai, Siriboon; Thomas, Chunpen; Srijaranai, Supalax

2014-03-01

Dispersive liquid microextraction (DLME) combined with dispersive µ-solid phase extraction (D-µ-SPE) has been developed as a new approach for the extraction of four pyrethroids (tetramethrin, fenpropathrin, deltamethrin and permethrin) prior to the analysis by high performance liquid chromatography (HPLC) with UV detection. 1-Octanol was used as the extraction solvent in DLME. Magnetic nanoparticles (Fe3O4) functionalized with 3-aminopropyl triethoxysilane (APTS) were used as the dispersive in DLME and as the adsorbent in D-µ-SPE. The extracted pyrethroids were separated within 30 min using isocratic elution with acetonitrile:water (72:28). The factors affecting the extraction efficiency were investigated. Under the optimum conditions, the enrichment factors were in the range of 51-108. Linearity was obtained in the range 0.5-400 ng mL(-1) (tetramethrin) and 5-400 ng mL(-1) (fenpropathrin, deltamethrin and permethrin) with the correlation coefficients (R(2)) greater than 0.995. Detection limits were 0.05-2 ng mL(-1) (water samples) and 0.02-2.0 ng g(-1) (vegetable samples). The relative standard deviations of peak area varied from 1.8 to 2.5% (n=10). The extraction recoveries of the four pyrethroids in field water and vegetable samples were 91.7-104.5%. The proposed method has high potential for use as a sensitive method for determination of pyrethroid residues in water and vegetable samples. Copyright © 2013 Elsevier B.V. All rights reserved.

Major inorganic elements in tap water samples in Peninsular Malaysia.

PubMed

Azrina, A; Khoo, H E; Idris, M A; Amin, I; Razman, M R

2011-08-01

Quality drinking water should be free from harmful levels of impurities such as heavy metals and other inorganic elements. Samples of tap water collected from 24 locations in Peninsular Malaysia were determined for inorganic element content. Minerals and heavy metals were analysed by spectroscopy methods, while non-metal elements were analysed using test kits. Minerals and heavy metals determined were sodium, magnesium, potassium, calcium, chromium, manganese, iron, nickel, copper, zinc, arsenic, cadmium and lead while the non-metal elements were fluoride, chloride, nitrate and sulphate. Most of the inorganic elements found in the samples were below the maximum permitted levels recommended by inter-national drinking water standard limits, except for iron and manganese. Iron concentration of tap water from one of the locations was higher than the standard limit. In general, tap water from different parts of Peninsular Malaysia had low concentrations of heavy metals and inorganic elements.

Fast methodology for the reliable determination of nonylphenol in water samples by minimal labeling isotope dilution mass spectrometry.

PubMed

Fabregat-Cabello, Neus; Castillo, Ángel; Sancho, Juan V; González, Florenci V; Roig-Navarro, Antoni Francesc

2013-08-02

In this work we have developed and validated an accurate and fast methodology for the determination of 4-nonylphenol (technical mixture) in complex matrix water samples by UHPLC-ESI-MS/MS. The procedure is based on isotope dilution mass spectrometry (IDMS) in combination with isotope pattern deconvolution (IPD), which provides the concentration of the analyte directly from the spiked sample without requiring any methodological calibration graph. To avoid any possible isotopic effect during the analytical procedure the in-house synthesized (13)C1-4-(3,6-dimethyl-3-heptyl)phenol was used as labeled compound. This proposed surrogate was able to compensate the matrix effect even from wastewater samples. A SPE pre-concentration step together with exhaustive efforts to avoid contamination were included to reach the signal-to-noise ratio necessary to detect the endogenous concentrations present in environmental samples. Calculations were performed acquiring only three transitions, achieving limits of detection lower than 100ng/g for all water matrix assayed. Recoveries within 83-108% and coefficients of variation ranging from 1.5% to 9% were obtained. On the contrary a considerable overestimation was obtained with the most usual classical calibration procedure using 4-n-nonylphenol as internal standard, demonstrating the suitability of the minimal labeling approach. Copyright © 2013 Elsevier B.V. All rights reserved.

40 CFR 265.92 - Sampling and analysis.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Sampling and analysis. 265.92 Section... FACILITIES Ground-Water Monitoring § 265.92 Sampling and analysis. (a) The owner or operator must obtain and... follow a ground-water sampling and analysis plan. He must keep this plan at the facility. The plan must...

40 CFR 265.92 - Sampling and analysis.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 26 2011-07-01 2011-07-01 false Sampling and analysis. 265.92 Section... FACILITIES Ground-Water Monitoring § 265.92 Sampling and analysis. (a) The owner or operator must obtain and... follow a ground-water sampling and analysis plan. He must keep this plan at the facility. The plan must...

Water Intake in a Sample of Greek Adults Evaluated with the Water Balance Questionnaire (WBQ) and a Seven-Day Diary

PubMed Central

Athanasatou, Adelais; Malisova, Olga; Kandyliari, Aikaterini; Kapsokefalou, Maria

2016-01-01

Awareness on the importance of hydration in health has created an unequivocal need to enrich knowledge on water intake of the general population and on the contribution of beverages to total water intake. We evaluated in the past water intake in a sample of Greek adults using two approaches. In study A, volunteers completed the Water Balance Questionnaire (WBQ), a food frequency questionnaire, designed to evaluate water intake (n = 1092; 48.1% males; 43 ± 18 years). In study B, a different population of volunteers recorded water, beverage, and food intake in seven-day diaries (n = 178; 51.1% males; 37 ± 12 years). Herein, data were reanalyzed with the objective to reveal the contribution of beverages in total water intake with these different methodologies. Beverage recording was grouped in the following categories: Hot beverages; milk; fruit and vegetable juices; caloric soft drinks; diet soft drinks; alcoholic drinks; other beverages; and water. Total water intake and water intake from beverages was 3254 (SE 43) mL/day and 2551 (SE 39) mL/day in study A; and 2349 (SE 59) mL/day and 1832 (SE 56) mL/day in study B. In both studies water had the highest contribution to total water intake, approximately 50% of total water intake, followed by hot beverages (10% of total water intake) and milk (5% of total water intake). These two approaches contribute information on water intake in Greece and highlight the contribution of different beverages; moreover, they point out differences in results obtained from different methodologies attributed to limitations in their use. PMID:27626443

Water quality monitoring: A comparative case study of municipal and Curtin Sarawak's lake samples

NASA Astrophysics Data System (ADS)

Anand Kumar, A.; Jaison, J.; Prabakaran, K.; Nagarajan, R.; Chan, Y. S.

2016-03-01

In this study, particle size distribution and zeta potential of the suspended particles in municipal water and lake surface water of Curtin Sarawak's lake were compared and the samples were analysed using dynamic light scattering method. High concentration of suspended particles affects the water quality as well as suppresses the aquatic photosynthetic systems. A new approach has been carried out in the current work to determine the particle size distribution and zeta potential of the suspended particles present in the water samples. The results for the lake samples showed that the particle size ranges from 180nm to 1345nm and the zeta potential values ranges from -8.58 mV to -26.1 mV. High zeta potential value was observed in the surface water samples of Curtin Sarawak's lake compared to the municipal water. The zeta potential values represent that the suspended particles are stable and chances of agglomeration is lower in lake water samples. Moreover, the effects of physico-chemical parameters on zeta potential of the water samples were also discussed.

Diversity of enterococcal species and characterization of high-level aminoglycoside resistant enterococci of samples of wastewater and surface water in Tunisia.

PubMed

Ben Said, Leila; Klibi, Naouel; Lozano, Carmen; Dziri, Raoudha; Ben Slama, Karim; Boudabous, Abdellatif; Torres, Carmen

2015-10-15

One hundred-fourteen samples of wastewater (n=64) and surface-water (n=50) were inoculated in Slanetz-Bartley agar plates supplemented or not with gentamicin (SB-Gen and SB plates, respectively) for enterococci recovery. Enterococci were obtained from 75% of tested samples in SB media (72% in wastewater; 78% in surface-water), and 85 enterococcal isolates (one/positive-sample) were obtained. Enterococcus faecium was the most prevalent species (63.5%), followed by Enterococcus faecalis (20%), Enterococcus hirae (9.4%), Enterococcus casseliflavus (4.7%), and Enterococcus gallinarum/Enterococcus durans (2.4%). Antibiotic resistance detected among these enterococci was as follows [percentage/detected gene (number isolates)]: kanamycin [29%/aph(3')-IIIa (n=22)], streptomycin [8%/ant(6)-Ia (n=4)], erythromycin [44%/erm(B) (n=34)], tetracycline [18%/tet(M) (n=6)/tet(M)-tet(L) (n=9)], chloramphenicol [2%/cat(A) (n=1)], ciprofloxacin [7%] and trimethoprim-sulfamethoxazole [94%]. High-level-gentamicin resistant (HLR-G) enterococci were recovered from 15 samples in SB-Gen or SB plates [12/64 samples of wastewater (19%) and 3/50 samples of surface-water (6%)]; HLR-G isolates were identified as E. faecium (n=7), E. faecalis (n=6), and E. casseliflavus (n=2). These HLR-G enterococci carried the aac(6')-Ie-aph(2")-Ia and erm(B) genes, in addition to aph(3')-IIIa (n=10), ant(6)-Ia (n=9), tet(M) (n=13), tet(L) (n=8) and cat(A) genes (n=2). Three HLR-G enterococci carried the esp virulence gene. Sequence-types detected among HLR-G enterococci were as follows: E. faecalis (ST480, ST314, ST202, ST55, and the new ones ST531 and ST532) and E. faecium (ST327, ST12, ST296, and the new ones ST985 and ST986). Thirty-two different PFGE patterns were detected among 36 high-level-aminoglycoside-resistant enterococci recovered in water samples. Diverse genetic lineages of HLR-G enterococci were detected in wastewater and surface-water in Tunisia. Water can represent an important source for the

Trace analysis of parabens preservatives in drinking water treatment sludge, treated, and mineral water samples.

PubMed

Marta-Sanchez, Ana Victoria; Caldas, Sergiane Souza; Schneider, Antunielle; Cardoso, Sónia Maria Vaz Sanches; Primel, Ednei Gilberto

2018-05-01

Parabens have been widely used as antimicrobial agents, mainly in food products, pharmaceuticals, and cosmetics. Although they are known as safe preservatives, they also cause some harm to human health, which has been discussed lately. Therefore, the aim of this study was to evaluate the occurrence of nine parabens (including isomers) in mineral and drinking waters, besides in drinking water treatment sludge (DWTS) samples with determination by liquid chromatography tandem mass spectrometry (LC-MS/MS). Both methods solid phase extraction (SPE) and QuEChERS were validated. Calibration curves showed a correlation coefficient of 0.99 for all compounds. LOQ values ranged from 0.04 to 4 μg L -1 in aqueous matrices and from 5 to 500 ng g -1 in DWTS. Recoveries between 70 and 115% were reached with RSD below 20% for all compounds in SPE whereas recoveries between 62 and 119% were found with RSD below 20% for almost all compounds in QuEChERS. Matrix effect had low values (< 20%); it was only above 20% for methylparaben in the SPE and for pentylparaben in the QuEChERS. Using a quick and simple extraction procedures with SPE, QuEChERS, and LC-MS/MS analyses, these methods proved to be selective and sensitive. They were successfully applied to real samples (treated water, mineral water, and sludge), and methylparaben was detected at concentration levels below 0.242 μg L -1 in mineral and treated water samples and 10 ng g -1 in DWTS samples.

Magnetic stirrer induced dispersive ionic-liquid microextraction for the determination of vanadium in water and food samples prior to graphite furnace atomic absorption spectrometry.

PubMed

Naeemullah; Kazi, Tasneem Gul; Tuzen, Mustafa

2015-04-01

A new dispersive liquid-liquid microextraction, magnetic stirrer induced dispersive ionic-liquid microextraction (MS-IL-DLLME) was developed to quantify the trace level of vanadium in real water and food samples by graphite furnace atomic absorption spectrometry (GFAAS). In this extraction method magnetic stirrer was applied to obtained a dispersive medium of 1-butyl-3-methylimidazolium hexafluorophosphate [C4MIM][PF6] in aqueous solution of (real water samples and digested food samples) to increase phase transfer ratio, which significantly enhance the recovery of vanadium - 4-(2-pyridylazo) resorcinol (PAR) chelate. Variables having vital role on desired microextraction methods were optimised to obtain the maximum recovery of study analyte. Under the optimised experimental variables, enhancement factor (EF) and limit of detection (LOD) were achieved to be 125 and 18 ng L(-1), respectively. Validity and accuracy of the desired method was checked by analysis of certified reference materials (SLRS-4 Riverine water and NIST SRM 1515 Apple leaves). The relative standard deviation (RSD) for 10 replicate determinations at 0.5 μg L(-1) of vanadium level was found to be <5.0%. This method was successfully applied to real water and acid digested food samples. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Matrix effect and application of field-amplified sample injection in the analysis of four tetracyclines in waters by capillary electrohoresis].

PubMed

2014-08-01

The system abilities of two chromatographic techniques, capillary electrophoresis (CE) and high performance liquid chromatography (HPLC), were compared for the analysis of four tetracyclines (tetracycline, chlorotetracycline, oxytetracycline and doxycycline). The pH, concentration of background electrolyte (BGE) were optimized for the analysis of the standard mixture sample, meanwhile, the effects of separation voltage and water matrix (pH value and hardness) effects were investigated. In hydrodynamic injection (HDI) mode, a good quantitative linearity and baseline separation within 9. 0 min were obtained for the four tetracyclines at the optimal conditions; the analytical time was about half of that of HPLC. The limits of detection (LODs) were in the range of 0. 28 - 0. 62 mg/L, and the relative standard deviations (RSDs) (n= 6) of migration time and peak area were 0. 42% - 0. 56% and 2. 24% - 2. 95%, respectively. The obtained recoveries spiked in tap water and fishpond water were at the ranges of 96. 3% - 107. 2% and 87. 1% - 105. 2%, respectively. In addition, the stacking method, field-amplified sample injection (FASI), was employed to improve the sensitivity, and the LOD was down to the range of 17.8-35.5 μg/L. With FASI stacking, the RSDs (n=6) of migration time and peak area were 0. 85%-0. 95% and 1. 69%-3.43%, respectively. Due to the advantages of simple sample pretreatment and fast speed, CE is promising in the analysis of the antibiotics in environmental water.

Comparative Study of Radon Concentration with Two Techniques and Elemental Analysis in Drinking Water Samples of the Jammu District, Jammu and Kashmir, India.

PubMed

Kumar, Ajay; Kaur, Manpreet; Mehra, Rohit; Sharma, Dinesh Kumar; Mishra, Rosaline

2017-10-01

The level of radon concentration has been assessed using the Advanced SMART RnDuo technique in 30 drinking water samples from Jammu district, Jammu and Kashmir, India. The water samples were collected from wells, hand pumps, submersible pumps, and stored waters. The randomly obtained 14 values of radon concentration in water sources using the SMART RnDuo technique have been compared and cross checked by a RAD7 device. A good positive correlation (R = 0.88) has been observed between the two techniques. The overall value of radon concentration in various water sources has ranged from 2.45 to 18.43 Bq L, with a mean value of 8.24 ± 4.04 Bq L, and it agreed well with the recommended limit suggested by the European Commission and UNSCEAR. However, the higher activity of mean radon concentration was found in groundwater drawn from well, hand and submersible pumps as compared to stored water. The total annual effective dose due to radon inhalation and ingestion ranged from 6.69 to 50.31 μSv y with a mean value of 22.48 ± 11.03 μSv y. The total annual effective dose was found to lie within the safe limit (100 μSv y) suggested by WHO. Heavy metal analysis was also carried out in various water sources by using an atomic absorption spectrophotometer (AAS), and the highest value of heavy metals was found mostly in groundwater samples. The obtained results were compared with Indian and International organizations like WHO and the EU Council. Among all the samples, the elemental analysis is not on the exceeding side of the permissible limit.

A high-throughput headspace gas chromatographic technique for the determination of nitrite content in water samples.

PubMed

Zhang, Shu-Xin; Peng, Rong; Jiang, Ran; Chai, Xin-Sheng; Barnes, Donald G

2018-02-23

This paper reports on a high-throughput headspace gas chromatographic method (HS-GC) for the determination of nitrite content in water sample, based on GC measurement of cyclohexene produced from the reaction between nitrite and cyclamate in a closed vial. The method has a relative standard deviation of <3.5%; The differences between the results of the nitrite measurements obtained by this method and those of a reference method were less than 5.8% and the recoveries of the method were in the range of 94.8-102% (for a spiked nitrite content range from 0.002 to 0.03 mg/L). The limit of detection of the method was 0.46 μg L -1 . Due to an overlapping mode in the headspace auto-sampler system, the method can provide an automated and high-throughput nitrite analysis for the surface water samples. In short, the present HS-GC method is simple, accurate, and sensitive, and it is very suitable to be used in the batch sample testing. Copyright © 2018 Elsevier B.V. All rights reserved.

Interim results of quality-control sampling of surface water for the Upper Colorado River National Water-Quality Assessment Study Unit, water years 1995-96

USGS Publications Warehouse

Spahr, N.E.; Boulger, R.W.

1997-01-01

Quality-control samples provide part of the information needed to estimate the bias and variability that result from sample collection, processing, and analysis. Quality-control samples of surface water collected for the Upper Colorado River National Water-Quality Assessment study unit for water years 1995?96 are presented and analyzed in this report. The types of quality-control samples collected include pre-processing split replicates, concurrent replicates, sequential replicates, post-processing split replicates, and field blanks. Analysis of the pre-processing split replicates, concurrent replicates, sequential replicates, and post-processing split replicates is based on differences between analytical results of the environmental samples and analytical results of the quality-control samples. Results of these comparisons indicate that variability introduced by sample collection, processing, and handling is low and will not affect interpretation of the environmental data. The differences for most water-quality constituents is on the order of plus or minus 1 or 2 lowest rounding units. A lowest rounding unit is equivalent to the magnitude of the least significant figure reported for analytical results. The use of lowest rounding units avoids some of the difficulty in comparing differences between pairs of samples when concentrations span orders of magnitude and provides a measure of the practical significance of the effect of variability. Analysis of field-blank quality-control samples indicates that with the exception of chloride and silica, no systematic contamination of samples is apparent. Chloride contamination probably was the result of incomplete rinsing of the dilute cleaning solution from the outlet ports of the decaport sample splitter. Silica contamination seems to have been introduced by the blank water. Sampling and processing procedures for water year 1997 have been modified as a result of these analyses.

Lead Concentration Levels in Water Samples Collected in Alameda County, CA

NASA Astrophysics Data System (ADS)

Sethy, D.; Hoang, R.; Yu, I.; Hernandez, N.; Fang, K.; Zhang, W.; Li, J.; Munui, K. N.; Sot, R.; Luong, K.; Bonzo, R.; Sankar, R.; Chiu, D.; Rodriguez, V. A.

2016-12-01

The recent health crisis in Flint, Michigan has attracted an amount of interest in other public utilities' water supplies and infrastructure with regards to concerns over the presence of lead. In an effort to begin assessing the potential for a health crisis similar to that experienced in Flynt, during 2016 our team measured lead concentration levels in water samples by collected in Alameda County. More than 12 sites were selected from which samples were collected. These sites included parks, schools, and private residences. At each site 500mL samples were collected and prepared for later analysis. Samples were subjected to an analytical chemistry technique designed to isolate and concentrate lead to detectable levels of 1 part per billion (ppb). All 8 samples yielded detectable levels of lead; all samples were also well below the EPA regulatory 15 ppb. Two samples collected in West Oakland parks were found to have the highest and lowest levels: DeFremery (4 ppb) and Raimondi (1ppb), respectively. Though preliminary in nature, results from this study suggest that further investigations should be undertaken to assess possible lead contamination associated with drinking water sources in Alameda County.

Sampling and analysis for radon-222 dissolved in ground water and surface water

USGS Publications Warehouse

DeWayne, Cecil L.; Gesell, T.F.

1992-01-01

Radon-222 is a naturally occurring radioactive gas in the uranium-238 decay series that has traditionally been called, simply, radon. The lung cancer risks associated with the inhalation of radon decay products have been well documented by epidemiological studies on populations of uranium miners. The realization that radon is a public health hazard has raised the need for sampling and analytical guidelines for field personnel. Several sampling and analytical methods are being used to document radon concentrations in ground water and surface water worldwide but no convenient, single set of guidelines is available. Three different sampling and analytical methods - bubbler, liquid scintillation, and field screening - are discussed in this paper. The bubbler and liquid scintillation methods have high accuracy and precision, and small analytical method detection limits of 0.2 and 10 pCi/l (picocuries per liter), respectively. The field screening method generally is used as a qualitative reconnaissance tool.

Characterization of specimens obtained by different sampling methods for evaluation of periodontal bacteria.

PubMed

Okada, Ayako; Sogabe, Kaoru; Takeuchi, Hiroaki; Okamoto, Masaaki; Nomura, Yoshiaki; Hanada, Nobuhiro

2017-12-27

Quantitative analysis of periodontal bacteria is considered useful for clinical diagnosis, evaluation and assessment of the risk of periodontal disease. The purpose of this study was to compare the effectiveness of sampling of saliva, supragingival and subgingival plaque for evaluation of periodontal bacteria. From each of 12 subjects, i) subgingival plaque was collected from the deepest pocket using a sterile paper point, ii) stimulated whole saliva was collected after chewing gum, and iii) supragingival plaque was collected using a tooth brush. These samples were sent to the medical examination laboratory for quantitative analysis of the counts of three periodontal bacterial species: Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia. The proportions of these bacteria in subgingival plaque were higher than those in saliva or supragingival plaque, but lower in subgingival plaque than in saliva or supragingival plaque. In several cases, periodontal bacteria were below the levels of detection in subgingival plaque. We concluded that samples taken from subgingival plaque may be more useful for evaluating the proportion of periodontal bacteria in deep pockets than is the case for other samples. Therefore, for evaluation of periodontal bacteria, clinicians should consider the characteristics of the specimens obtained using different sampling methods.

Effects of sterilization treatments on the analysis of TOC in water samples.

PubMed

Shi, Yiming; Xu, Lingfeng; Gong, Dongqin; Lu, Jun

2010-01-01

Decomposition experiments conducted with and without microbial processes are commonly used to study the effects of environmental microorganisms on the degradation of organic pollutants. However, the effects of biological pretreatment (sterilization) on organic matter often have a negative impact on such experiments. Based on the principle of water total organic carbon (TOC) analysis, the effects of physical sterilization treatments on determination of TOC and other water quality parameters were investigated. The results revealed that two conventional physical sterilization treatments, autoclaving and 60Co gamma-radiation sterilization, led to the direct decomposition of some organic pollutants, resulting in remarkable errors in the analysis of TOC in water samples. Furthermore, the extent of the errors varied with the intensity and the duration of sterilization treatments. Accordingly, a novel sterilization method for water samples, 0.45 microm micro-filtration coupled with ultraviolet radiation (MCUR), was developed in the present study. The results indicated that the MCUR method was capable of exerting a high bactericidal effect on the water sample while significantly decreasing the negative impact on the analysis of TOC and other water quality parameters. Before and after sterilization treatments, the relative errors of TOC determination could be controlled to lower than 3% for water samples with different categories and concentrations of organic pollutants by using MCUR.

Set Up of an Automatic Water Quality Sampling System in Irrigation Agriculture

PubMed Central

Heinz, Emanuel; Kraft, Philipp; Buchen, Caroline; Frede, Hans-Georg; Aquino, Eugenio; Breuer, Lutz

2014-01-01

We have developed a high-resolution automatic sampling system for continuous in situ measurements of stable water isotopic composition and nitrogen solutes along with hydrological information. The system facilitates concurrent monitoring of a large number of water and nutrient fluxes (ground, surface, irrigation and rain water) in irrigated agriculture. For this purpose we couple an automatic sampling system with a Wavelength-Scanned Cavity Ring Down Spectrometry System (WS-CRDS) for stable water isotope analysis (δ2H and δ18O), a reagentless hyperspectral UV photometer (ProPS) for monitoring nitrate content and various water level sensors for hydrometric information. The automatic sampling system consists of different sampling stations equipped with pumps, a switch cabinet for valve and pump control and a computer operating the system. The complete system is operated via internet-based control software, allowing supervision from nearly anywhere. The system is currently set up at the International Rice Research Institute (Los Baños, The Philippines) in a diversified rice growing system to continuously monitor water and nutrient fluxes. Here we present the system's technical set-up and provide initial proof-of-concept with results for the isotopic composition of different water sources and nitrate values from the 2012 dry season. PMID:24366178

Evaluation of storage and filtration protocols for alpine/subalpine lake water quality samples

Treesearch

John L. Korfmacher; Robert C. Musselman

2007-01-01

Many government agencies and other organizations sample natural alpine and subalpine surface waters using varying protocols for sample storage and filtration. Simplification of protocols would be beneficial if it could be shown that sample quality is unaffected. In this study, samples collected from low ionic strength waters in alpine and subalpine lake inlets...

Aqueous Processing of Atmospheric Organic Particles in Cloud Water Collected via Aircraft Sampling

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

Boone, Eric J.; Laskin, Alexander; Laskin, Julia

2015-07-21

Cloud water and below-cloud atmospheric particle samples were collected onboard a research aircraft during the Southern Oxidant and Aerosol Study (SOAS) over a forested region of Alabama in June 2013. The organic molecular composition of the samples was studied to gain insights into the aqueous-phase processing of organic compounds within cloud droplets. High resolution mass spectrometry with nanospray desorption electrospray ionization and direct infusion electrospray ionization were utilized to compare the organic composition of the particle and cloud water samples, respectively. Isoprene and monoterpene-derived organosulfates and oligomers were identified in both the particles and cloud water, showing the significant influencemore » of biogenic volatile organic compound oxidation above the forested region. While the average O:C ratios of the organic compounds were similar between the atmospheric particle and cloud water samples, the chemical composition of these samples was quite different. Specifically, hydrolysis of organosulfates and formation of nitrogen-containing compounds were observed for the cloud water when compared to the atmospheric particle samples, demonstrating that cloud processing changes the composition of organic aerosol.« less

Detection of outliers in water quality monitoring samples using functional data analysis in San Esteban estuary (Northern Spain).

PubMed

Díaz Muñiz, C; García Nieto, P J; Alonso Fernández, J R; Martínez Torres, J; Taboada, J

2012-11-15

Water quality controls involve large number of variables and observations, often subject to some outliers. An outlier is an observation that is numerically distant from the rest of the data or that appears to deviate markedly from other members of the sample in which it occurs. An interesting analysis is to find those observations that produce measurements that are different from the pattern established in the sample. Therefore, identification of atypical observations is an important concern in water quality monitoring and a difficult task because of the multivariate nature of water quality data. Our study provides a new method for detecting outliers in water quality monitoring parameters, using oxygen and turbidity as indicator variables. Until now, methods were based on considering the different parameters as a vector whose components were their concentration values. Our approach lies in considering water quality monitoring through time as curves instead of vectors, that is to say, the data set of the problem is considered as a time-dependent function and not as a set of discrete values in different time instants. The methodology, which is based on the concept of functional depth, was applied to the detection of outliers in water quality monitoring samples in San Esteban estuary. Results were discussed in terms of origin, causes, etc., and compared with those obtained using the conventional method based on vector comparison. Finally, the advantages of the functional method are exposed. Copyright © 2012 Elsevier B.V. All rights reserved.

Evaluation of Rock Powdering Methods to Obtain Fine-grained Samples for CHEMIN, a Combined XRD/XRF Instrument

NASA Technical Reports Server (NTRS)

Chipera, S. J.; Vaniman, D. T.; Bish, D. L.; Sarrazin, P.; Feldman, S.; Blake, D. F.; Bearman, G.; Bar-Cohen, Y.

2004-01-01

A miniature XRD/XRF (X-ray diffraction / X-ray fluorescence) instrument, CHEMIN, is currently being developed for definitive mineralogic analysis of soils and rocks on Mars. One of the technical issues that must be addressed to enable remote XRD analysis is how best to obtain a representative sample powder for analysis. For powder XRD analyses, it is beneficial to have a fine-grained sample to reduce preferred orientation effects and to provide a statistically significant number of crystallites to the X-ray beam. Although a two-dimensional detector as used in the CHEMIN instrument will produce good results even with poorly prepared powder, the quality of the data will improve and the time required for data collection will be reduced if the sample is fine-grained and randomly oriented. A variety of methods have been proposed for XRD sample preparation. Chipera et al. presented grain size distributions and XRD results from powders generated with an Ultrasonic/Sonic Driller/Corer (USDC) currently being developed at JPL. The USDC was shown to be an effective instrument for sampling rock to produce powder suitable for XRD. In this paper, we compare powder prepared using the USDC with powder obtained with a miniaturized rock crusher developed at JPL and with powder obtained with a rotary tungsten carbide bit to powders obtained from a laboratory bench-scale Retsch mill (provides benchmark mineralogical data). These comparisons will allow assessment of the suitability of these methods for analysis by an XRD/XRF instrument such as CHEMIN.

Identification and quantification of pesticide residues in water samples of Dhamrai Upazila, Bangladesh

NASA Astrophysics Data System (ADS)

Hasanuzzaman, M.; Rahman, M. A.; Salam, M. A.

2017-10-01

Being agricultural country, different types of pesticides are widely used in Bangladesh to prevent the crop losses due to pest attack which are ultimately drain to the water bodies. The present study was conducted to identify and quantify the organochlorine (DDT, DDE and DDD), organophosphorus (malathion, diazinon and chloropyrifos) and carbamate (carbaryl) residues in water samples of different sources from Dhamrai upazila of Bangladesh using high performance liquid chromatography (HPLC) equipped with ultra violate (UV) detector. Thirty water samples from fish pond, cultivated land and tube-well were collected in winter season to analyze the pesticide residues. Among the organophosphorus pesticides, malathion was present in seven water samples ranging from 42.58 to 922.8 μg/L, whereas diazinon was detected in water sample-8 (WS-8) and the concentration was 31.5 μg/L. None of the tested water samples was found to be contaminated with chlorpyrifos, carbaryl or DDT and its metabolites (DDE and DDD). Except for a tube-well water sample, concentrations of the detected residues are above the acceptable limit for human body as assigned by different organizations. To avoid the possible health hazards, the indiscriminate application of pesticides should be restricted and various substitute products like bio-pesticide should be introduced in a broad scale as soon as possible.

Results of soil, ground-water, surface-water, and streambed-sediment sampling at Air Force Plane 85, Columbus, Ohio, 1996

USGS Publications Warehouse

Parnell, J.M.

1997-01-01

The U.S. Geological Survey (USGS), in cooperation with Aeronautical Systems Center, Environmental Management Directorate, Restoration Division, prepared the Surface- and Ground- Water Monitoring Work Plan for Air Force Plant 85 (AFP 85 or Plant), Columbus, Ohio, under the Air Force Installation Restoration Program to characterize any ground-water, surface-water, and soil contamination that may exist at AFP 85. The USGS began the study in November 1996. The Plant was divided into nine sampling areas, which included some previously investi gated study sites. The investigation activities included the collection and presentation of data taken during drilling and water-quality sampling. Data collection focused on the saturated and unsatur ated zones and surface water. Twenty-three soil borings were completed. Ten monitoring wells (six existing wells and four newly constructed monitoring wells) were selected for water-quality sam pling. Surface-water and streambed-sediment sampling locations were chosen to monitor flow onto and off of the Plant. Seven sites were sampled for both surface-water and streambed-sediment quality. This report presents data on the selected inorganic and organic constituents in soil, ground water, surface water, and streambed sediments at AFP 85. The methods of data collection and anal ysis also are included. Knowledge of the geologic and hydrologic setting could aid Aeronautical Systems Center, Environmental Management Directorate, Restoration Division, and its governing regulatory agencies in future remediation studies.

Standard reference water samples for rare earth element determinations

USGS Publications Warehouse

Verplanck, P.L.; Antweiler, Ronald C.; Nordstrom, D. Kirk; Taylor, Howard E.

2001-01-01

Standard reference water samples (SRWS) were collected from two mine sites, one near Ophir, CO, USA and the other near Redding, CA, USA. The samples were filtered, preserved, and analyzed for rare earth element (REE) concentrations (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) by inductively coupled plasma-mass spectrometry (ICP-MS). These two samples were acid mine waters with elevated concentrations of REEs (0.45-161 ??g/1). Seventeen international laboratories participated in a 'round-robin' chemical analysis program, which made it possible to evaluate the data by robust statistical procedures that are insensitive to outliers. The resulting most probable values are reported. Ten to 15 of the participants also reported values for Ba, Y, and Sc. Field parameters, major ion, and other trace element concentrations, not subject to statistical evaluation, are provided.

Application of hollow cylindrical wheat stem for electromembrane extraction of thorium in water samples

NASA Astrophysics Data System (ADS)

Khajeh, Mostafa; Pedersen-Bjergaard, Stig; Barkhordar, Afsaneh; Bohlooli, Mousa

2015-02-01

In this study, wheat stem was used for electromembrane extraction (EME) for the first time. The EME technique involved the use of a wheat stem whose channel was filled with 3 M HCl, immersed in 10 mL of an aqueous sample solution. Thorium migrated from aqueous samples, through a thin layer of 1-octanol and 5%v/v Di-(2-ethylhexyl) phosphate (DEHP) immobilized in the pores of a porous stem, and into an acceptor phase solution present inside the lumen of the stem. The pH of donor and acceptor phases, extraction time, voltage, and stirring speed were optimized. At the optimum conditions, an enrichment factor of 50 and a limit of detection of 0.29 ng mL-1 was obtained for thorium. The developed procedure was then applied to the extraction and determination of thorium in water samples and in reference material.

Water sampling using a drone at Yugama crater lake, Kusatsu-Shirane volcano, Japan

NASA Astrophysics Data System (ADS)

Terada, Akihiko; Morita, Yuichi; Hashimoto, Takeshi; Mori, Toshiya; Ohba, Takeshi; Yaguchi, Muga; Kanda, Wataru

2018-04-01

Remote sampling of water from Yugama crater lake at Kusatsu-Shirane volcano, Japan, was performed using a drone. Despite the high altitude of over 2000 m above sea level, our simple method was successful in retrieving a 250 mL sample of lake water. The procedure presented here is easy for any researcher to follow who operates a drone without additional special apparatus. We compare the lake water sampled by drone with that sampled by hand at a site where regular samplings have previously been carried out. Chemical concentrations and stable isotope ratios are largely consistent between the two techniques. As the drone can fly automatically with the aid of navigation by Global Navigation Satellite System (GNSS), it is possible to repeatedly sample lake water from the same location, even when entry to Yugama crater lake is restricted due to the risk of eruption.[Figure not available: see fulltext.

Exploring the Legionella pneumophila positivity rate in hotel water samples from Antalya, Turkey.

PubMed

Sepin Özen, Nevgün; Tuğlu Ataman, Şenay; Emek, Mestan

2017-05-01

The genus Legionella is a fastidious Gram-negative bacteria widely distributed in natural waters and man made water supply systems. Legionella pneumophila is the aetiological agent of approximately 90% of reported Legionellosis cases, and serogroup 1 is the most frequent cause of infections. Legionnaires' disease is often associated with travel and continues to be a public health concern at present. The correct water management quality practices and rapid methods for analyzing Legionella species in environmental water is a key point for the prevention of Legionnaires' disease outbreaks. This study aimed to evaluate the positivity rates and serotyping of Legionella species from water samples in the region of Antalya, Turkey, which is an important tourism center. During January-December 2010, a total of 1403 samples of water that were collected from various hotels (n = 56) located in Antalya were investigated for Legionella pneumophila. All samples were screened for L. pneumophila by culture method according to "ISO 11731-2" criteria. The culture positive Legionella strains were serologically identified by latex agglutination test. A total of 142 Legionella pneumophila isolates were recovered from 21 (37.5%) of 56 hotels. The total frequency of L. pneumophila isolation from water samples was found as 10.1%. Serological typing of 142 Legionella isolates by latex agglutination test revealed that strains belonging to L. pneumophila serogroups 2-14 predominated in the examined samples (85%), while strains of L. pneumophila serogroup 1 were less numerous (15%). According to our knowledge, our study with the greatest number of water samples from Turkey demonstrates that L. pneumophila serogroups 2-14 is the most common isolate. Rapid isolation of L. pneumophila from environmental water samples is essential for the investigation of travel related outbreaks and the possible resources. Further studies are needed to have epidemiological data and to determine the types of L

Genotypic Characterization of Cryptosporidium hominis from Water Samples in São Paulo, Brazil

PubMed Central

Araújo, Ronalda S.; Dropa, Milena; Fernandes, Licia N.; Carvalho, Terezinha T.; Sato, Maria Inês Z.; Soares, Rodrigo M.; Matté, Glavur R.; Matté, Maria Helena

2011-01-01

The protozoan parasite Cryptosporidium has emerged as one of the most important water contaminants, causing waterborne outbreaks of diarrheal diseases worldwide. The small size of oocysts under the microscope and the possibility of changes in characteristics of oocysts, mainly in environmental samples, make the taxonomy of the genus difficult if morphologic characteristics are considered. This limitation encouraged the application of molecular methods to identify this microorganism. The aim of this study was to detect and identify by nested-polymerase chain reaction oocysts of Cryptosporidium present in water samples in the state of São Paulo, Brazil. Water samples were concentrated through a membrane filter, DNA was extracted by using a standard technique, and both amplification reactions used forward and reverse oligonucleotides that were complementary to Cryptosporidium 18S ribosomal RNA gene sequences. Thirty water samples from different sites of collection in the state of São Paulo were evaluated. Cryptosporidium oocysts were detected in 30% of the samples. By genoptyping, C. hominis and Cryptosporidium sp. were identified in recreational water and C. meleagridis was identified in surface water samples. This is the first report of C. hominis in environmental samples in Brazil. Although identification of Cryptosporidium is still a difficult task, molecular methods are essential for specific identification and are a helpful tool to aid to understand the epidemiology of this parasite in Brazil. PMID:22049036

Instrumental neutron activation analysis data for cloud-water particulate samples, Mount Bamboo, Taiwan

USGS Publications Warehouse

Lin, Neng-Huei; Sheu, Guey-Rong; Wetherbee, Gregory A.; Debey, Timothy M.

2013-01-01

Cloud water was sampled on Mount Bamboo in northern Taiwan during March 22-24, 2002. Cloud-water samples were filtered using 0.45-micron filters to remove particulate material from the water samples. Filtered particulates were analyzed by instrumental neutron activation analysis (INAA) at the U.S. Geological Survey National Reactor Facility in Denver, Colorado, in February 2012. INAA elemental composition data for the particulate materials are presented. These data complement analyses of the aqueous portion of the cloud-water samples, which were performed earlier by the Department of Atmospheric Sciences, National Central University, Taiwan. The data are intended for evaluation of atmospheric transport processes and air-pollution sources in Southeast Asia.

HPLC-FLD determination of 4-nonylphenol and 4-tert-octylphenol in surface water samples.

PubMed

Cruceru, Ioana; Iancu, Vasile; Petre, Jana; Badea, Irinel Adriana; Vladescu, Luminita

2012-05-01

A simple, sensitive and reliable HPLC-FLD method for the routine determination of 4-nonylphenol, 4-NP and 4-tert-octylphenol, 4-t-OP content in water samples was developed. The method consists in a liquid-liquid extraction of the target analytes with dichloromethane at pH  3.0-3.5 followed by the HPLC-FLD analysis of the organic extract using a Zorbax Eclipse XDB C8 column, isocratic elution with a mixed solvent acetonitrile/water 65:35, at a flow rate of 1.0 mL/min and applying a column temperature of 40°C. The method was validated and then applied with good results for the determination of 4-NP and 4-t-OP in Ialomiţa River water samples collected each month during 2006. The concentration levels of 4-NP and 4-t-OP vary between 0.08-0.17 μg/L with higher values of 0.24-0.37 μg/L in the summer months for 4-NP, and frequently <0.05 μg/L but also between 0.06-0.09 μg/L with higher values of 0.12-0.16 μg/L in July and August for 4-t-OP and were strongly influenced by sesonial and anthropic factors. The method was also applied on samples collected over 2 years 2007 and 2008 from urban wastewaters discharged into sewage or directly into the rivers by economic agents located in 30 Romanian towns. Good results were obtained when the method was used for analysis of effluents discharged into surface waters by 16 municipal wastewater treatment plants, during the year 2008.

Simultaneous determination of specific alpha and beta emitters by LSC-PLS in water samples.

PubMed

Fons-Castells, J; Tent-Petrus, J; Llauradó, M

2017-01-01

Liquid scintillation counting (LSC) is a commonly used technique for the determination of alpha and beta emitters. However, LSC has poor resolution and the continuous spectra for beta emitters hinder the simultaneous determination of several alpha and beta emitters from the same spectrum. In this paper, the feasibility of multivariate calibration by partial least squares (PLS) models for the determination of several alpha ( nat U, 241 Am and 226 Ra) and beta emitters ( 40 K, 60 Co, 90 Sr/ 90 Y, 134 Cs and 137 Cs) in water samples is reported. A set of alpha and beta spectra from radionuclide calibration standards were used to construct three PLS models. Experimentally mixed radionuclides and intercomparision materials were used to validate the models. The results had a maximum relative bias of 25% when all the radionuclides in the sample were included in the calibration set; otherwise the relative bias was over 100% for some radionuclides. The results obtained show that LSC-PLS is a useful approach for the simultaneous determination of alpha and beta emitters in multi-radionuclide samples. However, to obtain useful results, it is important to include all the radionuclides expected in the studied scenario in the calibration set. Copyright © 2016 Elsevier Ltd. All rights reserved.

Errors in measuring water potentials of small samples resulting from water adsorption by thermocouple psychrometer chambers.

PubMed

Bennett, J M; Cortes, P M

1985-09-01

The adsorption of water by thermocouple psychrometer assemblies is known to cause errors in the determination of water potential. Experiments were conducted to evaluate the effect of sample size and psychrometer chamber volume on measured water potentials of leaf discs, leaf segments, and sodium chloride solutions. Reasonable agreement was found between soybean (Glycine max L. Merr.) leaf water potentials measured on 5-millimeter radius leaf discs and large leaf segments. Results indicated that while errors due to adsorption may be significant when using small volumes of tissue, if sufficient tissue is used the errors are negligible. Because of the relationship between water potential and volume in plant tissue, the errors due to adsorption were larger with turgid tissue. Large psychrometers which were sealed into the sample chamber with latex tubing appeared to adsorb more water than those sealed with flexible plastic tubing. Estimates are provided of the amounts of water adsorbed by two different psychrometer assemblies and the amount of tissue sufficient for accurate measurements of leaf water potential with these assemblies. It is also demonstrated that water adsorption problems may have generated low water potential values which in prior studies have been attributed to large cut surface area to volume ratios.

Detection and genotyping of human papillomavirus in self-obtained cervicovaginal samples by using the FTA cartridge: new possibilities for cervical cancer screening.

PubMed

Lenselink, Charlotte H; de Bie, Roosmarie P; van Hamont, Dennis; Bakkers, Judith M J E; Quint, Wim G V; Massuger, Leon F A G; Bekkers, Ruud L M; Melchers, Willem J G

2009-08-01

This study assesses human papillomavirus (HPV) detection and genotyping in self-sampled genital smears applied to an indicating FTA elute cartridge (FTA cartridge). The study group consisted of 96 women, divided into two sample sets. All samples were analyzed by the HPV SPF(10)-Line Blot 25. Set 1 consisted of 45 women attending the gynecologist; all obtained a self-sampled cervicovaginal smear, which was applied to an FTA cartridge. HPV results were compared to a cervical smear (liquid based) taken by a trained physician. Set 2 consisted of 51 women who obtained a self-sampled cervicovaginal smear at home, which was applied to an FTA cartridge and to a liquid-based medium. DNA was obtained from the FTA cartridges by simple elution as well as extraction. Of all self-obtained samples of set 1, 62.2% tested HPV positive. The overall agreement between self- and physician-obtained samples was 93.3%, in favor of the self-obtained samples. In sample set 2, 25.5% tested HPV positive. The overall agreement for high-risk HPV presence between the FTA cartridge and liquid-based medium and between DNA elution and extraction was 100%. This study shows that HPV detection and genotyping in self-obtained cervicovaginal samples applied to an FTA cartridge is highly reliable. It shows a high level of overall agreement with HPV detection and genotyping in physician-obtained cervical smears and liquid-based self-samples. DNA can be obtained by simple elution and is therefore easy, cheap, and fast. Furthermore, the FTA cartridge is a convenient medium for collection and safe transport at ambient temperatures. Therefore, this method may contribute to a new way of cervical cancer screening.

Electro-driven extraction of inorganic anions from water samples and water miscible organic solvents and analysis by ion chromatography.

PubMed

Nojavan, Saeed; Bidarmanesh, Tina; Memarzadeh, Farkhondeh; Chalavi, Soheila

2014-09-01

A simple electromembrane extraction (EME) procedure combined with ion chromatography (IC) was developed to quantify inorganic anions in different pure water samples and water miscible organic solvents. The parameters affecting extraction performance, such as supported liquid membrane (SLM) solvent, extraction time, pH of donor and acceptor solutions, and extraction voltage were optimized. The optimized EME conditions were as follows: 1-heptanol was used as the SLM solvent, the extraction time was 10 min, pHs of the acceptor and donor solutions were 10 and 7, respectively, and the extraction voltage was 15 V. The mobile phase used for IC was a combination of 1.8 mM sodium carbonate and 1.7 mM sodium bicarbonate. Under these optimized conditions, all anions had enrichment factors ranging from 67 to 117 with RSDs between 7.3 and 13.5% (n = 5). Good linearity values ranging from 2 to 1200 ng/mL with coefficients of determination (R(2) ) between 0.987 and 0.999 were obtained. The LODs of the EME-IC method ranged from 0.6 to 7.5 ng/mL. The developed method was applied to different samples to evaluate the feasibility of the method for real applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

rGO-ZnO nanocomposites for high electrocatalytic effect on water oxidation obtained by microwave-hydrothermal method

NASA Astrophysics Data System (ADS)

Romeiro, Fernanda C.; Rodrigues, Mônica A.; Silva, Luiz A. J.; Catto, Ariadne C.; da Silva, Luis F.; Longo, Elson; Nossol, Edson; Lima, Renata C.

2017-11-01

Reduced graphene oxide-zinc oxide (rGO-ZnO) nanocomposites were successfully synthesized using a facile microwave-hydrothermal method under mild conditions, and their electrocatalytic properties towards O2 evolution were investigated. The microwave radiation played an important role in obtainment of well dispersed ZnO nanoparticles directly on reduced graphene oxide sheets without any additional reducing reagents or passivation agent. X-ray diffraction (XRD), Raman and infrared spectroscopies indicated the reduction of GO as well as the successful synthesis of rGO-ZnO nanocomposites. The chemical states of the samples were shown by XPS analyses. Due to the synergic effect, the resulting nanocomposites exhibited high electronic interaction between ZnO and rGO sheets, which improved the electrocatalytic oxidation of water with low onset potential of 0.48 V (vs. Ag/AgCl) in neutral pH and long-term stability, with high current density during electrolysis. The overpotential for water oxidation decreased in alkaline pH, suggesting useful insight on the catalytic mechanism for O2 evolution.

Efficacy of the detection of Legionella in hot and cold water samples by culture and PCR. II. Examination of native samples from various sources.

PubMed

Stojek, Nimfa Maria; Wójcik-Fatla, Angelina; Dutkiewicz, Jacek

2012-01-01

A total of 123 water samples were examined in parallel by culture and semi-nested PCR for the presence of Legionella. They comprised: 35 samples of hot water distributed by the urban municipal water supply system (MWSS) taken in institutions, 45 samples of hot water distributed by urban MWSS taken in dwellings, 27 samples of cold water distributed by rural MWSS taken in dwellings, and 16 samples of cold well water taken in rural areas. The greatest frequency of the isolation of Legionella by culture (88.6%) was recorded in the samples of hot water from the urban institutions, having been greater compared to all other sources (p<0.001). The frequency of Legionella isolation from hot water in urban dwellings (28.9%) was significantly greater compared to the combined value (2.3%) for cold water from rural MWSS and wells (p<0.001). Strains belonging to Legionella pneumophila serogroups 2-14 predominated in the examined samples, while strains of L. pneumophila serogroup 1 and strains of Legionella spp. (other than L. pneumophila) were 3-fold less numerous. The rates of positive findings in the semi-nested PCR (stage 2) were greater than culture isolations in all kinds of samples, except for urban institutions. The correlation between the culture and PCR results was positive for samples of hot water from urban MWSS (p<0.01), but not for samples of cold water from rural MWSS and wells (p>0.5). A significant correlation was found between rates of PCR-positive results and numbers of Legionella pneumophila serogroups 2-14 strains, but not for other Legionella serogroups or species. In conclusion, our results support the opinion that though PCR cannot be a substitute for the isolation of Legionella by culture, it could be regarded as an useful complementary method.

A survey sampling approach for pesticide monitoring of community water systems using groundwater as a drinking water source.

PubMed

Whitmore, Roy W; Chen, Wenlin

2013-12-04

The ability to infer human exposure to substances from drinking water using monitoring data helps determine and/or refine potential risks associated with drinking water consumption. We describe a survey sampling approach and its application to an atrazine groundwater monitoring study to adequately characterize upper exposure centiles and associated confidence intervals with predetermined precision. Study design and data analysis included sampling frame definition, sample stratification, sample size determination, allocation to strata, analysis weights, and weighted population estimates. Sampling frame encompassed 15 840 groundwater community water systems (CWS) in 21 states throughout the U. S. Median, and 95th percentile atrazine concentrations were 0.0022 and 0.024 ppb, respectively, for all CWS. Statistical estimates agreed with historical monitoring results, suggesting that the study design was adequate and robust. This methodology makes no assumptions regarding the occurrence distribution (e.g., lognormality); thus analyses based on the design-induced distribution provide the most robust basis for making inferences from the sample to target population.

A Improved and Highly Effective Seabed Surface Sand Sampling Device

NASA Astrophysics Data System (ADS)

Liu, Ying

2017-04-01

In marine geology research, it is necessary to obtain a sufficient quantity of seabed surface samples, while also ensuring that the samples are in their original state. Currently, there are a number of seabed surface sampling devices available, but it is very difficult to obtain sand samples using ordinary seabed surface sampling devices, whereas machine-controlled seabed surface sampling devices are unable to dive into deeper regions of water. To obtain larger quantities of samples in their original states, many researchers have tried to improve seabed surface sampling devices, but these efforts have generally produced ambiguous results. To resolve the aforementioned issue, we have designed an improved and highly effective seabed surface sand sampling device, which incorporates the strengths of a variety of sampling devices; it is capable of diving into deeper water regions to obtain sand samples, and is also suited for use in streams, rivers, lakes and seas with varying levels of flow velocities and depth.

Recovery of diverse microbes in high turbidity surface water samples using dead-end ultrafiltration

PubMed Central

Mull, Bonnie; Hill, Vincent R.

2015-01-01

Dead-end ultrafiltration (DEUF) has been reported to be a simple, field-deployable technique for recovering bacteria, viruses, and parasites from large-volume water samples for water quality testing and waterborne disease investigations. While DEUF has been reported for application to water samples having relatively low turbidity, little information is available regarding recovery efficiencies for this technique when applied to sampling turbid water samples such as those commonly found in lakes and rivers. This study evaluated the effectiveness of a DEUF technique for recoveringMS2 bacteriophage, enterococci, Escherichia coli, Clostridium perfringens, and Cryptosporidium parvum oocysts in surface water samples having elevated turbidity. Average recovery efficiencies for each study microbe across all turbidity ranges were: MS2 (66%), C. parvum (49%), enterococci (85%), E. coli (81%), and C. perfringens (63%). The recovery efficiencies for MS2 and C. perfringens exhibited an inversely proportional relationship with turbidity, however no significant differences in recovery were observed for C. parvum, enterococci, or E. coli. Although ultrafilter clogging was observed, the DEUF method was able to process 100-L surface water samples at each turbidity level within 60 min. This study supports the use of the DEUF method for recovering a wide array of microbes in large-volume surface water samples having medium to high turbidity. PMID:23064261

Superoxygenated Water as an Experimental Sample for NMR Relaxometry

ERIC Educational Resources Information Center

Nestle, Nikolaus; Dakkouri, Marwan; Rauscher, Hubert

2004-01-01

The increase in NMR relaxation rates as a result of dissolved paramagnetic species on the sample of superoxygenated drinking water is demonstrated. It is concluded that oxygen content in NMR samples is an important issue and can give rise to various problems in the interpretation of both spectroscopic and NMR imaging or relaxation experiments.

"Nanofiltration" Enabled by Super-Absorbent Polymer Beads for Concentrating Microorganisms in Water Samples.

PubMed

Xie, Xing; Bahnemann, Janina; Wang, Siwen; Yang, Yang; Hoffmann, Michael R

2016-02-15

Detection and quantification of pathogens in water is critical for the protection of human health and for drinking water safety and security. When the pathogen concentrations are low, large sample volumes (several liters) are needed to achieve reliable quantitative results. However, most microbial identification methods utilize relatively small sample volumes. As a consequence, a concentration step is often required to detect pathogens in natural waters. Herein, we introduce a novel water sample concentration method based on superabsorbent polymer (SAP) beads. When SAP beads swell with water, small molecules can be sorbed within the beads, but larger particles are excluded and, thus, concentrated in the residual non-sorbed water. To illustrate this approach, millimeter-sized poly(acrylamide-co-itaconic acid) (P(AM-co-IA)) beads are synthesized and successfully applied to concentrate water samples containing two model microorganisms: Escherichia coli and bacteriophage MS2. Experimental results indicate that the size of the water channel within water swollen P(AM-co-IA) hydrogel beads is on the order of several nanometers. The millimeter size coupled with a negative surface charge of the beads are shown to be critical in order to achieve high levels of concentration. This new concentration procedure is very fast, effective, scalable, and low-cost with no need for complex instrumentation.

Use of an Electronic Tongue System and Fuzzy Logic to Analyze Water Samples

NASA Astrophysics Data System (ADS)

Braga, Guilherme S.; Paterno, Leonardo G.; Fonseca, Fernando J.

2009-05-01

An electronic tongue (ET) system incorporating 8 chemical sensors was used in combination with two pattern recognition tools, namely principal component analysis (PCA) and Fuzzy logic for discriminating/classification of water samples from different sources (tap, distilled and three brands of mineral water). The Fuzzy program exhibited a higher accuracy than the PCA and allowed the ET to classify correctly 4 in 5 types of water. Exception was made for one brand of mineral water which was sometimes misclassified as tap water. On the other hand, the PCA grouped water samples in three clusters, one with the distilled water; a second with tap water and one brand of mineral water, and the third with the other two other brands of mineral water. Samples in the second and third clusters could not be distinguished. Nevertheless, close grouping between repeated tests indicated that the ET system response is reproducible. The potential use of the Fuzzy logic as the data processing tool in combination with an electronic tongue system is discussed.

40 CFR 257.23 - Ground-water sampling and analysis requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... parameters shall be determined after considering the number of samples in the background data base, the data... considering the number of samples in the background data base, the data distribution, and the range of the... of § 257.22(a)(1). (f) The number of samples collected to establish ground-water quality data must be...

40 CFR 257.23 - Ground-water sampling and analysis requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... parameters shall be determined after considering the number of samples in the background data base, the data... considering the number of samples in the background data base, the data distribution, and the range of the... of § 257.22(a)(1). (f) The number of samples collected to establish ground-water quality data must be...

Mixed functional monomers-based monolithic adsorbent for the effective extraction of sulfonylurea herbicides in water and soil samples.

PubMed

Pei, Miao; Zhu, Xiangyu; Huang, Xiaojia

2018-01-05

Effective extraction is a key step in the determination of sulfonylurea herbicides (SUHs) in complicated samples. According to the chemical properties of SUHs, a new monolithic adsorbent utilizing acrylamidophenylboronic acid and vinylimidazole as mixed functional monomers was synthesized. The new adsorbent was employed as the extraction phase of multiple monolithic fiber solid-phase microextraction (MMF-SPME) of SUHs, and the extracted SUHs were determined by high-performance liquid chromatography with diode array detection (HPLC-DAD). Results well evidence that the prepared adsorbent could extract SUHs in environmental waters and soil effectively through multiply interactions such as boronate affinity, dipole-dipole and π-π interactions. Under the optimized extraction conditions, the limits of detection for target SUHs in environmental water and soil samples were 0.018-0.17μg/L and 0.14-1.23μg/kg, respectively. At the same time, the developed method also displayed some analytical merits including wide linear dynamic ranges, good method reproducibility, satisfactory sensitivity and low consume of organic solvent. Finally, the developed were successfully applied to monitor trace SUHs in environmental water and soil samples. The recoveries at three fortified concentrations were in the range of 70.6-119% with RSD below 11% in all cases. The obtained results well demonstrate the excellent practical applicability of the developed MMF-SPME-HPLC-DAD method for the monitoring of SUHs in water and soil samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Concentration of polycyclic aromatic hydrocarbons in water samples from different stages of treatment

NASA Astrophysics Data System (ADS)

Pogorzelec, Marta; Piekarska, Katarzyna

2017-11-01

The aim of this study was to analyze the presence and concentration of selected polycyclic aromatic hydrocarbons in water samples from different stages of treatment and to verify the usefulness of semipermeable membrane devices for analysis of drinking water. For this purpose, study was conducted for a period of 5 months. Semipermeable membrane devices were deployed in a surface water treatment plant located in Lower Silesia (Poland). To determine the effect of water treatment on concentration of PAHs, three sampling places were chosen: raw water input, stream of water just before disinfection and treated water output. After each month of sampling SPMDs were changed for fresh ones and prepared for further analysis. Concentrations of fifteen polycyclic aromatic hydrocarbons were determined by high performance liquid chromatography (HPLC). Presented study indicates that the use of semipermeable membrane devices can be an effective tool for the analysis of aquatic environment, including monitoring of drinking water, where organic micropollutants are present at very low concentrations.

Evaluation of minerals content of drinking water in Malaysia.

PubMed

Azlan, Azrina; Khoo, Hock Eng; Idris, Mohd Aizat; Ismail, Amin; Razman, Muhammad Rizal

2012-01-01

The drinking and mineral water samples obtained from different geographical locations had concentrations of the selected minerals lower than the standard limits, except for manganese, arsenic, and fluoride. The concentrations of manganese and arsenic in two mineral water samples were slightly higher than the standard international recommended limits. One mineral water sample had a fluoride concentration higher than the standard limits, whereas manganese was not detected in nine drinking and mineral water samples. Most of the selected minerals found in the tap water samples were below the international standard limits, except for iron and manganese. The concentrations of iron and manganese in the tap water samples were higher than the standard limits, which were obtained from one and three of the studied locations, respectively. The potable water obtained from various manufacturers and locations in Peninsular Malaysia is safe for consumption, as the minerals concentrations were below the standard limits prescribed by the Malaysian Food Regulations of 1985. The data obtained may also provide important information related to daily intake of these minerals from drinking water.

Evaluation of Minerals Content of Drinking Water in Malaysia

PubMed Central

Azlan, Azrina; Khoo, Hock Eng; Idris, Mohd Aizat; Ismail, Amin; Razman, Muhammad Rizal

2012-01-01

The drinking and mineral water samples obtained from different geographical locations had concentrations of the selected minerals lower than the standard limits, except for manganese, arsenic, and fluoride. The concentrations of manganese and arsenic in two mineral water samples were slightly higher than the standard international recommended limits. One mineral water sample had a fluoride concentration higher than the standard limits, whereas manganese was not detected in nine drinking and mineral water samples. Most of the selected minerals found in the tap water samples were below the international standard limits, except for iron and manganese. The concentrations of iron and manganese in the tap water samples were higher than the standard limits, which were obtained from one and three of the studied locations, respectively. The potable water obtained from various manufacturers and locations in Peninsular Malaysia is safe for consumption, as the minerals concentrations were below the standard limits prescribed by the Malaysian Food Regulations of 1985. The data obtained may also provide important information related to daily intake of these minerals from drinking water. PMID:22649292

Determination of trace inorganic mercury species in water samples by cloud point extraction and UV-vis spectrophotometry.

PubMed

Ulusoy, Halil Ibrahim

2014-01-01

A new micelle-mediated extraction method was developed for preconcentration of ultratrace Hg(II) ions prior to spectrophotometric determination. 2-(2'-Thiazolylazo)-p-cresol (TAC) and Ponpe 7.5 were used as the chelating agent and nonionic surfactant, respectively. Hg(II) ions form a hydrophobic complex with TAC in a micelle medium. The main factors affecting cloud point extraction efficiency, such as pH of the medium, concentrations of TAC and Ponpe 7.5, and equilibration temperature and time, were investigated in detail. An overall preconcentration factor of 33.3 was obtained upon preconcentration of a 50 mL sample. The LOD obtained under the optimal conditions was 0.86 microg/L, and the RSD for five replicate measurements of 100 microg/L Hg(II) was 3.12%. The method was successfully applied to the determination of Hg in environmental water samples.

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; in-bottle acid digestion of whole-water samples

USGS Publications Warehouse

Hoffman, G.L.; Fishman, M. J.; Garbarino, J.R.

1996-01-01

Water samples for trace-metal determinations routinely have been prepared in open laboratories. For example, the U.S. Geological Survey method I-3485-85 (Extraction Procedure, for Water- Suspended Sediment) is performed in a laboratory hood on a laboratory bench without any special precautions to control airborne contamination. This method tends to be contamination prone for several trace metals primarily because the samples are transferred, acidified, digested, and filtered in an open laboratory environment. To reduce trace-metal contamination of digested water samples, procedures were established that rely on minimizing sample-transfer steps and using a class-100 clean bench during sample filtration. This new procedure involves the following steps: 1. The sample is acidified with HCl directly in the original water-sample bottle. 2. The water-sample bottle with the cap secured is heated in a laboratory oven. 3. The digestate is filtered in a class-100 laminar-flow clean bench. The exact conditions used (that is, oven temperature, time of heating, and filtration methods) for this digestion procedure are described. Comparisons between the previous U.S Geological Survey open-beaker method I-3485-85 and the new in-bottle procedure for synthetic and field-collected water samples are given. When the new procedure is used, blank concentrations for most trace metals determined are reduced significantly.

Water barrier properties of starch films reinforced with cellulose nanocrystals obtained from sugarcane bagasse.

PubMed

Slavutsky, Aníbal M; Bertuzzi, María A

2014-09-22

Water transport in edible films based on hydrophilic materials such as starch, is a complex phenomenon due to the strong interaction of sorbed water molecules with the polymeric structure. Cellulose nanocrystals (CNC) were obtained from sugarcane bagasse. Starch and starch/CNC films were formulated and their water barrier properties were studied. The measured film solubility, contact angle, and water sorption isotherm indicated that reinforced starch/CNC films have a lower affinity to water molecules than starch films. The effects that the driving force and the water activity (aw) values at each side of the film have on permeability were analyzed. Permeability, diffusivity, and solubility coefficients indicated that the permeation process depends mostly on the tortuous pathway formed by the incorporation of CNC and therefore were mainly controlled by water diffusion. The interaction between CNC and starch chain is favoured by the chemical similarities of both molecules. Copyright © 2014 Elsevier Ltd. All rights reserved.

Pushpoint sampling for defining spatial and temporal variations in contaminant concentrations in sediment pore water near the ground-water / surface-water interface

USGS Publications Warehouse

Zimmerman, Marc J.; Massey, Andrew J.; Campo, Kimberly W.

2005-01-01

During four periods from April 2002 to June 2003, pore-water samples were taken from river sediment within a gaining reach (Mill Pond) of the Sudbury River in Ashland, Massachusetts, with a temporary pushpoint sampler to determine whether this device is an effective tool for measuring small-scale spatial variations in concentrations of volatile organic compounds and selected field parameters (specific conductance and dissolved oxygen concentration). The pore waters sampled were within a subsurface plume of volatile organic compounds extending from the nearby Nyanza Chemical Waste Dump Superfund site to the river. Samples were collected from depths of 10, 30, and 60 centimeters below the sediment surface along two 10-meter-long, parallel transects extending into the river. Twenty-five volatile organic compounds were detected at concentrations ranging from less than 1 microgram per liter to hundreds of micrograms per liter (for example, 1,2-dichlorobenzene, 490 micrograms per liter; cis-1,2-dichloroethene, 290 micrograms per liter). The most frequently detected compounds were either chlorobenzenes or chlorinated ethenes. Many of the compounds were detected only infrequently. Quality-control sampling indicated a low incidence of trace concentrations of contaminants. Additional samples collected with passive-water-diffusion-bag samplers yielded results comparable to those collected with the pushpoint sampler and to samples collected in previous studies at the site. The results demonstrate that the pushpoint sampler can yield distinct samples from sites in close proximity; in this case, sampling sites were 1 meter apart horizontally and 20 or 30 centimeters apart vertically. Moreover, the pushpoint sampler was able to draw pore water when inserted to depths as shallow as 10 centimeters below the sediment surface without entraining surface water. The simplicity of collecting numerous samples in a short time period (routinely, 20 to 30 per day) validates the use of a

Algae viability over time in a ballast water sample

NASA Astrophysics Data System (ADS)

Gollasch, Stephan; David, Matej

2018-03-01

The biology of vessels' ballast water needs to be analysed for several reasons, one of these being performance tests of ballast water management systems. This analysis includes a viability assessment of phytoplankton. To overcome logistical problems to get algae sample processing gear on board of a vessel to document algae viability, samples may be transported to land-based laboratories. Concerns were raised how the storage conditions of the sample may impact algae viability over time and what the most appropriate storage conditions were. Here we answer these questions with a long-term algae viability study with daily sample analysis using Pulse-Amplitude Modulated (PAM) fluorometry. The sample was analysed over 79 days. We tested different storage conditions: fridge and room temperature with and without light. It seems that during the first two weeks of the experiment the viability remains almost unchanged with a slight downwards trend. In the continuing period, before the sample was split, a slightly stronger downwards viability trend was observed, which occurred at a similar rate towards the end of the experiment. After the sample was split, the strongest viability reduction was measured for the sample stored without light at room temperature. We concluded that the storage conditions, especially regarding temperature and light exposure, have a stronger impact on algae viability compared to the storage duration and that inappropriate storage conditions reduce algal viability. A sample storage time of up to two weeks in a dark and cool environment has little influence on the organism viability. This indicates that a two week time duration between sample taking on board a vessel and the viability measurement in a land-based laboratory may not be very critical.

Recovery of diverse microbes in high turbidity surface water samples using dead-end ultrafiltration.

PubMed

Mull, Bonnie; Hill, Vincent R

2012-12-01

Dead-end ultrafiltration (DEUF) has been reported to be a simple, field-deployable technique for recovering bacteria, viruses, and parasites from large-volume water samples for water quality testing and waterborne disease investigations. While DEUF has been reported for application to water samples having relatively low turbidity, little information is available regarding recovery efficiencies for this technique when applied to sampling turbid water samples such as those commonly found in lakes and rivers. This study evaluated the effectiveness of a DEUF technique for recovering MS2 bacteriophage, enterococci, Escherichia coli, Clostridium perfringens, and Cryptosporidium parvum oocysts in surface water samples having elevated turbidity. Average recovery efficiencies for each study microbe across all turbidity ranges were: MS2 (66%), C. parvum (49%), enterococci (85%), E. coli (81%), and C. perfringens (63%). The recovery efficiencies for MS2 and C. perfringens exhibited an inversely proportional relationship with turbidity, however no significant differences in recovery were observed for C. parvum, enterococci, or E. coli. Although ultrafilter clogging was observed, the DEUF method was able to process 100-L surface water samples at each turbidity level within 60 min. This study supports the use of the DEUF method for recovering a wide array of microbes in large-volume surface water samples having medium to high turbidity. Published by Elsevier B.V.

Guidance for the Development of Air Force Storm Water Sampling Programs

DTIC Science & Technology

1993-09-01

38 Storm Water Quality Monitoring ................. 39 Determining Flow Rate ....................... 42 Weirs and Flumes... water quality monitoring it is not possible to analyze the entire nmoff from a drainage basin. The objective of water quality sampling is to collect a...development of storm water pollution prevention plans. Best management practices can also be developed to control the pollution sources identified. In storm

A Simple Alternative Method for Preservation of 2-Methylisoborneol in Water Samples

PubMed Central

Lin, Tsair-Fuh

2018-01-01

2-Methylisoborneol (2-MIB) is one of the most commonly observed taste and odor (T&O) compounds present in drinking water sources. As it is biodegradable, a preservation agent, typically mercury chloride, is needed if the water is not analyzed right after sampling. Since mercury is a toxic metal, an alternative chemical that is cheaper and less toxic is desirable. In this study, two chemicals commonly used in water treatment processes, chlorine (as sodium hypochlorite) and KMnO4 (potassium permanganate), are studied to determine their feasibility as preservation agents for 2-MIB in water. Preservation experiments were first conducted in deionized water spiked with 2-MIB and with chlorine or permanganate at 4 and 25 °C. The results indicate that 2-MIB concentrations in the water samples spiked with both chemicals remained almost constant within 14 days for all the tested conditions, suggesting that oxidation and volatilization did not cause the loss of 2-MIB in the system. The experiments were further conducted for three different reservoir water samples with 30–60 ng/L of indulgent 2-MIB. The experimental results demonstrated that preservation with permanganate may have underestimated the 2-MIB concentration in the samples as a result of the formation of manganese dioxide particles in natural water and adsorption of 2-MIB onto the particles. Chlorine was demonstrated to be a good preservation agent for all three tested natural waters since oxidation of 2-MIB was negligible and biodegradation was inhibited. When the residual chlorine concentrations were controlled to be higher than 0.5 mg/L on the final day (day 14) of the experiments, the concentration reduction of 2-MIB became lower than 13% at both of the tested temperatures. The results demonstrated that sodium hypochlorite can be used as an alternative preservation agent for 2-MIB in water before analysis. PMID:29783625

Antibiotic residues in milk samples obtained from cows after treatment for papillomatous digital dermatitis.

PubMed

Britt, J S; Carson, M C; von Bredow, J D; Condon, R J

1999-09-15

To determine whether there would be detectable antibiotic residues in milk obtained from dairy cattle with papillomatous digital dermatitis (PDD) after topical treatment with oxytetracycline. Randomized controlled clinical trial. 28 lactating Holstein cows with PDD. Cows were assigned to 2 treatment groups. Treatment 1 (n = 16) consisted of spraying of PDD lesions with 15 ml of a solution containing 100 mg of oxytetracycline/ml; lesions were sprayed twice daily for 7 days, using a garden sprayer. Treatment 2 (n = 12) consisted of a one-time application of a bandage that consisted of cotton soaked with 20 ml of a solution containing 100 mg of oxytetracycline/ml. Milk samples were obtained before and after treatment and assayed for tetracycline content by use of high-performance liquid chromatography and a commercially available tetracycline screening test. None of the cows in either treatment group had violative residues of oxytetracycline in milk samples. Producers treating lactating cows that have PDD, via topical application of oxytetracycline solution at the concentrations reported in this study, have a low risk of causing violative antibiotic residues in milk.

Influence of enrichment broths on multiplex PCR detection of total coliform bacteria, Escherichia coli and Clostridium perfringens, in spiked water samples.

PubMed

Worakhunpiset, S; Tharnpoophasiam, P

2009-07-01

Although multiplex PCR amplification condition for simultaneous detection of total coliform bacteria, Escherichia coli and Clostridium perfringens in water sample has been developed, results with high sensitivity are obtained when amplifying purified DNA, but the sensitivity is low when applied to spiked water samples. An enrichment broth culture prior PCR analysis increases sensitivity of the test but the specific nature of enrichment broth can affect the PCR results. Three enrichment broths, lactose broth, reinforced clostridial medium and fluid thioglycollate broth, were compared for their influence on sensitivity and on time required with multiplex PCR assay. Fluid thioglycollate broth was the most effective with shortest enrichment time and lowest detection limit.

FILTRATION OF GROUND WATER SAMPLES FOR METALS ANALYSIS

EPA Science Inventory

The filtration of a ground water samples with 0.45 um filters for determination of 'dissolved' metals is not only inaccurate for distinguishing between dissolved and particulate phases, but if used for estimates of mobile contaminant loading in a given aquifer, may result in sign...

Concentration and characteristics of depleted uranium in water, air and biological samples collected in Serbia and Montenegro.

PubMed

Jia, Guogang; Belli, Maria; Sansone, Umberto; Rosamilia, Silvia; Gaudino, Stefania

2005-09-01

During the Balkan conflicts, in 1995 and 1999, depleted uranium (DU) rounds were employed and were left in the battlefield. Health concern is related to the risk arising from contamination of the environment with DU penetrators and dust. In order to evaluate the impact of DU on the environment and population in Serbia and Montenegro, radiological surveys of DU in water, air and biological samples were carried out over the period 27 October-5 November 2001. The uranium isotopic concentrations in biological samples collected in Serbia and Montenegro, mainly lichens and barks, were found to be in the range of 0.67-704 Bqkg(-1) for (238)U, 0.48-93.9 Bqkg(-1) for (234)U and 0.02-12.2 Bqkg(-1) for (235)U, showing uranium levels to be higher than in the samples collected at the control sites. Moreover, (236)U was detectable in some of the samples. The isotopic ratios of (234)U/(238)U showed DU to be detectable in many biological samples at all examined sites, especially in Montenegro, indicating widespread ground-surface DU contamination, albeit at very low level. The uranium isotopic concentrations in air obtained from the air filter samples collected in Serbia and Montenegro were found to be in the range of 1.99-42.1 microBqm(-3) for (238)U, 0.96-38.0 microBqm(-3) for (234)U, and 0.05-1.83 microBqm(-3) for (235)U, being in the typical range of natural uranium values. Thus said, most of the air samples are DU positive, this fact agreeing well with the widespread DU contamination detected in the biological samples. The uranium concentrations in water samples collected in Serbia and Montenegro were found to be in the range of 0.40-21.9 mBql(-1) for (238)U, 0.27-28.1 mBql(-1) for (234)U, and 0.01-0.88 mBql(-1) for (235)U, these values being much lower than those in mineral water found in central Italy and below the WHO guideline for drinking water. From a radiotoxicological point of view, at this moment there is no significant radiological risk related to these investigated

Identification of Phyllosilicates in Mudstone Samples Using Water Releases Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater, Mars

NASA Technical Reports Server (NTRS)

Hogancamp, J. V. (Clark); Ming, D. W.; McAdam, A. C.; Archer, P. D.; Morris, R. V.; Bristow, T. F.; Rampe, E. B.; Mahaffy, P. R.; Gellert, R.

2017-01-01

The Sample Analysis at Mars (SAM) instrument on board the Curiosity Rover has detected high temperature water releases from mud-stones in the areas of Yellowknife Bay, Pahrump Hills, Naukluft Plateau, and Murray Buttes in Gale crater. Dehydroxylation of phyllosilicates may have caused the high temperature water releases observed in these samples. Because each type of phyllosilicate undergoes dehydroxylation at distinct temperatures, these water releases can be used to help constrain the type of phyllosilicate present in each sample.

Dithizone-functionalized solid phase extraction-displacement elution-high performance liquid chromatography-inductively coupled plasma mass spectrometry for mercury speciation in water samples.

PubMed

Yin, Yong-guang; Chen, Ming; Peng, Jin-feng; Liu, Jing-fu; Jiang, Gui-bin

2010-06-15

A novel and simple solid phase extraction (SPE)-high performance liquid chromatography (HPLC)-inductively coupled plasma mass spectrometry (ICP-MS) method was developed for determination of inorganic mercury (IHg), methylmercury MeHg and ethylmercury (EtHg) in water samples in the present work. The procedure involves pre-functionalization of the commercially available C18 SPE column with dithizone, loading water sample, displacement elution of mercury species by Na(2)S(2)O(3) solution, followed by HPLC-ICP-MS determination. Characterization and optimization of operation parameters of this new SPE procedure were discussed, including eluting reagent selection, concentration of eluting reagent, volume of eluting reagent, effect of NaCl and humic acid in sample matrix. At optimized conditions, the detection limits of mercury species for 100mL water sample were about 3ngL(-1) and the average recoveries were 93.7, 83.4, and 71.7% for MeHg, IHg and EtHg, respectively, by spiking 0.2microgL(-1) mercury species into de-ion water. Stability experiment reveals that both the dithizone-functionalized SPE cartridge and the mercury species incorporated were stable in the storage procedure. These results obtained demonstrate that SPE-HPLC-ICP-MS is a simple and sensitive technique for the determination of mercury species at trace level in water samples with high reproducibility and accuracy.

Magnetic solid-phase extraction of five pyrethroids from environmental water samples followed by ultrafast liquid chromatography analysis.

PubMed

Yu, Xi; Sun, Ying; Jiang, Chunzhu; Sun, Xiumin; Gao, Yan; Wang, Yuanpeng; Zhang, Hanqi; Song, Daqian

2012-08-30

In this study, the polystyrene-coated magnetic nanoparticles (MNPs/PSt) were successfully prepared and characterized by Fourier transform infrared spectroscopy, transmission electron microscopy and vibrating sample magnetometry. The as-prepared MNPs/PSt were used as the adsorbent in magnetic solid phase extraction of five pyrethroids, including lambda-cyhalothrin, deltamethrin, esfenvalerate, permethrin, bifenthrin, in environmental water samples. The five pyrethroids were determined by ultra fast liquid chromatography-ultraviolet spectrometry. The influencing factors, including amount of MNPs/Pst, extraction time, pH value, type and volume of desorption solvent and desorption time, were examined and optimized. The extraction recoveries obtained with merely 50mg of MNPs/Pst were very satisfactory. The whole extraction process could be completed within 0.5h. The MNPs/PSt can be reused after an easy washing process. Thus, a simple, green, economical, time saving and effective method for pyrethroids analysis in environmental water samples was established. A high enrichment factor of 500 was achieved and the limits of detection for lambda-cyhalothrin, deltamethrin, esfenvalerate, permethrin, bifenthrin were 0.015±0.001 ng mL(-1), 0.012±0.001 ng mL(-1), 0.026±0.001 ng mL(-1), 0.020±0.001 ng mL(-1), 0.013±0.001 ng mL(-1), respectively. Recoveries obtained by analyzing spiked water samples at three concentration levels (0.100±0.001 ng mL(-1), 1.000±0.001 ng mL(-1), 10.000±0.001 ng mL(-1)) were between 78.97±8.38% and 96.05±8.38%. The standard curves for the five pyrethroids showed good linearity with the correlation coefficients in the range of 0.9994-0.9999. The intra-day and inter-day precision were satisfactory with the RSDs in the range of 2.05-5.52% and 2.73-8.38%, respectively. Copyright © 2012 Elsevier B.V. All rights reserved.

Correlation between E. coli levels and the presence of foodborne pathogens in surface irrigation water: Establishment of a sampling program.

PubMed

Truchado, Pilar; Hernandez, Natalia; Gil, Maria I; Ivanek, Renata; Allende, Ana

2018-01-01

To establish the association between microbial indicators and the presence of foodborne pathogens in irrigation water, Escherichia coli was enumerated using two quantification methods (plate counts and PMA-qPCR) and presence/absence of pathogenic microorganisms, including five strains from the Shiga toxigenic E. coli (O157:H7, O26, O103, O111 and O145) and Salmonella spp. were evaluated. The results confirmed that surface water can be considered a microbial hazard when used for irrigation. The levels of viable E. coli were very similar to those of cultivable E. coli, except for irrigation water obtained from water reservoirs. Comparison between the E. coli counts in samples positive and negative for the presence of pathogenic bacteria for the evaluated water sources identified E. coli level of 2.35 log cfu/100 mL as a cut-off able to correctly predict positive and negative samples with 93% sensitivity and 66% specificity, respectively. Thus, for the samples with levels of E. coli under 2.35 log cfu/100 mL (e.g., 2.24 log cfu/100 mL) there was a 90% probability that the samples were not contaminated with pathogenic microorganism in locations with similar prevalence. E. coli levels in irrigation water were affected by the ambient temperature confirming that water source and climate conditions should be taken into account by growers when designing a sampling program and the frequency of the monitoring to make a better and more efficient use of their resources. Copyright © 2017 Elsevier Ltd. All rights reserved.

Water evaporation: a transition path sampling study.

PubMed

Varilly, Patrick; Chandler, David

2013-02-07

We use transition path sampling to study evaporation in the SPC/E model of liquid water. On the basis of thousands of evaporation trajectories, we characterize the members of the transition state ensemble (TSE), which exhibit a liquid-vapor interface with predominantly negative mean curvature at the site of evaporation. We also find that after evaporation is complete, the distributions of translational and angular momenta of the evaporated water are Maxwellian with a temperature equal to that of the liquid. To characterize the evaporation trajectories in their entirety, we find that it suffices to project them onto just two coordinates: the distance of the evaporating molecule to the instantaneous liquid-vapor interface and the velocity of the water along the average interface normal. In this projected space, we find that the TSE is well-captured by a simple model of ballistic escape from a deep potential well, with no additional barrier to evaporation beyond the cohesive strength of the liquid. Equivalently, they are consistent with a near-unity probability for a water molecule impinging upon a liquid droplet to condense. These results agree with previous simulations and with some, but not all, recent experiments.

Glufosinate ammonium clean-up procedure from water samples using SPE

NASA Astrophysics Data System (ADS)

Tayeb M., A.; Ismail B., S.; Mardiana-Jansar, K.; Ta, Goh Choo; Agustar, Hani Kartini

2015-09-01

For the determination of glufosinate ammonium residue in soil and water samples, different solid phase extraction (SPE) sorbent efficiency was studied. Four different SPE sorbents i.e.: CROMABOND PS-H+, CROMABOND PS-OH-, ISOLUTE ENV+, Water Sep-Pak and OASIS HLB were used. Sample clean-up performance was evaluated using high performance liquid chromatography (Agilent 1220 infinity LC) with fluorescence detector. Detection of FMO-derivatives was done at λ ex = 260 nm and λ em= 310 nm. OASIS HLB column was the most suitable for the clean-up in view of the overall feasibility of the analysis.

Monitoring water quality in Toronto's urban stormwater ponds: Assessing participation rates and data quality of water sampling by citizen scientists in the FreshWater Watch.

PubMed

Scott, Andrew B; Frost, Paul C

2017-08-15

From 2013 to 2015, citizen scientist volunteers in Toronto, Canada were trained to collect and analyze water quality in urban stormwater ponds. This volunteer sampling was part of the research program, FreshWater Watch (FWW), which aimed to standardize urban water sampling efforts from around the globe. We held training sessions for new volunteers twice yearly and trained a total of 111 volunteers. Over the course of project, ~30% of volunteers participated by collecting water quality data after the training session with 124 individual sampling events at 29 unique locations in Toronto, Canada. A few highly engaged volunteers were most active, with 50% of the samples collected by 5% of trainees. Stormwater ponds generally have poor water quality demonstrated by elevated phosphate concentrations (~30μg/L), nitrate (~427μg/L), and turbidity relative to Canadian water quality standards. Compared to other urban waterbodies in the global program, nutrient concentrations in Toronto's urban stormwater ponds were lower, while turbidity was not markedly different. Toronto FWW (FWW-TO) data was comparable to that measured by standard lab analyses and matched results from previous studies of stormwater ponds in Toronto. Combining observational and chemical data acquired by citizen scientists, macrophyte dominated ponds had lower phosphate concentrations while phytoplankton dominated ponds had lower nitrate concentrations, which indicates a potentially important and unstudied role of internal biogeochemical processes on pond nutrient dynamics. This experience in the FWW demonstrates the capabilities and constraints of citizen science when applied to water quality sampling. While analytical limits on in-field analyses produce higher uncertainty in water quality measurements of individual sites, rapid data collection is possible but depends on the motivation and engagement of the group of volunteers. Ongoing efforts in citizen science will thus need to address sampling effort

USDA Forest Service national protocols for sampling air pollution-sensitive waters

Treesearch

T. J. Sullivan

2012-01-01

The first step in designing a surface water sampling program is identifying one or more problems or questions that require information on water quality. Common water quality problems include nutrient enrichment (from a variety of causes), effects of atmospheric deposition (acidification, eutrophication, toxicity), and effects of major disturbances such as fire or pest...

Errors in Measuring Water Potentials of Small Samples Resulting from Water Adsorption by Thermocouple Psychrometer Chambers 1

PubMed Central

Bennett, Jerry M.; Cortes, Peter M.

1985-01-01

The adsorption of water by thermocouple psychrometer assemblies is known to cause errors in the determination of water potential. Experiments were conducted to evaluate the effect of sample size and psychrometer chamber volume on measured water potentials of leaf discs, leaf segments, and sodium chloride solutions. Reasonable agreement was found between soybean (Glycine max L. Merr.) leaf water potentials measured on 5-millimeter radius leaf discs and large leaf segments. Results indicated that while errors due to adsorption may be significant when using small volumes of tissue, if sufficient tissue is used the errors are negligible. Because of the relationship between water potential and volume in plant tissue, the errors due to adsorption were larger with turgid tissue. Large psychrometers which were sealed into the sample chamber with latex tubing appeared to adsorb more water than those sealed with flexible plastic tubing. Estimates are provided of the amounts of water adsorbed by two different psychrometer assemblies and the amount of tissue sufficient for accurate measurements of leaf water potential with these assemblies. It is also demonstrated that water adsorption problems may have generated low water potential values which in prior studies have been attributed to large cut surface area to volume ratios. PMID:16664367

Flotation-separation of aluminum from some water samples using powdered marble waste and oleic acid.

PubMed

Ghazy, Shaban el-Sayed; Samra, Salem el-Sayed; Mahdy, Abd el-Fattah Mohammed; el-Morsy, Sherin Mohammed

2003-10-01

Bench-scale experiments were conducted in the laboratory, aiming to remove aluminum from water. They were based on the use of powdered marble wastes (PMW), which are inexpensive and produced in large quantity, and thus potentially cause environmental problems, as an effective inorganic sorbent and oleic acid (HOL) as surfactant. The main parameters (solution pHs, sorbent, surfactant and aluminum concentrations, shaking time, ionic strength and the presence of foreign ions) that influence the sorptive-flotation process were examined. Good results were obtained under the optimum conditions, for which nearly 100% of aluminum at pH 7 and at room temperature (approximately 25 degrees C) was removed. The procedure was successfully applied to the recovery of aluminum spiked to some natural water samples. Moreover, a sorption and flotation mechanism is suggested.

Assessment of PDMS-water partition coefficients: implications for passive environmental sampling of hydrophobic organic compounds

USGS Publications Warehouse

DiFilippo, Erica L.; Eganhouse, Robert P.

2010-01-01

Solid-phase microextraction (SPME) has shown potential as an in situ passive-sampling technique in aquatic environments. The reliability of this method depends upon accurate determination of the partition coefficient between the fiber coating and water (Kf). For some hydrophobic organic compounds (HOCs), Kf values spanning 4 orders of magnitude have been reported for polydimethylsiloxane (PDMS) and water. However, 24% of the published data examined in this review did not pass the criterion for negligible depletion, resulting in questionable Kf values. The range in reported Kf is reduced to just over 2 orders of magnitude for some polychlorinated biphenyls (PCBs) when these questionable values are removed. Other factors that could account for the range in reported Kf, such as fiber-coating thickness and fiber manufacturer, were evaluated and found to be insignificant. In addition to accurate measurement of Kf, an understanding of the impact of environmental variables, such as temperature and ionic strength, on partitioning is essential for application of laboratory-measured Kf values to field samples. To date, few studies have measured Kf for HOCs at conditions other than at 20 degrees or 25 degrees C in distilled water. The available data indicate measurable variations in Kf at different temperatures and different ionic strengths. Therefore, if the appropriate environmental variables are not taken into account, significant error will be introduced into calculated aqueous concentrations using this passive sampling technique. A multiparameter linear solvation energy relationship (LSER) was developed to estimate log Kf in distilled water at 25 degrees C based on published physicochemical parameters. This method provided a good correlation (R2 = 0.94) between measured and predicted log Kf values for several compound classes. Thus, an LSER approach may offer a reliable means of predicting log Kf for HOCs whose experimental log Kf values are presently unavailable. Future

Field guide for collecting samples for analysis of volatile organic compounds in stream water for the National Water-Quality Assessment Program

USGS Publications Warehouse

Shelton, Larry R.

1997-01-01

For many years, stream samples for analysis of volatile organic compounds have been collected without specific guidelines or a sampler designed to avoid analyte loss. In 1996, the U.S. Geological Survey's National Water-Quality Assessment Program began aggressively monitoring urban stream-water for volatile organic compounds. To assure representative samples and consistency in collection procedures, a specific sampler was designed to collect samples for analysis of volatile organic compounds in stream water. This sampler, and the collection procedures, were tested in the laboratory and in the field for compound loss, contamination, sample reproducibility, and functional capabilities. This report describes that sampler and its use, and outlines field procedures specifically designed to provide contaminant-free, reproducible volatile organic compound data from stream-water samples. These guidelines and the equipment described represent a significant change in U.S. Geological Survey instructions for collecting and processing stream-water samples for analysis of volatile organic compounds. They are intended to produce data that are both defensible and interpretable, particularly for concentrations below the microgram-per-liter level. The guidelines also contain detailed recommendations for quality-control samples.

Factors controlling elevated lead concentrations in water samples from aquifer systems in Florida

USGS Publications Warehouse

Katz, B.G.; Bullen, M.P.; Bullen, T.D.; Hansard, Paul

1999-01-01

Concentrations of total lead (Pb) and dissolved Pb exceeded the U.S. Environmental Protection Agency action level of 15 micrograms per liter (mg/L) in approximately 19 percent and 1.3 percent, respectively, of ground-water samples collected during 1991-96 from a statewide network of monitoring wells designed to delineate background water quality of Florida's major aquifer systems. Differences in total Pb concentrations among aquifer systems reflect the combined influence of anthropogenic sources and chemical conditions in each system. A highly significant (p<0.001) difference in median total Pb concentrations was found for water samples from wells with water-level recording devices that contain Pb-counterweights (14 mg/L) compared to non-recorder wells (2 mg/L). Differences between total Pb concentrations for recorder and non-recorder wells are even more pronounced when compared for each aquifer system. The largest differences for recorder status are found for the surficial aquifer system, where median total Pb concentrations are 44 and 2.4 mg/L for recorder wells and non-recorder wells, respectively. Leaching of Pb from metal casing materials is another potential source of Pb in ground water samples. Median total Pb concentrations in water samples from the surficial, intermediate, and Floridan aquifer systems are higher from recorder wells cased with black iron than for recorder wells with steel and PVC casing material. Stable isotopes of Pb were used in this study to distinguish between anthropogenic and natural sources of Pb in ground water, as Pb retains the isotopic signature of the source from which it is derived. Based on similarities between slopes and intercepts of trend lines for various sample types (plots of 206Pb/204Pb versus 208Pb/204Pb and 207Pb/204Pb versus 208Pb/204Pb) the predominant source of total Pb in water samples from the surficial aquifer system is corrosion of Pb counterweights. It is likely that only ground-water samples, not the aquifer

Verification of spectrophotometric method for nitrate analysis in water samples

NASA Astrophysics Data System (ADS)

Kurniawati, Puji; Gusrianti, Reny; Dwisiwi, Bledug Bernanti; Purbaningtias, Tri Esti; Wiyantoko, Bayu

2017-12-01

The aim of this research was to verify the spectrophotometric method to analyze nitrate in water samples using APHA 2012 Section 4500 NO3-B method. The verification parameters used were: linearity, method detection limit, level of quantitation, level of linearity, accuracy and precision. Linearity was obtained by using 0 to 50 mg/L nitrate standard solution and the correlation coefficient of standard calibration linear regression equation was 0.9981. The method detection limit (MDL) was defined as 0,1294 mg/L and limit of quantitation (LOQ) was 0,4117 mg/L. The result of a level of linearity (LOL) was 50 mg/L and nitrate concentration 10 to 50 mg/L was linear with a level of confidence was 99%. The accuracy was determined through recovery value was 109.1907%. The precision value was observed using % relative standard deviation (%RSD) from repeatability and its result was 1.0886%. The tested performance criteria showed that the methodology was verified under the laboratory conditions.

UMTRA project water sampling and analysis plan, Durango, Colorado

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

Not Available

1994-01-01

Surface remedial action has been completed at the Uranium Mill Tailings Remedial Action Project in Durango, Colorado. Contaminated soil and debris have been removed from the former processing site and placed in the Bodo Canyon disposal cell. Ground water at the former uranium mill/tailings site and raffinate pond area has been contaminated by the former milling operations. The ground water at the disposal site was not impacted by the former milling operations at the time of the cell`s construction. Activities for fiscal 1994 involve ground water sampling and site characterization of the disposal site.

Molecular identification of Blastocystis sp. subtypes in water samples collected from Black sea, Turkey.

PubMed

Koloren, Zeynep; Gulabi, Berivan Basak; Karanis, Panagiotis

2018-04-01

The aim of this study was to identify the subtypes of Blastocystis sp. and complete a phylogenetic analysis of 268 water samples that were collected from the Samsun, Amasya and Sinop Provinces of the Black Sea in Turkey, between the years 2011 and 2014. Blastocystis sp. was investigated in 48 uncultured sea water samples that were collected from 4 sites within the Sinop Province. A total of 100 river water samples were collected from 37 sites in the Samsun Province and 120 river water samples were collected from 10 sampling sites within the Amasya Province. The small subunit (SSU) rDNA gene Polymerase chain reaction (PCR) were performed for the detection of Blastocytis sp. and the PCR-positive samples were sequenced. Subsequently, the (SSU) rDNA sequences were aligned by Bioedit and phylogenetic trees were constructed for Blastocystis with reference to the genotypes from GenBank. Blastocystis sp. were found in 3 out of the 75 (4%) river water samples that were collected from the Samsun Province. Six of the 120 (5%) river water samples and 1 out of the 48 (2%) seawater samples were positive for Blastocystis in the Amasya and Sinop Provinces. There were two different subtypes (ST; 1 and 3) found from sequencing all of the samples from the investigated sites. Two and one PCR products were found to be positive for ST1 and ST3 from the different samples collected within the Samsun Province. Two and 4 PCR products from the Amasya Province were ST1 and ST3, respectively and only one sample from the Sinop Province was found to be positive for ST1. This is the first report to identify and report the occurrence of Blastocystis subtypes within the Black Sea of Turkey. Copyright © 2018 Elsevier B.V. All rights reserved.

Freshwater macroinvertebrate samples from a water quality monitoring network in the Iberian Peninsula.

PubMed

Escribano, Nora; Oscoz, Javier; Galicia, David; Cancellario, Tommaso; Durán, Concha; Navarro, Patricia; Ariño, Arturo H

2018-06-05

This dataset gathers information about the macroinvertatebrate samples and environmental variables collected on rivers of the Ebro River Basin (NE Iberian Peninsula), the second largest catchment in the Iberian Peninsula. The collection is composed of 1,776 sampling events carried out between 2005 and 2015 at more than 400 sampling sites. This dataset is part of a monitoring network set up by the Ebro Hydrographic Confederation, the official body entrusted with the care of the basin, to fulfill the requirements of the European Water Framework Directive. Biological indices based on the freshwater macroinvertebrate communities were used to evaluate the ecological status of the water bodies within the basin. Samples were qualitatively screened for all occurring taxa. Then, all individuals from all taxa in a quantitative subsample of each sample were counted. Biological indices were calculated to estimate water quality at each sampling site. All samples are kept at the Museum of Zoology of the University of Navarra.

Freshwater macroinvertebrate samples from a water quality monitoring network in the Iberian Peninsula

PubMed Central

Escribano, Nora; Oscoz, Javier; Galicia, David; Cancellario, Tommaso; Durán, Concha; Navarro, Patricia; Ariño, Arturo H.

2018-01-01

This dataset gathers information about the macroinvertatebrate samples and environmental variables collected on rivers of the Ebro River Basin (NE Iberian Peninsula), the second largest catchment in the Iberian Peninsula. The collection is composed of 1,776 sampling events carried out between 2005 and 2015 at more than 400 sampling sites. This dataset is part of a monitoring network set up by the Ebro Hydrographic Confederation, the official body entrusted with the care of the basin, to fulfill the requirements of the European Water Framework Directive. Biological indices based on the freshwater macroinvertebrate communities were used to evaluate the ecological status of the water bodies within the basin. Samples were qualitatively screened for all occurring taxa. Then, all individuals from all taxa in a quantitative subsample of each sample were counted. Biological indices were calculated to estimate water quality at each sampling site. All samples are kept at the Museum of Zoology of the University of Navarra. PMID:29870034

Analytical procedures for the determination of fuel combustion products, anti-corrosive compounds, and de-icing compounds in airport runoff water samples.

PubMed

Sulej, Anna Maria; Polkowska, Żaneta; Astel, Aleksander; Namieśnik, Jacek

2013-12-15

The purpose of this study is to propose and evaluate new procedures for determination of fuel combustion products, anti-corrosive and de-icing compounds in runoff water samples collected from the airports located in different regions and characterized by different levels of the activity expressed by the number of flights and the number of passengers (per year). The most difficult step in the analytical procedure used for the determination of PAHs, benzotriazoles and glycols is sample preparation stage, due to diverse matrix composition, the possibility of interference associated with the presence of components with similar physicochemical properties. In this study, five different versions of sample preparation using extraction techniques, such as: LLE and SPE, were tested. In all examined runoff water samples collected from the airports, the presence of PAH compounds and glycols was observed. In majority of the samples, BT compounds were determined. Runoff water samples collected from the areas of Polish and British international airports as well as local airports had similar qualitative composition, but quantitative composition of the analytes was very diverse. New and validated analytical methodologies ensure that the necessary information for assessing the negative impact of airport activities on the environment can be obtained. © 2013 Elsevier B.V. All rights reserved.

RAPID SEPARATION METHOD FOR EMERGENCY WATER AND URINE SAMPLES

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

Maxwell, S.; Culligan, B.

2008-08-27

The Savannah River Site Environmental Bioassay Lab participated in the 2008 NRIP Emergency Response program administered by the National Institute for Standards and Technology (NIST) in May, 2008. A new rapid column separation method was used for analysis of actinides and {sup 90}Sr the NRIP 2008 emergency water and urine samples. Significant method improvements were applied to reduce analytical times. As a result, much faster analysis times were achieved, less than 3 hours for determination of {sup 90}Sr and 3-4 hours for actinides. This represents a 25%-33% improvement in analysis times from NRIP 2007 and a {approx}100% improvement compared tomore » NRIP 2006 report times. Column flow rates were increased by a factor of two, with no significant adverse impact on the method performance. Larger sample aliquots, shorter count times, faster cerium fluoride microprecipitation and streamlined calcium phosphate precipitation were also employed. Based on initial feedback from NIST, the SRS Environmental Bioassay Lab had the most rapid analysis times for actinides and {sup 90}Sr analyses for NRIP 2008 emergency urine samples. High levels of potential matrix interferences may be present in emergency samples and rugged methods are essential. Extremely high levels of {sup 210}Po were found to have an adverse effect on the uranium results for the NRIP-08 urine samples, while uranium results for NRIP-08 water samples were not affected. This problem, which was not observed for NRIP-06 or NRIP-07 urine samples, was resolved by using an enhanced {sup 210}Po removal step, which will be described.« less

Methods for collecting algal samples as part of the National Water-Quality Assessment Program

USGS Publications Warehouse

Porter, Stephen D.; Cuffney, Thomas F.; Gurtz, Martin E.; Meador, Michael R.

1993-01-01

Benthic algae (periphyton) and phytoplankton communities are characterized in the U.S. Geological Survey's National Water-Quality Assessment Program as part of an integrated physical, chemical, and biological assessment of the Nation's water quality. This multidisciplinary approach provides multiple lines of evidence for evaluating water-quality status and trends, and for refining an understanding of the factors that affect water-quality conditions locally, regionally, and nationally. Water quality can be characterized by evaluating the results of qualitative and quantitative measurements of the algal community. Qualitative periphyton samples are collected to develop of list of taxa present in the sampling reach. Quantitative periphyton samples are collected to measure algal community structure within selected habitats. These samples of benthic algal communities are collected from natural substrates, using the sampling methods that are most appropriate for the habitat conditions. Phytoplankton samples may be collected in large nonwadeable streams and rivers to meet specific program objectives. Estimates of algal biomass (chlorophyll content and ash-free dry mass) also are optional measures that may be useful for interpreting water-quality conditions. A nationally consistent approach provides guidance on site, reach, and habitat selection, as well as information on methods and equipment for qualitative and quantitative sampling. Appropriate quality-assurance and quality-control guidelines are used to maximize the ability to analyze data locally, regionally, and nationally.

Comparative proteomic analysis using samples obtained with laser microdissection and saturation dye labelling.

PubMed

Wilson, Kate E; Marouga, Rita; Prime, John E; Pashby, D Paul; Orange, Paul R; Crosier, Steven; Keith, Alexander B; Lathe, Richard; Mullins, John; Estibeiro, Peter; Bergling, Helene; Hawkins, Edward; Morris, Christopher M

2005-10-01

Comparative proteomic methods are rapidly being applied to many different biological systems including complex tissues. One pitfall of these methods is that in some cases, such as oncology and neuroscience, tissue complexity requires isolation of specific cell types and sample is limited. Laser microdissection (LMD) is commonly used for obtaining such samples for proteomic studies. We have combined LMD with sensitive thiol-reactive saturation dye labelling of protein samples and 2-D DIGE to identify protein changes in a test system, the isolated CA1 pyramidal neurone layer of a transgenic (Tg) rat carrying a human amyloid precursor protein transgene. Saturation dye labelling proved to be extremely sensitive with a spot map of over 5,000 proteins being readily produced from 5 mug total protein, with over 100 proteins being significantly altered at p < 0.0005. Of the proteins identified, all showed coherent changes associated with transgene expression. It was, however, difficult to identify significantly different proteins using PMF and MALDI-TOF on gels containing less than 500 mug total protein. The use of saturation dye labelling of limiting samples will therefore require the use of highly sensitive MS techniques to identify the significantly altered proteins isolated using methods such as LMD.

Spatial distributions and seasonal variations of organochlorine pesticides in water and soil samples in Bolu, Turkey.

PubMed

Karadeniz, Hatice; Yenisoy-Karakaş, Serpil

2015-03-01

In this study, a total of 75 water samples (38 groundwater and 37 surface water samples) and 54 surface soil samples were collected from the five districts of Bolu, which is located in the Western Black Sea Region of Turkey in the summer season of 2009. In the autumn season, 17 water samples (surface water and groundwater samples) and 17 soil samples were collected within the city center to observe the seasonal changes of organochlorine pesticides (OCPs). Groundwater and surface water samples were extracted using solid phase extraction. Soil samples were extracted ultrasonically. Sixteen OCP compounds in the standard solution were detected by a gas chromatography-electron capture detector (GC-ECD). Therefore, the method validation was performed for those 16 OCP compounds. However, 13 OCP compounds could be observed in the samples. The concentrations of most OCPs were higher in samples collected in the summer than those in the autumn. The most frequently observed pesticides were endosulfan sulfate and 4,4'-dichlorodiphenyltrichloroethane (DDT) in groundwater samples, α-HCH in surface water samples, and endosulfan sulfate in soil samples. The average concentration of endosulfan sulfate was the highest in water and soil samples. Compared to the literature values, the average concentrations in this study were lower values. Spatial distribution of OCPs was evaluated with the aid of contour maps for the five districts of Bolu. Generally, agricultural processes affected the water and soil quality in the region. However, non-agricultural areas were also affected by pesticides. The concentrations of pesticides were below the legal limits of European directives for each pesticide.

40 CFR 258.53 - Ground-water sampling and analysis requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... considering the number of samples in the background data base, the data distribution, and the range of the... the background data base, the data distribution, and the range of the concentration values for each... samples collected to establish ground-water quality data must be consistent with the appropriate...

40 CFR 258.53 - Ground-water sampling and analysis requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... considering the number of samples in the background data base, the data distribution, and the range of the... the background data base, the data distribution, and the range of the concentration values for each... samples collected to establish ground-water quality data must be consistent with the appropriate...

Development of Sampling and Preservation Techniques to Retard Chemical and Biological Changes in Water Samples

DTIC Science & Technology

1983-06-24

and vali- date methods for the analysis of the 12 munitions in water and sediment. Two high performance liquid chromatographic (IIPLC-UV) systems...t from Re.po.r) 11i. SUP•L.EMENTARY NOTES 1S. KEY WORDS (Conrinuo.on rovers* old* It necessary and Identify by biock number) Methods development...munition and 4-munition groups in sediment The method for eight munitions (DNP, RDX, TNB, DNB, 2,4-DNT, TNT, tetryl and DPA) in water samples consists of

Assessment of water quality index of bore well water samples from some selected locations of South Gujarat, India.

PubMed

Tripathi, S; Patel, H M; Srivastava, P K; Bafna, A M

2013-10-01

The present study calculates the water quality index (WQI) of some selected sites from South Gujarat (India) and assesses the impact of industries, agriculture and human activities. Chemical parameters were monitored for the calculation of WQI of some selected bore well samples. The results revealed that the WQI of the some bore well samples exceeded acceptable levels due to the dumping of wastes from municipal, industrial and domestic sources and agricultural runoff as well. Inverse Distance Weighting (IDW) was implemented for interpolation of each water quality parameter (pH, EC, alkalinity, total hardness, chloride, nitrate and sulphate) for the entire sampled area. The bore water is unsuitable for drinking and if the present state of affairs continues for long, it may soon become an ecologically dead bore.

Detection and Genotyping of Human Papillomavirus in Self-Obtained Cervicovaginal Samples by Using the FTA Cartridge: New Possibilities for Cervical Cancer Screening ▿

PubMed Central

Lenselink, Charlotte H.; de Bie, Roosmarie P.; van Hamont, Dennis; Bakkers, Judith M. J. E.; Quint, Wim G. V.; Massuger, Leon F. A. G.; Bekkers, Ruud L. M.; Melchers, Willem J. G.

2009-01-01

This study assesses human papillomavirus (HPV) detection and genotyping in self-sampled genital smears applied to an indicating FTA elute cartridge (FTA cartridge). The study group consisted of 96 women, divided into two sample sets. All samples were analyzed by the HPV SPF10-Line Blot 25. Set 1 consisted of 45 women attending the gynecologist; all obtained a self-sampled cervicovaginal smear, which was applied to an FTA cartridge. HPV results were compared to a cervical smear (liquid based) taken by a trained physician. Set 2 consisted of 51 women who obtained a self-sampled cervicovaginal smear at home, which was applied to an FTA cartridge and to a liquid-based medium. DNA was obtained from the FTA cartridges by simple elution as well as extraction. Of all self-obtained samples of set 1, 62.2% tested HPV positive. The overall agreement between self- and physician-obtained samples was 93.3%, in favor of the self-obtained samples. In sample set 2, 25.5% tested HPV positive. The overall agreement for high-risk HPV presence between the FTA cartridge and liquid-based medium and between DNA elution and extraction was 100%. This study shows that HPV detection and genotyping in self-obtained cervicovaginal samples applied to an FTA cartridge is highly reliable. It shows a high level of overall agreement with HPV detection and genotyping in physician-obtained cervical smears and liquid-based self-samples. DNA can be obtained by simple elution and is therefore easy, cheap, and fast. Furthermore, the FTA cartridge is a convenient medium for collection and safe transport at ambient temperatures. Therefore, this method may contribute to a new way of cervical cancer screening. PMID:19553570

Protocol to obtain targeted transcript sequence data from snake venom samples collected in the Colombian field.

PubMed

Fonseca, Alejandra; Renjifo-Ibáñez, Camila; Renjifo, Juan Manuel; Cabrera, Rodrigo

2018-03-21

Snake venoms are a mixture of different molecules that can be used in the design of drugs for various diseases. The study of these venoms has relied on strategies that use complete venom extracted from animals in captivity or from venom glands that require the sacrifice of the animals. Colombia, a country with political and geographical conflicts has difficult access to certain regions. A strategy that can prevent the sacrifice of animals and could allow the study of samples collected in the field is necessary. We report the use of lyophilized venom from Crotalus durissus cumanensis as a model to test, for the first time, a protocol for the amplification of complete toxins from Colombian venom samples collected in the field. In this protocol, primers were designed from conserved region from Crotalus sp. mRNA and EST regions to maximize the likelihood of coding sequence amplification. We obtained the sequences of Metalloproteinases II, Disintegrins, Disintegrin-Like, Phospholipases A 2, C-type Lectins and Serine proteinases from Crotalus durissus cumanensis and compared them to different Crotalus sp sequences available on databases obtaining concordance between the toxins amplified and those reported. Our strategy allows the use of lyophilized venom to obtain complete toxin sequences from samples collected in the field and the study of poorly characterized venoms in challenging environments. Copyright © 2018 Elsevier Ltd. All rights reserved.

U.S. Geological Survey nutrient preservation experiment; nutrient concentration data for surface-, ground-, and municipal-supply water samples and quality-assurance samples

USGS Publications Warehouse

Patton, Charles J.; Truitt, Earl P.

1995-01-01

This report is a compilation of analytical results from a study conducted at the U.S. Geological Survey, National Water Quality Laboratory (NWQL) in 1992 to assess the effectiveness of three field treatment protocols to stabilize nutrient concentra- tions in water samples stored for about 1 month at 4C. Field treatments tested were chilling, adjusting sample pH to less than 2 with sulfuric acid and chilling, and adding 52 milligrams of mercury (II) chloride per liter of sample and chilling. Field treatments of samples collected for determination of ammonium, nitrate plus nitrite, nitrite, dissolved Kjeldahl nitrogen, orthophosphate, and dissolved phosphorus included 0.45-micrometer membrane filtration. Only total Kjeldahl nitrogen and total phosphorus were determined in unfiltered samples. Data reported here pertain to water samples collected in April and May 1992 from 15 sites within the continental United States. Also included in this report are analytical results for nutrient concentrations in synthetic reference samples that were analyzed concurrently with real samples.

Evaluation of low-cost disposable polymeric materials for sorptive extraction of organic pollutants in water samples.

PubMed

Prieto, Ailette; Rodil, Rosario; Quintana, José Benito; Rodríguez, Isaac; Cela, Rafael; Möder, Monika

2012-02-24

The capabilities of four commercially available and low cost polymeric materials for the extraction of polar and non-polar contaminants (logK(ow)=-0.07-6.88, from caffeine to octocrylene, respectively) from water samples was compared. Tested sorbents were polyethersulphone, polypropylene and Kevlar, compared to polydimethylsiloxane as reference material. Parameters that affect the extraction process such as pH and ionic strength of the sample, extraction time and desorption conditions were thoroughly investigated. A set of experimental partition coefficients (K(pw)), at two different experimental conditions, was estimated for the best suited materials and compared with the theoretical octanol-water (K(ow)) partition coefficients of the analytes. Polyethersulphone displayed the largest extraction yields for both polar and non-polar analytes, with higher K(pw) and lower matrix effects than polydimethylsiloxane and polypropylene. Thus, a sorptive microextraction method, followed by large volume injection (LVI) gas chromatography-tandem mass spectrometry (GC-MS/MS), was proposed using the former sorbent (2 mg) for the simultaneous determination of model compounds in water samples. Good linearity (>0.99) was obtained for most of the analytes, except in the case of 4-nonylphenol (0.9466). Precision (n=4) at 50 and 500 ng L(-1) levels was in the 2-24% and limits of detection (LODs) were in the 0.6-25 ng L(-1) range for all the analytes studied. Copyright © 2011 Elsevier B.V. All rights reserved.

Profiling physicochemical and planktonic features from discretely/continuously sampled surface water.

PubMed

Oita, Azusa; Tsuboi, Yuuri; Date, Yasuhiro; Oshima, Takahiro; Sakata, Kenji; Yokoyama, Akiko; Moriya, Shigeharu; Kikuchi, Jun

2018-04-24

There is an increasing need for assessing aquatic ecosystems that are globally endangered. Since aquatic ecosystems are complex, integrated consideration of multiple factors utilizing omics technologies can help us better understand aquatic ecosystems. An integrated strategy linking three analytical (machine learning, factor mapping, and forecast-error-variance decomposition) approaches for extracting the features of surface water from datasets comprising ions, metabolites, and microorganisms is proposed herein. The three developed approaches can be employed for diverse datasets of sample sizes and experimentally analyzed factors. The three approaches are applied to explore the features of bay water surrounding Odaiba, Tokyo, Japan, as a case study. Firstly, the machine learning approach separated 681 surface water samples within Japan into three clusters, categorizing Odaiba water into seawater with relatively low inorganic ions, including Mg, Ba, and B. Secondly, the factor mapping approach illustrated Odaiba water samples from the summer as rich in multiple amino acids and some other metabolites and poor in inorganic ions relative to other seasons based on their seasonal dynamics. Finally, forecast-error-variance decomposition using vector autoregressive models indicated that a type of microalgae (Raphidophyceae) grows in close correlation with alanine, succinic acid, and valine on filters and with isobutyric acid and 4-hydroxybenzoic acid in filtrate, Ba, and average wind speed. Our integrated strategy can be used to examine many biological, chemical, and environmental physical factors to analyze surface water. Copyright © 2018. Published by Elsevier B.V.

Monitoring the aftermath of Flint drinking water contamination crisis: Another case of sampling bias?

PubMed

Goovaerts, Pierre

2017-07-15

The delay in reporting high levels of lead in Flint drinking water, following the city's switch to the Flint River as its water supply, was partially caused by the biased selection of sampling sites away from the lead pipe network. Since Flint returned to its pre-crisis source of drinking water, the State has been monitoring water lead levels (WLL) at selected "sentinel" sites. In a first phase that lasted two months, 739 residences were sampled, most of them bi-weekly, to determine the general health of the distribution system and to track temporal changes in lead levels. During the same period, water samples were also collected through a voluntary program whereby concerned citizens received free testing kits and conducted sampling on their own. State officials relied on the former data to demonstrate the steady improvement in water quality. A recent analysis of data collected by voluntary sampling revealed, however, an opposite trend with lead levels increasing over time. This paper looks at potential sampling bias to explain such differences. Although houses with higher WLL were more likely to be sampled repeatedly, voluntary sampling turned out to reproduce fairly well the main characteristics (i.e. presence of lead service lines (LSL), construction year) of Flint housing stock. State-controlled sampling was less representative; e.g., sentinel sites with LSL were mostly built between 1935 and 1950 in lower poverty areas, which might hamper our ability to disentangle the effects of LSL and premise plumbing (lead fixtures and pipes present within old houses) on WLL. Also, there was no sentinel site with LSL in two of the most impoverished wards, including where the percentage of children with elevated blood lead levels tripled following the switch in water supply. Correcting for sampling bias narrowed the gap between sampling programs, yet overall temporal trends are still opposite. Copyright © 2017 Elsevier B.V. All rights reserved.

Hollow fiber supported ionic liquid membrane microextraction for determination of sulfonamides in environmental water samples by high-performance liquid chromatography.

PubMed

Tao, Yong; Liu, Jing-Fu; Hu, Xia-Lin; Li, Hong-Cheng; Wang, Thanh; Jiang, Gui-Bin

2009-08-28

By using ionic liquid as membrane liquid and tri-n-octylphosphine oxide (TOPO) as additive, hollow fiber supported liquid phase microextraction (HF-LPME) was developed for the determination of five sulfonamides in environmental water samples by high-performance liquid chromatography with ultraviolet detection The extraction solvent and the parameters affecting the extraction enrichment factor such as the type and amount of carrier, pH and volume ratio of donor phase and acceptor phase, extraction time, salt-out effect and matrix effect were optimized. Under the optimal extraction conditions (organic liquid membrane phase: [C(8)MIM][PF(6)] with 14% TOPO (w/v); donor phase: 4mL, pH 4.5 KH(2)PO(4) with 2M Na(2)SO(4); acceptor phase: 25microL, pH 13 NaOH; extraction time: 8 h), low detection limits (0.1-0.4microg/L, RSDor=0.999) were obtained for all the analytes. The presence of humic acid (0-25mg/L dissolved organic carbon) and bovine serum albumin (0-100microg/mL) had no significant effect on the extraction efficiency. Good spike recoveries over the range of 82.2-103.2% were obtained when applying the proposed method on five real environmental water samples. These results indicated that this present method was very sensitive and reliable with good repeatabilities and excellent clean-up in water samples. The proposed method confirmed hollow fiber supported ionic liquid membrane based LPME to be robust to monitoring trace levels of sulfadiazine, sulfamerazine, sulfamethazine, sulfadimethoxine and sulfamethoxazole in aqueous samples.

Modification of kanamycin-esculin-azide agar to improve selectivity in the enumeration of fecal streptococci from water samples.

PubMed

Audicana, A; Perales, I; Borrego, J J

1995-12-01

Kanamycin-esculin-azide agar was modified by increasing the concentration of sodium azide to 0.4 g liter-1 and replacing kanamycin sulfate with 5 mg of oxolinic acid liter-1. The modification, named oxolinic acid-esculin-azide (OAA) agar, was compared with Slanetz-Bartley and KF agars by using drinking water and seawater samples. The OAA agar showed higher specificity, selectivity, and recovery efficiencies than those obtained by using the other media. In addition, no confirmation of typical colonies was needed when OAA agar was used, which significantly shortens the time of sample processing and increases the accuracy of the method.

Analysis of Ballast Water Sampling Port Designs Using Computational Fluid Dynamics

DTIC Science & Technology

2008-02-01

straight, vertical, upward-flowing pipe having a sample port diameter between 1.5 and 2.0 times the basic isokinetic diameter as defined in this report...water, flow modeling, sample port, sample pipe, particle trajectory, isokinetic sampling 18. Distribution Statement This document is available to...2.0 times the basic isokinetic diameter as defined in this report. Sample ports should use ball valves for isolation purposes and diaphragm or

Characterizing Hydrological Processes in Vadose Zone by Direct Infiltration Water Sampling.

NASA Astrophysics Data System (ADS)

Mori, Y.; Higashi, N.; Somura, H.; Takeda, I.; Inoue, M.

2007-12-01

These days, planted forest mountainside was roughly maintained due to the population descent and small birth rate. Because thinning operation would delayed, forest was always dark and floor weed was rare. Management induced non point source pollution like surface soil erosion was suspected, however, we could not approach to the source with the stream water analysis. Therefore, direct soil water sampling device using glass fiber capillary force was developed to examine hydrological processes in watershed. In our design, water was collected just by the capillary force and let the excess water down through so that infiltration water was truly sampled and solute concentration kept the same quality as in soil water. The experiment was conducted at two neighboring Japanese cedar planted forest under different management, i.e., south slope was roughly maintained and west slope was well maintained by thinning operation. Load discharges were higher in south slope and lower in west slope. Infiltration water analysis revealed that ion concentration was gradually decreased at west slope, however in south slope, it dropped to lower level in soil water and increased again in stream water. The trend showed that soil buffering function was poor in south slope. Actually, disk permeameter survey revealed that hydraulic conductivity was small in south slope; TOC and biological activity were lower. This entire soil environment explained the water environmental differences in stream water. Because changes in soil environment affects water environment in the future, monitoring or examination of soil environment was considered as preventive measure for environmentally sound water and solute circulation in watershed.

“Nanofiltration” Enabled by Super-Absorbent Polymer Beads for Concentrating Microorganisms in Water Samples

NASA Astrophysics Data System (ADS)

Xie, Xing; Bahnemann, Janina; Wang, Siwen; Yang, Yang; Hoffmann, Michael R.

2016-02-01

Detection and quantification of pathogens in water is critical for the protection of human health and for drinking water safety and security. When the pathogen concentrations are low, large sample volumes (several liters) are needed to achieve reliable quantitative results. However, most microbial identification methods utilize relatively small sample volumes. As a consequence, a concentration step is often required to detect pathogens in natural waters. Herein, we introduce a novel water sample concentration method based on superabsorbent polymer (SAP) beads. When SAP beads swell with water, small molecules can be sorbed within the beads, but larger particles are excluded and, thus, concentrated in the residual non-sorbed water. To illustrate this approach, millimeter-sized poly(acrylamide-co-itaconic acid) (P(AM-co-IA)) beads are synthesized and successfully applied to concentrate water samples containing two model microorganisms: Escherichia coli and bacteriophage MS2. Experimental results indicate that the size of the water channel within water swollen P(AM-co-IA) hydrogel beads is on the order of several nanometers. The millimeter size coupled with a negative surface charge of the beads are shown to be critical in order to achieve high levels of concentration. This new concentration procedure is very fast, effective, scalable, and low-cost with no need for complex instrumentation.

“Nanofiltration” Enabled by Super-Absorbent Polymer Beads for Concentrating Microorganisms in Water Samples

PubMed Central

Xie, Xing; Bahnemann, Janina; Wang, Siwen; Yang, Yang; Hoffmann, Michael R.

2016-01-01

Detection and quantification of pathogens in water is critical for the protection of human health and for drinking water safety and security. When the pathogen concentrations are low, large sample volumes (several liters) are needed to achieve reliable quantitative results. However, most microbial identification methods utilize relatively small sample volumes. As a consequence, a concentration step is often required to detect pathogens in natural waters. Herein, we introduce a novel water sample concentration method based on superabsorbent polymer (SAP) beads. When SAP beads swell with water, small molecules can be sorbed within the beads, but larger particles are excluded and, thus, concentrated in the residual non-sorbed water. To illustrate this approach, millimeter-sized poly(acrylamide-co-itaconic acid) (P(AM-co-IA)) beads are synthesized and successfully applied to concentrate water samples containing two model microorganisms: Escherichia coli and bacteriophage MS2. Experimental results indicate that the size of the water channel within water swollen P(AM-co-IA) hydrogel beads is on the order of several nanometers. The millimeter size coupled with a negative surface charge of the beads are shown to be critical in order to achieve high levels of concentration. This new concentration procedure is very fast, effective, scalable, and low-cost with no need for complex instrumentation. PMID:26876979

Analysis of pharmaceutical and other organic wastewater compounds in filtered and unfiltered water samples by gas chromatography/mass spectrometry

USGS Publications Warehouse

Zaugg, Steven D.; Phillips, Patrick J.; Smith, Steven G.

2014-01-01

types were determined by use of the capillary-column gas chromatography/mass spectrometry. The performance of each method was assessed by using data on recoveries of compounds in fortified surface-water, wastewater, and reagent-water samples. These experiments (referred to as spike experiments) consist of fortifying (or spiking) samples with known amounts of target analytes. Surface-water-spike experiments were performed by using samples obtained from a stream in Colorado (unfiltered method) and a stream in New York (filtered method). Wastewater spike experiments for both the filtered and unfiltered methods were performed by using a treated wastewater obtained from a single wastewater treatment plant in New York. Surface water and wastewater spike experiments were fortified at both low and high concentrations and termed low- and high-level spikes, respectively. Reagent water spikes were assessed in three ways: (1) set spikes, (2) a low-concentration fortification experiment, and (3) a high-concentration fortification experiment. Set spike samples have been determined since 2009, and consist of analysis of fortified reagent water for target compounds included for each group of 10 to18 environmental samples analyzed at the NWQL. The low-concentration and high-concentration reagent spike experiments, by contrast, represent a one-time assessment of method performance. For each spike experiment, mean recoveries ranging from 60 to 130 percent indicate low bias, and relative standard deviations (RSDs) less than ( Of the compounds included in the filtered method, 21 had mean recoveries ranging from 63 to 129 percent for the low-level and high-level surface-water spikes, and had low ()132 percent]. For wastewater spikes, 24 of the compounds included in the filtered method had recoveries ranging from 61 to 130 percent for the low-level and high-level spikes. RSDs were 130 percent) or variable recoveries (RSDs >30 percent) for low-level wastewater spikes, or low recoveries ( Of

Measuring pesticides in surface waters - continuous versus event-based sampling design

NASA Astrophysics Data System (ADS)

Eyring, J.; Bach, M.; Frede, H.-G.

2009-04-01

Monitoring pesticides in surface waters is still a work- and cost-intensive procedure. Therefore, studies are normally carried out with a low monitoring frequency or with only a small selection of substances to be analyzed. In this case, it is not possible to picture the high temporal variability of pesticide concentrations, depending on application dates, weather conditions, cropping seasons and other factors. In 2007 the Institute of Landscape Ecology and Resource Management at Giessen University implemented a monitoring program during two pesticide application periods aiming to produce a detailed dataset of pesticide concentration for a wide range of substances, and which would also be suitable for the evaluation of catchment-scale pesticide exposure models. The Weida catchment in Thuringia (Eastern Germany) was selected as study area due to the availability of detailed pesticide application data for this region. The samples were taken from the river Weida at the gauge Zeulenroda, where it flows into a drinking water reservoir. The catchment area is 102 km². 67% of the area are in agricultural use, the main crops being winter wheat, maize, winter barley and winter rape. Dominant soil texture classes are loamy sand and loamy silt. About one third of the agricultural area is drained. The sampling was carried out in cooperation with the water supply agency of Thuringia (Fernwasserversorgung Thueringen). The sample analysis was done by the Institute of Environmental Research at Dortmund University. Two sampling schemes were carried out using two automatic samplers: continuous sampling with composite samples bottled two times per week and event-based sampling triggered by a discharge threshold. 53 samples from continuous sampling were collected. 19 discharge events were sampled with 45 individual samples (one to six per event). 34 pesticides and two metabolites were analyzed. 21 compounds were detected, nine of which having concentrations above the drinking water

Hexagonal ice in pure water and biological NMR samples.

PubMed

Bauer, Thomas; Gath, Julia; Hunkeler, Andreas; Ernst, Matthias; Böckmann, Anja; Meier, Beat H

2017-01-01

Ice, in addition to "liquid" water and protein, is an important component of protein samples for NMR spectroscopy at subfreezing temperatures but it has rarely been observed spectroscopically in this context. We characterize its spectroscopic behavior in the temperature range from 100 to 273 K, and find that it behaves like pure water ice. The interference of magic-angle spinning (MAS) as well as rf multiple-pulse sequences with Bjerrum-defect motion greatly influences the ice spectra.

Effect of Sampling Depth on Air-Sea CO2 Flux Estimates in River-Stratified Arctic Coastal Waters

NASA Astrophysics Data System (ADS)

Miller, L. A.; Papakyriakou, T. N.

2015-12-01

In summer-time Arctic coastal waters that are strongly influenced by river run-off, extreme stratification severely limits wind mixing, making it difficult to effectively sample the surface 'mixed layer', which can be as shallow as 1 m, from a ship. During two expeditions in southwestern Hudson Bay, off the Nelson, Hayes, and Churchill River estuaries, we confirmed that sampling depth has a strong impact on estimates of 'surface' pCO2 and calculated air-sea CO2 fluxes. We determined pCO2 in samples collected from 5 m, using a typical underway system on the ship's seawater supply; from the 'surface' rosette bottle, which was generally between 1 and 3 m; and using a niskin bottle deployed at 1 m and just below the surface from a small boat away from the ship. Our samples confirmed that the error in pCO2 derived from typical ship-board versus small-boat sampling at a single station could be nearly 90 μatm, leading to errors in the calculated air-sea CO2 flux of more than 0.1 mmol/(m2s). Attempting to extrapolate such fluxes over the 6,000,000 km2 area of the Arctic shelves would generate an error approaching a gigamol CO2/s. Averaging the station data over a cruise still resulted in an error of nearly 50% in the total flux estimate. Our results have implications not only for the design and execution of expedition-based sampling, but also for placement of in-situ sensors. Particularly in polar waters, sensors are usually deployed on moorings, well below the surface, to avoid damage and destruction from drifting ice. However, to obtain accurate information on air-sea fluxes in these areas, it is necessary to deploy sensors on ice-capable buoys that can position the sensors in true 'surface' waters.

Chemical analyses of water samples from the Picher mining area, northeast Oklahoma and southeast Kansas

USGS Publications Warehouse

Parkhurst, David L.

1987-01-01

Chemical analyses are presented for 169 water samples from Tar Creek drainage and the Picher lead-zinc mining area of northeast Oklahoma and southeast Kansas. Water samples were taken from November 1983 through February 1986 from the abandoned mines, from points of mine-water discharge, and from surface-water locations upstream and downstream from mine discharge area. The pH, temperature, alkalinity, dissolved oxygen, and specific conductance were measured in the field. Laboratory analyses routinely included the major ions plus aluminum, cadmium, copper, iron, lead, manganese, nickel, and zinc. Non-routine analyses of dissolved gases and tritium are presented. Stable carbon-isotope ratios for 11 mine-water samples and three carbonate-rock samples are reported. Miscellaneous stream-discharge measurements made at the time of sampling or taken from gaging-station records are included in the report.

Water vapor over Europe obtained from remote sensors and compared with a hydrostatic NWP model

NASA Astrophysics Data System (ADS)

Johnsen, K.-P.; Kidder, S. Q.

Due to its high-variability water vapor is a crucial parameter in short-term numerical weather prediction. Integrated water vapor (IWV) data obtained from a network of groundbased Global Positioning System (GPS) receivers mainly over Germany and passive microwave measurements of the Advanced Microwave Sounding Unit (AMSU-A) are compared with the high-resolution regional weather forecast model HRM of the Deutscher Wetterdienst (DWD). Time series of the IWV at 74 GPS stations obtained during the first complete year of the GFZ/GPS network between May 2000 and April 2001 are applied together with colocated forecasts of the HRM model. The low bias (0.08 kg/m 2) between the HRM model and the GPS data can mainly be explained by the bias between the ECMWF analysis data used to initilize the HRM model and the GPS data. The IWV standard deviation between the HRM model and the GPS data during that time is about 2.47 kg/ m2. GPS stations equipped with surface pressure sensors show about 0.29 kg/ m2 lower standard deviation compared with GPS stations with interpolated surface pressure from synoptic stations. The NOAA/NESDIS Total Precipitable Water algorithm is applied to obtain the IWV and to validate the model above the sea. While the mean IWV obtained from the HRM model is about 2.1 kg/ m2 larger than from the AMSU-A data, the standard deviations are 2.46 kg/ m2 (NOAA-15) and 2.29 kg/ m2 (NOAA-16) similar to the IWV standard deviation between HRM and GPS data.

Multiport well design for sampling of ground water at closely spaced vertical intervals

USGS Publications Warehouse

Delin, G.N.; Landon, M.K.

1996-01-01

Detailed vertical sampling is useful in aquifers where vertical mixing is limited and steep vertical gradients in chemical concentrations are expected. Samples can be collected at closely spaced vertical intervals from nested wells with short screened intervals. However, this approach may not be appropriate in all situations. An easy-to-construct and easy-to-install multiport sampling well to collect ground-water samples from closely spaced vertical intervals was developed and tested. The multiport sampling well was designed to sample ground water from surficial sand-and-gravel aquifers. The device consists of multiple stainless-steel tubes within a polyvinyl chloride (PVC) protective casing. The tubes protrude through the wall of the PVC casing at the desired sampling depths. A peristaltic pump is used to collect ground-water samples from the sampling ports. The difference in hydraulic head between any two sampling ports can be measured with a vacuum pump and a modified manometer. The usefulness and versatility of this multiport well design was demonstrated at an agricultural research site near Princeton, Minnesota where sampling ports were installed to a maximum depth of about 12 m below land surface. Tracer experiments were conducted using potassium bromide to document the degree to which short-circuiting occurred between sampling ports. Samples were successfully collected for analysis of major cations and anions, nutrients, selected herbicides, isotopes, dissolved gases, and chlorofluorcarbon concentrations.

Magnetic hydrophilic-lipophilic balance sorbent for efficient extraction of chemical warfare agents from water samples.

PubMed

Singh, Varoon; Purohit, Ajay Kumar; Chinthakindi, Sridhar; Goud D, Raghavender; Tak, Vijay; Pardasani, Deepak; Shrivastava, Anchal Roy; Dubey, Devendra Kumar

2016-02-19

Magnetic hydrophilic-lipophilic balance (MHLB) hybrid resin was prepared by precipitation polymerization using N-vinylpyrrolidone (PVP) and divinylbenzene (DVB) as monomers and Fe2O3 nanoparticles as magnetic material. These resins were successfully applied for the extraction of chemical warfare agents (CWAs) and their markers from water samples through magnetic dispersive solid-phase extraction (MDSPE). By varying the ratios of monomers, resin with desired hydrophilic-lipophilic balance was prepared for the extraction of CWAs and related esters of varying polarities. Amongst different composites Fe2O3 nanoparticles coated with 10% PVP+90% DVB exhibited the best recoveries varying between 70.32 and 97.67%. Parameters affecting the extraction efficiencies, such as extraction time, desorption time, nature and volume of desorption solvent, amount of extraction sorbent and the effect of salts on extraction were investigated. Under the optimized conditions, linearity was obtained in the range of 0.5-500 ng mL(-1) with correlation ranging from 0.9911-0.9980. Limits of detection and limits of quantification were 0.5-1.0 and 3.0-5.0 ng mL(-1) respectively with RSDs varying from 4.88-11.32% for markers of CWAs. Finally, the developed MDSPE method was employed for extraction of analytes from water samples of various sources and the OPCW proficiency test samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Optimizing stream water mercury sampling for calculation of fish bioaccumulation factors

USGS Publications Warehouse

Riva-Murray, Karen; Bradley, Paul M.; Journey, Celeste A.; Brigham, Mark E.; Scudder Eikenberry, Barbara C.; Knightes, Christopher; Button, Daniel T.

2013-01-01

Mercury (Hg) bioaccumulation factors (BAFs) for game fishes are widely employed for monitoring, assessment, and regulatory purposes. Mercury BAFs are calculated as the fish Hg concentration (Hgfish) divided by the water Hg concentration (Hgwater) and, consequently, are sensitive to sampling and analysis artifacts for fish and water. We evaluated the influence of water sample timing, filtration, and mercury species on the modeled relation between game fish and water mercury concentrations across 11 streams and rivers in five states in order to identify optimum Hgwater sampling approaches. Each model included fish trophic position, to account for a wide range of species collected among sites, and flow-weighted Hgwater estimates. Models were evaluated for parsimony, using Akaike’s Information Criterion. Better models included filtered water methylmercury (FMeHg) or unfiltered water methylmercury (UMeHg), whereas filtered total mercury did not meet parsimony requirements. Models including mean annual FMeHg were superior to those with mean FMeHg calculated over shorter time periods throughout the year. FMeHg models including metrics of high concentrations (80th percentile and above) observed during the year performed better, in general. These higher concentrations occurred most often during the growing season at all sites. Streamflow was significantly related to the probability of achieving higher concentrations during the growing season at six sites, but the direction of influence varied among sites. These findings indicate that streamwater Hg collection can be optimized by evaluating site-specific FMeHg - UMeHg relations, intra-annual temporal variation in their concentrations, and streamflow-Hg dynamics.

Investigations of Sample Stability in Water Chemistry Samples: Implications for the National Aquatic Resource Surveys

EPA Science Inventory

Water samples collected for the EPA's National Aquatic Resource Surveys (NARS) typically arrive at an analytical laboratory 2 or 3 days after collection (longer if collected from a remote location), at which point they are stabilized (filtration and/or acid preservation) until an...

Microbial profiling of South African acid mine water samples using next generation sequencing platform.

PubMed

Kamika, I; Azizi, S; Tekere, M

2016-07-01

This study monitored changes in bacterial and fungal structure in a mine water in a monthly basis over 4 months. Over the 4-month study period, mine water samples contained more bacteria (91.06 %) compared to fungi (8.94 %). For bacteria, mine water samples were dominated by Proteobacteria (39.14 to 65.06 %) followed by Firmicutes (26.34 to 28.9 %) in summer, and Cyanobacteria (27.05 %) in winter. In the collected samples, 18 % of bacteria could not be assigned to a phylum and remained unclassified suggesting hitherto vast untapped microbial diversity especially during winter. The fungal domain was the sole eukaryotic microorganism found in the mine water samples with unclassified fungi (68.2 to 91 %) as the predominant group, followed by Basidiomycota (6.9 to 27.8 %). The time of collection, which was linked to the weather, had higher impact on bacterial community than fungal community. The bacterial operational taxonomic units (OTUs) ranged from 865 to 4052 over the 4-month sampling period, while fungal OTUs varied from 73 to 249. The diversity indices suggested that the bacterial community inhabiting the mine water samples were more diverse than the fungal community. The canonical correspondence analysis (CCA) results highlighted that the bacterial community variance had the strongest relationship with water temperature, conductivity, pH, and dissolved oxygen (DO) content, as compared to fungi and water characteristics, had the greatest contribution to both bacterial and fungal community variance. The results provided the relationships between microbial community and environmental variables in the studied mining sites.

Alternative solvent-based methyl benzoate vortex-assisted dispersive liquid-liquid microextraction for the high-performance liquid chromatographic determination of benzimidazole fungicides in environmental water samples.

PubMed

Santaladchaiyakit, Yanawath; Srijaranai, Supalax

2014-11-01

Vortex-assisted dispersive liquid-liquid microextraction using methyl benzoate as an alternative extraction solvent for extracting and preconcentrating three benzimidazole fungicides (i.e., carbendazim, thiabendazole, and fluberidazole) in environmental water samples before high-performance liquid chromatographic analysis has been developed. The selected microextraction conditions were 250 μL of methyl benzoate containing 300 μL of ethanol, 1.0% w/v sodium acetate, and vortex agitation speed of 2100 rpm for 30 s. Under optimum conditions, preconcentration factors were 14.5-39.0 for the target fungicides. Limits of detection were obtained in the range of 0.01-0.05 μg/L. The proposed method was then applied to surface water samples and the recovery evaluations at three spiked concentration levels of 5, 30, and 50 μg/L were obtained in the range of 77.4-110.9% with the relative standard deviation <7.4%. The present method was simple, rapid, low cost, sensitive, environmentally friendly, and suitable for the trace analysis of the studied fungicides in environmental water samples. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dispersive liquid-liquid microextraction applied to isolation and concentration of alkylphenols and their short-chained ethoxylates in water samples.

PubMed

Zgoła-Grześkowiak, Agnieszka

2010-03-12

Dispersive liquid-liquid microextraction (DLLME) coupled with high-performance liquid chromatography with fluorescence detector was applied for the determination of alkylphenols and their short-chained ethoxylates in water samples. Development of DLLME procedure included optimisation of some important parameters such as kind and volume of extracting and dispersing solvents. Under optimised conditions 50 microL of trichloroethylene in 1.5 mL of acetone were rapidly injected into 5 mL of a water sample. After centrifuging the organic phase containing the analytes was taken for evaporation with a gentle nitrogen purge and reconstituted to 50 microL of acetonitrile. The aliquot of this solution was analysed with the use of HPLC. For octylphenol (OP) and octylphenol ethoxylates (OPEOs) linearity was satisfactory in the range 8-1000 microg L(-1) and for nonylphenol (NP) and nonylphenol ethoxylates (NPEOs) linearity was in the range from 50 to about 3000 microg L(-1). Limit of quantitation was 0.1 microg L(-1) for OP and OPEOs and 0.3 microg L(-1) for NP and NPEOs. Satisfactory recoveries between 66 and 79% were obtained for environmental samples. The results showed that DLLME is a simple, rapid and sensitive analytical method for the preconcentration of trace amounts of alkylphenols and their ethoxylates in environmental water samples. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Efficient sample preparation method based on solvent-assisted dispersive solid-phase extraction for the trace detection of butachlor in urine and waste water samples.

PubMed

Aladaghlo, Zolfaghar; Fakhari, Alireza; Behbahani, Mohammad

2016-10-01

In this work, an efficient sample preparation method termed solvent-assisted dispersive solid-phase extraction was applied. The used sample preparation method was based on the dispersion of the sorbent (benzophenone) into the aqueous sample to maximize the interaction surface. In this approach, the dispersion of the sorbent at a very low milligram level was achieved by inserting a solution of the sorbent and disperser solvent into the aqueous sample. The cloudy solution created from the dispersion of the sorbent in the bulk aqueous sample. After pre-concentration of the butachlor, the cloudy solution was centrifuged and butachlor in the sediment phase dissolved in ethanol and determined by gas chromatography with flame ionization detection. Under the optimized conditions (solution pH = 7.0, sorbent: benzophenone, 2%, disperser solvent: ethanol, 500 μL, centrifuged at 4000 rpm for 3 min), the method detection limit for butachlor was 2, 3 and 3 μg/L for distilled water, waste water, and urine sample, respectively. Furthermore, the preconcentration factor was 198.8, 175.0, and 174.2 in distilled water, waste water, and urine sample, respectively. Solvent-assisted dispersive solid-phase extraction was successfully used for the trace monitoring of butachlor in urine and waste water samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

User's guide for polyethylene-based passive diffusion bag samplers to obtain volatile organic compound concentrations in wells. Part 2, Field tests

USGS Publications Warehouse

Vroblesky, Don A.

2001-01-01

Diffusion samplers installed in observation wells were found to be capable of yielding representative water samples for chlorinated volatile organic compounds. The samplers consisted of polyethylene bags containing deionized water and relied on diffusion of chlorinated volatile organic compounds through the polyethylene membrane. The known ability of polyethylene to transmit other volatile compounds, such as benzene and toluene, indicates that the samplers can be used for a variety of volatile organic compounds. In wells at the study area, the volatile organic compound concentrations in water samples obtained using the samplers without prior purging were similar to concentrations in water samples obtained from the respective wells using traditional purging and sampling approaches. The low cost associated with this approach makes it a viable option for monitoring large observation-well networks for volatile organic compounds.

Filtration recovery of extracellular DNA from environmental water samples

EPA Science Inventory

qPCR methods are able to analyze DNA from microbes within hours of collecting water samples, providing the promptest notification and public awareness possible when unsafe pathogenic levels are reached. Health risk, however, may be overestimated by the presence of extracellular ...

Adsorption of Water on Simulated Moon Dust Samples

NASA Technical Reports Server (NTRS)

Goering, John P.; Sah, Shweta; Burghaus, Uwe; Street, Kenneth W., Jr.

2008-01-01

A lunar regolith simulant dust sample (JSC-1a) supported on a silica wafer (SiO2/Si(111)) has been characterized by scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX), and Auger electron spectroscopy (AES). The adsorption kinetics of water has been studied primarily by thermal desorption spectroscopy (TDS) and also by collecting isothermal adsorption transients. The support has been characterized by water TDS. JSC-1a consists mostly of aluminosilicate glass and other minerals containing Fe, Na, Ca, and Mg. The particle sizes span the range from a few microns up to 100 microns. At small exposures, H2O TDS is characterized by broad (100 to 450 K) structures; at large exposures distinct TDS peaks emerge that are assigned to amorphous solid water (145 K) and crystalline ice (165 K). Water dissociates on JSC-1a at small exposures but not on the bare silica support. It appears that rather porous condensed ice layers form at large exposures. At thermal impact energies, the initial adsorption probability amounts to 0.92+/-0.05.

HYDROLYSIS OF MTBE IN GROUND WATER SAMPLES PRESERVED WITIH HYDROCHLORIC ACID

EPA Science Inventory

Conventional sampling and analytical protocols have poor sensitivity for fuel oxygenates that are alcohols, such as TBA. Because alcohols tend to stay with the water samples, they are not efficiently transferred to the gas chromatograph for separation and analysis. A common tec...

Sea urchin fertilization assay: an evaluation of assumptions related to sample salinity adjustment and use of natural and synthetic marine waters for testing.

PubMed

Jonczyk, E; Gilron, G; Zajdlik, B

2001-04-01

Most industrial effluents discharged into the marine coastal environment are freshwater in nature and therefore require manipulation prior to testing with marine organisms. The sea urchin fertilization test is a common marine bioassay used for routine environmental monitoring, investigative evaluations, and/or regulatory testing of effluents and sediment pore waters. The existing Canadian and U.S. Environmental Protection Agencies test procedures using sea urchin (and sand dollar) gametes allow for sample salinity adjustment using either brine or dry salts. Moreover, these procedures also allow for the use of either natural or synthetic marine water for culturing/holding test organisms and for full-scale testing. At present, it is unclear to what extent these variables affect test results for whole effluents. The test methods simply state that there are no data available and that the use of artificial dry sea salts should be considered provisional. We conducted a series of concurrent experiments aimed at comparing the two different treatments of sample salinity adjustment and the use of natural versus synthetic seawater in order to test these assumptions and evaluate effects on the estimated end points generated by the sea urchin fertilization sublethal toxicity test. Results from these experiments indicated that there is no significant difference in test end points when dry salts or brine are used for sample salinity adjustment. Similarly, results obtained from parallel (split-sample) industrial effluent tests with natural and artificial seawater suggest that both dilution waters produce similar test results. However, data obtained from concurrent tests with the reference toxicant, copper sulfate, showed higher variability and greater sensitivity when using natural seawater as control/dilution water.

Improving methodological aspects of the analysis of five regulated haloacetic acids in water samples by solid-phase extraction, ion-pair liquid chromatography and electrospray tandem mass spectrometry.

PubMed

Prieto-Blanco, M C; Alpendurada, M F; López-Mahía, P; Muniategui-Lorenzo, S; Prada-Rodríguez, D; Machado, S; Gonçalves, C

2012-05-30

Haloacetic acids (HAAs) are organic pollutants originated from the drinking water disinfection process, which ought to be controlled and minimized. In this work a method for monitoring haloacetic acids (HAAs) in water samples is proposed, which can be used in quality control laboratories using the techniques most frequently available. Among its main advantages we may highlight its automated character, including minimal steps of sample preparation, and above all, its improved selectivity and sensitivity in the analysis of real samples. Five haloacetic acids (HAA5) were analyzed using solid-phase extraction (SPE) combined with ion-pair liquid chromatography and tandem mass spectrometry. For the optimization of the chromatographic separation, two amines (triethylamine, TEA and dibutylamine, DBA) as ion pair reagents were compared, and a better selectivity and sensitivity was obtained using DBA, especially for monohaloacetic acids. SPE conditions were optimized using different polymeric adsorbents. The electrospray source parameters were studied for maximum precursor ion accumulation, while the collision cell energy of the triple quadrupole mass spectrometer was adjusted for optimum fragmentation. Precursor ions detected were deprotonated, dimeric and decarboxylated ions. The major product ions formed were: ionized halogen atom (chloride and bromide) and decarboxylated ions. After enrichment of the HAAs in Lichrolut EN adsorbent, the limits of detection obtained by LC-MS/MS analysis (between 0.04 and 0.3 ng mL(-1)) were comparable to those obtained by GC-MS after derivatization. Linearity with good correlation coefficients was obtained over two orders of magnitude irrespective of the compound. Adequate recoveries were achieved (60-102%), and the repeatability and intermediate precision were in the range of 2.4-6.6% and 3.8-14.8%, respectively. In order to demonstrate the usefulness of the method for routine HAAs monitoring, different types of water samples were

Comparison of Enterococcus faecium and Enterococcus faecalis Strains Isolated from Water and Clinical Samples: Antimicrobial Susceptibility and Genetic Relationships

PubMed Central

Castillo-Rojas, Gonzalo; Mazari-Hiríart, Marisa; Ponce de León, Sergio; Amieva-Fernández, Rosa I.; Agis-Juárez, Raúl A.; Huebner, Johannes; López-Vidal, Yolanda

2013-01-01

Enterococci are part of the normal intestinal flora in a large number of mammals, and these microbes are currently used as indicators of fecal contamination in water and food for human consumption. These organisms are considered one of the primary causes of nosocomial and environmental infections due to their ability to survive in the environment and to their intrinsic resistance to antimicrobials. The aims of this study were to determine the biochemical patterns and antimicrobial susceptibilities of Enterococcus faecalis and E. faecium isolates from clinical samples and from water (groundwater, water from the Xochimilco wetland, and treated water from the Mexico City Metropolitan Area) and to determine the genetic relationships among these isolates. A total of 121 enterococcus strains were studied; 31 and 90 strains were isolated from clinical samples and water (groundwater, water from the Xochimilco wetland, and water for agricultural irrigation), respectively. Identification to the species level was performed using a multiplex PCR assay, and antimicrobial profiles were obtained using a commercial kit. Twenty-eight strains were analyzed by pulsed-field gel electrophoresis (PFGE). E. faecium strains isolated from water showed an atypical biochemical pattern. The clinical isolates showed higher resistance to antibiotics than those from water. Both the enterococci isolated from humans, and those isolated from water showed high genetic diversity according to the PFGE analysis, although some strains seemed to be closely related. In conclusion, enterococci isolated from humans and water are genetically different. However, water represents a potential route of transmission to the community and a source of antimicrobial resistance genes that may be readily transmitted to other, different bacterial species. PMID:23560050

Comparison of Enterococcus faecium and Enterococcus faecalis Strains isolated from water and clinical samples: antimicrobial susceptibility and genetic relationships.

PubMed

Castillo-Rojas, Gonzalo; Mazari-Hiríart, Marisa; Ponce de León, Sergio; Amieva-Fernández, Rosa I; Agis-Juárez, Raúl A; Huebner, Johannes; López-Vidal, Yolanda

2013-01-01

Enterococci are part of the normal intestinal flora in a large number of mammals, and these microbes are currently used as indicators of fecal contamination in water and food for human consumption. These organisms are considered one of the primary causes of nosocomial and environmental infections due to their ability to survive in the environment and to their intrinsic resistance to antimicrobials. The aims of this study were to determine the biochemical patterns and antimicrobial susceptibilities of Enterococcus faecalis and E. faecium isolates from clinical samples and from water (groundwater, water from the Xochimilco wetland, and treated water from the Mexico City Metropolitan Area) and to determine the genetic relationships among these isolates. A total of 121 enterococcus strains were studied; 31 and 90 strains were isolated from clinical samples and water (groundwater, water from the Xochimilco wetland, and water for agricultural irrigation), respectively. Identification to the species level was performed using a multiplex PCR assay, and antimicrobial profiles were obtained using a commercial kit. Twenty-eight strains were analyzed by pulsed-field gel electrophoresis (PFGE). E. faecium strains isolated from water showed an atypical biochemical pattern. The clinical isolates showed higher resistance to antibiotics than those from water. Both the enterococci isolated from humans, and those isolated from water showed high genetic diversity according to the PFGE analysis, although some strains seemed to be closely related. In conclusion, enterococci isolated from humans and water are genetically different. However, water represents a potential route of transmission to the community and a source of antimicrobial resistance genes that may be readily transmitted to other, different bacterial species.

Water-quality trend analysis and sampling design for the Souris River, Saskatchewan, North Dakota, and Manitoba

USGS Publications Warehouse

Vecchia, Aldo V.

2000-01-01

concentrations of most major ions, dissolved boron, and dissolved arsenic during 1987-91 and decreases in concentrations of the same constituents during 1992-96.  Significant trends at the two sites located near the downstream boundary crossing between North Dakota and Manitoba included increases in dissolved sodium, dissolved chloride, and total phosphorus during 1977-86, decreases in dissolved oxygen and dissolved boron and increases in total phosphorus and dissolved iron during 1987-91, and a decrease in total phosphorus during 1992-96. The time-series model also was used to determine the sensitivity of various sampling designs for monitoring future water-quality trends in the Souris River.  It was determined that at least two samples per year are required in each of three seasons--March through June, July through October, and November through February--to obtain reasonable sensitivity for detecting trends in each season.  In addition, substantial improvements occurred in sensitivity for detecting trends by adding a third sample for major ions and trace elements in March through June, adding a third sample for nutrients in July through October, and adding a third sample for nutrients, trace elements, and dissolved oxygen in November through February.

Understanding the origin and evolution of water in the Moon through lunar sample studies.

PubMed

Anand, Mahesh; Tartèse, Romain; Barnes, Jessica J

2014-09-13

A paradigm shift has recently occurred in our knowledge and understanding of water in the lunar interior. This has transpired principally through continued analysis of returned lunar samples using modern analytical instrumentation. While these recent studies have undoubtedly measured indigenous water in lunar samples they have also highlighted our current limitations and some future challenges that need to be overcome in order to fully understand the origin, distribution and evolution of water in the lunar interior. Another exciting recent development in the field of lunar science has been the unambiguous detection of water or water ice on the surface of the Moon through instruments flown on a number of orbiting spacecraft missions. Considered together, sample-based studies and those from orbit strongly suggest that the Moon is not an anhydrous planetary body, as previously believed. New observations and measurements support the possibility of a wet lunar interior and the presence of distinct reservoirs of water on the lunar surface. Furthermore, an approach combining measurements of water abundance in lunar samples and its hydrogen isotopic composition has proved to be of vital importance to fingerprint and elucidate processes and source(s) involved in giving rise to the lunar water inventory. A number of sources are likely to have contributed to the water inventory of the Moon ranging from primordial water to meteorite-derived water ice through to the water formed during the reaction of solar wind hydrogen with the lunar soil. Perhaps two of the most striking findings from these recent studies are the revelation that at least some portions of the lunar interior are as water-rich as some Mid-Ocean Ridge Basalt source regions on Earth and that the water in the Earth and the Moon probably share a common origin. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Understanding the origin and evolution of water in the Moon through lunar sample studies

PubMed Central

Anand, Mahesh; Tartèse, Romain; Barnes, Jessica J.

2014-01-01

A paradigm shift has recently occurred in our knowledge and understanding of water in the lunar interior. This has transpired principally through continued analysis of returned lunar samples using modern analytical instrumentation. While these recent studies have undoubtedly measured indigenous water in lunar samples they have also highlighted our current limitations and some future challenges that need to be overcome in order to fully understand the origin, distribution and evolution of water in the lunar interior. Another exciting recent development in the field of lunar science has been the unambiguous detection of water or water ice on the surface of the Moon through instruments flown on a number of orbiting spacecraft missions. Considered together, sample-based studies and those from orbit strongly suggest that the Moon is not an anhydrous planetary body, as previously believed. New observations and measurements support the possibility of a wet lunar interior and the presence of distinct reservoirs of water on the lunar surface. Furthermore, an approach combining measurements of water abundance in lunar samples and its hydrogen isotopic composition has proved to be of vital importance to fingerprint and elucidate processes and source(s) involved in giving rise to the lunar water inventory. A number of sources are likely to have contributed to the water inventory of the Moon ranging from primordial water to meteorite-derived water ice through to the water formed during the reaction of solar wind hydrogen with the lunar soil. Perhaps two of the most striking findings from these recent studies are the revelation that at least some portions of the lunar interior are as water-rich as some Mid-Ocean Ridge Basalt source regions on Earth and that the water in the Earth and the Moon probably share a common origin. PMID:25114308

Natural radioactivity in various water samples and radiation dose estimations in Bolu province, Turkey.

PubMed

Gorur, F Korkmaz; Camgoz, H

2014-10-01

The level of natural radioactivity for Bolu province of north-western Turkey was assessed in this study. There is no information about radioactivity measurement reported in water samples in the Bolu province so far. For this reason, gross α and β activities of 55 different water samples collected from tap, spring, mineral, river and lake waters in Bolu were determined. The mean activity concentrations were 68.11 mBq L(-1), 169.44 mBq L(-1) for gross α and β in tap water. For all samples the gross β activity is always higher than the gross α activity. All value of the gross α were lower than the limit value of 500 mBq L(-1) while two spring and one mineral water samples were found to have gross β activity concentrations of greater than 1000 mBq L(-1). The associated age-dependent dose from all water ingestion in Bolu was estimated. The total dose for adults had an average value exceeds the WHO recommended limit value. The risk levels from the direct ingestion of the natural radionuclides in tap and mineral water in Bolu were determinated. The mean (210)Po and (228)Ra risk the value of tap and mineral waters slightly exceeds what some consider on acceptable risk of 10(-4) or less. Copyright © 2014 Elsevier Ltd. All rights reserved.

Modification of kanamycin-esculin-azide agar to improve selectivity in the enumeration of fecal streptococci from water samples.

PubMed Central

Audicana, A; Perales, I; Borrego, J J

1995-01-01

Kanamycin-esculin-azide agar was modified by increasing the concentration of sodium azide to 0.4 g liter-1 and replacing kanamycin sulfate with 5 mg of oxolinic acid liter-1. The modification, named oxolinic acid-esculin-azide (OAA) agar, was compared with Slanetz-Bartley and KF agars by using drinking water and seawater samples. The OAA agar showed higher specificity, selectivity, and recovery efficiencies than those obtained by using the other media. In addition, no confirmation of typical colonies was needed when OAA agar was used, which significantly shortens the time of sample processing and increases the accuracy of the method. PMID:8534085

USE OF COMMERCIAL TELEPHONE DIRECTORY FOR OBTAINING A POPULATION-BASED SAMPLE OF WOMEN OF REPRODUCTIVE AGE

EPA Science Inventory

Using Commercial Telephone Directories to Obtain a Population-Based Sample for Mail Survey of Women of Reproductive Age

Danelle T. Lobdella, Germaine M. Buckb, John M. Weinerc, Pauline Mendolaa

aUnited States Environmental Protection Agency, Office of Research and ...

Molecular Method for Detection of Total Coliforms in Drinking Water Samples

PubMed Central

Boudreau, Dominique K.; Bisson, Marc-Antoine; Dion-Dupont, Vanessa; Bouchard, Sébastien; Nkuranga, Martine; Bergeron, Michel G.; Rodriguez, Manuel J.

2014-01-01

This work demonstrates the ability of a bacterial concentration and recovery procedure combined with three different PCR assays targeting the lacZ, wecG, and 16S rRNA genes, respectively, to detect the presence of total coliforms in 100-ml samples of potable water (presence/absence test). PCR assays were first compared to the culture-based Colilert and MI agar methods to determine their ability to detect 147 coliform strains representing 76 species of Enterobacteriaceae encountered in fecal and environmental settings. Results showed that 86 (58.5%) and 109 (74.1%) strains yielded a positive signal with Colilert and MI agar methods, respectively, whereas the lacZ, wecG, and 16S rRNA PCR assays detected 133 (90.5%), 111 (75.5%), and 146 (99.3%) of the 147 total coliform strains tested. These assays were then assessed by testing 122 well water samples collected in the Québec City region of Canada. Results showed that 97 (79.5%) of the samples tested by culture-based methods and 95 (77.9%), 82 (67.2%), and 98 (80.3%) of samples tested using PCR-based methods contained total coliforms, respectively. Consequently, despite the high genetic variability of the total coliform group, this study demonstrated that it is possible to use molecular assays to detect total coliforms in potable water: the 16S rRNA molecular assay was shown to be as efficient as recommended culture-based methods. This assay might be used in combination with an Escherichia coli molecular assay to assess drinking water quality. PMID:24771030

Comparison of water-quality samples collected by siphon samplers and automatic samplers in Wisconsin

USGS Publications Warehouse

Graczyk, David J.; Robertson, Dale M.; Rose, William J.; Steur, Jeffrey J.

2000-01-01

In small streams, flow and water-quality concentrations often change quickly in response to meteorological events. Hydrologists, field technicians, or locally hired stream ob- servers involved in water-data collection are often unable to reach streams quickly enough to observe or measure these rapid changes. Therefore, in hydrologic studies designed to describe changes in water quality, a combination of manual and automated sampling methods have commonly been used manual methods when flow is relatively stable and automated methods when flow is rapidly changing. Auto- mated sampling, which makes use of equipment programmed to collect samples in response to changes in stage and flow of a stream, has been shown to be an effective method of sampling to describe the rapid changes in water quality (Graczyk and others, 1993). Because of the high cost of automated sampling, however, especially for studies examining a large number of sites, alternative methods have been considered for collecting samples during rapidly changing stream conditions. One such method employs the siphon sampler (fig. 1). also referred to as the "single-stage sampler." Siphon samplers are inexpensive to build (about $25- $50 per sampler), operate, and maintain, so they are cost effective to use at a large number of sites. Their ability to collect samples representing the average quality of water passing though the entire cross section of a stream, however, has not been fully demonstrated for many types of stream sites.

Geochemical results from stream-water and stream-sediment samples collected in Colorado and New Mexico

USGS Publications Warehouse

Hageman, Philip L.; Todd, Andrew S.; Smith, Kathleen S.; DeWitt, Ed; Zeigler, Mathew P.

2013-01-01

Scientists from the U.S. Geological Survey are studying the relationship between watershed lithology and stream-water chemistry. As part of this effort, 60 stream-water samples and 43 corresponding stream-sediment samples were collected in 2010 and 2011 from locations in Colorado and New Mexico. Sample sites were selected from small to midsize watersheds composed of a high percentage of one rock type or geologic unit. Stream-water and stream-sediment samples were collected, processed, preserved, and analyzed in a consistent manner. This report releases geochemical data for this phase of the study.

A novel HS-SBSE system coupled with gas chromatography and mass spectrometry for the analysis of organochlorine pesticides in water samples.

PubMed

Grossi, Paula; Olivares, Igor R B; de Freitas, Diego R; Lancas, Fernando M

2008-10-01

A methodology to analyze organochlorine pesticides (OCPs) in water samples has been accomplished by using headspace stir bar sorptive extraction (HS-SBSE). The bars were in house coated with a thick film of PDMS in order to properly work in the headspace mode. Sampling was done by a novel HS-SBSE system whereas the analysis was performed by capillary GC coupled mass spectrometric detection (HS-SBSE-GC-MS). The extraction optimization, using different experimental parameters has been established by a standard equilibrium time of 120 min at 85 degrees C. A mixture of ACN/toluene as back extraction solvent promoted a good performance to remove the OCPs sorbed in the bar. Reproducibility between 2.1 and 14.8% and linearity between 0.96 and 1.0 were obtained for pesticides spiked in a linear range between 5 and 17 ng/g in water samples during the bar evaluation.

Multi-residue analysis method for analysis of pharmaceuticals using liquid chromatography-time of flight/mass spectrometry (LC-TOF/MS) in water sample

NASA Astrophysics Data System (ADS)

Al-Qaim, Fouad Fadhil; Abdullah, Md Pauzi; Othman, Mohamed Rozali

2013-11-01

In this work, a developed method using solid - phase extraction (SPE) followed by liquid chromatography - time of flight mass spectrometry (LC-ESI-TOF/MS) was developed and validated for quantification and confirmation of eleven pharmaceuticals with different therapeutic classes in water samples, Malaysia. These compounds are caffeine (CAF), prazosin (PRZ), enalapril (ENL), carbamazepine (CBZ), nifedipine (NFD), levonorgestrel (LNG), simvastatin (SMV), hydrochlorothiazide (HYD), gliclazide (GLIC), diclofenac-Na (DIC-Na) and mefenamic acid (MEF). LC was performed on a Dionex Ultimate 3000/LC 09115047 (USA) system. Chromatography was performed on a Thermo Scientific C18 (250 mm × 2.1 mm, i.d.: 5μm) column. Several parameters were optimised such as; mobile phase, gradient elution, collision energy and solvent elution for extraction of compounds from water. The recoveries obtained ranged from 30-148 % in river water. Five pharmaceutical compounds were detected in the surface water samples: caffeine, prazosin, enalpril, diclofenac-Na and mefenamic acid. The developed method is precise and accepted recoveries were got. In addition, this method is suitable to identify and quantify trace concentrations of pharmaceuticals in surface water.

Preservation of commonly applied fluorescent tracers in complex water samples

NASA Astrophysics Data System (ADS)

Cao, Viet; Schaffer, Mario; Jin, Yulan; Licha, Tobias

2017-06-01

Water sample preservation and pre-treatment are important steps for achieving accurate and reproductive results from tracer tests. However, this is particularly challenging for complex water mixtures prior to fluorescence analysis. In this study, the interference of iron and calcium precipitation with nine commonly applied conservative tracers, uranine, eosin, 1-naphthalene sulfonate, 1,5-naphthalene disulfonate, 2,6-naphthalene disulfonate, 4-amino-1-naphthalene sulfonate, 6-hydroxy-2-naphthalene sulfonate, 1,3,6-naphthalene trisulfonate, and 1,3,6,8-pyrene tetrasulfonate, was investigated in batch experiments. In general, the observed results are influenced by precipitates. A technique consisting of pH adjustment and centrifugation is described for preserving samples and avoiding the impact of these precipitates on the tracer test results.

Determination of the amount of Cs-137 in the sea water obtained from the Dardanelles

NASA Astrophysics Data System (ADS)

Ataseven, D.; Şen, S.

2017-02-01

After the Chernobyl accident, high concentrations of Cs-137 radioisotope reached the Black Sea through dry and wet fallout. Therefore, a number of studies were performed to determine the current activity of Cs-137 near this region in the sea water and in marine organisms. Cs-137 activity was determined in the Dardanelles sea water taken from three separate locations and two different depths for each location. The old data base obtained in our previous studies was updated.

Does the bathing water classification depend on sampling strategy? A bootstrap approach for bathing water quality assessment, according to Directive 2006/7/EC requirements.

PubMed

López, Iago; Alvarez, César; Gil, José L; Revilla, José A

2012-11-30

Data on the 95th and 90th percentiles of bacteriological quality indicators are used to classify bathing waters in Europe, according to the requirements of Directive 2006/7/EC. However, percentile values and consequently, classification of bathing waters depend both on sampling effort and sample-size, which may undermine an appropriate assessment of bathing water classification. To analyse the influence of sampling effort and sample size on water classification, a bootstrap approach was applied to 55 bacteriological quality datasets of several beaches in the Balearic Islands (Spain). Our results show that the probability of failing the regulatory standards of the Directive is high when sample size is low, due to a higher variability in percentile values. In this way, 49% of the bathing waters reaching an "Excellent" classification (95th percentile of Escherichia coli under 250 cfu/100 ml) can fail the "Excellent" regulatory standard due to sampling strategy, when 23 samples per season are considered. This percentage increases to 81% when 4 samples per season are considered. "Good" regulatory standards can also be failed in bathing waters with an "Excellent" classification as a result of these sampling strategies. The variability in percentile values may affect bathing water classification and is critical for the appropriate design and implementation of bathing water Quality Monitoring and Assessment Programs. Hence, variability of percentile values should be taken into account by authorities if an adequate management of these areas is to be achieved. Copyright © 2012 Elsevier Ltd. All rights reserved.

A rapid method for the sampling of atmospheric water vapour for isotopic analysis.

PubMed

Peters, Leon I; Yakir, Dan

2010-01-01

Analysis of the stable isotopic composition of atmospheric moisture is widely applied in the environmental sciences. Traditional methods for obtaining isotopic compositional data from ambient moisture have required complicated sampling procedures, expensive and sophisticated distillation lines, hazardous consumables, and lengthy treatments prior to analysis. Newer laser-based techniques are expensive and usually not suitable for large-scale field campaigns, especially in cases where access to mains power is not feasible or high spatial coverage is required. Here we outline the construction and usage of a novel vapour-sampling system based on a battery-operated Stirling cycle cooler, which is simple to operate, does not require any consumables, or post-collection distillation, and is light-weight and highly portable. We demonstrate the ability of this system to reproduce delta(18)O isotopic compositions of ambient water vapour, with samples taken simultaneously by a traditional cryogenic collection technique. Samples were collected over 1 h directly into autosampler vials and were analysed by mass spectrometry after pyrolysis of 1 microL aliquots to CO. This yielded an average error of < +/-0.5 per thousand, approximately equal to the signal-to-noise ratio of traditional approaches. This new system provides a rapid and reliable alternative to conventional cryogenic techniques, particularly in cases requiring high sample throughput or where access to distillation lines, slurry maintenance or mains power is not feasible. Copyright 2009 John Wiley & Sons, Ltd.

White HDPE bottles as source of serious contamination of water samples with Ba and Zn.

PubMed

Reimann, Clemens; Grimstvedt, Andreas; Frengstad, Bjørn; Finne, Tor Erik

2007-03-15

During a recent study of surface water quality factory new white high-density polyethylene (HDPE) bottles were used for collecting the water samples. According to the established field protocol of the Geological Survey of Norway the bottles were twice carefully rinsed with water in the field prior to sampling. Several blank samples using milli-Q (ELGA) water (>18.2 MOmega) were also prepared. On checking the analytical results the blanks returned values of Ag, Ba, Sr, V, Zn and Zr. For Ba and Zn the values (c. 300 microg/l and 95 microg/l) were about 10 times above the concentrations that can be expected in natural waters. A laboratory test of the bottles demonstrated that the bottles contaminate the samples with significant amounts of Ba and Zn and some Sr. Simple acid washing of the bottles prior to use did not solve the contamination problem for Ba and Zn. The results suggest that there may exist "clean" and "dirty" HDPE bottles depending on manufacturer/production process. When collecting water samples it is mandatory to check bottles regularly as a possible source of contamination.

High-frequency, long-duration water sampling in acid mine drainage studies: a short review of current methods and recent advances in automated water samplers

USGS Publications Warehouse

Chapin, Thomas

2015-01-01

Hand-collected grab samples are the most common water sampling method but using grab sampling to monitor temporally variable aquatic processes such as diel metal cycling or episodic events is rarely feasible or cost-effective. Currently available automated samplers are a proven, widely used technology and typically collect up to 24 samples during a deployment. However, these automated samplers are not well suited for long-term sampling in remote areas or in freezing conditions. There is a critical need for low-cost, long-duration, high-frequency water sampling technology to improve our understanding of the geochemical response to temporally variable processes. This review article will examine recent developments in automated water sampler technology and utilize selected field data from acid mine drainage studies to illustrate the utility of high-frequency, long-duration water sampling.

[The Investigation of Acanthamoeba and Other Free Living Amoeba in Swab Samples Obtained from Conjunctiva and Eye Lid].

PubMed

Yünlü, Önder; Özçelik, Semra; Arıcı, Mustafa Kemal

2015-09-01

In the study, it is aimed to determine the prevalence of Acanthamoeba and other free-living amoeba (FLA) species in the swab samples obtained from conjunctiva and lower eye lid. For this purpose, swab samples from the 500 patients'eye lid and conjunctiva were obtained who admitted to Cumhuriyet University, Research and Application Hospital, Department of Ophthalmology with variety of reasons. Swab samples were carried out using sterile cotton swab in steril tubes. The swab samples were inoculated onto non-nutrient agar (NNA). Live Escherichia coli was used as food source for the growth of the FLA. The NNA plates were incubated at 300C and examined daily using ligth microscope for two weeks. For morphotyping of the trophozoites and cysts of the FLA were used taxonomic keys. Two of the 500 swab samples (0.4%) were positive for FLA. One of them (0.2%) were identified as Acanthamoeba spp. and other was identified as Hartmannella spp. However, these patients did not reveal any complaints yet. FLA both themselves and bacteria carrying in their body as reservoirs are potential pathogen. The rapid spread of Acanthamoeba keratitis in recent years reveal that these microorganisms are in contact with the eyes.

Obtaining Self-Samples to Diagnose Curable Sexually Transmitted Infections: A Systematic Review of Patients’ Experiences

PubMed Central

Paudyal, Priyamvada; Llewellyn, Carrie; Lau, Jason; Mahmud, Mohammad; Smith, Helen

2015-01-01

Background Routine screening is key to sexually transmitted infection (STI) prevention and control. Previous studies suggest that clinic-based screening programmes capture only a small proportion of people with STIs. Self-sampling using non- or minimally invasive techniques may be beneficial for those reluctant to actively engage with conventional sampling methods. We systematically reviewed studies of patients’ experiences of obtaining self-samples to diagnose curable STIs. Methods We conducted an electronic search of MEDLINE, EMBASE, CINAHL, PsychINFO, BNI, and Cochrane Database of Systematic Reviews to identify relevant articles published in English between January 1980 and March 2014. Studies were included if participants self-sampled for the diagnosis of a curable STI and had specifically sought participants’ opinions of their experience, acceptability, preferences, or willingness to self-sample. Results The initial search yielded 558 references. Of these, 45 studies met the inclusion criteria. Thirty-six studies assessed patients’ acceptability and experiences of self-sampling. Pooled results from these studies shows that self-sampling is a highly acceptable method with 85% of patients reporting the method to be well received and acceptable. Twenty-eight studies reported on ease of self-sampling; the majority of patients (88%) in these studies found self-sampling an “easy” procedure. Self-sampling was favoured compared to clinician sampling, and home sampling was preferred to clinic-based sampling. Females and older participants were more accepting of self-sampling. Only a small minority of participants (13%) reported pain during self-sampling. Participants were willing to undergo self-sampling and recommend others. Privacy and safety were the most common concerns. Conclusion Self-sampling for diagnostic testing is well accepted with the majority having a positive experience and willingness to use again. Standardization of self-sampling procedures

Detection by PCR of pathogenic protozoa in raw and drinkable water samples in Colombia.

PubMed

Triviño-Valencia, Jessica; Lora, Fabiana; Zuluaga, Juan David; Gomez-Marin, Jorge E

2016-05-01

We evaluated the presence of DNA of Giardia, Toxoplasma, and Cryptosporidium by PCR, and of Giardia and Cryptosporidium genera by immunofluorescence antibody test (IFAT), in water samples, before, during, and after plant treatment for drinkable water. We applied this method in 38 samples of 10 l of water taken from each of the water treatment steps and in 8 samples taken at home (only for Toxoplasma PCR) in Quindio region in Colombia. There were 8 positive samples for Cryptosporidium parvum (21 %), 4 for Cryptosporidium hominis (10.5 %), 27 for Toxoplasma gondii (58.6 %), 2 for Giardia duodenalis assemblage A (5.2 %), and 5 for G. duodenalis assemblage B (13.1 %). By IFAT, 23 % were positive for Giardia and 21 % for Cryptosporidium. An almost perfect agreement was found between IFAT and combined results of PCR, by Kappa composite proportion analysis. PCR positive samples were significantly more frequent in untreated raw water for C. parvum (p = 0.02). High mean of fecal coliforms, high pH values, and low mean of chlorine residuals were strongly correlated with PCR positivity for G. duodenalis assemblage B. High pH value was correlated with PCR positivity for C. parvum. Phylogenetic analysis of DNA sequences was possible, showing water and human clinical sequences for Toxoplasma within the same phylogenetic group for B1 repeated sequence. PCR assay is complementary to IFAT assay for monitoring of protozoa in raw and drinkable water, enabling species identification and to look for phylogenetic analysis in protozoa from human and environmental sources.

Preconcentration and determination of rare-earth elements in iron-rich water samples by extraction chromatography and plasma source mass spectrometry (ICP-MS).

PubMed

Hernández González, Carolina; Cabezas, Alberto J Quejido; Díaz, Marta Fernández

2005-11-15

A 100-fold preconcentration procedure based on rare-earth elements (REEs) separation from water samples with an extraction chromatographic column has been developed. The separation of REEs from matrix elements (mainly Fe, alkaline and alkaline-earth elements) in water samples was performed loading the samples, previously acidified to pH 2.0 with HNO(3), in a 2ml column preconditioned with 20ml 0.01M HNO(3). Subsequently, REEs were quantitatively eluted with 20ml 7M HNO(3). This solution was evaporated to dryness and the final residue was dissolved in 10ml 2% HNO(3) containing 1mugl(-1) of cesium used as internal standard. The solution was directly analysed by inductively coupled plasma mass spectrometry (ICP-MS), using ultrasonic nebulization, obtaining quantification limits ranging from 0.05 to 0.10 ngl(-1). The proposed method has been applied to granitic waters running through fracture fillings coated by iron and manganese oxy-hydroxides in the area of the Ratones (Cáceres, Spain) old uranium mine.

Microbial quality of drinking water from microfiltered water dispensers.

PubMed

Sacchetti, R; De Luca, G; Dormi, A; Guberti, E; Zanetti, F

2014-03-01

A comparison was made between the microbial quality of drinking water obtained from Microfiltered Water Dispensers (MWDs) and that of municipal tap water. A total of 233 water samples were analyzed. Escherichia coli (EC), enterococci (ENT), total coliforms (TC), Staphylococcus aureus, Pseudomonas aeruginosa and heterotrophic plate count (HPC) at 22 °C and 37 °C were enumerated. In addition, information was collected about the principal structural and functional characteristics of each MWD in order to study the various factors that might influence the microbial quality of the water. EC and ENT were not detected in any of the samples. TC were never detected in the tap water but were found in 5 samples taken from 5 different MWDs. S. aureus was found in a single sample of microfiltered water. P. aeruginosa was found more frequently and at higher concentrations in the samples collected from MWDs. The mean HPCs at 22 °C and 37 °C were significantly higher in microfiltered water samples compared to those of the tap water. In conclusion, the use of MWDs may increase the number of bacteria originally present in tap water. It is therefore important to monitor the quality of the dispensed water over time, especially if it is destined for vulnerable users. Copyright © 2013 Elsevier GmbH. All rights reserved.

An Optimized DNA Analysis Workflow for the Sampling, Extraction, and Concentration of DNA obtained from Archived Latent Fingerprints.

PubMed

Solomon, April D; Hytinen, Madison E; McClain, Aryn M; Miller, Marilyn T; Dawson Cruz, Tracey

2018-01-01

DNA profiles have been obtained from fingerprints, but there is limited knowledge regarding DNA analysis from archived latent fingerprints-touch DNA "sandwiched" between adhesive and paper. Thus, this study sought to comparatively analyze a variety of collection and analytical methods in an effort to seek an optimized workflow for this specific sample type. Untreated and treated archived latent fingerprints were utilized to compare different biological sampling techniques, swab diluents, DNA extraction systems, DNA concentration practices, and post-amplification purification methods. Archived latent fingerprints disassembled and sampled via direct cutting, followed by DNA extracted using the QIAamp® DNA Investigator Kit, and concentration with Centri-Sep™ columns increased the odds of obtaining an STR profile. Using the recommended DNA workflow, 9 of the 10 samples provided STR profiles, which included 7-100% of the expected STR alleles and two full profiles. Thus, with carefully selected procedures, archived latent fingerprints can be a viable DNA source for criminal investigations including cold/postconviction cases. © 2017 American Academy of Forensic Sciences.

Relationship between sweat chloride, sodium, and age in clinically obtained samples.

PubMed

Traeger, Nadav; Shi, Qiuhu; Dozor, Allen J

2014-01-01

The relationship between sweat electrolytes and age is uncertain, as is the value of measuring sodium or the chloride:sodium ratio. 13,785 sweat tests performed over 23 years at one center through the Macroduct collection in clinically obtained samples were analyzed. Sweat chloride tended to decrease over the first year of life, slowly increase until the fourth decade, then either level off or slightly decrease. In children, sweat sodium overlapped between those with positive and negative sweat tests, but not in adults. If the sweat test was positive, there was a higher likelihood of having a chloride:sodium ratio >1, but most subjects with a ratio >1 did not have CF. Sweat chloride and sodium vary with age. Measurement of sweat sodium did not add discriminatory value. The proportion of subjects with a chloride:sodium ratio >1, with or without CF, varied greatly between age ranges. © 2013. Published by Elsevier B.V. on behalf of European Cystic Fibrosis Society. All rights reserved.

Molecular method for detection of total coliforms in drinking water samples.

PubMed

Maheux, Andrée F; Boudreau, Dominique K; Bisson, Marc-Antoine; Dion-Dupont, Vanessa; Bouchard, Sébastien; Nkuranga, Martine; Bergeron, Michel G; Rodriguez, Manuel J

2014-07-01

This work demonstrates the ability of a bacterial concentration and recovery procedure combined with three different PCR assays targeting the lacZ, wecG, and 16S rRNA genes, respectively, to detect the presence of total coliforms in 100-ml samples of potable water (presence/absence test). PCR assays were first compared to the culture-based Colilert and MI agar methods to determine their ability to detect 147 coliform strains representing 76 species of Enterobacteriaceae encountered in fecal and environmental settings. Results showed that 86 (58.5%) and 109 (74.1%) strains yielded a positive signal with Colilert and MI agar methods, respectively, whereas the lacZ, wecG, and 16S rRNA PCR assays detected 133 (90.5%), 111 (75.5%), and 146 (99.3%) of the 147 total coliform strains tested. These assays were then assessed by testing 122 well water samples collected in the Québec City region of Canada. Results showed that 97 (79.5%) of the samples tested by culture-based methods and 95 (77.9%), 82 (67.2%), and 98 (80.3%) of samples tested using PCR-based methods contained total coliforms, respectively. Consequently, despite the high genetic variability of the total coliform group, this study demonstrated that it is possible to use molecular assays to detect total coliforms in potable water: the 16S rRNA molecular assay was shown to be as efficient as recommended culture-based methods. This assay might be used in combination with an Escherichia coli molecular assay to assess drinking water quality. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Diffusion and drive-point sampling to detect ordnance-related compounds in shallow ground water beneath Snake Pond, Cape Cod, Massachusetts, 2001-02

USGS Publications Warehouse

LeBlanc, Denis R.

2003-01-01

Diffusion samplers and temporary drive points were used to test for ordnance-related compounds in ground water discharging to Snake Pond near Camp Edwards at the Massachusetts Military Reservation, Cape Cod, MA. The contamination resulted from artillery use and weapons testing at various ranges upgradient of the pond.The diffusion samplers were constructed with a high-grade cellulose membrane that allowed diffusion of explosive compounds, such as RDX (Hexahydro-1,3,5-trinitro-1,3,5-triazine) and HMX (Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine), into deionized water inside the samplers. Laboratory tests confirmed that the cellulose membrane was permeable to RDX and HMX. One transect of 22 diffusion samplers was installed and retrieved in August-September 2001, and 12 transects with a total of 108 samplers were installed and retrieved in September-October 2001. The diffusion samplers were buried about 0.5 feet into the pond-bottom sediments by scuba divers and allowed to equilibrate with the ground water beneath the pond bottom for 13 to 27 days before retrieval. Water samples were collected from temporary well points driven about 2-4 feet into the pond bottom at 21 sites in December 2001 and March 2002 for analysis of explosives and perchlorate to confirm the diffusion-sampling results. The water samples from the diffusion samplers exhibited numerous chromatographic peaks, but evaluation of the photo-diode-array spectra indicated that most of the peaks did not represent the target compounds. The peaks probably are associated with natural organic compounds present in the soft, organically enriched pond-bottom sediments. The presence of four explosive compounds at five widely spaced sites was confirmed by the photo-diode-array analysis, but the compounds are not generally found in contaminated ground water near the ranges. No explosives were detected in water samples obtained from the drive points. Perchlorate was detected at less than 1 microgram per liter in

Improving the accuracy of sediment-associated constituent concentrations in whole storm water samples by wet-sieving

USGS Publications Warehouse

Selbig, W.R.; Bannerman, R.; Bowman, G.

2007-01-01

Sand-sized particles (>63 ??m) in whole storm water samples collected from urban runoff have the potential to produce data with substantial bias and/or poor precision both during sample splitting and laboratory analysis. New techniques were evaluated in an effort to overcome some of the limitations associated with sample splitting and analyzing whole storm water samples containing sand-sized particles. Wet-sieving separates sand-sized particles from a whole storm water sample. Once separated, both the sieved solids and the remaining aqueous (water suspension of particles less than 63 ??m) samples were analyzed for total recoverable metals using a modification of USEPA Method 200.7. The modified version digests the entire sample, rather than an aliquot, of the sample. Using a total recoverable acid digestion on the entire contents of the sieved solid and aqueous samples improved the accuracy of the derived sediment-associated constituent concentrations. Concentration values of sieved solid and aqueous samples can later be summed to determine an event mean concentration. ?? ASA, CSSA, SSSA.

Ground-water quality in east-central New Jersey, and a plan for sampling networks

USGS Publications Warehouse

Harriman, D.A.; Sargent, B.P.

1985-01-01

Groundwater quality was evaluated in seven confined aquifers and the water table aquifer in east-central New Jersey based on 237 analyses of samples collected in 1981-82, and 225 older analyses. Investigation of the effect of land use on water quality and several sampling network proposals for the region are reported. Generally, water in the confined aquifers is of satisfactory quality for human consumption and most other uses. Iron (Fe) and manganese (Mn) concentrations exceed U.S. EPA drinking water standards in some wells screened in the Potomac-Raritan-Magothy aquifer system. Sodium (Na) concentrations in samples from three wells more than 800 ft deep in the Englishtown aquifer exceed the standard. Iron and Mn concentrations in this aquifer may also exceed the standards. Iron concentrations in the Wenonah-Mount Laurel aquifer exceed the standard. Based on 15 analyses of water from the Vincetown aquifer, Mn is the only constituent that exceeds the drinking water standard. In the Manasquan aquifer, 4 of the 16 Na determinations exceed the standard, and 8 of 16 Fe determinations exceed the standard. Water quality in the Atlantic City 800-ft sand is generally satisfactory. However, 12 Fe and 1 of 12 Mn determinations exceed the standards. For the Rio Grande water-bearing zone, 1 of 3 Fe determinations exceed the standard. The Kirkwood-Cohansey aquifer system (the water table aquifer) was the most thoroughly sampled (249 chemical analyses from 209 wells). Dissolved solids, chloride, Fe, nitrate, and Mn concentrations exceed drinking water standards in some areas. The results of chi-square tests of constituent distributions based on analyses from 158 wells in the water table aquifer indicate that calcium is higher in industrial and commercial areas; and Mg, chloride, and nitrate-plus-nitrite is higher in residential areas. (Author 's abstract)

Effects of soil water saturation on sampling equilibrium and kinetics of selected polycyclic aromatic hydrocarbons.

PubMed

Kim, Pil-Gon; Roh, Ji-Yeon; Hong, Yongseok; Kwon, Jung-Hwan

2017-10-01

Passive sampling can be applied for measuring the freely dissolved concentration of hydrophobic organic chemicals (HOCs) in soil pore water. When using passive samplers under field conditions, however, there are factors that might affect passive sampling equilibrium and kinetics, such as soil water saturation. To determine the effects of soil water saturation on passive sampling, the equilibrium and kinetics of passive sampling were evaluated by observing changes in the distribution coefficient between sampler and soil (K sampler/soil ) and the uptake rate constant (k u ) at various soil water saturations. Polydimethylsiloxane (PDMS) passive samplers were deployed into artificial soils spiked with seven selected polycyclic aromatic hydrocarbons (PAHs). In dry soil (0% water saturation), both K sampler/soil and k u values were much lower than those in wet soils likely due to the contribution of adsorption of PAHs onto soil mineral surfaces and the conformational changes in soil organic matter. For high molecular weight PAHs (chrysene, benzo[a]pyrene, and dibenzo[a,h]anthracene), both K sampler/soil and k u values increased with increasing soil water saturation, whereas they decreased with increasing soil water saturation for low molecular weight PAHs (phenanthrene, anthracene, fluoranthene, and pyrene). Changes in the sorption capacity of soil organic matter with soil water content would be the main cause of the changes in passive sampling equilibrium. Henry's law constant could explain the different behaviors in uptake kinetics of the selected PAHs. The results of this study would be helpful when passive samplers are deployed under various soil water saturations. Copyright © 2017 Elsevier Ltd. All rights reserved.