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Sample records for mibk

  1. Influence of Salts on the Partitioning of 5-Hydroxymethylfurfural in Water/MIBK.

    PubMed

    Mohammad, Sultan; Held, Christoph; Altuntepe, Emrah; Köse, Tülay; Sadowski, Gabriele

    2016-04-28

    This study investigates the influence of electrolytes on the performance of extracting 5-hydroxymethylfurfural (HMF) from aqueous media using methyl isobutyl ketone (MIBK). For that purpose, liquid-liquid phase equilibria (LLE) of quaternary systems containing HMF, water, MIBK and salts were measured at atmospheric pressure and 298.15 K. The salts under investigation were composed of one of the anions NO(3-), SO4(2-), Cl(-), or CH3COO(-) and of one of the alkali cations Li(+), Na(+), or K(+). On the basis of these LLE data, the partition coefficient of HMF between the aqueous and the MIBK phase KHMF was determined. It could be shown that KHMF significantly depends on the kind and concentration of the added salt. Weak electrolytes (e.g., sulfates, acetates) caused salting-out, whereas nitrates caused salting-in of HMF to the aqueous phase. Unexpectedly, LiCl caused salting-out at low LiCl concentrations and salting-in at LiCl concentrations higher than 3 mol/kgH2O. The model electrolyte perturbed-chain SAFT (ePC-SAFT) was used to predict the salt influence on the LLE in the quaternary systems water/MIBK/HMF/salt in good agreement with the experimental data. On the basis of ePC-SAFT, it could be concluded that the different salting-out/salting-in behavior of the various salts is mainly caused by their different tendency to form ion pairs in aqueous solutions. PMID:27027570

  2. Methyl isobutyl ketone (MIBK)

    Integrated Risk Information System (IRIS)

    EPA / 635 / R - 03 / 002 TOXICOLOGICAL REVIEW OF METHYL ISOBUTYL KETONE ( CAS No . 108 - 10 - 1 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) March 2003 U.S . Environmental Protection Agency Washington DC DISCLAIMER This document has been reviewed in accordan

  3. Analytical validation applied to simultaneous determination of solvents dichloromethane (DCM), methyl isobutyl ketone (MIBK), tetrahydrofuran (THF) and toluene (TOL) in urine by headspace extraction and injection on chromatographic system with a flame ionization detector

    NASA Astrophysics Data System (ADS)

    Muna, E. D. M.; Pereira, R. P.

    2016-07-01

    The determination of the volatile organic solvents dichloromethane (DCM), methyl isobutyl ketone (MIBK), tetrahydrofuran (THF) and toluene (TOL) is applied on toxicological monitoring of employees in various industrial activities. The gas chromatography technique with flame ionization detector and headspace injection system has been applied. The analytical procedure developed allows the simultaneous determination of the above-mentioned solvents and the accuracy of the method was tested following the INMETRO guidelines through the DOQ-CGRE 008 Rev.04-July/2011.

  4. Methyl isobutyl ketone as a solvent for wax deoiling

    SciTech Connect

    Larikov, V.I.; Pereverzev, A.N.; Roshchin, Y.N.; Sokolova, S.P.

    1983-09-01

    The solvency of methyl isobutyl ketone (MIBK) for use in deoiling and cold-fractionation of solid paraffin waxes is investigated by a visual polytherm method in the temperature interval 0-36 C. The capability of MIBK for precipitating solid hydrocarbons from solution was found to be greater than acetone/toluene or MEK/toluene, with only MEK better in this respect than MIBK. The quantity of wax remaining in the filtrate is examined. The critical solution temperatures are investigated and it is shown that MIBK surpasses MEK. The results obtained indicate that MIBK is extremely promising for use in processes of deoiling and cold fractionation of waxes.

  5. 40 CFR Appendix A to Part 439 - Tables

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Acetone 1 Ketones. 4-Methyl-2-pentanone (MIBK) Ammonia (aqueous) Miscellaneous. 2 Acetonitrile Methyl.... Chloroform 1 Methylene chloride 1 Chlorobenzene Ammonia (aqueous) Diethyl amine Triethyl amine Acetone 1...

  6. 40 CFR Appendix A to Part 439 - Tables

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Acetone 1 Ketones. 4-Methyl-2-pentanone (MIBK) Ammonia (aqueous) Miscellaneous. 2 Acetonitrile Methyl.... Chloroform 1 Methylene chloride 1 Chlorobenzene Ammonia (aqueous) Diethyl amine Triethyl amine Acetone 1...

  7. Solvent extraction of N-Cyclohexyl-N-Nitrosohydroxylamine (cnha) into some organic solvents and of the Cu(II)-cnha complex into methyl isobutyl ketone.

    PubMed

    Rauret, G; Pineda, L; Ventura, M; Compaño, R

    1986-02-01

    The distribution equilibria of N-cyclohexyl-N-nitrosohydroxylamine (cnha) in the water-chloroform, water-hexane, water-methyl isobutyl ketone (MIBK) and water-isopentyl alcohol systems, and of the Cu(II)-cnha complex in the water-MIBK system have been studied. From the distribution data the dissociation and distribution constants of the reagent have been calculated; their values are pK(a) = 5.55 +/- 0.10; log K(DR) = 2.46 +/- 0.05 (chloroform), 1.76 +/- 0.11 (MIBK), 1.06 +/- 0.07 (hexane) and 1.48 +/- 0.06 (isopentyl alcohol). In the same way the values of the distribution and stability constants of the Cu(II) complex have been obtained; log K(DC) = 3.51; log beta(1) = 7.23 +/- 0.10 and log beta(2) = 12.00 +/- 0.08. For the determination of cnha in the aqueous phase saturated with MIBK, a spectrophotometric method based on the coloured complex formed by the reagent with Fe(III) has been established. Finally, an analytical method for Cu(II) by atomic-absorption spectrometry after its extraction with cnha into MIBK, is proposed. Its detection limit is 4.6 mug l ., its precision +/- 2.1% and its accuracy 97.5%. This method has been applied to the determination of the copper content in the surface water of the Congest River of Catalonia (Spain). PMID:18964050

  8. Solvent extraction of phenols from water

    SciTech Connect

    Greminger, D.C.; Burns, G.P.; Lynn, S.; Hanson, D.H.; King, C.J.

    1980-02-01

    Methyl isobutyl ketone (MIBK) and diisopropyl ether (DIPE) have been evaluated as solvents for extraction of phenols, at high dilution, from water. Equilibrium distribution coefficients (K/sub D/) have been measured for phenol, dihydroxybenzenes and trihydroxybenzenes in both solvents as a function of pH. Particularly for the multihydric phenols, MIBK gives substantially higher values of K/sub D/ than does DIPE. The effect of pH can be described quantitatively through a simple ionization model, using published values of dissociation constants for the various phenols. Some method for removal of residual dissolved solvent must ordinarily be included in any extraction process for phenols. Possibilities include atmospheric-steam or inert-gas stripping, vacuum-steam stripping, and extraction with a second solvent. Vacuum-steam stripping is a particularly attractive choice for removal of MIBK; this reinforces the utility of MIBK as a solvent. The optimal temperature for vacuum stripping is generally the temperature of the extraction operation, which in turn is related to the effect of temperature on K/sub D/. Values of K/sub D/ for phenol-water-MIBK were determined at 30, 50, and 75/sup 0/C, and were found to decrease with increasing temperature at all concentrations.

  9. Dissolution And Swelling Studies Of Poly(Methyl Methacrylate) Resist Films

    NASA Astrophysics Data System (ADS)

    Papanu, J. S.; Manjkow, J.; Hess, D. W.; Soong, D. S.; Bell, A. T.

    1987-08-01

    The swelling and dissolution of thin film poly(methyl methacrylate), PMMA, in methyl isobutyl ketone (MIBK), and in solvent/nonsolvent mixtures of MIBK/methanol and methyl ethyl ketone/isopropanol have been investigated. Films were monitored using in situ ellipsometry. Parametric studies of the effects of molecular weight, molecular weight distribution, softbaking quench rate, solvent size, and temperature were performed with MIBK. These parameters were shown to have a significant effect on dissolution. The effects of solvent composition and temperature on swelling and dissolution were investigated with the binary solvents. Ternary diagrams based on Flory-Huggins interaction parameters were used to interpret the thermodynamics of swelling and dissolution. A narrow transition region (NTR) where the developer changed from a swelling to dissolving agent with a small change in composition or temperature was observed.

  10. A proton transfer reaction mass spectrometry based system for determining plant uptake of volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Tani, Akira; Kato, Shungo; Kajii, Yoshizumi; Wilkinson, Michael; Owen, Sue; Hewitt, Nick

    In order to evaluate the contribution that higher plants make to the removal of volatile organic compounds from the atmosphere, a measurement system consisting of a proton transfer reaction mass spectrometer (PTR-MS), CO 2 analyzer, diffusion devise and leaf enclosure was established. The uptake of VOCs by Golden Pothos ( Epipremnum aureum) was investigated. The overall relative error associated with measurements made using this system was <2.2% when a Golden Pothos leaf was exposed to 75-750 ppbv of methyl isobutyl ketone (MIBK). Even at the lowest MIBK concentration, more than 2.2% of the inflowing VOC was lost to the leaf, representing a detectable and positive MIBK uptake rate by the plant. The results of the investigation were compared with a measurement system based on gas chromatography analysis and it was shown that the use of a PTR-MS based system can significantly increase the certainties in determining the rate of VOC uptake by plants.

  11. Identification and separation of the organic compounds in coal-gasification condensate waters. [5,5 dimethyl hydantoin, dihydroxy benzenes, acetonitrile

    SciTech Connect

    Mohr, D.H. Jr.; King, C.J.

    1983-08-01

    A substantial fraction of the organic solutes in condensate waters from low-temperature coal-gasification processes are not identified by commonly employed analytical techniques, have low distriution coefficients (K/sub C/) into diisopropyl ether (DIPE) or methyl isobutyl ketone (MIBK), and are resistant to biological oxidation. These compounds represent an important wastewater-treatment problem. Analytical techniques were developed to detect these polar compounds, and the liquid-liquid phase equilibria were measured with several solvents. A high-performance liquid - chromatography (HPLC) technique was employed to analyze four condensate-water samples from a slagging fixed-bed gasifier. A novel sample-preparation technique, consisting of an azeotropic distillation with isopropanol, allowed identification of compounds in the HPLC eluant by combined gas chromatography and mass spectrometry. 5,5-dimethyl hydantoin and related compounds were identified in condensate waters for the first time, and they account for 1 to 6% of the chemical oxygen demand (COD). Dimethyl hydatoin has a K/sub D/ of 2.6 into tributyl phosphate (TBP) and much lower K/sub D/ values into six other solvents. It is also resistant to biological oxidation. Phenols (59 to 76% of the COD), dihydroxy benzenes (0.02 to 9.5% of the COD), and methanol, acetonitrile, and acetone (15% of the COD in one sample) were also detected. Extraction with MIBK removed about 90% of the COD. MIBK has much higher K/sub D/ values than DIPE for dihydroxy benzenes. Chemical reactions occurred during storage of condensate-water samples. The reaction products had low K/sub D/ values into MIBK. About 10% of the COD had a K/sub D/ of nearly zero into MIBK. These compounds were not extracted by MIBK over a wide range of pH. 73 references, 6 figures, 35 tables.

  12. The determination of aluminum, copper, iron, and lead in glycol formulations by atomic absorption spectroscopy

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Initial screening tests and the results obtained in developing procedures to determine Al, Cu, Fe, and Pb in glycol formulations are described. Atomic absorption completion was selected for Cu, Fe and Pb, and after comparison with emission spectroscopy, was selected for Al also. Before completion, carbon, iron, and lead are extracted with diethyl dithio carbamate (DDC) into methyl isobutyl ketone (MIBK). Aluminum was also extracted into MIBK using 8-hydroxyquinoline as a chelating agent. As little as 0.02 mg/l carbon and 0.06 mg/l lead or iron may be determined in glycol formulations. As little as 0.3 mg/l aluminum may be determined.

  13. The direct conversion of sugars into 2,5-furandicarboxylic acid in a triphasic system.

    PubMed

    Yi, Guangshun; Teong, Siew Ping; Zhang, Yugen

    2015-04-13

    A one-pot conversion of sugars into 2,5-furandicarboxylic acid (FDCA) is demonstrated in a triphasic system: tetraethylammonium bromide (TEAB) or water-methyl isobutyl ketone (MIBK)-water. In this reaction, sugars are first converted into 5-hydroxymethylfurfural (HMF) in TEAB or water (Phase I). The HMF in Phase I is then extracted to MIBK (Phase II) and transferred to water (Phase III), where HMF is converted into FDCA. Phase II plays multiple roles: as a bridge for HMF extraction, transportation and purification. Overall FDCA yields of 78 % and 50 % are achieved from fructose and glucose respectively. PMID:25766123

  14. Determination of silver in soils, sediments, and rocks by organic-chelate extraction and atomic absorption spectrophotometry

    USGS Publications Warehouse

    Chao, T.T.; Ball, J.W.; Nakagawa, H.M.

    1971-01-01

    A useful method for the determination of silver in soil, sediment, and rock samples in geochemical exploration has been developed. The sample is digested with concentrated nitric acid, and the silver extracted with triisooctyl thiophosphate (TOTP) in methyl isobutyl ketone (MIBK) after dilution of the acid digest to approximately 6 M. The extraction of silver into the organic extractant is quantitative and not affected by the nitric acid concentration from 4 M to 8 M, or by different volumes of TOTP-MIBK. The extracted silver is stable and remains in the organic phase up to several days. The silver concentration is determined by atomic absorption spectrophotometry. ?? 1971.

  15. The direct conversion of sugars into 2,5-furandicarboxylic acid in a triphasic system.

    PubMed

    Yi, Guangshun; Teong, Siew Ping; Zhang, Yugen

    2015-04-13

    A one-pot conversion of sugars into 2,5-furandicarboxylic acid (FDCA) is demonstrated in a triphasic system: tetraethylammonium bromide (TEAB) or water-methyl isobutyl ketone (MIBK)-water. In this reaction, sugars are first converted into 5-hydroxymethylfurfural (HMF) in TEAB or water (Phase I). The HMF in Phase I is then extracted to MIBK (Phase II) and transferred to water (Phase III), where HMF is converted into FDCA. Phase II plays multiple roles: as a bridge for HMF extraction, transportation and purification. Overall FDCA yields of 78 % and 50 % are achieved from fructose and glucose respectively.

  16. Studies on the interaction between ethanol and two industrial solvents (methyl isobutyl ketone) in mice

    SciTech Connect

    Granvil, C.P.; Sharkawi, M.; Plaa, G.L. )

    1991-03-11

    Methyl n-butyl ketone (MnBK) and methyl isobutyl ketone (MiBK) prolong the duration of ethanol-induced loss of righting reflex (EILRR) in mice. MnBK was almost twice as potent in this regard. To explain this difference, the metabolism of both ketones was studied in male CD-1 mice using GC. MiBK was converted to 4-methyl-2-pentanol (4MPOL) and 4-hydroxy methyl isobutyl ketone (HMP). MnBK metabolites were 2-hexanol (2HOL) and 2,5-hexanedione (2,5HD). The effects of both ketones and metabolites on EILRR and ethanol (E) elimination were studied in mice. The ketones and their metabolites were dissolved in corn oil and injected intraperitoneally 30 min before E 4g/kg for EILRR and 2g/kg for E elimination. In the following doses: MnBK, 5; MiBK, 5; 2HOL, 2.5; 4MPOL, 2.5; and HMP 2.5, significantly prolonged EILRR. Concentrations of E in blood and brain upon return of the righting reflex were similar in solvent-treated and control animals. The mean elimination rate of E was slower in groups given MnBK or 2HOL than in control animals. No change in E elimination was observed with MiBK, HMP, 4MPOL, or 2, 5HD.

  17. Manganese dioxide causes spurious gold values in flame atomic-absorption readings from HBr-Br2 digestions

    USGS Publications Warehouse

    Campbell, W.L.

    1981-01-01

    False readings, apparently caused by the presence of high concentrations of manganese dioxide, have been observed in our current flame atomic-absorption procedure for the determination of gold. After a hydrobromic acid (HBr)-bromine (Br2) leach, simply heating the sample to boiling to remove excess Br2 prior to extraction with methyl-isobutyl-ketone (MIBK) eliminates these false readings. ?? 1981.

  18. Stabilizing agents for calibration in the determination of mercury using solid sampling electrothermal atomic absorption spectrometry.

    PubMed

    Zelinková, Hana; Červenka, Rostislav; Komárek, Josef

    2012-01-01

    Tetramethylene dithiocarbamate (TMDTC), diethyldithiocarbamate (DEDTC), and thiourea were investigated as stabilizing agents for calibration purposes in the determination of mercury using solid sampling electrothermal atomic absorption spectrometry (SS-ETAAS). These agents were used for complexation of mercury in calibration solutions and its thermal stabilization in a solid sampling platform. The calibration solutions had the form of methyl isobutyl ketone (MIBK) extracts or MIBK-methanol solutions with the TMDTC and DEDTC chelates and aqueous solutions with thiourea complexes. The best results were obtained for MIBK-methanol solutions in the presence of 2.5 g L(-1) TMDTC. The surface of graphite platforms for solid sampling was modified with palladium or rhenium by using electrodeposition from a drop of solutions. The Re modifier is preferable due to a higher lifetime of platform coating. A new SS-ETAAS procedure using the direct sampling of solid samples into a platform with an Re modified graphite surface and the calibration against MIBK-methanol solutions in the presence of TMDTC is proposed for the determination of mercury content in solid environmental samples, such as soil and plants.

  19. Removal of iron interferences by solvent extraction for geochemical analysis by atomic-absorption spectrophotometry

    USGS Publications Warehouse

    Zhou, L.; Chao, T.T.; Sanzolone, R.F.

    1985-01-01

    Iron is a common interferent in the determination of many elements in geochemical samples. Two approaches for its removal have been taken. The first involves removal of iron by extraction with methyl isobutyl ketone (MIBK) from hydrochloric acid medium, leaving the analytes in the aqueous phase. The second consists of reduction of iron(III) to iron(II) by ascorbic acid to minimize its extraction into MIBK, so that the analytes may be isolated by extraction. Elements of interest can then be determined using the aqueous solution or the organic extract, as appropriate. Operating factors such as the concentration of hydrochloric acid, amounts of iron present, number of extractions, the presence or absence of a salting-out agent, and the optimum ratio of ascorbic acid to iron have been determined. These factors have general applications in geochemical analysis by atomic-absorption spectrophotometry. ?? 1985.

  20. Integration of extrusion and clean fractionation processes as a pre-treatment technology for prairie cordgrass.

    PubMed

    Brudecki, Grzegorz; Cybulska, Iwona; Rosentrater, Kurt

    2013-05-01

    Prairie cordgrass (PCG) was pretreated by sequential extrusion and clean fractionation (CF) processing. Following CF, PCG was fractionated into cellulose, hemicellulose and lignin-rich fractions. Cellulose pulp was then enzymatically hydrolyzed, producing glucose. The main purpose of this study was to produce the highest glucose yield as possible. The effects of time, temperature, catalyst concentration and solvent mixture composition on the fractionation were tested. Different proportions of methyl isobutyl ketone (MIBK), ethanol and water with sulfuric acid as a catalyst were evaluated. Optimal conditions for sequential extrusion and clean fractionation (39 min, 129 °C, 0.69% catalyst, and 28% MIBK) resulted in higher glucose yield (92%), and more lignin (87%) and xylan (95%) removal than for clean fractionation alone. Pairwise comparison of raw PCG with extruded PCG clean fractionation revealed no difference in glucose yields, but xylan and AIL removal were higher in the case of clean fractionation of the pre-extruded PCG.

  1. Flame and flameless atomic-absorption determination of tellurium in geological materials

    USGS Publications Warehouse

    Chao, T.T.; Sanzolone, R.F.; Hubert, A.E.

    1978-01-01

    The sample is digested with a solution of hydrobromic acid and bromine and the excess of bromine is expelled. After dilution of the solution to approximately 3 M in hydrobromic acid, ascorbic acid is added to reduce iron(III) before extraction of tellurium into methyl isobutyl ketone (MIBK). An oxidizing air-acetylene flame is used to determine tellurium in the 0.1-20 ppm range. For samples containing 4-200 ppb of tellurium, a carbon-rod atomizer is used after the MIBK extract has been washed with 0.5 M hydrobromic acid to remove the residual iron. The flame procedure is useful for rapid preliminary monitoring, and the flameless procedure can determine tellurium at very low concentrations. ?? 1978.

  2. The effect of nutrient deficiency on removal of organic solvents from textile manufacturing wastewater during activated sludge treatment.

    PubMed

    Freedman, D L; Payauys, A M; Karanfil, T

    2005-02-01

    Textile manufacturing wastewater is often deficient in nitrogen and phosphorus and contains hazardous solvents, including methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), toluene (TOL), and xylenes (XYL). The objectives of this study were to evaluate the effectiveness of a short-term batch assay for predicting when a nutrient deficient condition exists in textile wastewater activated sludge, and to determine if nutrient deficiency affects biodegradation of MEK, MIBK, TOL,and p-XYL to a greater or lesser extent than bulk soluble chemical oxygen demand (sCOD). Addition of N + P significantly improved sCOD removal during treatment of textile wastewater in laboratory-scale sequencing batch reactors (SBRs). Batch tests using mixed liquor suspended solids (MLSS) from the SBRs correctly predicted the nutrient deficiency in the reactors that received unamended wastewater. During batch tests in sealed containers (to prevent volatilization) when N + P were added, the solvents biodegraded faster and to a greater extent than the bulk wastewater sCOD. MEK and MIBK were also completely consumed in MLSS from the SBR that received unamended wastewater, indicating that a shortage of nutrients did not significantly impact biodegradation of these ketones. However, nutrient deficient conditions significantly decreased the rate of TOL and p-XYL biodegradation. The difference in biodegradability of the ketones and monoaromatics under nutrient deficient conditions may be related to loss of plasmids required for aerobic catabolism of TOL and p-XYL. These results demonstrate that N + P addition to nutrient-deficient textile wastewater improves bulk sCOD removal and also significantly improves the biodegradability of TOL and p-XYL, thereby reducing the amount released to the atmosphere by volatilization.

  3. Simple analysis of total mercury and methylmercury in seafood using heating vaporization atomic absorption spectrometry.

    PubMed

    Yoshimoto, Keisuke; Anh, Hoang Thi Van; Yamamoto, Atsushi; Koriyama, Chihaya; Ishibashi, Yasuhiro; Tabata, Masaaki; Nakano, Atsuhiro; Yamamoto, Megumi

    2016-01-01

    This study aimed to develop a simpler method for determining total mercury (T-Hg) and methylmercury (MeHg) in biological samples by using methyl isobutyl ketone (MIBK) in the degreasing step. The fat in the samples was extracted by MIBK to the upper phase. T-Hg transferred into the water phase. This was followed by the extraction of MeHg from the water phase using HBr, CuCl2 and toluene. The MeHg fraction was reverse-extracted into L-cysteine-sodium acetate solution from toluene. The concentrations of T-Hg and MeHg were determined by heating vaporization atomic absorption spectrometry. Certified reference materials for T-Hg and MeHg in hair and fish were accurately measured using this method. This method was then applied to determine T-Hg and MeHg concentrations in the muscle, liver and gonads of seafood for the risk assessment of MeHg exposure. The mean T-Hg and MeHg concentrations in squid eggs were 0.023 and 0.022 µg/g, and in squid nidamental glands 0.052 and 0.049 µg/g, respectively. The MeHg/T-Hg ratios in the eggs and nidamental glands of squid were 94.4% and 96.5%, respectively. The mean T-Hg and MeHg concentrations in the gonads of sea urchins were 0.043 and 0.001 µg/g, respectively, with a MeHg/T-Hg ratio of 3.5%. We developed an efficient analytical method for T-Hg and MeHg using MIBK in the degreasing step. The new information on MeHg concentration and MeHg/T-Hg ratios in the egg or nidamental glands of squid and gonads of sea urchin will also be useful for risk assessment of mercury in seafood. PMID:27432235

  4. Development Characteristics of PMMA in alternative alcohol:water mixtures

    NASA Astrophysics Data System (ADS)

    Ocola, Leonidas E.

    2015-03-01

    The most widely used resist in electron beam lithography is polymethylmethacrylate (PMMA). The standard developers used are solution mixtures of isopropanol (IPA) and methyl isobutyl ketone (MIBK) in a ratio of 3:1 and mixtures of IPA and water (H2O) in a ratio of 7:3. The Globally Harmonized System (GHS) classification entry for IPA includes: Specific target organ toxicity - single exposure (Category 3). MIBK is much more hazardous than IPA. The only GHS classification entry for Ethanol is: Flammable liquids (Category 2), i.e. more environmentally safe. Using Ethanol/H2O as a developer will therefore enable lower hazardous waste disposal costs to cleanrooms. We find Ethanol/H2O at 85% volume (2:1 molar) exhibits excellent lithography results as good as with IPA/H2O, and better contrast and sensitivity than IPA/H2O and MIBK/IPA developers. Lithographic data shows trends similar to published cosolvency data, but differ too much to be explained by it. In addition, unusual development at 50% volume concentrations for both IPA and Ethanol in H2O show dramatic pothole formation instead of uniform thickness loss found in standard contrast curve exposures. We believe local pockets of concentrated alcohol water molar mixtures are responsible for such behavior. This work was supported by the Department of Energy under Contract No. DE-AC02-06CH11357. Use of the Center for Nanoscale Materials was supported by the U. S. Department of Energy, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.

  5. Simple analysis of total mercury and methylmercury in seafood using heating vaporization atomic absorption spectrometry.

    PubMed

    Yoshimoto, Keisuke; Anh, Hoang Thi Van; Yamamoto, Atsushi; Koriyama, Chihaya; Ishibashi, Yasuhiro; Tabata, Masaaki; Nakano, Atsuhiro; Yamamoto, Megumi

    2016-01-01

    This study aimed to develop a simpler method for determining total mercury (T-Hg) and methylmercury (MeHg) in biological samples by using methyl isobutyl ketone (MIBK) in the degreasing step. The fat in the samples was extracted by MIBK to the upper phase. T-Hg transferred into the water phase. This was followed by the extraction of MeHg from the water phase using HBr, CuCl2 and toluene. The MeHg fraction was reverse-extracted into L-cysteine-sodium acetate solution from toluene. The concentrations of T-Hg and MeHg were determined by heating vaporization atomic absorption spectrometry. Certified reference materials for T-Hg and MeHg in hair and fish were accurately measured using this method. This method was then applied to determine T-Hg and MeHg concentrations in the muscle, liver and gonads of seafood for the risk assessment of MeHg exposure. The mean T-Hg and MeHg concentrations in squid eggs were 0.023 and 0.022 µg/g, and in squid nidamental glands 0.052 and 0.049 µg/g, respectively. The MeHg/T-Hg ratios in the eggs and nidamental glands of squid were 94.4% and 96.5%, respectively. The mean T-Hg and MeHg concentrations in the gonads of sea urchins were 0.043 and 0.001 µg/g, respectively, with a MeHg/T-Hg ratio of 3.5%. We developed an efficient analytical method for T-Hg and MeHg using MIBK in the degreasing step. The new information on MeHg concentration and MeHg/T-Hg ratios in the egg or nidamental glands of squid and gonads of sea urchin will also be useful for risk assessment of mercury in seafood.

  6. Anaerobic treatment of gasifier effluents. Quarterly report

    SciTech Connect

    Cross, W.H.; Chian, E.S.K.; Pohland, F.G.; Giabbai, M.; Harper, S.R.; Kharkar, S.; Cheng, S.S.; Shuey, P.S.

    1982-01-01

    This report summarizes the work performed during the quarter ending December 30, 1981. The major efforts have been directed toward the continued acclimation of two anaerobic treatment systems, start up of a third anaerobic treatment system, GC/MS characterization of the coal gasification wastewater, data acquisition for determination of distribution coefficients for the extraction of phenol from the wastewater using MIBK, and preliminary design of a solvent extraction system for wastewater pretreatment. The progress of these efforts are depicted in the Gannt Chart, along with project expenditures for the above contract, and are presented in detail in the following sections.

  7. Purification of biomass-derived 5-hydroxymethylfurfural and its catalytic conversion to 2,5-furandicarboxylic Acid.

    PubMed

    Yi, Guangshun; Teong, Siew Ping; Li, Xiukai; Zhang, Yugen

    2014-08-01

    A simple and effective water extraction method is presented for the purification 5-hydroxylmethylfurfural (HMF) obtained from a biomass dehydration system. Up to 99% of the HMF can be recovered and the HMF in aqueous solution is directly converted to 2,5-furandicarboxylic acid (FDCA) as the sole product. This purification technique allows an integrated process to produce FDCA from fructose via HMF prepared in an isopropanol monophasic system, with an overall FDCA yield of 83% obtained. From Jerusalem raw artichoke biomass to FDCA via HMF prepared in a water/MIBK (methyl isobutyl ketone) biphasic system, an overall FDCA yield of 55% is obtained. PMID:24889713

  8. Determination of traces of silver in waters by anion exchange and atomic absorption spectrophotometry

    USGS Publications Warehouse

    Chao, T.T.; Fishman, M. J.; Ball, J.W.

    1969-01-01

    A method has been developed for the accurate determination of 0.1-1 ??g of silver per liter of water. The method permits stabilization of silver in water without loss to container walls. Optimum conditions have been established for the complete recovery of silver from water with an anion-exchange column, for quantitative elution of silver from the resin, and for measurement of silver by atomic absorption spectrophotometry after chelation with ammonium pyrrolidine dithiocarbamate and extraction of the chelate with MIBK. Silver in the 1-10 ??g 1 range can be determined by extraction without pre-concentration on an ion-exchange resin. ?? 1969.

  9. Continuous exposure of animals to methylisobutylketone

    NASA Technical Reports Server (NTRS)

    Vernot, E. H.; Macewen, J. D.; Harris, E. S.

    1971-01-01

    Continuous exposure of dogs, monkeys, mice, and rats to MIBK for two weeks and all animals except mice for 90 days resulted in measurable adverse effects only in the case of rats. Rat kidney weights and kidney to body weight ratios were significantly elevated after exposure to 410 mg/cu m for two weeks, and kidney and liver organ weights and organ to body weight ratios were elevated after exposure to 820 mg/cu m for two weeks and to 410 mg/cu m for 90 days.

  10. Preconcentration of heavy metals in urine and quantification by inductively coupled plasma atomic emission spectrometry.

    PubMed

    López-Artíguez, M; Cameán, A; Repetto, M

    1993-01-01

    This paper describes a method for the determination of heavy metals (Co, Ni, Cu, Cd, Pb) in urine by inductively coupled plasma atomic emission spectrometry (ICP-AES). The method proposed requires purification of the samples with activated charcoal under acidic conditions before preconcentration by complexation with ammonium pyrrolidinedithiocarbamate (APDC). The formed complexes are extracted with methyl isobutyl ketone (MIBK) and the resulting residue is finally digested under acid oxidant conditions. Because of its low detection limit (below 10 micrograms/L), this procedure can be applied conveniently for toxicological diagnostic purposes. PMID:8429621

  11. A comparative study of fungal and bacterial biofiltration treating a VOC mixture.

    PubMed

    Estrada, José M; Hernández, Sergio; Muñoz, Raúl; Revah, Sergio

    2013-04-15

    Bacterial biofilters usually exhibit a high microbial diversity and robustness, while fungal biofilters have been claimed to better withstand low moisture contents and pH values, and to be more efficient coping with hydrophobic volatile organic compounds (VOCs). However, there are only few systematic evaluations of both biofiltration technologies. The present study compared fungal and bacterial biofiltration for the treatment of a VOC mixture (propanal, methyl isobutyl ketone-MIBK, toluene and hexanol) under the same operating conditions. Overall, fungal biofiltration supported lower elimination capacities than its bacterial counterpart (27.7 ± 8.9 vs 40.2 ± 5.4 gCm(-3) reactor h(-1)), which exhibited a final pressure drop 60% higher than that of the bacterial biofilter due to mycelial growth. The VOC mineralization ratio was also higher in the bacterial bed (≈ 63% vs ≈ 43%). However, the substrate biodegradation preference order was similar for both biofilters (propanal>hexanol>MIBK>toluene) with propanal partially inhibiting the consumption of the rest of the VOCs. Both systems supported an excellent robustness versus 24h VOC starvation episodes. The implementation of a fungal/bacterial coupled system did not significantly improve the VOC removal performance compared to the individual biofilter performances. PMID:23454457

  12. Solvent sublation and spectrometric determination of iron(II) and total iron using 3-(2-pyridyl)-5,6-bis(4-phenylsulfonic acid)-1,2,4-triazine and tetrabutylammonium bromide.

    PubMed

    Akl, Magda Ali; Mori, Yoshihito; Sawada, Kiyoshi

    2006-09-01

    Solvent sublation has been studied for the separation and determination of trace iron(II) in various kinds of water samples. A strongly magenta-colored anionic [Fe(FZ)3](4-) complex was formed at pH 5.0 upon adding 3-(2-pyridyl)-5,6-bis(4-phenylsulfonic acid)-1,2,4-triazine (ferrozine, FZ) to the sample solution. Tetrabutylammonium bromide (TBAB) was added in the solution to form the (TBA)4[Fe(FZ)3)] ion pair, and an oleic acid (HOL) surfactant was added. Then, the (TBA)4[Fe(FZ)3] ion pairs were floated by vigorous shaking in the flotation cell and extracted into methyl isobutyl ketone (MIBK) on the surface of the aqueous solution. The iron collected in the MIBK layer was measured directly by spectrophotometry and/or flame atomic-absorption spectrophotometry. Different experimental variables that may affect the sublation efficiency were thoroughly investigated. The molar absorptivity of the (TBA)4[Fe(FZ)3] ion pair was 2.8 x 10(4) l mol(-1) cm(-1) in the aqueous layer. Beer's law held up to 1.0 mg L(-1) Fe(II) in the aqueous as well as in the organic layers. The adopted solvent sublation method was successfully applied for the determination of Fe(II) in natural water samples with a preconcentration factor of 200. The application was extended to determine iron in pharmaceutical samples. PMID:16966804

  13. A comparative study in treating two VOC mixtures in trickle bed air biofilters.

    PubMed

    Cai, Zhangli; Kim, Daekeun; Sorial, George A

    2007-06-01

    Two independent parallel trickling bed air biofilters (TBABs) ("A" and "B") with two different typical VOC mixtures were investigated. Toluene, styrene, methyl ethyl ketone (MEK), and methyl isobutyl ketone (MIBK) were the target VOCs in the mixtures. Biofilter "A" was fed equal molar ratio of the VOCs and biofilter "B" was fed a mixture based on EPA 2003 emission report. Backwashing and substrate starvation operation were conducted as biomass control. Biofilter "A" and "B" maintained 99% overall removal efficiency for influent concentration up to 500 and 300 ppmv under backwashing operating condition, respectively. The starvation study indicated that it can be an effective biomass control for influent concentrations up to 250 ppmv for biofilter "A" and 300 ppmv for "B". Re-acclimation of biofilter performance was delayed with increase of influent concentration for both biofilters. Starvation operation helped the biofilter to recover at low concentrations and delayed re-acclimation at high concentrations. Furthermore, re-acclamation for biofilter "B" was delayed due to its high toluene content as compared to biofilter "A". The pseudo first-order removal rate constant decreased with increase of volumetric loading rate for both biofilters. MEK and MIBK were completely removed in the upper 3/8 media depth. While biofilter depth utilization for the removal of styrene and toluene increased with increase of influent concentrations for both biofilters. However, toluene removal utilized more biofilter depth for biofilter "B" as compared to biofilter "A".

  14. Determination of total tin in silicate rocks by graphite furnace atomic absorption spectrometry

    USGS Publications Warehouse

    Elsheimer, H.N.; Fries, T.L.

    1990-01-01

    A method is described for the determination of total tin in silicate rocks utilizing a graphite furnace atomic absorption spectrometer with a stabilized-temperature platform furnace and Zeeman-effect background correction. The sample is decomposed by lithium metaborate fusion (3 + 1) in graphite crucibles with the melt being dissolved in 7.5% hydrochloric acid. Tin extractions (4 + 1 or 8 + 1) are executed on portions of the acid solutions using a 4% solution of tricotylphosphine oxide in methyl isobutyl ketone (MIBK). Ascorbic acid is added as a reducing agent prior to extraction. A solution of diammonium hydrogenphosphate and magnesium nitrate is used as a matrix modifier in the graphite furnace determination. The limit of detection is > 10 pg, equivalent to > 1 ??g l-1 of tin in the MIBK solution or 0.2-0.3 ??g g-61 in the rock. The concentration range is linear between 2.5 and 500 ??g l-1 tin in solution. The precision, measured as relative standard deviation, is < 20% at the 2.5 ??g l-1 level and < 7% at the 10-30 ??g l-1 level of tin. Excellent agreement with recommended literature values was found when the method was applied to the international silicate rock standards BCR-1, PCC-1, GSP-1, AGV-1, STM-1, JGb-1 and Mica-Fe. Application was made to the determination of tin in geological core samples with total tin concentrations of the order of 1 ??g g-1 or less.

  15. GFAAS determination of ultratrace quantities of organotins in sea-water by using enhancement methods.

    PubMed

    Parks, E J; Blair, W R; Brinckman, F E

    1985-08-01

    Tributyltin in sea-water is preconcentrated by extraction into toluene and determined by enhanced graphite-furnace atomic-absorption (GFAAS) at ultratrace concentrations (as low as 1.0 mug l .) equal to or lower than the toxic limits for aquatic organotins. Toluene is preferred to MIBK, chloroform or hexane as the solvent. Sea salts, in concentrations as low as 0.1%, critically interfere with GFAAS tin determinations, and must be removed by washing the extract with demineralized water. Signal enhancement effected by inserting L'vov platforms in the graphite furnace tubes or by adding ammonium dichromate to the analyte solution is nearly additive when both methods of enhancement are combined.

  16. Atomic absorption spectrophotometric determination of microgram levels of Co, Ni, Cu, Pb, and Zn in soil and sediment extracts containing large amounts of Mn and Fe

    USGS Publications Warehouse

    Chao, T.T.; Sanzolone, R.F.

    1973-01-01

    An atomic absorption spectrophotometric method has been developed for the determination of seven metal ions in the hydroxylamine extract of soils and sediments. Mn, Fe, and Zn are directly determined in the aqueous extract upon dilution. Co, Ni, Cu, and Pb in a separate aliquot of the extract are chelated with APDC (ammonium pyrrolidine dithiocarbamate) and extracted into MIBK (methyl isobutyl ketone) before determination. Data are presented to show the quantitative recovery of microgram levels of Co, Ni, Cu, and Pb by APDC-MIBK chelation-extraction from synthetic solutions containing as much as 2,000 ug/ml (micrograms per milliliter) Mn or 50 ug/ml Fe. Recovery of known amounts of the metal ions from sample solutions is equally satisfactory. Reproducible results are obtained by replicate analyses of two sediment samples for the seven metals.

  17. A Bio-Catalytic Approach to Aliphatic Ketones

    PubMed Central

    Xiong, Mingyong; Deng, Jin; Woodruff, Adam P.; Zhu, Minshan; Zhou, Jun; Park, Sun Wook; Li, Hui; Fu, Yao; Zhang, Kechun

    2012-01-01

    Depleting oil reserves and growing environmental concerns have necessitated the development of sustainable processes to fuels and chemicals. Here we have developed a general metabolic platform in E. coli to biosynthesize carboxylic acids. By engineering selectivity of 2-ketoacid decarboxylases and screening for promiscuous aldehyde dehydrogenases, synthetic pathways were constructed to produce both C5 and C6 acids. In particular, the production of isovaleric acid reached 32 g/L (0.22 g/g glucose yield), which is 58% of the theoretical yield. Furthermore, we have developed solid base catalysts to efficiently ketonize the bio-derived carboxylic acids such as isovaleric acid and isocaproic acid into high volume industrial ketones: methyl isobutyl ketone (MIBK, yield 84%), diisobutyl ketone (DIBK, yield 66%) and methyl isoamyl ketone (MIAK, yield 81%). This hybrid “Bio-Catalytic conversion” approach provides a general strategy to manufacture aliphatic ketones, and represents an alternate route to expanding the repertoire of renewable chemicals. PMID:22416247

  18. Development of a test method for carbonyl compounds from stationary source emissions

    SciTech Connect

    Zhihua Fan; Peterson, M.R.; Jayanty, R.K.M.

    1997-12-31

    Carbonyl compounds have received increasing attention because of their important role in ground-level ozone formation. The common method used for the measurement of aldehydes and ketones is 2,4-dinitrophenylhydrazine (DNPH) derivatization followed by high performance liquid chromatography and ultra violet (HPLC-UV) analysis. One of the problems associated with this method is the low recovery for certain compounds such as acrolein. This paper presents a study in the development of a test method for the collection and measurement of carbonyl compounds from stationary source emissions. This method involves collection of carbonyl compounds in impingers, conversion of carbonyl compounds to a stable derivative with O-2,3,4,5,6-pentafluorobenzyl hydroxylamine hydrochloride (PFBHA), and separation and measurement by electron capture gas chromatography (GC-ECD). Eight compounds were selected for the evaluation of this method: formaldehyde, acetaldehyde, acrolein, acetone, butanal, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), and hexanal.

  19. Determination of gas phase adsorption isotherms--a simple constant volume method.

    PubMed

    Kim, Daekeun; Cai, Zhangli; Sorial, George A

    2006-08-01

    Single and ternary solute gas phase adsorption isotherms were conducted in this study to evaluate the effectiveness of a simple constant volume method, which was utilized by using Tedlar gas sampling bags as a constant volume batch reactor. For this purpose, gas phase adsorption of toluene, methyl ethyl ketone (MEK), and methyl isobutyl ketone (MIBK) on two types of activated carbons, BPL-bituminous base and OVC--coconut base, were investigated. For the single solute adsorption, the experimental adsorption data were found to be well correlated with Freundlich and Myers adsorption equations. The pore size distribution of adsorbents was found to affect their adsorption capacities; its effect was dependant on the solute concentration. The ternary adsorption experimental isotherms were accurately predicted by using the well-known model, i.e., ideal adsorbed solution theory (IAST).

  20. Determination of gold, indium, tellurium and thallium in the same sample digest of geological materials by atomic-absorption spectroscopy and two-step solvent extraction

    USGS Publications Warehouse

    Hubert, A.E.; Chao, T.T.

    1985-01-01

    A rock, soil, or stream-sediment sample is decomposed with hydrofluoric acid, aqua regia, and hydrobromic acid-bromine solution. Gold, thallium, indium and tellurium are separated and concentrated from the sample digest by a two-step MIBK extraction at two concentrations of hydrobromic add. Gold and thallium are first extracted from 0.1M hydrobromic acid medium, then indium and tellurium are extracted from 3M hydrobromic acid in the presence of ascorbic acid to eliminate iron interference. The elements are then determined by flame atomic-absorption spectrophotometry. The two-step solvent extraction can also be used in conjunction with electrothermal atomic-absorption methods to lower the detection limits for all four metals in geological materials. ?? 1985.

  1. Evaluation of performance impairment by spacecraft contaminants

    NASA Technical Reports Server (NTRS)

    Geller, I.; Hartman, R. J., Jr.; Mendez, V. M.

    1977-01-01

    The environmental contaminants (isolated as off-gases in Skylab and Apollo missions) were evaluated. Specifically, six contaminants were evaluated for their effects on the behavior of juvenile baboons. The concentrations of contaminants were determined through preliminary range-finding studies with laboratory rats. The contaminants evaluated were acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), trichloroethylene (TCE), heptane and Freon 21. When the studies of the individual gases were completed, the baboons were also exposed to a mixture of MEK and TCE. The data obtained revealed alterations in the behavior of baboons exposed to relatively low levels of the contaminants. These findings were presented at the First International Symposium on Voluntary Inhalation of Industrial Solvents in Mexico City, June 21-24, 1976. A preprint of the proceedings is included.

  2. Determination of trace amounts of tin in geological materials by atomic absorption spectrometry

    USGS Publications Warehouse

    Welsch, E.P.; Chao, T.T.

    1976-01-01

    An atomic absorption method is described for the determination of traces of tin in rocks, soils, and stream sediments. A dried mixture of the sample and ammonium iodide is heated to volatilize tin tetraiodide -which is then dissolved in 5 % hydrochloric acid, extracted into TOPO-MIBK, and aspirated into a nitrous oxide-acetylene flame. The limit of determination is 2 p.p.m. tin and the relative standard deviation ranges from 2 to 14 %. Up to 20 % iron and 1000 p.p.m. Cu, Pb, Zn, Mn, Hg, Mo, V, or W in the sample do not interfere. As many as 50 samples can be easily analyzed per man-day. ?? 1976.

  3. The determination of vanadium in brines by atomic absorption spectroscopy

    USGS Publications Warehouse

    Crump-Wiesner, Hans J.; Feltz, H.R.; Purdy, W.C.

    1971-01-01

    A standard addition method is described for the determination of vanadium in brines by atomic absorption spectroscopy with a nitrous oxide-acetylene flame. Sample pH is adjusted to 1.0 with concentrated hydrochloric acid and the vanadium is directly extracted with 5% cupferron in methyl isobutyl ketone (MIBK). The ketone layer is then aspirated into the flame and the recorded absorption values are plotted as a function of the concentration of the added metal. As little as 2.5 ??g l-1 of vanadium can be detected under the conditions of the procedure. Tungsten and tin interfere when present in excess of 5 and 10 ??g ml-1, respectively. The concentrations of the two interfering ions normally found in brines are well below interference levels. ?? 1971.

  4. Determination of silver, bismuth, cadmium, copper, lead, and zinc in geologic materials by atomic absorption spectrometry with tricaprylylmethylammonium chloride

    USGS Publications Warehouse

    Viets, J.G.

    1978-01-01

    Interferences commonly encountered in the determination of silver, bismuth, cadmium, copper, lead, and zinc at crustal abundance levels are effectively eliminated using a rapid, sensitive, organic extraction technique. A potassium chlorate-hydrochloric acid digestion solubilizes the metals not tightly bound in the silicate lattice of rocks, soils, and stream sediments. The six metals are selectively extracted into a 10% Aliquat 336-MIBK organic phase in the presence of ascorbic acid and potassium iodide. Metals in the organic extract are determined by flame atomic absorption spectrometry to the 0.02-ppm level for silver, cadmium, copper, and zinc and to the 0.2-ppm level for bismuth and lead with a maximum relative standard deviation of 18.8% for known reference samples. An additional hydrofluoric acid digestion may be used to determine metals substituted in the silicate lattice.

  5. Selective and recyclable depolymerization of cellulose to levulinic acid catalyzed by acidic ionic liquid.

    PubMed

    Ren, Huifang; Girisuta, Buana; Zhou, Yonggui; Liu, Li

    2015-03-01

    Cellulose depolymerization to levulinic acid (LA) was catalyzed by acidic ionic liquids (ILs) selectively and recyclably under hydrothermal conditions. The effects of reaction temperature, time, water amount and cellulose intake were investigated. Dilution effect becomes more pronounced at lower cellulose intake, dramatically improving the yield of LA to 86.1%. A kinetic model has been developed based on experimental data, whereby a good fit was obtained and kinetic parameters were derived. The relationships between IL structure, polymeric structure and depolymerization efficiency were established, shedding light on the in-depth catalytic mechanism of IL, inclusive of acidity and hydrogen bonding ability. The LA product can be readily separated through extraction by methyl isobutyl ketone (MIBK) and IL can be reused over five cycles without loss of activity. This environmentally friendly methodology can be applied to selective production of LA from versatile biomass feedstocks, including cellulose and derivatives, glucose, fructose and HMF.

  6. The determination of specific forms of aluminum in natural water

    USGS Publications Warehouse

    Barnes, R.B.

    1975-01-01

    A procedure for analysis and pretreatment of natural-water samples to determine very low concentrations of Al is described which distinguishes the rapidly reacting equilibrium species from the metastable or slowly reacting macro ions and colloidal suspended material. Aluminum is complexed with 8-hydroxyquinoline (oxine), pH is adjusted to 8.3 to minimize interferences, and the aluminum oxinate is extracted with methyl isobutyl ketone (MIBK) prior to analysis by atomic absorption. To determine equilibrium species only, the contact time between sample and 8-hydroxyquinoline is minimized. The Al may be extracted at the sample site with a minimum of equipment and the MIBK extract stored for several weeks prior to atomic absorption analysis. Data obtained from analyses of 39 natural groundwater samples indicate that filtration through a 0.1-??m pore size filter is not an adequate means of removing all insoluble and metastable Al species present, and extraction of Al immediately after collection is necessary if only dissolved and readily reactive species are to be determined. An average of 63% of the Al present in natural waters that had been filtered through 0.1-??m pore size filters was in the form of monomeric ions. The total Al concentration, which includes all forms that passed through a 0.1-??m pore size filter, ranged 2-70 ??g/l. The concentration of Al in the form of monomeric ions ranged from below detection to 57 ??g/l. Most of the natural water samples used in this study were collected from thermal springs and oil wells. ?? 1975.

  7. Pore-functionalized polymer membranes for preconcentration of heavy metal ions.

    PubMed

    Vasudevan, T; Das, Sadananda; Sodaye, Suparna; Pandey, A K; Reddy, A V R

    2009-04-15

    Functionalized membranes containing carboxylate, phosphate and sulfonate groups were prepared by UV-initiator induced graft polymerization of the functional monomer (acrylic acid, ethylene glycol methacrylate phosphate (EGMP) and 2-acrylamido-2-methyl-1-propane sulfonic acid) with a crosslinker (methylenebisacrylamide) in the pores of poly(propylene) host membranes. The functionalized membranes thus obtained were characterized by gravimetry, FTIR spectroscopy, radiotracers and scanning electron microscopy for the degree of grafting and water uptake, presence of functional groups, ion-exchange capacity, and physical structure of the membranes, respectively. The uptakes of Cs(+), Ag(+), Sr(2+), Cd(2+), Hg(2+), Zn(2+), Eu(3+), Am(3+), Hf(4+) and Pu(4+) ions in the functionalized membranes were studied as a function of acidity of the equilibrating aqueous solution. Among the functionalized membranes prepared in the present work, the EGMP-grafted membrane (with phosphate groups) showed acid concentration dependent selectivity towards multivalent metal ions like Eu(3+), Am(3+), Hf(4+) and Pu(4+). The solvent extraction studies of EGMP monomer in methyl isobutyl ketone (MIBK) solvent indicated that divalent and trivalent metal ions form complexes with EGMP in 1:2 proportion, but the distribution coefficients of trivalent metal ions were significantly higher that for the divalent ions. The uptakes of Eu(3+) ions in monomeric EGMP (dissolved in MIBK) and polymeric EGMP (in the forms of crosslinked gel and membrane) were studied as a function of concentration of H(+) ions in the equilibrating solution. This study indicated that polymeric EGMP has better binding ability towards Eu(3+) as compared to monomeric EGMP. The variation of distribution coefficients of Eu(3+)/Am(3+) in gel and membrane as a function of H(+) ion concentration in the equilibrating aqueous solution indicated that ionic species held in the membrane and gel were not same. These results indicated that

  8. Recovery of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) from Ralstonia eutropha cultures with non-halogenated solvents.

    PubMed

    Riedel, Sebastian L; Brigham, Christopher J; Budde, Charles F; Bader, Johannes; Rha, Chokyun; Stahl, Ulf; Sinskey, Anthony J

    2013-02-01

    Reduced downstream costs, together with high purity recovery of polyhydroxyalkanoate (PHA), will accelerate the commercialization of high quality PHA-based products. In this work, a process was designed for effective recovery of the copolymer poly(hydroxybutyrate-co-hydroxyhexanoate) (P(HB-co-HHx)) containing high levels of HHx (>15 mol%) from Ralstonia eutropha biomass using non-halogenated solvents. Several non-halogenated solvents (methyl isobutyl ketone, methyl ethyl ketone, and butyl acetate and ethyl acetate) were found to effectively dissolve the polymer. Isoamyl alcohol was found to be not suitable for extraction of polymer. All PHA extractions were performed from both dry and wet cells at volumes ranging from 2 mL to 3 L using a PHA to solvent ratio of 2% (w/v). Ethyl acetate showed both high recovery levels and high product purities (up to 99%) when using dry cells as starting material. Recovery from wet cells, however, eliminates a biomass drying step during the downstream process, potentially saving time and cost. When wet cells were used, methyl isobutyl ketone (MIBK) was shown to be the most favorable solvent for PHA recovery. Purities of up to 99% and total recovery yields of up to 84% from wet cells were reached. During polymer recovery with either MIBK or butyl acetate, fractionation of the extracted PHA occurred, based on the HHx content of the polymer. PHA with higher HHx content (17-30 mol%) remained completely in solution, while polymer with a lower HHx content (11-16 mol%) formed a gel-like phase. All PHA in solution could be precipitated by addition of threefold volumes of n-hexane or n-heptane to unfiltered PHA solutions. Effective recycling of the solvents in this system is predicted due to the large differences in the boiling points between solvent and precipitant. Our findings show that two non-halogenated solvents are good candidates to replace halogenated solvents like chloroform for recovery of high quality PHA. PMID:22903730

  9. Determination of Nickel, Vanadium and Iron in Crude Oil by Three-Phase Plasma Arc Spectrometry

    NASA Astrophysics Data System (ADS)

    Ghatass, Zekry F.

    2002-12-01

    Three-phase plasma arc (TPPA) with ultrasonic nebulizer is developed for simultaneous determination of trace elements in crude oil samples. Ultrasonic nebulizer is used instead of pneumatic nebulizer in order to minimize the problems caused by the oil viscosity during the operation. This system was used for determination of some trace elements (V, Ni, and Fe) in a crude oil samples. Methyl isobutyl ketone (MIBK) was used to dilute the oil samples. The TPPA instrument offers several advantages including a low cost power supply with no radio frequency, linear dynamic ranges from 4 to 5 of orders of magnitude, and detection limits (0.121, 0.313 and 0.242 (μg/ml) for Ni, V and Fe respectively. The average concentrations were 31 ± 0.45 (μg/ml) for Ni, 40 ± 0.88 (μg/ml) for V and 8 ± 0.74 (μg/ml) for Fe at Balaaiem fields and 2 ± 0.05 (μg/ml) for Ni, 4.8 ± 0.25 (μg/ml) for V and 2 ± 0.10 (μg/ml) for Fe at Wastern Desert fields.

  10. Methods for collection and analysis of geopressured geothermal and oil field waters

    SciTech Connect

    Lico, M.S.; Kharaka, Y.K.; Carothers, W.W.; Wright, V.A.

    1982-01-01

    Present methods are described for the collection, preservation, and chemical analysis of waters produced from geopressured geothermal and petroleum wells. Detailed procedures for collection include precautions and equipment necessary to ensure that the sample is representative of the water produced. Procedures for sample preservation include filtration, acidification, dilution for silica, methyl isobutyl ketone (MIBK) extraction of aluminum, addition of potassium permanganate to preserve mercury, and precipitation of carbonate species as strontium carbonate for stable carbon isotopes and total dissolved carbonate analysis. Characteristics determined at the well site are sulfide, pH, ammonia, and conductivity. Laboratory procedures are given for the analysis of lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, iron, manganese, zinc, lead, aluminum, and mercury by atomic absorption and flame emission spectroscopy. Chloride is determined by silver nitrate titration and fluoride by ion-specific electrode. Bromide and iodide concentrations are determined by the hypochlorite oxidation method. Sulfate is analyzed by titration using barium chloride with thorin indicator after pretreatment with alumina. Boron and silica are determined colorimetrically by the carmine and molybdate-blue methods, respectively. Aliphatic acid anions (C/sub 2/ through C/sub 5/) are determined by gas chromatography after separation and concentration in a chloroform-butanol mixture.

  11. Volatile organic compounds concentrations in residential indoor and outdoor and its personal exposure in Korea.

    PubMed

    Son, Busoon; Breysse, Patrick; Yang, Wonho

    2003-04-01

    To date, personal volatile organic compounds (VOCs) exposure and residential indoor and outdoor VOCs levels have not been characterized in Korea. In this study, residential indoor and outdoor VOCs concentrations were measured and compared simultaneously with the personal exposure for each of 30 participants in a medium city, Asan, and in a metropolitan city, Seoul. Factors that influence personal VOCs exposures were assessed in relation to house characteristics and time activity information. All VOC concentrations were measured using passive samplers during a 24-h period and analyzed using GC-MS. Ten target VOCs were benzene, trichloroethylene, toluene, o-xylene, p-xylene, ethylbenzene, MIBK, n-octane, styrene, and 1,2-dichlorobenzene. Residential indoor and outdoor VOCs concentrations measured in Seoul were significantly higher than those in Asan. Indoor/outdoor (I/O) ratios for all target compounds ranged from 0.94 to 1.51 and I/O ratios of Asan were a little higher than those of Seoul. Results indicate that time activity information can be used to predict personal exposures, although such predictions will result in an over estimation compared to measured exposures. Factors which influence the indoor VOCs level and its personal exposure in relation to house characteristics included house age, indoor smoking, and house type. PMID:12605940

  12. Methods for collection and analysis of geopressured geothermal and oil field waters

    USGS Publications Warehouse

    Lico, Michael S.; Kharaka, Yousif K.; Carothers, William W.; Wright, Victoria A.

    1982-01-01

    Present methods are described for the collection, preservation, and chemical analysis of waters produced from geopressured geothermal and petroleum wells. Detailed procedures for collection include precautions and equipment necessary to ensure that the sample is representative of the water produced. Procedures for sample preservation include filtration, acidification, dilution for silica, methyl isobutyl ketone (MIBK) extraction of aluminum, addition of potassium permanganate to preserve mercury, and precipitation of carbonate species as strontium carbonate for stable carbon isotopes and total dissolved carbonate analysis. Characteristics determined at the well site are sulfide, pH, ammonia, and conductivity. Laboratory procedures are given for the analysis of lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, iron, manganese, zinc, lead, aluminum, .and mercury by atomic absorption and flame emission spectroscopy. Chloride is determined by silver nitrate titration and fluoride by ion-specific electrode. Bromide and iodide concentrations are determined by the hypochlorite oxidation method. Sulfate is analyzed by titration using barium chloride with thorin indicator after pretreatment with alumina. Boron and silica are determined colorimetrically by the carmine and molybdate-blue methods, respectively. Aliphatic acid anions (C2 through C5) are determined by gas chromatography after separation and concentration in a chloroform-butanol mixture.

  13. 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)

  14. An automated flow injection system for metal determination by flame atomic absorption spectrometry involving on-line fabric disk sorptive extraction technique.

    PubMed

    Anthemidis, A; Kazantzi, V; Samanidou, V; Kabir, A; Furton, K G

    2016-08-15

    A novel flow injection-fabric disk sorptive extraction (FI-FDSE) system was developed for automated determination of trace metals. The platform was based on a minicolumn packed with sol-gel coated fabric media in the form of disks, incorporated into an on-line solid-phase extraction system, coupled with flame atomic absorption spectrometry (FAAS). This configuration provides minor backpressure, resulting in high loading flow rates and shorter analytical cycles. The potentials of this technique were demonstrated for trace lead and cadmium determination in environmental water samples. The applicability of different sol-gel coated FPSE media was investigated. The on-line formed complex of metal with ammonium pyrrolidine dithiocarbamate (APDC) was retained onto the fabric surface and methyl isobutyl ketone (MIBK) was used to elute the analytes prior to atomization. For 90s preconcentration time, enrichment factors of 140 and 38 and detection limits (3σ) of 1.8 and 0.4μgL(-1) were achieved for lead and cadmium determination, respectively, with a sampling frequency of 30h(-1). The accuracy of the proposed method was estimated by analyzing standard reference materials and spiked water samples. PMID:27260436

  15. Waterborne coatings for videotape

    SciTech Connect

    Cheng, S.; Fan, H.; Gogineni, N.; Jacobs, B.; Harrell, J.W.; Jefcoat, I.A.; Lane, A.M.; Nikles, D.E.

    1995-10-01

    Magnetic tape provides a low-cost, high-density information storage medium. There is a problem, however, because current manufacturing technology uses organic solvents to apply the magnetic wailing to the film. Here the authors describe a waterborne formulation that shows promise as a technology for pollution prevention. The organic solvents used in magnetic tape coating formulations include 2-butanone (methylethyl ketone [MEK]), 4-methyl-2-pentanone (methyl-iso-butyl ketone [MIBK]), tetrahydrofuran, toluene, and cyclohexanone. These solvents present an occupational hazard to the workers and emissions hazard to the environment. The authors developed a new waterborne coating formulation and prepared magnetic tape in a pilot coating trial. The tape has mechanical and magnetic properties comparable to those of the commercial VHS tape. There is a clear economic and environmental incentive to consider adopting this waterborne process for magnetic tape manufacture. This process is not commercial, and a development effort by a tape manufacturer is required to bring it to commercial reality. They have not addressed the important issue of long-term reliability of the materials package, an object of current research. However, they have made a case for a reexamination of the use of waterborne coating formulations by the magnetic tape industry.

  16. Complex reaction networks in high temperature hydrocarbon chemistry.

    PubMed

    Mutlay, İbrahim; Restrepo, Albeiro

    2015-03-28

    Complex chemical reaction mechanisms of high temperature hydrocarbon decomposition are represented as networks and their underlying graph topologies are analyzed as a dynamic system. As model reactants, 1,3-butadiene, acetylene, benzene, ethane, ethylene, methane, methyl isobutyl ketone (MIBK) and toluene are chosen in view of their importance for the global environment, energy technologies as well as their quantum chemical properties. Accurate kinetic mechanisms are computationally simulated and converted to bipartite graphs for the incremental conversion steps of the main reactant. Topological analysis of the resulting temporal networks reveals novel features unknown to classical chemical kinetics theory. The time-dependent percolation behavior of the chemical reaction networks shows infinite order phase transition and a unique correlation between the percolation thresholds and electron distribution of the reactants. These observations are expected to yield important applications in the development of a new theoretical perspective to chemical reactions and technological processes e.g. inhibition of greenhouse gases, efficient utilization of fossil fuels, and large scale carbon nanomaterial production. PMID:25720589

  17. Metal content and physicochemical parameters used as quality criteria in virgin argan oil: influence of the extraction method.

    PubMed

    Marfil, Rocio; Cabrera-Vique, Carmen; Giménez, Rafael; Bouzas, Paula R; Martínez, Olga; Sánchez, Jose Antonio

    2008-08-27

    Metal content was determined in 26 samples of virgin argan oil from Morocco. An ETA-AAS with previous sample dilution with MIBK technique was used. In oil obtained by traditional method, Fe ranged from 0.8 to 4.0 mg/kg, Cu from 160.4 to 695.7 microg/kg, Cr from 10.3 to 55.3 microg/kg, Mn from 18.1 to 70.8 microg/kg, and Pb from 28.5 to 450.0 microg/kg. In oil obtained by a half-industrialized method, Fe ranged from 0.8 to 1.7 mg/kg, Cu from 158.4 to 385.0 microg/kg, Cr from 10.0 to 48.1 microg/kg, Mn from 15.0 to 68.5 microg/kg, and Pb from 32.0 to 100.0 microg/kg. Acidity value, peroxide index, K270 and K232, humidity and sludge volatile, and insoluble sludges in petroleum ether were also determined. A high variability in these quality parameters and a decrease of the quality in the oils obtained by the traditional method were observed.

  18. Atomic absorption spectrometric determination of copper, zinc, and lead in geological materials

    USGS Publications Warehouse

    Sanzolone, R.F.; Chao, T.T.

    1976-01-01

    An atomic absorption spectrometric method is described for the determination of copper, zinc, and lead in geological materials. The sample is digested with HF-HCl-H2O2; the final solution for analysis is in 10 % (v/v) HCl. Copper and zinc are determined directly by aspirating the solution into an air-acetylene flame. A separate aliquot of the solution is used for determination of lead; lead is extracted into TOPO-MIBK from the acidic solution in the presence of iodide and ascorbic acid. For a 0.50-g sample, the limits of determination are 10-2000 p.p.m. for Cu and Zn, and 5-5000 p.p.m. for Pb. As much as 40 % Fe or Ca. and 10 % Al, Mg, or Mn in the sample do not interfere. The proposed method can be applied to the determination of copper, zinc, and lead in a wide range of geological materials including iron- and manganese-rich, calcareous and carbonate samples. ?? 1976.

  19. An on-line analysis of 7 odorous volatile organic compounds in the ambient air surrounding a large industrial complex

    NASA Astrophysics Data System (ADS)

    Kabir, Ehsanul; Kim, Ki-Hyun

    2010-09-01

    The concentrations of seven odorous volatile organic compounds (VOCs) including styrene (S), toluene (T), xylene (X), methyl ethyl ketone (MEK), isobutyl alcohol (i-BuAl), methyl isobutyl ketone (MIBK), and butyl acetate (BuAc) were measured continuously at hourly intervals from an on-line odor monitoring station in Ansan city, Korea (August 2005 to December 2007). Their concentration data (ppb) exhibited a narrow range of mean values despite large variabilities: 1.33 ± 8.81, 16.1 ± 96.6, 3.32 ± 11.5, 7.45 ± 10.3, 20.4 ± 2.38, 1.31 ± 1.16, and 2.43 ± 3.02, respectively. However, unlike aromatics, the distribution of other VOCs was characterized by infrequent occurrences, e.g., as large as 97.5% of i-BuAl data below detection limit. Comparison of temporal patterns indicates that aromatic VOCs are the highest in summer, while others tend to peak during fall (or summer). If the relative compositions of these VOCs were compared in terms of odor intensity, their contribution in the study area is unlikely significant as the malodor components. Evaluation of the data suggests that the distribution of the target VOCs should be affected more sensitively by local traffic activities rather than industrial processes in the surrounding area. Nonetheless, the potent roles of these volatile components should not be underestimated with respect to human health.

  20. A rapid, partial leach and organic separation for the sensitive determination of Ag, Bi, Cd, Cu, Mo, Pb, Sb, and Zn in surface geologic materials by flame atomic absorption

    USGS Publications Warehouse

    Viets, J.G.; Clark, J.R.; Campbell, W.L.

    1984-01-01

    A solution of dilute hydrochloric acid, ascorbic acid, and potassium iodide has been found to dissolve weakly bound metals in soils, stream sediments, and oxidized rocks. Silver, Bi, Cd, Cu, Mo, Pb, Sb, and Zn are selectively extracted from this solution by a mixture of Aliquat 336 (tricaprylyl methyl ammonium chloride) and MIBK (methyl isobutyl ketone). Because potentially interfering major and minor elements do not extract, the organic separation allows interference-free determinations of Ag and Cd to the 0.05 ppm level, Mo, Cu, and Zn to 0.5 ppm, and Bi, Pb, and Sb to 1 ppm in the sample using flame atomic absorption spectroscopy. The analytical absorbance values of the organic solution used in the proposed method are generally enhanced more than threefold as compared to aqueous solutions, due to more efficient atomization and burning characteristics. The leaching and extraction procedures are extremely rapid; as many as 100 samples may be analyzed per day, yielding 800 determinations, and the technique is adaptable to field use. The proposed method was compared to total digestion methods for geochemical reference samples as well as soils and stream sediments from mineralized and unmineralized areas. The partial leach showed better anomaly contrasts than did total digestions. Because the proposed method is very rapid and is sensitive to pathfinder elements for several types of ore deposits, it should be useful for reconnaissance surveys for concealed deposits. ?? 1984.

  1. Analytical applications of condensed phosphoric acid-I Determination of ferrous and total iron in iron ores after decomposition with condensed phosphoric acid.

    PubMed

    Mizoguchi, T; Ishii, H

    1978-06-01

    A simple method is described for the determination of ferrous and total iron in iron ores. Iron ores are dissolved by condensed phosphoric acid (CPA) very rapidly without any tedious and time-consuming manipulations such as elimination of silica and filtration. Under the proposed conditions (amount of sample 100 mg, amount of CPA added 10 g, heating temperature 290 degrees , heating time 30 min), magnetite, limonite and hematite are completely dissolved. The iron content can be determined in the presence of condensed phosphoric acid by titration with dichromate solution, if a slight modification is made. The total iron in iron ores, determined by the present method, is in agreement with that found by the JIS method. The ferrous iron in iron ores can be determined by dissolving the samples with CPA in a nitrogen atmosphere and titrating with dichromate solution. Chelatometric titration of iron after solvent extraction with MIBK from solutions prepared by use of CPA is found to be accurate for samples such as pyrite cinder. The ability of CPA to dissolve various materials has been investigated.

  2. Mechanism of transport and distribution of organic solvents in blood

    NASA Technical Reports Server (NTRS)

    Lam, C. W.; Galen, T. J.; Boyd, J. F.; Pierson, D. L.

    1990-01-01

    Little is known about the mechanism of transport and distribution of volatile organic compounds in blood. Studies were conducted on five typical organic solvents to investigate how these compounds are transported and distributed in blood. Groups of four to five rats were exposed for 2 hr to 500 ppm of n-hexane, toluene, chloroform, methyl isobutyl ketone (MIBK), or diethyl ether vapor; 94, 66, 90, 51, or 49%, respectively, of these solvents in the blood were found in the red blood cells (RBCs). Very similar results were obtained in vitro when aqueous solutions of these solvents were added to rat blood. In vitro studies were also conducted on human blood with these solvents; 66, 43, 65, 49, or 46%, respectively, of the added solvent was taken up by the RBCs. These results indicate that RBCs from humans and rats exhibited substantial differences in affinity for the three more hydrophobic solvents studied. When solutions of these solvents were added to human plasma and RBC samples, large fractions (51-96%) of the solvents were recovered from ammonium sulfate-precipitated plasma proteins and hemoglobin. Smaller fractions were recovered from plasma water and red cell water. Less than 10% of each of the added solvents in RBC samples was found in the red cell membrane ghosts. These results indicate that RBCs play an important role in the uptake and transport of these solvents. Proteins, chiefly hemoglobin, are the major carriers of these compounds in blood. It can be inferred from the results of the present study that volatile lipophilic organic solvents are probably taken up by the hydrophobic sites of blood proteins.

  3. Fate of 14C-Pyrene in soil-plant system amended with pig manure compost and Tween 80: a growth chamber study.

    PubMed

    Cheng, Ka Yu; Wong, Jonathan W C

    2008-11-01

    This paper evaluated the effects of a pig manure compost (PMC) and a nonionic surfactant Tween 80 on the fate of 14C-Pyrene (Pyr) in a soil-plant system (Agropyron elongatum). Soils spiked with 14C-4, 5, 9, 10-Pyr were amended with 7.5% (w/w) PMC together with or without 100mgkg(-1) of Tween 80. Unplanted soil without amendments was set as the control. Gas phases of the systems were monitored for 14CO2 over a 60 days period. The impact of PMC and Tween 80 on the apparent loss of the PAH and the distribution of 14C-activity in the systems was studied. 14C-activity associated with different soil fractions was further examined by using methyl-isobutyl-ketone (MIBK) fractionation method. The results showed that the addition of PMC could increase the dissipation of Pyr in vegetated soil from 12.1% to 58.7%, while the co-addition of Tween 80 and PMC could further enhance the dissipation to 90.3%. Pyr dissipation in soil was correlated with the mineralization of 14C-Pyr, indicating that Pyr dissipation was mainly due to mineralization. A higher formation of water-extractable metabolites was observed in soil amended with PMC and Tween 80, and this was correlated with a higher biomass accumulation of 14C-activity and higher bound residue formation in the soil. Overall, this study suggested that the co-application of PMC and Tween 80 could improve phytoremediation of Pyr-contaminated soil.

  4. Concentration levels of metals in vegetables grown in soils irrigated with river water in Addis Ababa, Ethiopia.

    PubMed

    Weldegebriel, Yirgaalem; Chandravanshi, Bhagwan Singh; Wondimu, Taddese

    2012-03-01

    Samples of vegetables, water and soil were collected from four vegetable farms in Addis Ababa to evaluate the extent and trend of metal accumulation in these systems and health risk concerns to consumers. Vegetable samples were digested in HNO(3) and HClO(4), soil samples in Aqua Regia and water samples were pre-concentrated with methyl isobutyl ketone (MIBK) using the chelating agent ammonium pyrrolidine dithiocarbamate (APDC). All the samples were analyzed for Co, Cr, Cu, Mn, Ni, Zn, Cd and Pb with flame atomic absorption spectrophotometer. The concentrations of Cd (0.12-1.13 mg kg(-1)) and Pb (0.11-0.89 mg kg(-1)) in the vegetables surpassed the maximum recommended levels. The total metal concentrations in soils were (mg kg(-1)): Cr, 9.9-22.8; Co, 28.0-47.3; Cu, 25.1-51.4, Mn, 1000-1054; Ni, 16.4-55.8; Zn, 146-149; Cd, 1.4-1.8 and Pb, 22.0-50.7. The trace metals Cd, Co, Cu, Mn and Ni in most of the water samples collected from Goffa, Kera and Akaki farms also surpassed irrigation water guideline limits, which might be a case for high accumulation of metals in the soils. However, the soil pH (6.5-7.6) and high cation exchange capacity (CEC), 38.41-50.18, coupled with high clay content, 37-51%, of the soil seemed to limit metal uptake by the vegetables. The physical parameters, pH (7.43-7.89) and electrical conductivity (0.33-1.54 dS/m) of irrigation waters measured at 25°C were found within the acceptable range. PMID:22062152

  5. Carrier element-free coprecipitation (CEFC) method for the separation, preconcentration and speciation of chromium using an isatin derivative.

    PubMed

    Bulut, Volkan Numan; Ozdes, Duygu; Bekircan, Olcay; Gundogdu, Ali; Duran, Celal; Soylak, Mustafa

    2009-01-19

    A new, simple, rapid and sensitive separation, preconcentration and speciation procedure for chromium in environmental liquid and solid samples has been established. The present speciation procedure for Cr(III) and Cr(VI) is based on combination of carrier element-free coprecipitation (CEFC) and flame atomic absorption spectrometric (FAAS) determinations. In this method a newly synthesized organic coprecipitant, 5-chloro-3-[4-(trifluoromethoxy) phenylimino]indolin-2-one (CFMEPI), was used without adding any carrier element for coprecipitation of chromium(III). After reduction of chromium(VI) by concentrated H(2)SO(4) and ethanol, the procedure was applied for the determination of total chromium. Chromium(VI) was calculated as the difference between the amount of total chromium and chromium(III). The optimum conditions for coprecipitation and speciation processes were investigated on several commonly tested experimental parameters, such as pH of the solution, amount of coprecipitant, sample volume, etc. No considerable interference was observed from the other investigated anions and cations, which may be found in natural water samples. The preconcentration factor was found to be 40. The detection limit for chromium(III) corresponding to three times the standard deviation of the blank (N=10) was found 0.7 microg L(-1). The present procedure was successfully applied for speciation of chromium in several liquid and solid environmental samples. In order to support the accuracy of the method, the certified reference materials (CRM-TMDW-500 Drinking Water and CRM-SA-C Sandy Soil C) were analyzed, and standard APDC-MIBK liquid-liquid extraction method was performed. The results obtained were in good agreement with the certified values. PMID:19100880

  6. Survey for cadmium, cobalt, chromium, copper, nickel, lead, zinc, calcium, and magnesium in Canadian drinking water supplies.

    PubMed

    Méranger, J C; Subramanian, K S; Chalifoux, C

    1981-01-01

    A second national survey was done to ascertain the levels of Cd, Co, Cr, Cu, Ni, Pb, Zn, Ca, and Mg in Canadian drinking water supplies. Raw, treated, and distributed water samples collected from 71 municipalities across Canada were analyzed both by atomic absorption spectrophotometry using the direct method and by an APDC-MIBK extraction procedure. As in the first national survey, the amounts of trace metals found in the 3 types of water samples were essentially the same. Contamination of the water supplies with these metals except Cu and Zn was minimal during treatment and distribution. For Canadian drinking water, the median and extreme values expressed as ng metal/mL water were: Cd less than or equal to 0.02 (less than or equal to 0.02-0.07), Co less than or equal to 2.0 (less than or equal to 2.0-6.0), Cr less than or equal to 2.0 (less than or equal to 2.0-4.1), Cu less than 10 (less than or equal to 10-900), Ni less than or equal to 2.0 (less than or equal to 2.0-69.0), Pb less than or equal to 1.0 (less than or equal to 1.0-79.7), and Zn less than or equal to 10 (less than or equal to 10-750). Hardness values as mg CaCO3/L ranged from 6.7 in St. John's, Newfoundland, to 328.3 in Portage La Prairie, Manitoba. The median values for the Canadian drinking water supplies were well below the maximum permissible limits set by Health and Welfare Canada and the World Health Organization. PMID:7204309

  7. Lead determination at ng/mL level by flame atomic absorption spectrometry using a tantalum coated slotted quartz tube atom trap.

    PubMed

    Demirtaş, İlknur; Bakırdere, Sezgin; Ataman, O Yavuz

    2015-06-01

    Flame atomic absorption spectrometry (FAAS) still keeps its importance despite the relatively low sensitivity; because it is a simple and economical technique for determination of metals. In recent years, atom traps have been developed to increase the sensitivity of FAAS. Although the detection limit of FAAS is only at the level of µg/mL, with the use of atom traps it can reach to ng/mL. Slotted quartz tube (SQT) is one of the atom traps used to improve sensitivity. In atom trapping mode of SQT, analyte is trapped on-line in SQT for few minutes using ordinary sample aspiration, followed by the introduction of a small volume of organic solvent to effect the revolatilization and atomization of analyte species resulting in a transient signal. This system is economical, commercially available and easy to use. In this study, a sensitive analytical method was developed for the determination of lead with the help of SQT atom trapping flame atomization (SQT-AT-FAAS). 574 Fold sensitivity enhancement was obtained at a sample suction rate of 3.9 mL/min for 5.0 min trapping period with respect to FAAS. Organic solvent was selected as 40 µL of methyl isobutyl ketone (MIBK). To obtain a further sensitivity enhancement inner surface of SQT was coated with several transition metals. The best sensitivity enhancement, 1650 fold enhancement, was obtained by the Ta-coated SQT-AT-FAAS. In addition, chemical nature of Pb species trapped on quartz and Ta surface, and the chemical nature of Ta on quartz surface were investigated by X-ray photoelectron spectroscopy (XPS) and Raman Spectroscopy. Raman spectrometric results indicate that tantalum is coated on SQT surface in the form of Ta2O5. XPS studies revealed that the oxidation state of Pb in species trapped on both bare and Ta coated SQT surfaces is +2. For the accuracy check, the analyses of standard reference material were performed by use of SCP SCIENCE EnviroMAT Low (EU-L-2) and results for Pb were to be in good agreement with

  8. RECOVERY OF LACTIC ACID FROM AMERICAN CRYSTAL SUGAR COMPANY WASTEWATER

    SciTech Connect

    Daniel J. Stepan; Edwin S. Olson; Richard E. Shockey; Bradley G. Stevens; John R. Gallagher

    2001-04-30

    This project has shown that the recovery of several valuable lactic acid products is both technically feasible and economically viable. One of the original objectives of this project was to recover lactic acid. However, the presence of a variety of indigenous bacteria in the wastewater stream and technical issues related to recovery and purification have resulted in the production of lactic acid esters. These esters could by hydrolyzed to lactic acid, but only with unacceptable product losses that would be economically prohibitive. The developed process is projected to produce approximately 200,000 lb per day of lactate esters from wastewater at a single factory at costs that compete with conventional solvents. The lactate esters are good solvents for polymers and resins and could replace acetone, methyl ethyl ketone, MIBK, and other polar solvents used in the polymer industry. Because of their low volatility and viscosity-lowering properties, they will be especially useful for inks for jet printers, alkyl resins, and high-solid paints. Owing to their efficiency in dissolving salts and flux as well as oils and sealants, lactate esters can be used in cleaning circuit boards and machine and engine parts. Unlike conventional solvents, lactate esters exhibit low toxicity, are biodegradable, and are not hazardous air pollutants. Another application for lactate esters is in the production of plasticizers. Severe health problems have been attributed to widely used phthalate ester plasticizers. The U.S. Department of Agriculture showed that replacement of these with inexpensive lactate esters is feasible, owing to their superior polymer compatibility properties. A very large market is projected for polymers prepared from lactic acid. These are called polylactides and are a type of polyester. Thermoplastics of this type have a variety of uses, including moldings, fibers, films, and packaging of both manufactured goods and food products. Polylactides form tough, orientable