Sample records for mibk

  1. Separation of niobium and tantalum on polyurethane foam pretreated with diantipyrylmethane, TBP or MIBK

    Microsoft Academic Search

    R. Caletka; V. Krivan

    1985-01-01

    Mit Hilfe der Radiotracer-Technik wurde die extraktion-chromatographische Trennung der Elemente Niob und Tantal voneinander sowie dieser zwei von anderen Elementen untersucht. Für diese Zwecke wurden Säulen aus Polyurethan-Schaumstoff, nach Imprägnieren mit Diantipyrylmethan in Dichlorethan, Tributylphosphat oder Methylisobutylketon, verwendet. Die Trennungen wurden aus HF- und HF\\/H2SO4-Medien vorgenommen. Eine quantitative Trennung der untersuchten Elemente wurde erreicht.

  2. 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.

  3. Ketone potentiation of haloalkane?induced hepato? and nephrotoxicity. I. dose?response relationships

    Microsoft Academic Search

    Pierre Raymond; Gabriel L. Plaa

    1995-01-01

    Carbon tetrachloride (CCl4) induced hepatotoxicity and chloroform (CHCl3) induced nephrotoxicity were evaluated in male Sprague?Dawley rats pretreated with acetone (A), methyl ethyl ketone (MEK), and methyl isobutyl ketone (MiBK). Dose?response relationships for A, MEK, and MiBK potentiation of CCl4?induced hepatotoxicity and CHCl3?induced nephrotoxicity were compared. A, MEK, and MiBK pretreatment at a dosage of 6.8 mmol\\/kg, given daily for 3

  4. Methyl isobutyl ketone as a solvent for wax deoiling

    Microsoft Academic Search

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

    1983-01-01

    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

  5. Controlling magnetic ordering in coupled nanomagnet arrays

    E-print Network

    Adeyeye, Adekunle

    alloy supermalloy. The nanomagnets were arranged on rectangular lattices of different periods. A high of methyl iso-butyl ketone (MIBK)/iso- propyl alcohol (IPA). A 7 nm thick layer of Ni80Fe14Mo5 (`supermalloy

  6. Development and molecular-weight issues on the lithographic performance of poly (methyl methacrylate)

    Microsoft Academic Search

    A. Olzierski; I. Raptis

    2004-01-01

    The effect of methyl isobutyl ketone, MIBK:IPA, IPA:H2O developers and the molecular-weight on the dissolution mechanism and on the overall lithographic performance of poly (methyl methacrylate) (PMMA) was studied. PMMA sensitivity decreases monotonically as MIBK relative concentration decreases. For isopropyl alcohol (IPA) concentration in the 60–90% range (IPA:H2O solutions) the contrast and sensitivity values are very high and almost similar.

  7. Removal of Methyl Isobutyl Ketone From Contaminated Air by Trickle-Bed Air Biofilter

    Microsoft Academic Search

    Zhangli Cai; Daekeun Kim; George A. Sorial

    2005-01-01

    A laboratory-scale trickle-bed air biofilter was evaluated for the removal of methyl isobutyl ketone MIBK from a waste gas stream. Six-millimeter 6m m Celite pellets R-635 were used as the biological attachment medium. Effects of MIBK volumetric loading rates on removal efficiency, biofilter reacclimation, biomass growth, and removal kinetics were studied under three different operating conditions, namely, backwashing and two

  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. 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.

  10. 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.

  11. 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.

  12. Analysis of both cobalt and selenium in feed?stuffs and in biological tissue by chelation?extraction and graphite furnace atomic absorption spectroscopy

    Microsoft Academic Search

    T. F. Brown; L. K. Zeringue

    1991-01-01

    A procedure for measuring cobalt in feedstuffs and biological tissues using ammonium pyrrolidine dithiocarbamate (APDC) and methyl isobutyl ketone (MIBK) chelation?extraction and graphite furnace atomic absorption spectroscopy is described. This procedure, except for the graphite furnace and spectrophotometer programs, is identical to another method for analysis of selenium in the same types of sample materials. Therefore, only one chelation?extraction is

  13. Evaluation of solvent selectivity in dewaxing and deoiling

    Microsoft Academic Search

    N. V. Alperovich; A. N. Leonidov; S. P. Sokolova

    1983-01-01

    Previous literature on the efficiency of solvents used in removing paraffin wax by decrystallization is insufficient. A method for evaluating selectivity and mixtures of solvents is offered. General solvents MEK, acetone, MIBK are tested in various raw materials, then graphed. It is found that the ratio of the slope of the curve for the temperature of equal solubility (TES) as

  14. 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.

  15. Chiroptical hot spots in twisted nanowire plasmonic oscillators

    E-print Network

    Cohen, Adam E.

    :3 MIBK:IPA for 40 s, yielding wire-shaped grooves in the PMMA. Metal was deposited via thermal-soluble conducting polymer (Showa Denko, Espacer 300; 30 s at 2000 rpm). The conductive layer was necessary-IR). The polarizer was mounted on a motorized rotation stage (Thorlabs PRM1Z8). A liquid crystal variable retarder

  16. Methyl isobutyl ketone exposure-related increases in specific measures of ?2u-globulin (?2u) nephropathy in male rats along with in vitro evidence of reversible protein binding.

    PubMed

    Borghoff, S J; Poet, T S; Green, S; Davis, J; Hughes, B; Mensing, T; Sarang, S S; Lynch, A M; Hard, G C

    2015-07-01

    Chronic exposure to methyl isobutyl ketone (MIBK) resulted in an increase in the incidence of renal tubule adenomas and occurrence of renal tubule carcinomas in male, but not female Fischer 344 rats. Since a number of chemicals have been shown to cause male rat renal tumors through the ?2u nephropathy-mediated mode of action, the objective of this study is to evaluate the ability of MIBK to induce measures of ?2u nephropathy including renal cell proliferation in male and female F344 rats following exposure to the same inhalation concentrations used in the National Toxicology Program (NTP) cancer bioassay (0, 450, 900, or 1800ppm). Rats were exposed 6h/day for 1 or 4 weeks and kidneys excised approximately 18h post exposure to evaluate hyaline droplet accumulation (HDA), ?2u staining of hyaline droplets, renal cell proliferation, and to quantitate renal ?2u concentration. There was an exposure-related increase in all measures of ?2u nephropathy in male, but not female rat kidneys. The hyaline droplets present in male rat kidney stained positively for ?2u. The changes in HDA and ?2u concentration were comparable to d-limonene, an acknowledged inducer of ?2u nephropathy. In a separate in vitro study using a two-compartment vial equilibration model to assess the interaction between MIBK and ?2u, the dissociation constant (Kd) was estimated to be 1.27×10(-5)M. This Kd is within the range of other chemicals known to bind to ?2u and cause nephropathy. Together, the exposure-related increase in measures of ?2u nephropathy, sustained increase in renal cell proliferation along with an indication of reversible binding of MIBK to ?2u, support the inclusion of MIBK in the category of chemicals exerting renal effects through a protein droplet ?2u nephropathy-mediated mode of action (MoA). PMID:25797582

  17. Treatment of UCG condensate by gas stripping, solvent extraction, activated carbon, and sludge

    SciTech Connect

    Humenick, M.J.; Shellenbarger, K.

    1986-01-01

    This paper reports on the continued study of the treatment of UCG condensate by various processing schemes. The purpose of this work was to obtain design data for use in providing an optimal rather than a universal treatment scheme for UCG wastewater condensate. In the past, several treatment schemes have been studied and design data collected and published. This work presents new options for consideration and evaluation. The laboratory experimental project studied the following options: treatment of UCG condensate by (a) solvent extraction (Methyl isobutyl ketone, MIBK), ammonia stripping, and activated sludge; (b) solvent extraction by MIBK, ammonia stripping, and activated sludge with supplemental powdered activated carbon addition to the activated sludge unit; (c) ammonia stripping and dilution of the stripped UCG condensate with contaminated pattern water before treatment of the mixture with activated sludge. Performance and kinetic information is provided for each option, along with a determination of relative toxicity of feeds and effluents for options (a) and (b).

  18. 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.

  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. Time evolution of developed contours in poly-(methyl methacrylate) electron resist

    Microsoft Academic Search

    James S. Greeneich

    1974-01-01

    The time evolution of exposure contours in poly-(methyl methacrylate) (PMMA) electron resist is calculated for several time-dependent developers comprised of various proportions of methyl isobutyl ketone (MIBK) and isopropyl alcohol (IPA). Contours are calculated for a line of charge incident on 4000 Å of resist coated on a low-atomic-number substrate. Parameters such as beam energy, incident charge per unit length,

  1. Determination of Ultra Trace Amounts of Cobalt in Fish by Graphite Furnace Zeeman Effect Atomic Absorption Spectrometry

    Microsoft Academic Search

    J. W. McMahon; A. E. Docherty; J. M. A. Judd; S. R. Gentner

    1986-01-01

    A method is described for determining stable cobalt concentrations in fish flesh and bone using polarized Zeeman effect graphite furnace atomic absorption spectrometry (ZAAS). Cobalt analysis on freshwater fish flesh samples (log dry weight) required predigestion and wet-ashing at 70–80°C. Cobalt is chelated with ammonium pyrrolidine dithiocarbamate (APDC) extracted with methyl isobutyl ketone (MIBK) and analysed by ZAAS. The mean

  2. Acetone transformation over Pt\\/H[Al]ZSM5 and Pt\\/H[Ga]ZSM5 catalysts

    Microsoft Academic Search

    L. Melo; A. Llanos; M. Mediavilla; D. Moronta

    2002-01-01

    Acetone transformation into methyl–isobutyl ketone (MIBK) under hydrogen atmosphere, using bifunctional catalysts of the platinum supported over medium-pore zeolites (MFI)-type, was studied. This methodology offers a number of advantages; however, since it implies working at low hydrogen pressure (PH2 ) with respect to the acetone pressure (PAc), a rapid catalyst deactivation is observed. Therefore, to minimize deactivation of bifunctional catalysts,

  3. Effect of the metallic\\/acid site (nPt\\/nA) ratio on the transformation of acetone towards methyl isobutyl ketone

    Microsoft Academic Search

    L. Melo; G. Giannetto; F. Alvarez; P. Magnoux; M. Guisnet

    1997-01-01

    Methyl isobutyl ketone (MIBK) was synthesized from acetone (Ac) and hydrogen over Pt-HZSM5 bifunctional catalysts. The reaction\\u000a was carried out at 160C, atmospheric pressure, and with a PH2\\/PAc molar ratio = 0.33, using a fixed bed and dynamic flow reactor. The results show that catalytic properties and coke formation\\u000a largely depend on the ratio between the number of accessible hydro-dehydrogenation

  4. A study on the solvent extraction of Pd\\/II\\/ with 1,2,3-benzotriazole into methyl iso-butyl ketone

    Microsoft Academic Search

    I. A. Mendes; Z. R. Turel

    1986-01-01

    A novel method has been developed for the extraction of Pd\\/II\\/ with 1,2,3-benzotriazole \\/1,2,3-BT\\/ into methyl isobutyl ketone \\/MIBK\\/ at a pH of 4.0. The effects of pH, time of equilibration, solvent, anions and cations on the extraction coefficient have been evaluated. The stoichiometry of the extracted species of 12 was obtained by the slope ratio method and by the

  5. Determination of Cd, Co, Cu, Fe and Ni at parts per billion level in high-purity gallium by graphite furnace atomic absorption spectrometry (GFAAS)

    Microsoft Academic Search

    Sunil Jai Kumar; S. Natarajan; J. Arunachalam; S. Gangadharan

    1990-01-01

    The determination of Cd, Co, Cu, Fe and Ni in 6N gallium by GFAAS is reported. The analytes are extracted as pyrrolidine dithiocarbamates into methyl-iso-butyl-ketone (MIBK) in the presence of tartrate. The conditions of extraction, quantity of reagents required and the matrix interference aspects are discussed. The method offers one-step matrix removal and preconcentration, leading to low experimental blanks.

  6. Determination of chromium(III) and chromium(VI) by ammonium pyrrolidinecarbodithioate-methyl isobutyl ketone furnace atomic absorption spectrometry

    Microsoft Academic Search

    Kunnath S. Subramanian

    1988-01-01

    The solution conditions and other parameters affecting the ammonium pyrrolidinecarbodithioate-methyl isobutyl ketone (APCD-MIBK) extraction system for the graphite furnace atomic absorption spectrometric determination of Cr(III) and Cr(VI) have been studied in detail. The parameters studied include pH of the aqueous phase prior to extraction, concentration of APDC, concentration of the potassium hydrogen phthalate buffer, the length of time needed for

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

    Microsoft Academic Search

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

    1983-01-01

    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

  8. Simultaneous determination of tartrazine, riboflavine, curcumin and erythrosine by derivative spectrophotometry

    Microsoft Academic Search

    J. J. Berzas Nevado; J. Rodriguez Flores; M. J. Villaseñor Llerena

    1994-01-01

    A quaternary mixture of Tartrazine (E-102), Riboflavine (E-101), Curcumin (E-100) and Erythrosine (E-127) can be analysed, by means of a previous extraction step using methyl isobutyl ketone (MIBK) as extracting agent, and resolving the binary mixtures obtained in the aqueous and organic phases by derivative spectrophotometry with measurements at the “zero-crossing” wavelengths and by derivative ratio spectra. The established conditions

  9. Extraction-flame atomic absorption determination of microtraces of copper, zinc, nickel, cobalt, manganese and iron in some alkali salts

    Microsoft Academic Search

    E. Ivanova; S. Mareva; N. Jordanov

    1980-01-01

    Der Mikrospurengehalt von Cu, Zn, Ni, Co, Mn und Fe in NaClO4, KCl, KOH, und KAl(SO4)2 · 12H2O wurde durch Flammenatomabsorption nach Extraktionsanreicherung mit einer 1-Phenyl-3-methyl-4-benzoylpyrazolon-5 (PMBP)-Lösung in MIBK bestimmt. Die Salz-Matrix weist keinen störenden Einflu\\\\ auf die quantitative Extraktion der Elementspuren auf. Die Bestimmung der Spuren im Konzentrationsgebiet von 10-3–10-6% erfolgt mit guter PrÄzision (Variationskoeffizient 2–8%) und Richtigkeit.

  10. 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.

  11. Evaluation of solvent selectivity in dewaxing and deoiling

    SciTech Connect

    Al'perovich, N.V.; Leonidov, A.N.; Sokolova, S.P.

    1983-05-01

    Previous literature on the efficiency of solvents used in removing paraffin wax by decrystallization is insufficient. A method for evaluating selectivity and mixtures of solvents is offered. General solvents MEK, acetone, MIBK are tested in various raw materials, then graphed. It is found that the ratio of the slope of the curve for the temperature of equal solubility (TES) as a function of the content of the solvent (that is, the solubility curve) to the slope of the corresponding denormalization curve is constant. This ratio gives a formula, and is therefore a criterion for selectivity. The greater the ratio, the higher the selectivity. The ratio is also generalized to solvents of any composition.

  12. 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.

  13. 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

  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. Health hazard evaluation report HETA 93-0448-2407, Thatcher Tubes, Division of Courtaulds US, Muscatine, Iowa

    SciTech Connect

    Parker, M.G.; Buchta, T.M.

    1994-03-01

    In response to a request from the International Chemical Worker Union, an investigation was begun of exposure in the press area of the plastic tube department at Thatcher Tubes, Muscatine, Iowa, a division of Courtaulds US. The request has been prompted by worker complaints of skin and respiratory sensitization to emissions from the plastic tube printing and curing operations. The company manufactured plastic squeeze tubes, employing about 300 workers over three shifts. Ultraviolet (UV) cured inks were used in the press area. Levels of methyl-ethyl-ketone (MEK) were well below recommended limits, ranging from 7.2 to 18.5 parts per million (ppm). Levels of methyl isobutyl ketone (MIBK), ethanol, isopropanol, and tolune were also below the suggested limits. Ozone and trimethylolpropane triacrylate (TMPTA) were not detected. The authors conclude that no specific exposure in the UV coating process clearly accounted for reported symptoms.

  16. 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. PMID:18963980

  17. 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.

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

    SciTech Connect

    Zhihua Fan; Peterson, M.R.; Jayanty, R.K.M. [Research Triangle Institute, Research Triangle Park, NC (United States)

    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 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.

  20. 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.

  1. 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.

  2. 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)

  3. 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.

  4. 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.

  5. Organic-inorganic hybrid resists for EUVL

    NASA Astrophysics Data System (ADS)

    Singh, Vikram; Kalyani, Vishwanath; Satyanarayana, V. S. V.; Pradeep, Chullikkattil P.; Ghosh, Subrata; Sharma, Satinder; Gonsalves, Kenneth E.

    2014-03-01

    Herein, we describe preliminary results on organic-inorganic hybrid photoresists, capable of showing line patterns up to 16 nm under e-beam exposure studies, prepared by incorporating polyoxometalates (POMs) clusters into organic photoresist materials. Various Mo and W based clusters such as (TBA)2[Mo6O19], (TBA)5(H)[P2V3W15O62] and (TBA)4[P2Mo18O61] (where TBA = tetrabutyl ammonium counter ion) have been incorporated into PMMA matrix by mixing POM solutions and standard PMMA polymer in anisole (MW ~ 95000, MicroChem) in 1:33 w/v ratio. E-beam exposure followed by development with MIBK solutions showed that these new organic-inorganic hybrid photoresists show good line patterns upto 16 nm, which were not observed in the case of control experiments done on pure PMMA polymer resist. The observed enhancement of resist properties in the case of hybrid resists could possibly be due to a combination of features imparted to the resist by the POM clusters such as increased sensitivity, etch resistance and thermal stability.

  6. Separation and preconcentration in a batch mode of Cd(II), Cr(III, VI), Cu(II), Mn(II, VII) and Pb(II) by solid-phase extraction by using of silica modified with N-propylsalicylaldimine.

    PubMed

    Abou-El-Sherbini, Khaled S; Kenawy, I M M; Hamed, Mohammad A; Issa, R M; Elmorsi, R

    2002-08-23

    The complexes formed between IE11 and Cd(II), Cr(III), Cu(II), Mn(II) and Pb(II) were identified and confirmed by IR, UV and pH-metric titration. The uptake behavior of porous silica modified with N-propylsalicylaldimine (IE11) and these metal ions were studied. Log k(d) was found to be within the range 2.19-5.16 depending on pH and time of stirring. IE11 was used in the separation and preconcentration of Cd(II), Cr(III, VI), Cu(II), Mn(II, VII) and Pb(II) from some natural water samples. Data were compared with those obtained by the solvent extraction method APDC/MIBK. The proposed methodology allows to verify an improvement in the water quality of Nile River probably attributed to high to moderate floods in the last few years. The method was found to be accurate and not subject to random error, i.e. precise. PMID:18968753

  7. Advantages/limitations of solvent extraction, ozonation, and carbon adsorption for reduction of nonbiodegradable residuals in METC fixed-bed gasification wastewaters. Final report

    SciTech Connect

    Neufeld, R.D.; Paladino, J.; Moretti, C.; Plautz, M.; Ali, F.

    1982-12-01

    This (second) year of effort examined the roll of solvent extraction, ozonation, and carbon adsorption for incorporation into the wastewater treatment scheme for purposes of enhancing process stability, decolorization, elimination of dilution water requirements, and minimization of nonbiodegradable residuals. This approach, while more costly, will better allow for direct discharge or reuse of gasification wastewaters. Di-isopropylether (DIPE) and methyl-isobutyl ketone (MIBK) were incorporated into a pretreatment step with free and fixed ammonia stripping followed by activated sludge treatment. Solvent extraction did not result in a decrease of nonbiodegradable residuals from the bioreactor, but did result in a highly stable operation of the bioreactors with no dilution water requirements and a minimal tendency for foaming and biodeflocculation. Ozonation of biofeed resulted in phenol being kinetically favored for oxidation. Ozonation of bioeffluents resulted in decolorization of wastewaters at low dosages, and first order kinetics in the reduction of nonbiodegradable TOC residuals. Steam stripping for ammonia removals, coupled with an understanding of anion/cation chemistry, led to a treatment system with minimization of salt additions. This is desirable if waste-waters are to be concentrated via evaporative techniques for partial reuse. Use of ozone followed by activated carbon further reduces nondegradable organics as may be desired for discharge or reuse purposes.

  8. 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.

  9. Dietary exposure to cadmium, lead and nickel among students from south-east Poland.

    PubMed

    Marzec, Zbigniew; Koch, Wojciech; Marzec, Agnieszka; ?ukiewicz-Sobczak, Wioletta

    2014-01-01

    The dietary intake of cadmium, lead and nickel was determined among students from three universities in the city of Lublin in south-east Poland to assess the levels of exposure to these contaminants, compared to PTWI and TDI values. The study was performed in 2006–2010 and involved 850 daily food rations of students. The technique of 24-hour dietary recall and diet duplicates was used. Cadmium, lead and nickel complexes with ammonium-pyrrolidindithiocarbamate were formed and extracted to the organic phase with 4-methylpentan-2-one–MIBK, in which their content was measured by flame atomic absorption spectrometry. The highest intake of the elements studied was observed in 2008. The data show that in none of the cases, the level of intake reached 70% of PTWI/TDI values, and thus the risk of developing diseases related to high exposure to these toxic metals absorbed from foodstuffs was low. The parameters of methods were checked during determinations by adding standard solutions to the samples before mineralization and by using two reference materials: Total diet ARC/CL HDP and Bovine muscle RM NIST 8414. The dietary exposure to lead and cadmium has significantly decreased in recent years, whereas the exposures to nickel remains on a stable level. PMID:25528928

  10. Sensitivity of early life stages of blueback herring to moderate acidity and aluminum in soft freshwater. [Alosa aestivalis

    SciTech Connect

    Klauda, R.J.; Palmer, R.E.; Lenkevich, M.J. (Johns Hopkins Univ., Shady Side, MD (USA))

    1987-03-01

    The sensitivity of the blueback herring Alosa aestivalis to acidity and aluminum (Al) in reconstituted, soft freshwater (23-25 mg l{sup {minus}1} hardness as CaCO{sub 3}) was investigated in a continuous exposure laboratory study. Mature (20-24 h postfertilization) embryos were more tolerant than 1- to 5-day-old yolk-sac larvae. Significant mortality of embryos occurred only when pH was 5.0 and the total Al concentration was 0.42 mg l{sup {minus}1} (predicted MIBK-extracted total monomeric Al = 0.34 mg l{sup {minus}1}). Moderate acidity dramatically decreased the survival of yolk-sac larvae. Mean mortality was 99% in pH 5.0 and 89% in pH 5.7 compared to 38% in pH 6.5 and 16% in pH 7.8 without Al. The toxicity of Al to yolk-sac larvae was pH- and dose-dependent. Total Al concentration up to 0.34 mg l{sup {minus}1} (predicted total monomeric Al up to 0.21 mg l{sup {minus}1}) were not toxic at pH 6.5 and 7.8. At pH 5.0 and 5.7, Al increased the rate at which yolk-sac larvae died during a 96-h exposure (i.e., time 50% morality decreased with increasing Al). Continuous exposure to a predicted total monomeric Al level of only 0.03 mg l{sup {minus}1} at pH 5.0 killed all yolk-sac larvae in <24 hours. The mechanisms of acid and Al toxicity were apparently physiological and not associated with extensive cellular damage. Acidification events measured in Chesapeake Bay tributaries may reduce survival of blueback herring yolk-sax larvae and embryos to those events.

  11. Catalytic destruction of hazardous organics in aqueous solutions

    SciTech Connect

    Baker, E.G.; Sealock, L.J. Jr.

    1988-04-01

    Pacific Northwest Laboratory (PNL) is developing a process for destroying hazardous organics and chlorinated organics in aqueous solutions. The process is targeted at liquid waste streams that are difficult and costly to treat with conventional or developing technologies. Examples of these waste streams include contaminated groundwater and surface water and industrial wastewater. Aqueous solutions are treated with a transition metal catalyst at 300/degree/C to 460/degree/C and 2000 to 5000 psig pressure to convert the wastes to innocuous gases. During proof-of-principle tests conducted in a 1-L batch reactor, destruction of over 99/percent/ (in most cases approaching 99.9/percent/) of the organic material was achieved. Hexone (methyl is isobutyl ketone, MIBK), p-cresol, hexane, benzene, and naphthalene were used as model waste materials. The only major product with all of the organic compounds was a gas containing 50/percent/ to 75/percent/ methane, 25/percent/ to 45/percent/ carbon dioxide, and 0/percent) to 5/percent/ hydrogen. Reduced nickel was the only effective catalyst and that the optimal operating conditions for destroying nonchlorinated organics were 350/degree/C to 400/degree/C, 2000 to 4000 psig, and 30/endash/ to 60/endash/min residence time. These tests also indicated that catalyst deactivation or fouling would not be a problem at these conditions. Chlorobenzene and trichloroethylene (TEC), were also tested. Destruction of both compounds was 99/percent/ or greater, but the products were different from those obtained from hydrocarbons. With TCE, the major product was carbon dioxide; with chlorobenzene the major product identified was benzene. In the tests with the chlorinated hydrocarbons, the chlorine was converted to HC1 and the reduced nickel was converted to nickel hydroxide, which may be detrimental to long-term catalyst activity. (15 refs., 8 figs., 6 tabs).

  12. 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.

  13. 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, self-supporting thin films and have, therefore, been used for adhesives, safety glass, and finishes. If the bacterial culture produces the L-lactic acid enanatiomer form exclusively, the L-lactide prepared from this form can be used for making polymers with good fiber-forming properties. We have not currently achieved the exclusive production of L-lactate in our efforts. However, markets in films and structural shapes are available for polymers and copolymers prepared from the mixed D,L-lactide forms that result from processing the D,L-lactic acid obtained from fermentation such as that occurring naturally in sugar beet wastewater. These materials are slowly biodegraded to harmless compounds in the environment, and they burn with a clean blue flame when incinerated. These materials represent excellent opportunities for utilization of the D,L-lactic mixture produced from natural fermentation of the ACS flume water. Esters can be converted into a lactide, and the alcohol released from the ester can be recycled with no net consumption of the alcohol. Lactide intermediates could be produced locally and shipped to polymer producers elsewhere. The polymer and copolymer markets are extremely large, and the role of lactides in these markets is continuously expanding. The overall process can be readily integrated into existing factory wastewater operations. There are several environmental benefits that would be realized at the factories with incorporation of the lactate recovery process. The process reduces the organic loading to the existing wastewater treatment system that should result in enhanced operability with respect to both solids handling and treated-water quality. A higher-quality treated water will also help reduce odor levels from holding ponds. Several water reuse opportunities are probable, depending on the quality of treated water from the FT process.