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1

One-Step MIBK Synthesis: A New Process from 2Propanol  

Microsoft Academic Search

The one-step MIBK synthesis from 2-propanol was investigated as an alternative process to current conventional technology that produces MIBK from acetone. The reaction was studied at 473 K and atmospheric pressure using bifunctional Cu-base catalysts. Single MIOx, binary MIMIIOx, and Cu-containing CuMI(MIIOx mixed oxides, where MI and MII are metal cations such as Mg2+, Al3+, or Ce3+, were obtained by

J. I. Di Cosimo; G. Torres; C. R. Apestegu??a

2002-01-01

2

Equilibrium and kinetic data of adsorption and separation for zirconium and hafnium onto MIBK extraction resin  

Microsoft Academic Search

The equilibrium and kinetics of methyl isobutyl ketone (MIBK) extraction resin for adsorption and separation of zirconium and hafnium were studied under the different conditions of acidity, initial total concentrations of zirconium and hafnium and temperature. The equilibrium data of both zirconium and hafnium are found to follow the Freundlich adsorption isotherm, and the Freundlich isotherm constants (KF) are 3.53

Zhi-gao XU; Yan-ke WU; Jian-dong ZHANG; Li ZHANG; Li-jun WANG

2010-01-01

3

Direct determination of several elements in MIBK extract by high-power nitrogen-oxygen mixed gas microwave-induced plasma optical emission spectrometry.  

PubMed

A nitrogen-oxygen mixed gas microwave-induced plasma with an Okamoto cavity was employed as an atomization and excitation source for emission spectrometric analysis of organic solvent samples. Nitrogen-oxygen mixed gas produces very a stable microwave-induced plasma that is highly robust to the loading of 4-methyl-2-pentanone (MIBK), possibly because the organic solvent is completely combusted in the oxygen-containing plasma. After extracting test solutions containing Al, Co, Cr(III), Cu, Fe(III), Mo(VI), Ni, Pb with MIBK, both the aqueous phase and the organic phase were aspirated into the microwave-induced plasma, yielding linear calibration curves for both the species in the aqueous phase (Al, Co, Cr, Ni, and Pb) and those in the organic phase (Fe and Mo). These results indicate that Fe and Mo can be extracted with MIBK, which is explained by the partition coefficients of these elements in MIBK. PMID:15931498

Maeda, Tetsuo; Wagatsuma, Kazuaki; Okamoto, Yukio

2005-06-02

4

Flame atomic-absorption determination of beryllium after extraction from NH(4)SCN medium with trioctylamine in MIBK.  

PubMed

A study has been made of the experimental conditions, errors, sensitivity, limits of detection and linear response range in the determination of beryllium by AAS in a nitrous oxide-acetylene flame, with aqueous or aqueous organic solutions or MIBK solutions containing the ion-pair [Be(SCN)(2-)(4)][(R(3)NH)(2+)(2)]. The interference of Al, Mg, Ti, V, Fe, Ca, Mn, Na, K, SiO(2-)(3), PO(3-)(4), Cl(-), SO(2-)(4), F(-), ClO(-)(4), H(2)BO(-)(3) and SCN(-) has been studied, and methods established for eliminating that of titanium, aluminium, fluoride and silicon. PMID:18963170

Castillo, J R; Belarra, M A; Dominguez, M; Aznárez, J

1982-06-01

5

Transient-state behavior of a biofilter removing mixtures of vapors of MEK and MIBK from air  

SciTech Connect

In the work reported here, selected aspects of the dynamic behavior of biofilters for waste air treatment have been investigated. Emphasis was placed on transient state elimination of mixtures of methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK) vapors and on explanation of the observed phenomena. The initial startup, the response of the biofilter to step changes in the pollutant loadings, responses to pollutant pulses, restarting after starvation, and the influence of step changes in gaseous phase oxygen partial pressure are presented and discussed.

Deshusses, M.A.; Hamer, G.; Dunn, I.J. [Swiss Federal Inst. of Tech., Zurich (Switzerland)

1996-03-05

6

[{sup 14}C]pyrene bound residue evaluation using MIBK fractionation method for creosote-contaminated soil  

SciTech Connect

The fate of [{sup 14}C]pyrene was evaluated in creosote-contaminated soil undergoing remediation in a prepared bed system at the Champion International Superfund site in Libby, MT. {sup 14}C-bound residue formation was evaluated using the methyl isobutyl ketone (MIBK) humic fractionation procedure, and it increased through 294 days of incubation in biologically active microcosms for humic acid, fulvic acid, bound humic acid, and mineral-associated organic carbon fractions. The relative affinity of the added pyrene and transformation products was highest for the humic acid fraction. Bound residue formation in PAH-contaminated soil was observed to be an important fate mechanism in the prepared bed system and may be an acceptable end point in the remediation of contaminated soil.

Nieman, J.K.C.; Sims, R.C.; Sims, J.L.; Sorensen, D.L.; McLean, J.E. [Utah State Univ., Logan, UT (United States); Rice, J.A. [South Dakota State Univ., Brookings, SD (United States). Dept. of Chemistry and Biochemistry

1999-03-01

7

Ketone potentiation of haloalkane?induced hepato? and nephrotoxicity. II. implication of monooxygenases  

Microsoft Academic Search

Previous results in Sprague?Dawley rats indicate that acetone (A), methyl ethyl ketone (MEK), and methyl isobutyl ketone (MiBK) pretreatment (3 d, po) at dosages of 6.8 and 13.6 mmol\\/kg potentiate CCl4 hepatotoxicity and CHCl3 nephrotoxicity, respectively. The potentiation potency profile observed was MiBK > A > MEK for liver and A > MEK ? MiBK for kidney toxicity (Raymond &

Pierre Raymond; Gabriel L. Plaa

1995-01-01

8

Biodegradation of volatile organic compounds from paint industries.  

PubMed

Methyl ethyl ketone (MEK) and methyl iso-butyl ketone (MIBK) constitute significant proportion of the total VOC emissions from manufacturing and application processes of surface coatings. Biodegradation of MEK and MIBK using an acclimatized mixed culture was evaluated, under aerobic condition. Biodegradation studies were carried out using MEK and MIBK as single substrates and in combination. Mixed-pollutant studies were conducted in MEK-dominated system, MIBK-dominated system, and MEK-MIBK equi-concentration systems to understand the concentration-dependent interaction of these compounds in a biosystem. Experimental data obtained from single-pollutant system was used to estimate the biokinetic parameters, viz. ?(max), K(s), K(i), and Y(T), for these compounds. Among the several bio-kinetic models tested, Monod inhibition model was best suited for predicting the biodegradation of these two VOCs. Four multiple-substrate models, viz. no-interaction, competitive, un-competitive, and non-competitive were used to study the nature of inhibition for different combinations of these compounds. The biodegradation of MEK and MIBK mixtures was found to be best described by competitive inhibition model. However, the predictions were not very good for systems where MEK concentration was higher than MIBK concentration. PMID:22573008

Datta, Aviraj; Philip, Ligy

2012-05-10

9

Solvents for Bulk Removal of Organics from Coal-Conversion Condensate Waters (Methyl Isobutyl Ketone, Diisopropyl Ether and Mixture of 25% W/W Trioctyl Phosphine Oxide in Diisobutyl Ketone).  

National Technical Information Service (NTIS)

In this work chemical analyses and experimental tests of extraction solvents are discussed for condensate waters from a coal gasification plant. The results of the study showed that methyl isobutyl ketone (MIBK) provides much higher distribution coefficie...

C. J. King D. H. Mohr

1983-01-01

10

40 CFR Appendix A to Part 439 - Tables  

Code of Federal Regulations, 2013 CFR

...formate Tetrahydrofuran 1 Ethers. Isopropyl ether Acetone 1 Ketones. 4-Methyl-2-pentanone (MIBK) Ammonia...Chlorobenzene Ammonia (aqueous) Diethyl amine Triethyl amine Acetone 1 4-methyl-2-pentanone n-Amyl acetate...

2013-07-01

11

Determination of Uranium in Urine by Fluorometry.  

National Technical Information Service (NTIS)

The report describes fluorometric determination of traces of uranium in the urine of mine workers and persons handling uranium. After preliminary treatment uranium is extracted by solvent extraction with TBP:MIBK mixtures. An aliquot of the extracted solu...

M. Afsar A. Aziz M. A. Mubarak

1978-01-01

12

Solvent extraction of phenols from water  

SciTech Connect

Methyl isobutyl ketone (MIBK) and diisopropyl ether (DIPE) were evaluated as solvents for extraction of phenols from water by measuring the equilibrium distribution coefficients (K/sub d/) as a function of pH for phenol, dihydroxybenzenes, and trihydroxybenzenes at 25/sup 0/C. MIBK gave much higher K/sub d/ values than DIPE, particularly for the polyhydric phenols, so that solvent-to-water mass flow ratios (S/W) exceeding 0.14 and 0.39 would be required at low pH for effective removal of di- and trihydric phenols, respectively, with MIBK, compared with S/W greater than or equal to 1.4 and 8, respectively, for DIPE. The effect of pH was described by a simple ionization model. In the phenol/water/MIBK system, K/sub d/ values increased with decreasing temperature (30 to 75/sup 0/C) at all concentrations, and at 30/sup 0/C, they were high enough for the effective extraction of phenol contained at up to 20% by wt in the organic phase. Vacuum steam stripping was the best choice for the removal of residual dissolved MIBK. Extraction with MIBK may thus be used to recover, rather than degrade, phenols contained in aqueous streams from refining, petrochemical, and coal conversion processes.

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

1980-01-01

13

Solvent extraction of phenols from water  

SciTech Connect

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.

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

1980-02-01

14

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

SciTech Connect

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.

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

1983-08-01

15

Mathematical modeling of emulsion liquid membrane pertraction of gold (III) from aqueous solutions  

Microsoft Academic Search

Modeling of emulsion liquid membrane pertraction of gold (III) ions from aqueous solutions using MIBK as carrier and LK-80 as emulsifier has been performed. Three models were considered: Advancing front model, diffusion controlled mass transfer inside and outside of globule model and finally, reaction and diffusion controlled mass transfer model. Results showed that the model considered as reaction and diffusion

Ali Kargari; Tahereh Kaghazchi; Mansoureh Soleimani

2006-01-01

16

Performance of PDMS and organofunctionalised PDMS membranes for the pervaporative recovery of organics from aqueous streams  

Microsoft Academic Search

Modified polysiloxane membranes containing different organofunctional side chains were produced and tested for the recovery of various organic contaminants from aqueous sterams, using the process of pervaporation. Four separate organic components, phenol, chloroform, pyridine and methylisobutylketone (MIBK), each representative of an industrially significant family of chemicals, were chosen for evaluation. In each case significant performance enhancements, over that achieved with

M. Bennett; B. J. Brisdon; R. England; R. W. Field

1997-01-01

17

Determination of gas phase adsorption isotherms—a simple constant volume method  

Microsoft Academic Search

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

Daekeun Kim; Zhangli Cai; George A. Sorial

2006-01-01

18

Continuous autorefrigerative dewaxing apparatus  

Microsoft Academic Search

A continuous autorefrigerant solvent dewaxing process is disclosed wherein a waxy oil is prediluted with a nonautorefrigerative solvent, such as ketone, preferably a mixture of mek\\/mibk, and then passed, at a temperature above its cloud point, to the top of a chilling zone, which is an autorefrigerant chilling zone operating on a continuous basis, and comprises a vertical, multi-staged tower,

Ryan

1982-01-01

19

Continuous autorefrigerative dewaxing process and apparatus  

Microsoft Academic Search

A continuous autorefrigerant solvent dewaxing process is disclosed wherein a waxy oil is prediluted with a nonautorefrigerative solvent, such as ketone, preferably a mixture of mek\\/mibk, and then passed, at a temperature above its cloud point, to the top of a chilling zone, which is an autorefrigerant chilling zone operating on a continuous basis, and comprises a vertical, multi-staged tower,

Ryan

1980-01-01

20

Development of an amine dehydrogenase for synthesis of chiral amines.  

PubMed

A leucine dehydrogenase has been successfully altered through several rounds of protein engineering to an enantioselective amine dehydrogenase. Instead of the wild-type ?-keto acid, the new amine dehydrogenase now accepts the analogous ketone, methyl isobutyl ketone (MIBK), which corresponds to exchange of the carboxy group by a methyl group to produce chiral (R)-1,3-dimethylbutylamine. PMID:22396126

Abrahamson, Michael J; Vázquez-Figueroa, Eduardo; Woodall, Nicholas B; Moore, Jeffrey C; Bommarius, Andreas S

2012-03-06

21

SML resist processing for high-aspect-ratio and high-sensitivity electron beam lithography  

NASA Astrophysics Data System (ADS)

A detailed process characterization of SML electron beam resist for high-aspect-ratio nanopatterning at high sensitivity is presented. SML contrast curves were generated for methyl isobutyl ketone (MIBK), MIBK/isopropyl alcohol (IPA) (1:3), IPA/water (7:3), n-amyl acetate, xylene, and xylene/methanol (3:1) developers. Using IPA/water developer, the sensitivity of SML was improved considerably and found to be comparable to benchmark polymethylmethacrylate (PMMA) resist without affecting the aspect ratio performance. Employing 30-keV exposures and ultrasonic IPA/water development, an aspect ratio of 9:1 in 50-nm half-pitch dense grating patterns was achieved representing a greater than two times improvement over PMMA. Through demonstration of 25-nm lift-off features, the pattern transfer performance of SML is also addressed.

Mohammad, Mohammad Ali; Dew, Steven K.; Stepanova, Maria

2013-03-01

22

SML resist processing for high-aspect-ratio and high-sensitivity electron beam lithography  

PubMed Central

A detailed process characterization of SML electron beam resist for high-aspect-ratio nanopatterning at high sensitivity is presented. SML contrast curves were generated for methyl isobutyl ketone (MIBK), MIBK/isopropyl alcohol (IPA) (1:3), IPA/water (7:3), n-amyl acetate, xylene, and xylene/methanol (3:1) developers. Using IPA/water developer, the sensitivity of SML was improved considerably and found to be comparable to benchmark polymethylmethacrylate (PMMA) resist without affecting the aspect ratio performance. Employing 30-keV exposures and ultrasonic IPA/water development, an aspect ratio of 9:1 in 50-nm half-pitch dense grating patterns was achieved representing a greater than two times improvement over PMMA. Through demonstration of 25-nm lift-off features, the pattern transfer performance of SML is also addressed.

2013-01-01

23

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

PubMed

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. PMID:23228457

Brudecki, Grzegorz; Cybulska, Iwona; Rosentrater, Kurt

2012-11-16

24

Experimental and modeling of selective separation of gold(III) ions from aqueous solutions by emulsion liquid membrane system  

Microsoft Academic Search

Selective separation of gold(III) ions from acidic aqueous solutions, using MIBK as carrier and LK-80 as emulsifier, has been investigated. The extraction results from model solution containing Au3+, Pd2+, Pt4+, Cu2+ and Fe3+, showed that only the Au3+ ions transported across the liquid membrane and nearly all of other ions remained in the external solution without change in their concentration.

Ali Kargari; Tahereh Kaghazchi; Baharak Mardangahi; Mansoureh Soleimani

2006-01-01

25

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

Microsoft Academic Search

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

I. A. Mendes; Z. R. Turel

1986-01-01

26

Effect of Changing VOC Influent Composition on the Microbial Community Structure of TBABs  

Microsoft Academic Search

Microbial communities in trickle bed air biofilters (TBABs) were evaluated under conditions of interchanging the feed volatile\\u000a organic compounds (VOCs) and VOC mixtures. Three independent TBABs (Biofilter “A,” “B,” and “C”) were run under interchanging\\u000a VOCs conditions with different initial VOCs. Two aromatic compounds (toluene and styrene) and two oxygenated compounds (methyl\\u000a ethyl ketone (MEK) and methyl isobutyl ketone (MIBK))

Zhangli Cai; George A. Sorial; Kai Zhang; Pascal Saikaly; Maher M. Zein; Daniel B. Oerther

2008-01-01

27

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

Microsoft Academic Search

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

Kunnath S. Subramanian

1988-01-01

28

Interfacing flow injection analysis (sequential injection analysis) and electro-thermal atomic absorption spectrometry determination of trace-levels of Cr(VI) via on-line pre-concentration by adsorption in a knotted reactor and by liquid–liquid extraction  

Microsoft Academic Search

Two time-based flow injection pre-concentration procedures are described for the analysis of ultra-trace-level concentrations of metal ions, as exemplified for the determination of Cr(VI). While the first approach exploits pre-concentration by on-line formation and extraction into MIBK of the non-polar complex formed of Cr(VI) ions with ammonium pyrrolidine dithiocarbamate (APDC), the second one is based on formation of the same

Steffen C. Nielsen; Elo H. Hansen

2000-01-01

29

A new approach for the production of 2,5-furandicarboxylic acid by in situ oxidation of 5-hydroxymethylfurfural starting from fructose  

Microsoft Academic Search

The production of 2,5-furandicarboxylic acid (FDCA) starting with fructose as substrate via acid-catalyzed formation and subsequent\\u000a oxidation of 5-hydroxymethylfurfural (HMF) was investigated. It was shown that an effective separation of the oxidation catalyst\\u000a from fructose in combination with extraction and derivatization of formed HMF in methyl isobutyl ketone (MIBK) leads to formation\\u000a of FDCA as final product. Two systems were

Martin Kröger; Ulf Prüße; Klaus-Dieter Vorlop

2000-01-01

30

Photocatalytic oxidation of ketones in the gas phase over TiO 2 thin films: a kinetic study on the influence of water vapor  

Microsoft Academic Search

Photocatalytic oxidation of two ketones having different hydrophilicity, acetone and methyl isobutyl ketone (MIBK), over TiO2 thin films supported on glass rings was studied under different relative humidity (RH) conditions. Adsorption isotherms of both ketones in the dark under different concentrations of water vapor were also measured and modeled considering a two-site Langmuir model. As expected, an increase in RH

Juan M Coronado; Michael E Zorn; Isabel Tejedor-Tejedor; Marc A Anderson

2003-01-01

31

Masking, chelation, and solvent extraction for the determination of sub-parts-per-million levels of trace elements in high iron and salt matrices  

Microsoft Academic Search

The ammonium pyrrolidine-N-carbodithioate (APCD or APDC) and a 4-methyl-2-pentanone (methyl isobutyl ketone or MIBK) system for the chelation and extraction of transition metals was investigated over the pH range of 0 < pH < 12. This system eliminated the interferences associated with high total dissolved solids. The masking effects of ammonium citrate and Tiron (4,5-dihydroxybenzene-1,3-disulfonic acid) were investigated for the

Mary Carol. Williams; Edward J. Cokal; Thomas M. Niemczyk

1986-01-01

32

DEVELOPMENT OF AN ARTIFICIAL NEURAL NETWORK MODEL FOR PREDICTING OIL CONTENT IN WAX IN AN OIL DEWAXING SYSTEM  

Microsoft Academic Search

The MIBK (m-i-b-ketone) dewaxing unit, located at the Landulpho Alves refinery, allows two different operating modes: the dewaxing and the oil removal. The former is comprised of an oil-wax separation process, which generates a wax stream with 2 - 5% oil. The latter involves the reprocessing of the wax stream to reduce its oil content. Both involve a two-stage filtration

C. Fontes; P. R. B. Guimarães; A. C. Gondim; S. B. Neves; L. Carvalho

33

SPE–GC\\/FTD determination of N-methyl-2-pyrrolidone and its metabolites in urine  

Microsoft Academic Search

An analytical method using a combination of solid-phase extraction (SPE) and gas chromatography with a flame thermionic detector (GC\\/FTD) was developed for determination of N-methyl-2-pyrrolidone (NMP), N-methylsuccinimide (MSI), and 2-hydroxy-N-methylsuccinimide (2-HMSI) in human urine. The SPE cartridge of poly(divinylbenzene\\/hydroxymethacrylate) used was directly loaded with urine sample, followed by elution with methyl isobutyl ketone (MIBK) and subsequent centrifugation, and the supernatant

Ryuichi Kubota; Yoko Endo; Akito Takeuchi; Yoshinori Inoue; Hiroko Ogata; Masanori Ogawa; Tomoo Nakagawa; Nobuhiko Onda; Ginji Endo

2007-01-01

34

Solvents for bulk removal of organics from coal-conversion condensate waters. [Methyl isobutyl ketone, diisopropyl ether and mixture of 25% w/w trioctyl phosphine oxide in diisobutyl ketone  

SciTech Connect

In this work chemical analyses and experimental tests of extraction solvents are discussed for condensate waters from a coal gasification plant. The results of the study showed that methyl isobutyl ketone (MIBK) provides much higher distribution coefficients than diisopropyl ether DIPE for phenol and dihydroxybenzenes. About 90% of the chemical oxygen demand (COD) from one condensate water sample had a sufficiently high K/sub D/ into MIBK that it could be removed by this solvent in a counter-current extraction process at an economically reasonable solvent-to-water ratio. TOPO (mixture of 25% w/w trioctyl phosphine oxide in diisobutyl ketone) in a suitable diluent has high equilibrium distribution coefficients for phenols and dihydroxybenzenes, and therefore has the potential to remove these compounds at lower solvent-to-water ratios. However, this solvent may be difficult to regenerate in a continuous condensate-water extraction process. Analytical techniques are discussed that provide higher recoveries for phenols and dihydroxybenzenes as compared to the standard MC/GC-MS technique. Hydantoins have been identified in four condensate water samples. About 20 to 30% of the COD remains unidentified in these four condensate water samples. Some of these unidentified compounds have very low values of K/sub D/ for extraction into MIBK. More information is required about these unidentified solutes before reliable solvent extraction processes can be designed. 6 tables.

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

1983-03-01

35

Screening method for determination of high levels of cadmium, lead, and copper in foods by polarized Zeeman atomic absorption spectrometry using discrete nebulization technique.  

PubMed

A screening method for determination of cadmium, lead, and copper in foods was developed. The sample (1-3 g) is digested with HNO3-H2SO4-HClO4 in a centrifuge tube attached to a straight glass tube that prevents loss of HNO3 by volatilization. After digestion, potassium iodide, H2SO4, and MIBK (4-methyl 2-pentanone) are added, and the metals are extracted with MIBK as metal iodides. The MIBK solution is injected and the metals are determined by flame polarized Zeeman atomic absorption spectrometry using a discrete nebulization technique. Recoveries of metals from fortified milk powder, unpolished rice, fish, beef, peanut butter, apple, and cabbage were satisfactory. The analytical results for NBS Oyster Tissue and NIES Pepperbush, Chlorella, and Mussel agreed with certified or reference values except lead in Pepperbush. The limits of quantitation for cadmium, lead, and copper were 0.01, 0.09, and 0.02 ppm, respectively. This method is simple and safe for routine analysis of high levels of cadmium, lead, and copper in foods. PMID:3417611

Saito, I; Oshima, H; Kawamura, N; Yamada, M

36

Dissolution of poly(p-hydroxystyrene): molecular weight effects  

NASA Astrophysics Data System (ADS)

In the present study, dissolution rates of PPHS films were measured in aqueous base solvents and in 4-methyl-2-pentanone (MIBK) using laser interferometry. Molecular weights from 6,000 to 100,000 were employed. The films (0.5 to 2 micrometers thick) were spun on silicon wafers from MIBK solutions and baked 1 hour at 160 degree(s)C. The most striking feature of dissolution behavior is the peculiar way in which rate varies with molecular weight. Below a molecular weight of about 20,000, the rate decreases with molecular weight as one might expect. Above 30,000, the rate in aqueous base is much higher and seems to be almost independent of molecular weight. The behavior in MIBK, while more conventional, shows some of the same features. Another feature found with PPHS that is not usual with other polymers is a decrease in dissolution rate with increased thickness. Conventional wisdom would predict that retained solvents (after baking) in thick films would accelerate dissolution compared to thin films. Moreover, the interferograms for thick films show no pronounced change in dissolution rate as the film dissolves. Baking conditions and the pH of the aqueous base developer also affect the dissolution behavior.

Long, Treva; Rodriguez, Ferdinand

1991-06-01

37

Electrical Conductivity Response toward Ketone Vapors of Poly(Para-Phenylene Vinylene)/Zeolite Y Composites  

NASA Astrophysics Data System (ADS)

Investigation of the effect of 3 different types of cation types in Zeolite Y; Zeolite Y(Si/Al=5.1, Na+), Zeolite Y(Si/Al=5.1, NH3+), Zeolite Y(Si/Al=5.1, H+) on the electrical conductivity sensitivity when exposed to the 3 different types of ketone vapors (Acetone, Methyl Ethyl Ketone(MEK) and Methyl Iso Buthyl Ketone(MIBK)), which are flammable and toxic components in order to improve the selectivity and sensitivity of dPPV/Zeolite Y and the interactions between the ketone molecules and the composites with respect to the electrical conductivity sensitivity are investigated though the infrared spectroscopy(FTTIR). All composites show definite positive responses towards the ketone vapors (Acetone, Methyl Ethyl Ketone (MEK), Methyl Iso-Buthyl Ketone (MIBK)). The electrical conductivity sensitivities of the composites increase linearly with increasing surface area of the Zeolite Y. The highest electrical conductivity sensitivity is obtained with the dPPV_/Zeolite Y (Si/Al = 5.1, NH4+), higher than those of dPPV_/Zeolite Y (Si/Al = 5.1, Na+) and dPPV_/Zeolite Y (Si/Al = 5.1, H+) when exposed to acetone. Amongst the Ketone vapors, acetone induces the highest electrical conductivity sensitivity, whereas MIBK induces the lowest electrical conductivity sensitivity.

Kamonsawas, Jirarat; Sirivat, Anuvat

2012-02-01

38

Effect of standard phase differences between gas and liquid and the resulting experimental bias in the analysis of gaseous volatile organic compounds.  

PubMed

Liquid- or gas-phase standards can be used for the analysis of VOCs in air. Once the accuracy is secured in the standard preparation stage, the use of gas-phase standard should be more reliable with the least matrix effect. However, it is not difficult to find that the liquid-phase standard is used more preferably in many laboratories for several reasons (e.g., low expense, easy handling, etc.). As such, one needs to accurately evaluate any possible bias stemming from the use of different standard phases. To this end, standards for 8 VOCs consisting of 4 aromatic compounds (benzene (B), toluene (T), styrene (S) and p-xylene (p-X)) and 4 others (methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), butyl acetate (BuAc), and isobutyl alcohol (i-BuAl)) were prepared in both liquid and gas phases. Each standard was analyzed by the initial collection on the adsorption tube and by the combined application of thermal-desorption-gas chromatography-mass spectrometry (TD/GC/MS). The results indicated that experimental bias between the two phases, if expressed in terms of percent difference (PD), was very low in many target VOCs (B (1.09%), T (2.41%), p-X (3.64%), MEK (6.76%), and MIBK (0.17%)), while it was not in some targets (e.g., >10%: e.g., S, i-BuAl, and BuAc). In an ancillary experiment, biases were evaluated further by (1) calibrating gaseous samples against liquid phase standard and via (2) comparison between two different types of gas phase standards. In conclusion, treatment of different standards (e.g., between the same or different phases) will inevitably induce biases in most VOCs, although certain volatiles (e.g., benzene, MIBK, etc.) are virtually unaffected by such variables in a practical sense. PMID:22244142

Kim, Yong-Hyun; Kim, Ki-Hyun

2011-11-28

39

Liquid-liquid extraction of palladium and gold by the sulphide podand 1,12-di-2-thienyl-2,5,8,11-tetrathiadodecane.  

PubMed

The extraction properties of the sulphide podand 1,12-di-2-thienyl-2,5,8,11-tetrathiadodecane (TTD), an open-chain neutral polythioether with six sulphur donor atoms in 1,2-dichloroethane, chloroform and MIBK for Pd and Au in hydrochloric, nitric and perchloric acid media have been examined. The kinetic aspects of the extraction of palladium(II) from hydrochloric acid by TTD and dioctyl sulphide (DOS) were compared. The rate of Pd extraction with TTD is considerably higher than that with DOS, especially with chloroform. Combined use of a reducing agent and TTD enhances the extraction of gold(III) into 1,2-dichloroethane. PMID:18965057

Lachowicz, E; Czapiuk, M

1990-10-01

40

Selective extraction, separation and speciation of iron in different samples using 4-acetyl-5-methyl-1-phenyl-1 H-pyrazole-3-carboxylic acid  

Microsoft Academic Search

A method for speciation, preconcentration and separation of Fe(II) and Fe(III) in different matrices was developed using solvent extraction and flame atomic absorption spectrometry. 4-Acetyl-5-methyl-1-phenyl-1H-pyrazole-3-carboxylic acid (AMPC) was used as a new complexing reagent for Fe(III). The Fe(III)–AMPC complex was extracted into methyl isobutyl ketone (MIBK) phase in the pH range 1.0–2.5, and Fe(II) ion remained in aqueous phase at

?erife Saçmac?; ?enol Kartal

2008-01-01

41

Identification and separation of the organic compounds in coal-gasification condensate waters  

SciTech Connect

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 distribution coefficients (K/sub D/) 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, the 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. Solvents containing trioctyl phosphine oxide (TOPO) have high K/sub D/ values for phenol and dihydroxy benzenes. A fraction of the compounds which are not removed by MIBK may be Lewis acids, because some of them were extracted by the strong Lewis bases, TBP and TOPO.

Mohr, D.H. Jr.

1983-01-01

42

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

PubMed

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

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

2013-02-08

43

Transient behavior of biofilters: Start-up, carbon balances, and interactions between pollutants  

SciTech Connect

The work describes the aerobic biodegradation of volatile organic compound (VOC) mixtures from effluent air streams in laboratory-scale compost based biofilters. A rapid start-up of the system (3--5 d) was observed and 82% of the carbon in the influent pollutant (methyl ethyl ketone) was recovered as carbon dioxide in the exhaust air after this period. Biofilter performance and carbon dioxide production were also investigated during and after 0.5--1-h step inputs of 2--10 g m{sup {minus}3} of hexane, acetone, 1-propanol, and/or methyl isobutyl ketone (MIBK) during steady methyl ethyl ketone (MEK) treatment. Carbon dioxide patterns suggest that pulsed pollutants were first sorbed onto the packing material and subsequently degraded within 2--5 h. Hexane was not sorbed, and thus not degraded to a significant extent. Little effect was observed of the step inputs on the overall MEK removal process, mainly because the reactors were operated well below MEK breakthrough loading. However, the analysis of MEK profiles within the biofilter bed showed that significant inhibition did indeed occur. An even more important inhibition was observed between 1-propanol, MIBK, and acetone, when such a mixture was injected into the reactor. Practical design of biofilters should consider the possibility of reduced performances due to the presence of multiple VOCs in the waste air stream.

Deshusses, M.A. [Univ. of California, Riverside, CA (United States). Coll. of Engineering

1997-06-01

44

Evaluation of the coadsorption effect of water vapor and organic vapors on charcoal sampling tubes  

SciTech Connect

The purpose of this study was to investigate some of the factors influencing the potential interference caused by water vapor when collecting organic vapors on 100 mg charcoal tubes. Atmospheres containing known concentrations of organic vapors at predetermined relative humidities were produced in a flow dilution system. Atmospheres of the solvents toluene, methyl chloroform, methyl isobutyl ketone (MIBK), cyclohexane, acetone, isopropanol, acetonitrile, ethyl acetate, 1-butanol, and perchloroethylene, were screened at 0 and 90% relative humidity to select solvents which exhibited varying degrees of effect of humidity for more detailed study. The solvents toluene, methyl chloroform, MIBK and cyclohexane were studied at concentrations ranging from 50 to 1400 ppm or 1/4 to 8 times the OSHA 8-hour Permissible Exposure Limit (PEL) concentration which enabled comparison of the different solvents at similar molar concentrations. Water vapor levels of approximately 0, 50, 70, 80, and 90% relative humidity at 25/sup 0/C were tested for each concentration of each solvent. The recoveries obtained for the recommended air volume samples taken at all combinations of solvent concentration and humidity ranged from 0.54 to 1.54.

Wells, W.H. Jr.

1986-01-01

45

A bio-catalytic approach to aliphatic ketones.  

PubMed

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

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

2012-03-13

46

Determination of tellurium in geochemical materials by flameless atomic-absorption spectroscopy.  

PubMed

A method is described for the determination of tellurium at nanogram levels in rocks and in other complex materials by the use of flameless atomic-absorption spectroscopy. A very selective organic extraction procedure is applied to avoid matrix interference effects during extraction of Te and the atomization stage in the graphite furnace. Prior separation of iron and other interfering elements is achieved by a combined cupferron-ethyl acetate extraction. Tellerium is extracted from 6M hydrochloric acid with MIBK and stripped into aqueous medium. Pipetting of the aqueous extract into the graphite furnace gives fairly good instrumental reproducibility (2-3% error). Detection limits of about 10 ppM Te for a 0.5-g sample have been achieved with the medium-performance apparatus used. Results for Te in some geochemical reference materials are reported. Indications are given for the determination of Sb and Mo in the same solutions. PMID:18962397

Sighinolfi, G P; Santos, A M; Martinelli, G

1979-02-01

47

Quinoline-2-aldehyde thiosemicarbazone (QAT) as spectrophotometric reagent for palladium and nickel.  

PubMed

A procedure is described for the extractive spectrophotometric determination of nickel and palladium with quinoline-2-aldehyde thiosemicarbazone. At pH 7.5 nickel forms a 1:2 complex which is soluble in chloroform and has an absorption maximum at 460 nm. Palladium forms a 1:2 complex with maximum absorbance at 510 nm which can be extracted into MIBK from 1M HCl. Both complexes are stable and conform to Beer's law. The molar absorptivities for nickel and palladium are 1.58 x 10(4) and 2.6 x 10(3) 1.mole(-1). cm(-1) respectively. The proposed method is suitable for detection and determination of nickel and palladium in the presence of associated metal ions. The results of the analysis of synthetic mixtures and standard samples are reported. PMID:18962496

Khasnis, D V; Shinde, V M

1979-07-01

48

Health-hazard evaluation report HETA 85-256-1716, AMF Head Division, Boulder, Colorado  

SciTech Connect

A request was made by a representative of AMF Head Division of Boulder, Colorado, for an evaluation to be made of possible employee exposure to methylene-bisphenyl-isocyanate (BDI), methylene-chloride, 1,1,1-trichloroethane, naphtha, sodium-hydroxide, methyl-ethyl-ketone (MEK), and methyl-isobutyl-ketone (MIBK). The author concluded that noise exposure was excessive for employees working in racket stripping, refill, and fill/sand refinishing areas. No dangerous exposure levels were found for the chemicals under study with the exception of methylene chloride, which may be a health hazard for employees directly involved with its use due to its carcinogenicity. It is recommended that employees exposed to 1,1,1-trichloroethane and sodium hydroxide wear proper clothing to prevent direct contact or splashing onto the skin.

Pryor, P.

1986-07-01

49

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

SciTech Connect

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.

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

1994-03-01

50

Fourth derivative spectrophotometric determination of fungicide thiram (tetramethyldithiocarbamate) using sodium molybdate and its application.  

PubMed

A procedure has been developed for the direct fourth derivative spectrophotometric determination of tetramethyldithiocarbamate by converting it into its molybdenum complex, which is then extracted in to methyl isobutyl ketone (MIBK). Beer's law is obeyed over the concentration range 24mugmL(-1) in the final solution. The analytical sensitivity is calculated to be 0.004(d(4)A/dlambda(4)) mug(-1)mL(-1) from the slope of the calibration curve. The detection limit is 0.3mugmL(-1) for thiram (signal to noise ratio = 2). Various parameters, such as effect of acid concentration, interference of a large number of ions in the determination of thiram have been studied in detail. The method is sensitive, highly selective and can be used for the determination of thiram in a commercial sample, in mixtures with various dithiocarbamates (zineb, maneb, etc.) and from wheat grains. PMID:18969809

Sharma, Vaneet Kumar; Aulakh, J S; Malik, A K

2005-01-30

51

Enhanced production of 6-aminopenicillanic acid in aqueous methyl isobutyl ketone system with immobilized penicillin G acylase.  

PubMed

Enzymatic hydrolysis of penicillin G for production of 6-amino-penicillanic-acid (6-APA) was achieved by using penicillin G acylase as catalyst in an aqueous-methylisobutyl ketone (MIBK) system. The optimization was carried out and it was found that the best conversion was improved 10% more than the aqueous system, which was obtained at the conditions: initial pH 8.0, 5.0% (W/V) substrate (penicillin G), and temperature at 35 degrees C, and the ratio of aqueous and organic phase was 3:1. The stability of the biocatalyst was studied at the operational conditions. After 5 cycles of semi-batch reactions, the residual activity of penicillin G acylase was 69.2% of the initial activity. There was no apparent loss of the yield of product. This process has a potential application in the industrial scale production of 6-APA because it simplifies the process effectively. PMID:20024793

Fang, Shu-Guang; Qiang, Tan; Liu, Rui-Jiang; Xu, Xi-Ming; Zhang, Ye-Wang

2010-01-01

52

Spectrophotometric and AAS determination of trace amounts of cobalt after preconcentration by using alpha-benzilmonoxime-microcrystalline naphthalene.  

PubMed

The formed cobalt-a-benzilmonoxime complex was adsorbed onto microcrystalline naphthalene. Then it was determined by zero and first derivative spectrophotometry and by atomic absorption spectrophotometry (AAS) after dissolving into chloroform and methylisobutylketone (MIBK), respectively. Under optimum conditions, cobalt in the range of 1.0 - 20.0, 0.4 - 30.0 and 2.5 - 50.0 microg could be determined by spectrophotometry, first derivative spectrophotometry and AAS method, respectively. By the method, a preconcentration factor equal to approximately 30 for cobalt was obtained. The effect of diverse ions on the determination of 5.0 microg cobalt was also studied. The method was successfully applied to some pharmaceuticals and synthetic alloy samples. PMID:15352516

Eskandari, Habibollah; Karkaragh, Gholam Hassan Imanzadeh; Saghseloo, Ali Ghanbari; Dehaghi, Ghadamali Bagherian

2004-08-01

53

Solvent-dependent conformation of amylose tris(phenylcarbamate) as deduced from scattering and viscosity data.  

PubMed

The z-average mean-square radius of gyration S(2)(z), the particle scattering function P(k), the second virial coefficient, and the intrinsic viscosity [eta] have been determined for amylose tris(phenylcarbamate) (ATPC) in methyl acetate (MEA) at 25 degrees C, in ethyl acetate (EA) at 33 degrees C, and in 4-methyl-2-pentanone (MIBK) at 25 degrees C by light and small-angle X-ray scattering and viscometry as functions of the weight-average molecular weight in a range from 2 x 10(4) to 3 x 10(6). The first two solvents attain the theta state, whereas the last one is a good solvent for the amylose derivative. Analysis of the S(2)(z), P(k), and [eta] data based on the wormlike chain yields h (the contour length or helix pitch per repeating unit) = 0.37 +/- 0.02 and lambda(-1) (the Kuhn segment length) = 15 +/- 2 nm in MEA, h = 0.39 +/- 0.02 and lambda(-1) = 17 +/- 2 nm in EA, and h = 0.42 +/- 0.02 nm and lambda(-1) = 24 +/- 2 nm in MIBK. These h values, comparable with the helix pitches (0.37-0.40 nm) per residue of amylose triesters in the crystalline state, are somewhat larger than the previously determined h of 0.33 +/- 0.02 nm for ATPC in 1,4-dioxane and 2-ethoxyethanol, in which intramolecular hydrogen bonds are formed between the C==O and NH groups of the neighbor repeating units. The slightly extended helices of ATPC in the ketone and ester solvents are most likely due to the replacement of those hydrogen bonds by intermolecular hydrogen bonds between the NH groups of the polymer and the carbonyl groups of the solvent. PMID:19402142

Fujii, Taichi; Terao, Ken; Tsuda, Maiko; Kitamura, Shinichi; Norisuye, Takashi

2009-09-01

54

Determination of organic contaminants in aqueous samples by near-infrared spectroscopy  

SciTech Connect

The feasibility of determining low levels of organic solvents in water by near-infrared (near-IR) spectroscopy is investigated. Mixture samples of tributyl phosphate (TBP) and methyl iso-butyl ketone (MIBK) are determined in aqueous solutions over the concentration range of 1-160 ppm. Through the use of C-H combination bands in the region of 5000-4000 cm-1, sufficient selectivity is obtained to determine each compound in the presence of the other. Separate multivariate calibration models are computed for each compound by use of a combination of bandpass Fourier digital filtering and partial least-squares (PLS) regression with both analysis of absorbance and single-beam spectra. A genetic algorithm is used to implement a joint optimization of the parameters governing the filtering and PLS calculations. Through the use of this procedure, a calibration model based on absorbance spectra is computed for MIBK with a standard error of prediction (SEP) of 3.82 ppm over the 1-160 ppm range. This five-term model utilizes the spectral range of 4495-4335 cm-1. A similar nine-term model based on absorbance spectra is computed for TBP over the 4620-4320 cm-1 range. For the range of 1-100 ppm, an SEP of 4.84 ppm is achieved. The results obtained from the analysis of single-beam spectra are comparable with those obtained in the analysis of absorbance data. Calibration models computed with samples prepared in natural water are also found to have a similar level of performance. These results establish the feasibility of using near-IR spectroscopy to screen water samples for solvent contamination. (c) 2000 Society for Applied Spectroscopy.

Ding, Qing [Center for Intelligent Chemical Instrumentation, Department of Chemistry and Biochemistry, Clippinger Laboratories, Ohio University, Athens, Ohio 45701 (United States); Boyd, Brian L. [Center for Intelligent Chemical Instrumentation, Department of Chemistry and Biochemistry, Clippinger Laboratories, Ohio University, Athens, Ohio 45701 (United States); Small, Gary W. [Center for Intelligent Chemical Instrumentation, Department of Chemistry and Biochemistry, Clippinger Laboratories, Ohio University, Athens, Ohio 45701 (United States)

2000-07-01

55

The determination of specific forms of aluminum in natural water  

USGS Publications Warehouse

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.

Barnes, R. B.

1975-01-01

56

Effect of sequential removal of organic matter on the surface morphology of humin  

SciTech Connect

Natural organic matter in soils interacts with surfaces of inorganic materials, primarily aluminosilicates or clay minerals, to form a strongly associated organo-mineral composite known as humin. Because of humin`s insolubility, it is recognized as the primary sorbent of many anthropogenic organic compounds (AOCs) introduced into soil systems. This recognition has significant implications for understanding the fate and transport of AOCs, the effective remediation of contaminated sites, and the formulation and application of various agrochemicals. Humin was isolated from four soil samples. Surface area, surface charge, porosity measurements, and fractal analysis of small-angle X-ray scattering data were used to characterize changes in the surface properties resulting from selective removal of the various components of organic matter from humin. Organic matter was removed selectively from humin by Soxhlet extraction, disaggregation with the methylisobutylketone (MIBK) method, and bromine oxidation. The surface fractal dimensions decreased while surface area increased, and surface pore size decreased upon removal of organic matter. These results suggest that the mineral components of humin have smooth surfaces over length scales of {approximately}1 to 15 run, and that it is the organic matter coatings that are responsible for their surface roughness. The surfaces of all the components of humin were found to be dominated by micro and mesopores that could be responsible for humin`s high sorptive uptake of organic chemicals.

Malekani, K.; Rice, J.A. [South Dakota State Univ., Brookings, SD (United States); Lin, Jar-Shyong [Oak Ridge National Lab., TN (United States)

1997-05-01

57

Use of. beta. -diketones for the isolation and separation of elements in carbonate media  

SciTech Connect

The extraction of uranium, thorium, plutonium, americium, curium, berkelium, californium, europium, and cerium from solutions of K/sub 2/CO/sub 3/ and KHCO/sub 3/ using TTA and PMBP in MIBK was studied, and the composition of the extractable compounds was established. It was shown that under definite conditions ..beta..-diketones extract many elements sufficiently completely within a broad range of carbonate ion concentrations; moreover, the extraction of the actinides decreases in the series Me/sup (III)/ > Me/sup (IV)/ > Me/sup (VI)/, while that of the trivalent transplutonium elements decreases in the sequence Am > Cm > Cf > Bk. Since increasing the carbonate ion concentration has less of an influence on the extraction of americium and curium than on the extraction of uranium, plutonium, and others, this predetermines the possibility of using the system studied not only for the extraction of the actinides but also for the purification of trivalent americium and curium from a number of elements. The separation factors of Am/sup (III)/ and U/sup (VI)/, Am/sup (III)/ and Pu/sup (IV)/, Am/sup (III)/ and Cs/sup (I)/ are equal to 2 x 10/sup 4/, 1 x 10/sup 1/, and 1 x 10/sup -5/, respectively.

Karalova, Z.K.; Devirts, E.A.; Myasoedov, B.F.

1987-09-01

58

In situ atom trapping of Bi on W-coated slotted quartz tube flame atomic absorption spectrometry and interference studies  

NASA Astrophysics Data System (ADS)

Analytical performances of metal coated slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS) and slotted quartz tube in situ atom trapping flame atomic absorption spectrometry (SQT-AT-FAAS) systems were evaluated for determination of Bi. Non-volatile elements such as Mo, Zr, W and Ta were tried as coating materials. It was observed that W-coated SQT gave the best sensitivity for the determination of Bi for SQT-FAAS and SQT-AT-FAAS. The parameters for W-coated SQT-FAAS and W-coated SQT-AT-FAAS were optimized. Sensitivity of FAAS for Bi was improved as 4.0 fold by W-coated SQT-FAAS while 613 fold enhancement in sensitivity was achieved by W-coated SQT-AT-FAAS using 5.0 min trapping with respect to conventional FAAS. MIBK was selected as organic solvent for the re-atomization of Bi from the trapping surface. Limit of detection values for W-coated SQT-FAAS and W-coated SQT-AT-FAAS was obtained as 0.14 ?g mL- 1 and 0.51 ng mL- 1, respectively. Linear calibration plot was obtained in the range of 2.5-25.0 ng mL- 1 for W-coated SQT-AT-FAAS. Accuracy of the W-coated SQT-AT-FAAS system was checked by analyzing a standard reference material, NIST 1643e.

K?l?nç, Ersin; Bak?rdere, Sezgin; Ayd?n, F?rat; Ataman, O. Yavuz

2013-11-01

59

Synthesis of ultrapure ZBLAN glass for laser refrigeration  

NASA Astrophysics Data System (ADS)

The fluorozirconate glass ZBLAN:1%Yb3+ was synthesized, for the first time, from fluoride precursors that were individually purified by solvent extraction and hydrofluoric (HF) gas treatment. The synthesis used aqueous solutions of high-purity commercial precursors that were subjected to ultra-filtration followed by solvent extraction using ammonium pyrrolidine dithiocarbamate (APDC) and methyl-isobutyl-ketone (MIBK). The purified metal fluorides were precipitated and treated in hot HF gas to remove water, hydroxyl (OH-), and oxide impurities. ZBLAN:1%Yb3+ was fabricated from these precursors by melting under inert atmosphere, yielding glasses with excellent mechanical properties and having a clear, bubble-free, and crystallite-free matrix. The effect of adding 0.5 mol% of In3+ as an oxidizer to suppress the reduction of Zr4+ and the accompanying formation of black precipitates was studied. We found evidence for an oxidizer concentration threshold of ~0.8 mol%. Glasses made from purified fluorides formed black precipitates even with the addition of 0.5 mol% In3+, while glasses made from commercial fluorides did not. In the latter, additional oxidizers were likely present in the form of transition-metal impurities. An In3+ oxidizer concentration of >0.8 mol% is expected to eliminate the black precipitates in purified glasses and to yield ZBLAN:Yb3+ glass for efficient laser cooling.

Hehlen, Markus P.; Epstein, Richard I.; Patterson, Wendy M.

2008-03-01

60

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

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.

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

1984-01-01

61

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

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

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

2002-08-23

62

Extraction procedure may not be feasible for cadmium analysis of tissues, such as horse kidney cortex, having a very high cadmium content  

SciTech Connect

In the light of the discrepancy between data on cadmium in horse kidney in the U.S. and what has been reported in Europe the present authors have tested the analytical procedure used by Penumarthy et al. (1980). Cadmium in reference pig kidney and horse kidney cortex was determined by flame atomic absorption spectrophotometry after wet digestion, dissolving of the residue in water, complexing with APDC and extraction into MIBK. The ratio between the measured amount (minus blank) and the calculated amount of cadmium in the samples was 86% for blank with addition of 0.5 ..mu..g cadmium and 91% for low-level pig kidney cortex with or without the addition of 0.5 ..mu..g cadmium. The ratio was unacceptably low for horse kidney cortex having a concentration of greater than or equal to 117 ..mu..g/g dry wt. Concentrations of this magnitude are also found in human kidney and in human and horse liver. Data of Penumarthy et al. (1980) are also unusual in that the average cadmium concentration was 3.4 ..mu..g/g wet wt in horse liver and 2.5 ..mu..g/g in horse kidney. As a rule, cadmium concentration in kidney exceeds that in liver by a factor of 2-15. The capacity of the extraction procedure appears to be insufficient at high and intermediate cadmium levels. 1 table (JMT)

Elinder, C.G. (The Karenlinska Inst., Stockholm, Sweden); Lind, B.; Piscator, M.; Sundstedt, K.; Akerberg, S.

1981-12-01

63

A new ZEP520/P(MMA-MAA)/ZEP520 trilayer process for T-shaped gate using synchrotron-based proximity x-ray lithography  

NASA Astrophysics Data System (ADS)

T-shaped gate formation is a important process step in the fabrication of high frequency monolithic microwave integrated circuits (MMIC), many different lithography process have been used for this purpose, such as bi-layer or tri-layer using e-beam lithography, hybrid UV-e-beam lithography. Proximity x-ray lithography (PXL) has shown many advantages in the MMIC manufacturing, such as high resolution, large process windows, low cost and high throughout, and so on. In this article, a new ZEP520/P(MMA-MAA)/ZEP520 tri-layer process using synchrotron-based PXL is proposed for the T-shaped gate formation, without any additional intermediate layer, the resists intermixing problem has been solved successfully, a dark-field isolated trench x-ray mask was used for this purpose. A three stage development process using xylene for the head, MIBK:IPA=1:3 for the middle and xylene for the foot was also used. Initial work has shown this process to be robust.

Xie, Changqing; Chen, Dapeng; Niu, Jiebing; Liu, Ming; Ye, Tianchun; Yi, Futing; Peng, Liangqiang

2005-01-01

64

Predicting Optimal Resolving Power for Ambient Pressure Ion Mobility Spectrometry (IMS)  

PubMed Central

Although diffusion theory predicts that IMS resolving power increases with the square root of the voltage applied across the drift tube, in practice there exists an optimum voltage above which resolving power decreases. This optimum voltage was determined to be both compound and initial ion pulse width-dependent. A “conditional” resolving power equation is introduced that can be used to quickly approximate realistic resolving powers for specific instrumental operating parameters and compounds. Using four common environmental contaminants [trichloroethylene (TCE), tetrachloroethylene (PCE), methyl tert-butyl ether (MTBE) and methyl iso-butyl ketone (MIBK)], diffusion-limited (theoretical), Rd, conditional, Rc, and actual (or measured), Rm, IMS resolving powers were determined and compared for a small IMS instrument designed for subsurface measurements. Detection limits determined at the optimal resolving power for the environmental contaminants ranged from 18 parts per trillion volume-to-volume (pptv) to 80 parts per billion volume-to-volume (ppbv). The maximal measured resolving power for our small, ambient-pressure stand-alone IMS ranged from 42 to 54, yielding an IMS resolving power efficiency, defined as Rm/Rc × 100%, of 56 to 74% of the maximal conditional resolving power possible.

Kanu, Abu B.; Gribb, Molly M.; Hill, Herbert H

2010-01-01

65

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

USGS Publications Warehouse

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.

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

1982-01-01

66

An investigation into the short term and medium term health impacts of personal incapacitant sprays. A follow up of patients reported to the National Poisons Information Service (London)  

PubMed Central

Objectives: The aim of this study is to describe the pattern of ill health after personal incapacitant spray (PIS) exposures reported to the National Poisons Information Service—London (NPIS-L) and the Chemical Incident Response Service and to evaluate the relation between sub-categories of PIS exposure and adverse health effects. Methods: Case series study of patients reported to the NPIS-L, by attending medical personnel during the period 16 January to 31 September 1998. Data collected by questionnaire sent to these medical personnel. Results: Several "adverse" symptoms, particularly dermatitis and blisters were reported for cases exposed to police PIS. These cases were more frequent than in those people exposed to non-police PIS. Adverse effects occurring more than six hours after exposure were also observed, which is in conflict with the recorded immediate, short lived, and self limiting symptoms that PIS are designed to cause. Most patients with persisting symptoms required further treatment. Conclusions: These findings suggest that the formulation of CS (o-chlorobenzylidine malononitrile) with MiBK (methyl iso-butyl ketone) used by the police is more harmful that has been previously assumed. If confirmed then the continued use of this formulation should be reviewed because of longer duration of adverse effects. Less concentrated formulations may reduce the severity or persistence of the adverse effects.

Euripidou, E; MacLehose, R; Fletcher, A

2004-01-01

67

Determination of dissolved aluminum in water samples  

USGS Publications Warehouse

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)

Afifi, A. A.

1983-01-01

68

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

SciTech Connect

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.

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

1982-01-01

69

SPE-GC/FTD determination of N-methyl-2-pyrrolidone and its metabolites in urine.  

PubMed

An analytical method using a combination of solid-phase extraction (SPE) and gas chromatography with a flame thermionic detector (GC/FTD) was developed for determination of N-methyl-2-pyrrolidone (NMP), N-methylsuccinimide (MSI), and 2-hydroxy-N-methylsuccinimide (2-HMSI) in human urine. The SPE cartridge of poly(divinylbenzene/hydroxymethacrylate) used was directly loaded with urine sample, followed by elution with methyl isobutyl ketone (MIBK) and subsequent centrifugation, and the supernatant was injected into the capillary GC using a DB1701. This method allowed efficient separation of NMP, MSI, and 2-HMSI, which were nearly free of interference by other GC peaks arising from urine. Recoveries of NMP, MSI, and 2-HMSI from the SPE cartridge were about 98, 101, and 67%, respectively, with limits of detection of 0.04, 0.02, and 0.06 mg/L, respectively, which met the regulatory requirements. The present method was used for assay in biological monitoring of workers exposed to NMP in their occupational environment. PMID:17485256

Kubota, Ryuichi; Endo, Yoko; Takeuchi, Akito; Inoue, Yoshinori; Ogata, Hiroko; Ogawa, Masanori; Nakagawa, Tomoo; Onda, Nobuhiko; Endo, Ginji

2007-04-25

70

Catalytic destruction of hazardous organics in aqueous solutions  

SciTech Connect

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).

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

1988-04-01

71

Americium and europium extraction from carbonate solutions by 1-phenyl-3-methyl-4-benzoylpyrazolone -5  

SciTech Connect

Trivalent TPEs and REEs are extractable from carbonate solutions by 1-pheny-3-methyl-4-benzoylpyrazolone-5 (PMBP). The effect of concentration of KHCO/sub 3/ and K/sub 2/CO/sub 3/, extractant, metal, and other factors on the extent of extraction of the elements has been clarified. The kinetics of extraction of the elements from carbonate solutions has been studied. It has been shown that in the KHCO/sub 3/ concentration range 0.2-2.0 M americium and europium are extracted by PMBP solutions in different diluents with distribution coefficients lying within n x 10/sup 2/-n x 10/sup 3/. From K/sub 2/CO/sub 3/ solutions the elements are extracted better by PMBP solutions in methyl isobutyl ketone (MIBK). It has been shown that metal concentration in the range 1x10/sup -5/. 5x10/sup -3/ g-ion x liter/sup -1/ does not affect extraction (log E = 3). Extracts based on PMBP with a metal content higher than 5x10/sup -3/g-ion x liter/sup -1/ were obtained by absolute concentrating method and were used for the study of /sup 13/C NMR spectra. The composition of thecompounds extracted by PMBP from carbonate solutions was determined by /sup 13/C NMR spectroscopy and extraction. The conditions of europium and americium reextraction from extracts based on PMBP by complexones, their mixtures with alkalis and other substances were studied. The scopes for using the system PMBP-carbonate solutions to separate and concentrate TPEs and REEs has been examined.

Karalova, Z.K.; Deviris E.A.; Fedorov, L.A.; Myasoedov, B.F.; Rukov, M.S.

1986-09-01

72

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

PubMed

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

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

2011-11-05