Showing papers on "Methyl isobutyl ketone published in 1991"

Flame Atomic Absorption Spectrometric Determination of Cadmium, Cobalt, and Nickel in Biological Samples Using a Flow Injection System with On-Line Preconcentration by Co-precipitation without Filtration

Abstract: Cadmium, cobalt, and nickel at ng/g to μg/g levels in plant and animal tissue reference materials and at μg/L levels in blood and urine were determined by flame atomic absorption spectrometry. The analyte elements were preconcentrated and separated from the bulk of the matrix by on-line co-precipitation with the hexamethylene ammonium hexamethylene dithiocarbamate iron(II) chelate complex in a flow injection system. The precipitate was collected in a knotted reactor made from 150-cm-long, 0.5-mm-i.d. Microline tubing without using a filter. The precipitate was dissolved in methyl isobutyl ketone and introduced directly into the nebulizer-burner system of an atomic absorption spectrometer. Ascorbic acid in an HC1/KC1 buffer was added on-line in order to reduce iron(III) to iron(II) because of its much better efficiency as a collector for trace elements. Reagent concentrations were optimized so that at least 200 mg/L of iron and 15 mg/L of copper could be tolerated in the sample solution without causing significant interferences. The portion of the analyte retained in the collector was about 70% for cadmium and 50% for cobalt and nickel. Enrichment factors of 24, 19, and 20 were obtained for cadmium, cobalt, and nickel, respectively, with the use of a 40-s co-precipitation time, resulting in enhancement factors, including the effect of the organic solvent, of 52, 43, and 52, respectively. The detection limits (3σ) for cadmium, cobalt and nickel were 0.15, 1.3, and 1.5 μg/L, respectively, and the precision was 1.5% RSD for 10 μg/L, Cd, 2.7% RSD for 50 μg/L Co, and 1.8% RSD for 50 μg/L Ni. The analytical results obtained for a number of standard reference materials and control samples were in good agreement with the certified or recommended values.

Determination of gadolinium in biological materials using graphite furnace atomic absorption spectrometry with a tantalum boat after solvent extraction.

Abstract: A method was developed for the determination of gadolinium (Gd) in biological material using graphite furnace atomic absorption spectrometry (GFAAS). The element is first extracted into methyl isobutyl ketone and then reextracted into hydrochloric acid. Factors influencing the recovery of extraction such as pH, choice of chelating agents, and hydrochloric acid concentration have been investigated. The element is determined under STPF (stabilized temperature platform furnace) conditions with atomization from a tantalum boat. Under optimized furnace conditions, the use of the tantalum boat improved sensitivity substantially compared to the use of pyrolytically coated graphite tubes. Around 150 measurements could be performed with 1 boat. Memory effects, being a common problem in the GFAAS determination of lanthanoids, were no longer observed after insertion of the boat. The characteristic mass and detection limit (2SD; SD = standard deviation) of the Gd determination are 1000 and 2060 pg, respectively. The precision evaluated as the relative standard deviation (RSD) of six analyses was below 10% for tissue Gd concentrations ranging from 0.92 to 72.0 micrograms g-1. The recovery of added analyte ranged between 92.0% and 99.3%. The method was found to be suitable for studying the pharmacokinetics and biodistribution of Gd in rats.

Saturated and Unsaturated Ketones Manufactured by Heterogeneous Catalysis

Abstract: Summary Acidic ion exhange resins are used for manufacturing both bulk chemicals and fine chemicals. The present paper relates to different routes of producing methyl isobutyl ketone (MIBK), methyl isopropyl ketone (MIK) and methyl isopropenyl ketone (MIPK) using a palladium-doped ion exchange resin as a catalyst. A new process variant for alternatively manufacturing MIPK and MIK with the same equipment is delineated.

Determination of Nickel in Biological Samples by Electrothermal Atomization-Atomic Absorption Spectrometry Involving a Prior Extraction with 1,5-Bis (Di-2-Pyridylmethylene) Thiocarbono-Hydrazide

Abstract: The use of 1,5-bis(di-2-pyridylmethylene) thiocarbono-hydrazide as a reagent for the extraction of Ni(II), Co(II), Zn(II), Fe(II), Cd(II) and Cu(II) into methyl isobutyl ketone has been studied, and a method for the determination of nickel at ultra-trace (ng/ml) level has been developed, by using electrothermal-atomization (graphite furnace) atomic absorption spectrometry involving a prior extraction with the cited extracting reagent. The chief advantage of the proposed method lies in its maximum allowed aqueous-to-organic phase volume ratio of 15. It has been successfully applied to the determination of nickel substrates in various biological samples.

Catalytic synthesis of azines from H2 O2 /NH3 /carbonyl compounds

Abstract: Azines are synthesized from aqueous hydrogen peroxide, ammonia and a carbonyl compound, e.g., acetone, methyl ethyl ketone or methyl isobutyl ketone, in the presence of a catalytically effective amount of immixture of an amide of a weak acid and an ammonium salt corresponding to such weak acid. A more general high output such process comprises (a) interreacting aqueous hydrogen peroxide, ammonia and a carbonyl compound in the presence of a catalytically effective amount of immixture comprising an amide of a weak acid, (b) separating the azine thus produced from the medium of reaction, (c) reconstituting the amount of the amide in the medium of reaction to the initial amount thereof present at the onset of step (a), and (d) recycling such reconstituted medium of reaction to step (a).

Method for producing methyl isobutyl ketone

Abstract: A method for producing methyl isobutyl ketone, which comprises contacting acetone and hydrogen in the presence of palladium and a metal oxide and/or metal hydroxide treated with an organosilicon compound of the formula (I): R.sub.a.sup.1 (OR.sup.2).sub.b X.sub.c Si (I) wherein each of R 1 and R 2 is a group selected from the group consisting of hydrogen, and alkyl, vinyl and aryl groups having a total carbon number of at most 30, which may have substituents, and R 1 and R 2 may be the same or different from each other, X is an element selected from the group consisting of hydrogen, fluorine, chlorine, bromine and iodine, and a, b and c are 0≦a<4, 0≦b≦4 and 0≦c≦4, respectively, and a+b+c=4.

Determination of nickel in biological samples by inductively coupled plasma spectrometry after extraction with 1,5-bis(di-2-pyridylmethylene)thiocarbonohydrazide

Abstract: An ICP-AES method for the determination of nickel subtraces after extraction of the metal into methyl isobutyl ketone(MIBK) containing 1,5-bis-(di-2-pyridylmethylene)thiocarbonohydrazide is suggested. The complex formed is quite soluble in MIBK, so that the determination of concentrations down to 15 times lower than those by the direct non-extractive method is possible. In addition, the extraction step enhances the selectivity. The described method was applied to the determination of nickel in various biological materials, such as red cabbage, algae, liver, kidney, brain and urine.

Production of noble metal fine particles using emulsion type liquid film method

Abstract: PURPOSE:To produce noble metal particles in water drips in oil by adding water drips in oil type emulsion composing of metal ion extract agent, organic phase containing water insoluble organic solvent and water phase containing reducing agent into noble metal salt water solution CONSTITUTION:The extract agent for metal ion (methyl isobutyl ketone, etc), organic phase containing the water insoluble organic solvent (kerosine, etc) and the water phase containing the reducing agent (sulfurous acid, etc) are mixed under existence of surfactant (sorbitan monooleate, etc) to produce the water drip in oil type emulsion This water drip in oil type emulsion is added into the noble metal salt aq solution to develop the noble metal particles (Au, Pt, Pd, Rh, Ir, etc) in the water drip in the oil By this method, the noble metal is concnd and recovered and the fine particles are produced

New epoxy resin, resin composition and cured material thereof

Abstract: PURPOSE: To obtain the title new resin suitable for sealing electronic parts, having low reduction in melt viscosity, excellent workability, providing a cured material with a low content of hydrolyzing chlorine, high heat resistance and low water absorption properties by epoxidizing a naphthol polymer containing no methylene chain. CONSTITUTION: A naphthol resin (e.g. 1-naphthol polymer) shown by formula I (R is H, 1-4C alkyl, aryl or halogen; n is 0-10) having excellent thermal stability is reacted with an epihalohydrin compound (e.g. epichlorohydrin) shown by formula II (X is halogen) in a nitrogen atmosphere in the presence of a basic compound (e.g. sodium hydroxide) at 60°C, formed water and water in an aqueous solution of sodium hydroxide are continuously removed out of the reaction system by azeotropy and the reaction product is extracted with a solvent such as methyl isobutyl ketone to give a new epoxy resin based on a naphthol shown by formula III free from methylene chain. COPYRIGHT: (C)1992,JPO&Japio

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

Abstract: 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 now required to measure both cobalt and selenium in the same sample. No evidence was seen of interference from other metals in the sample materials used in this study.

Electrically insulating sheathing material

Abstract: PURPOSE:To prepare a liq. electrically insulating sheathing material excellent in the resistance to moisture and thermal shock and workability by compounding a specific resol-type substd. phenolic resin, an epoxy resin, a solvent, and a dye. CONSTITUTION:A resol-type substd. phenolic resin obtd. by reacting phenols mainly comprising a substd. phenol of the formula (wherein R1 is H or CH3; and R2 is 1-4C alkyl or 6C aryl) (e.g. cresol) with an aldehyde (e.g. HCHO) in the presence of a nitrogen-contg. catalyst (e.g. NH3), an epoxy resin (e.g. Epikote 1004), a solvent (e.g. a methyl isobutyl ketone/methyl cellosolve mixture), and a dye are compounded.

Composition for forming surface protective film

Abstract: PURPOSE:To obtain the subject composition, composed of a specific (meth)acrylic acid ester monomer or oligomer and a low-boiling solvent therefor, having a high hardness without causing cracks, etc., by bending etc. CONSTITUTION:The objective composition composed of (A) an acrylic or methacrylic acid ester monomer or oligomer having =3 (preferably >=5) acrylic functionality and (B) a low-boiling solvent such as ethanol, toluene, ethyl acetate, methyl cellosolve, acetone, methyl isobutyl ketone, methyl ethyl ketone, ethyl cellosolve or isopropyl alcohol. The aforementioned composition is applied to the surface of a substrate such as an optical card or flexible disk and then cured by exposure to ionizing radiation.

Extraction Spectrophotometric Method for the Determination of Uranium in Geological Samples Using a Ternary Complex of 2-(p-Methylphenylazo)pyridine and Thiocyanate

Abstract: An uranyl ion (UO22+) reacts with 2-(p-methylphenylazo)pyridine in thiocyanate system. The species is extractable quantitatively into methyl isobutyl ketone (MIBK) in the presence of nitrate ion, showing an absorption maximum at 370nm. Beer′s law is obeyed over the range 0.15-1.5μg of uranium/ml. The molar absorptivity and Sandell′s sensitivity are 0.166×104 l mol-1 cm-1 (on the basis of uranium content) and 0.0014μg/cm2, respectively. Various international geochemical reference samples were chosen to check the validity of the method. The results obtained were in good agreement with the published data.

Methyl isobutyl ketone の代謝と生物学的モニタリング 第2編 Methyl isobutyl ketone 暴露作業者の尿中代謝産物

Abstract: A field study on the metabolites of methyl isobutyl ketone (MIBK) in the urine of 20 workers who were exposed to mixed solvents containing MIBK, and in that of a subject exposed to pure MIBK with 3 separate control subjects were observed. One of the urinary metabolites, 4-methyl-2-pentanol (4M2P) was identified by gas chromatography-mass spectrometry only in the urine of workers exposed to MIBK. Time-weighted average concentration of the mixed solvents for 8 hours were as follows ; MIBK 21.9±15.1 ppm (m±SD), toluene 18.3±8.9 ppm, ethyl benzene 9.6±4.6 ppm, xylene (total) 18.9±12.5 ppm. The regression equation between MIBK concentration X (ppm) in air and 4M2P concentration Y (mg/g creatinine) in the urine was : Y=25X-10.25. Its correlation coefficient was 0.63. Thus the urinary concentration of 4M2P corresponding TLV (Threshould Limit Values : 50ppm) of MIBK was 2.61 (mg/g creatinine). In a subject exposed to pure MIBK, the time-weighted average concentration of MIBK for 6 hours was 42.3ppm and 4M2P concentration in the urine was 0.42 (mg/g creatinine).

Aromatic resin and its production

Abstract: PURPOSE:To obtain an arom. resin excellent in heat resistance and curability by reacting carbazole with a dihydroxymethylbenzene or dihalomethylbenzene compd. as a cross-linker. CONSTITUTION:100 mol of carbazole is reacted with 50-300 mol of at least one cross-linker selected from the group consisting of a dihydroxymethylbenzene compd. and a dihalomethylbenzene compd. to give an arom. resin having structural units of formula I (wherein Bn is a group of formula II; and (m) is 0 or 1). The reaction is conducted in the prezence of a protonic acid such as an org. sulfonic acid, sulfuric acid, oxalic acid, or hydrochloric acid at 90-200 deg.C, pref. in the presence of a solvent such as methyl isobutyl ketone to facilitate the progress of the reacton. The obtd. resin softens at 50-150 deg.C and is thermally curable in the presence of a cure accelerator.

Purification of perfluoro(propylvinyl ether)

Abstract: PURPOSE:To purify perfluoro(propylvinyl ether) with effectively separating hydrogen fluoride adduct of the perfluoro(propylvinyl ether) by subjecting crude perfluoro(propylvinyl ether) to extractive distillation with using a specific ketone as a solvent. CONSTITUTION:Crude perfluoro(propylvinyl ether) containing hydrogen fluoride adduct of perfluoro(propylvinyl ether), generally crude perfluoro(propylvinyl ether) obtained by a thermo-decomposing method is subjected to extractive distillation using ketone having >=100 deg.C boiling point (e.g. methyl isobutyl ketone, 2-hexanone, 2-heptanone or acetonyl acetone) as a solvent to purify perfluoro(propylvinyl ether). Said compound is suitable for obtaining a copolymer with tetrafluoroethylene and improves moldability of the resultant copolymer.

Process for producing a hafnium extraction scrub solvent

Abstract: A scrub solution is made up for use in starting up a hafnium liquid-liquid extraction system. An aqueous zirconium oxychloride-containing solution is contacted with methyl isobutyl ketone containing less than 1 Molar thiocyanic acid. The aqueous solution is maintained at a chloride concentration of 1.6 to 3.5 Normal (as HCl) by addition of concentrated hydrochloric acid. Ammonium thiocyanate is added to the acidified aqueous stream to produce thiocyanic acid. The high acidity of the aqueous solution drives the thiocyanic acid into the methyl isobutyl ketone without the chloride anions having a depressing affect on the transfer. The thiocyanic acid-containing MIBK may then be used as a scrubbing solvent to start up the hafnium extraction system.

Coating method with bismuth oxide

Abstract: PURPOSE:To form a bismuth oxide coating film having a uniform thickness and a smooth surface by suspending bismuth oxide powder in ketone as a solvent, placing electrodes in the resulting suspension, supplying electric current and electrodepositing bismuth oxide on a substrate fitted with a cathode terminal CONSTITUTION:Ketone as a solvent 13 is filled into a cell 10 for electrophoresis housed in an ultrasonic generator 11 and bismuth oxide powder is suspended in the solvent 13 Electrodes 15, 17 are placed in the resulting suspension, DC high voltage square-wave pulse is impressed with a power source 19 and a control system 20 and bismuth oxide is electrodeposited on the surface of an electrode substrate 15 fitted with a cathode terminal Acetone, methyl isobutyl ketone or methyl ethyl ketone is suitable for use as the ketone as the dispersive solvent 13 The uniformly dispersed state of the bismuth oxide powder is stably maintained for a long time and an electrolyte coating film having a uniform thickness and a smooth surface is formed

Dissolution Rates of Copolymers Based on 4-Hydroxystyrene and Styrene

Abstract: : Copolymers were synthesized by free-radical polymerization using 4- acetoxystyrene and styrene in various ratios. These polymers then were hydrolyzed to the corresponding 4-hydroxystyrene (phenol) copolymers. The dissolution rates of the copolymers (using laser interferometry) decreased with a decrease in hydroxyl group content in aqueous developers (sodium hydroxide, potassium hydroxide, and a tetramethylammonium hydroxide based commercial developer). While an increase in pH value enhances the dissolution, an increase in cation size of these hydroxides at constant pH decreases the dissolution rate. The polymers become essentially insoluble in aqueous developers when the content of the monomer containing the hydroxyl group is less than 70 mole%. The dissolution rate of P(4HS/S) in organic solvents, methyl isobutyl ketone (MIBK), isopropyl alcohol (IPA), and their mixtures, increases as the styrene content increases. However, in IPA, dissolution rate goes through a maximum and then drops down with styrene content greater than 50 mole%. In mixtures of these two solvents, the polymer dissolves faster than it does in either pure solvent.

Kinetics of the Ring-Opening Carbonylation of Ethyloxirane with Hydrido Tetracarbonyl Cobalt.

Abstract: The rate of CO uptake in the reaction of HCo(CO) 4 with ethyloxirane, which gives (3-hydroxypentanoyl)cobalt tetracarbonyl as the major product in an n-octane/methyl isobutyl ketone solvent mixture at 15° C, is first order with respect to HCo(CO) 4 and ethyloxirane, and independent of the concentration of CO(CO) 4 − 4 or CO. The reaction is faster with DCo(CO) 4 . A preequilibrium ion pair formation and a subsequent rate-determining internal substitution, followed by fast CO insertion, accounts for these results.

Liquid resin composition for semiconductor

Abstract: PURPOSE:To suppress the corrosion of an aluminum wiring on the surface of a semiconductor element when used as a protective resin for the semiconductor element and to improve the humidity resistance by compounding a specific fluorocopolymer with aminosilane and an org solvent CONSTITUTION:The title liq resin compsn is prepd by compounding, as the essential components, 100 ptswt vinylidene fluoride-hexafluoropropylene copolymer of the formula wherein m/n is 1-20; 03-5 ptswt aminosilane; and an org solvent, pref a ketone such as methyl ketone or methyl isobutyl ketone, a polar solvent such as dimethylformamide or N-methyl-2-pyrrolidone, or a combination of these solvents