Showing papers on "Methyl isobutyl ketone published in 1976"

Rapid determination of dipicolinic acid in the spores of Clostridium species by gas-liquid chromatography.

Abstract: A gas-liquid chromatographic procedure has been developed to quantitate dipicolinic acid in bacterial spores The culture, washed from a plate, was hydrolyzed with acid containing the internal standard, pyridine-2,4-dicarboxylate, and then extracted into methyl isobutyl ketone The internal standard and dipicolinic acid were then extracted into a small volume of trimethylphenylammonium hydroxide Injection of the resultant quaternary ammonium salts into a gas chromatograph yielded, via thermal decomposition, the methyl ester derivatives of the dipicolinic acid and the internal standard The amount of dipicolinic acid in the sample was determined from a standard curve The method was sensitive to 100 ng of dipicolinic acid per sample and was 1,000 to 5,000 times more sensitive than the commonly used methods Preparation of the sample required less than 15 h and less than 15 min of the analyst's time

Determination of Fe, Cu, Ni, and Mn in fats and oils by flameless atomic absorption spectroscopy

Abstract: The determination of Fe, Cu, Ni, and Mn is performed by flameless atomic absorption spectroscopy The procedure is applicable to oils, including crudes, and also fats such as hydrogenated oils A solution of the sample is analyzed directly, and absorbance values are compared to standards Matrix-matching is not required, and virtually any concentration of metal can be analyzed since both sample concentration and aliquot volume are variable Solvent selection is based on the results of a stability study and includes methyl isobutyl ketone (MIBK) for Cu and Mn determinations and MIBK with a small amount of HNO3 added for Fe and Ni Sensitivity approximated 80 picograms for Fe, 100 pg for Cu, 525 pg for Ni, and 30 pg for Mn Absorbance values of appropriate aliquots, each having the equivalent of 010 ppm Fe, are compared to determine the effect of variation of pipette size on response Pipette size ranged from 5 µl to 50 µl Responses using multiple 50 µl volumes are also recorded Sources of error in procedure, error analyses, and proper pipetting technique are given

Determination of gold in geological samples at parts per milliard levels by flameless atomic-absorption spectroscopy

Abstract: A method is described for the determination of gold at ppM levels in geological materials by the use of flameless A. A. spectroscopy. The gold is separated as bromoaurate from HBr solution by methyl isobutyl ketone (MIBK). The MIBK phase is pipetted directly into an HGA-2000 Graphite Furnace. Detection limits of about 0.6–0.8 ppM Au for a 1-g sample are achieved. The error of determination (relative standard deviation) varies in the range 5–50%, depending on the absolute gold level.

Treatment of waste water from the preparation of 6-substituted 3-mercapto-4-amino-1,2,4-triazine-5-ones

Abstract: A process for the treatment of waste water obtained in the condensation of thiocarbohydrazide and an aqueous solution of an α-keto carboxylic acid such as, e.g., 3,3-dimethyl-2-oxo-butyric acid, which comprises mixing said waste water with a water-immiscible ketone, preferably selected from the group consisting of methyl isobutyl ketone, cyclohexanone and pinacolone, said ketone being employed in an amount sufficient to form two phases, separating said two phases, and discharging as waste the aqueous phase. Advantageously the pH of the waste water is no higher than about 6 and its temperature is 20° to 50° C. The organic phase comprises the ketone containing dissolved therein an adduct of the ketone with thiocarbohydrazide and/or similar amino materials originally present in waste water. The excess of the ketone may be recovered from the organic phase by distillation, or the organic phase may be treated with alkali to effect hydrolysis of such adducts, the ketone separated and recycled and the amino materials recovered.

The Effect of Anions in the Fluorimetric Determination of Uranium after Extraction from Calcium Nitrate Salting-out Solution

Abstract: The effect of perchlorate, chloride, sulphate, phosphate and fluoride on the fluorimetric determination of uranium after the extraction of uranium into methyl isobutyl ketone from saturated calcium nitrate-EDTA solution has been established. Recoveries of uranium from perchlorate, chloride and sulphate media are above 85%, and a correction can be made to compensate for the anion effect. Phosphate and fluoride interfere badly. The anion effect may be minimized by increasing the volume of the organic phase.

Method for isolation of 3-hydroxy steroids and 3-keto steroids

Abstract: An improved process for isolating 3-hydroxy steroids and 3-keto steroids from mixtures thereof with lipids by dissolving the mixtures in an organic solvent, mixing the dissolved mixture with a metal salt to form insoluble adducts of the steroids, separating the insoluble adducts and splitting the adducts to regenerate the free steroids, which comprises using methyl isobutyl ketone and/or methyl n-amyl ketone as the solvent and calcium bromide as the metal salt.

The effect of anions in the fluorimetric determination of uranium after extraction from acid-deficient aluminium nitrate solution

Abstract: The effect of perchlorate, chloride, sulphate, phosphate and fluoride on the fluorimetric determination of uranium after the extraction of uranium into methyl isobutyl ketone from acid-deficient aluminium nitrate solution has been established. Recoveries of uranium from perchlorate and sulphate media after addition of 1 ml of 15M nitric acid are 100%. Chloride interferes, and a correction must be made to compensate for the anion effect. Phosphate and fluoride in amounts up to 25 mg give recoveries of at least 95%. The anion effect may be minimized by increasing the volume of the organic phase.

Purification of phosphoric acid by solvent extraction using hexanones

Abstract: Wet process phosphoric acid may be purified by solvent extraction to produce a product of greater purity and concentration than has hitherto been attainable by employing an acyclic hexanone, preferably methyl isobutyl ketone as the solvent. Preferably the extraction of the acid into the ketone and the release into water are carried out in 2 actual or theoretical counter-current stages. Alternatively the release may be carried out into an aqueous solution of a base.

Chromatographic studies on the partition of PTH-amino acids in formamide systems

Abstract: Phenylthiohydantoin (PTH) derivatives of five amino acids were chromatographed on a paper impregnated with formamide and developed with toluene solutions of diethyl, di-n-propyl or methyl isobutyl ketone. RM values of the PTH-amino acids varied linearly with the logarithm of per cent concentration of ketone, the slopes of the lines being related to the presence of proton donor groups in the, molecules of the PTH-amino acids.

Determination of some trace elements (Fe, Co, Cr, Zn, Cu, Mn, and In) in different series of standard reference samples by neutron-activation analysis

Abstract: In this paper methods of determining traces of Fe, Co, Cr, Zn, Cu, Mn and In in standard reference materials by neutron-activation analysis are described. The maximum selectivity and sensitivity for measurements of these elements was obtained by combining ion-exchange, extraction and precipitation methods with use of an NaI(Tl) detector. After a long irradiation, addition of carriers and dissolution of samples, Fe, Co, Zn and Cr were separated on a Dowex 1X8 anion-exchange column from 10M HCl medium. Chromium passes through the column under these conditions and is separated from interferences by extraction of Cr2O72− with methyl isobutyl ketone. The other three elements are selectively eluted with HCl of different concentrations (5M, 0.5M, 0.01M). Cobalt and zinc are extracted as the dithiocarbamates from the fractions obtained, and iron with tributyl phosphate. Separation and determination of Cu, Zn, Mn and In as their short-lived isotopes is based on extraction of their dithiocarbamates into CCl4 under specific conditions. The purity of theγ-spectra obtained, the high chemical yields and good reproducibility, indicate that these methods are suitable for determination of these trace elements in a wide spectrum of inorganic materials.

Formulation of Sumithion

Abstract: Chemically pure Sumithion forms in yellowish crystals which melt at 03°C, while the technical grade containing 95% or more of the pure material is a yellowish brown liquid which does not crystallize at such a low temperature as —10°C