Search results for "Methyl isobutyl ketone"
showing 6 items of 6 documents
Atomic Absorption Spectrophotometric Determination of Cobalt in Foods
1985
A method is reported for determination of chromium in foodstuffs. Organic matter is digested with nitric acid, followed by oxidation to Cr(VI) and extraction with methyl isobutyl ketone (MIBK) after HCl addition. Chromium determinations are performed by flame absorption spectroscopy. Absence of interferences is verified and recovery tests are performed on food samples. Quantitation limit (3.8 ng/mL), accuracy (NBS Standard Reference Material 1,573 Tomato Leaves, 4,500 +/- 500 ng/g, found 3,860 +/- 409 ng/g), and precision (CV for vegetable matrix = 9.05%, CV for animal matrix = 14.95%) of the procedure are evaluated.
Cr(III)/Cr(VI) speciation in aerosol particles by extractive separation and thermal ionization isotope dilution mass spectrometry
1997
An isotope dilution mass spectrometric (IDMS) method, using the formation of positive thermal ions, was developed for Cr(III) and Cr(VI) speciation in aerosol particles. Cr(III) and Cr(VI) spike species, enriched in 53Cr, were applied for the isotope dilution step. After leaching of filter collected aerosol samples by an alkaline solution at pH 13, species separation was carried out by extraction with a liquid anion exchanger in methyl isobutyl ketone. Cr(VI) in the organic phase was re-extracted into an ammoniacal solution and chromium was then isolated from both fractions of species by electrodeposition. Detection limits of 30 pg/m3 for Cr(III) and of 8 pg/m3 for Cr(VI) were achieved in a…
The use of emulsions in the preparation of samples and standards for analysis by atomic-absorption spectroscopy determination of Cu and Fe in mibk ex…
1984
The use of aqueous/organic emulsions is shown to give advantages in the AAS determination of Cu and Fe extracted as their pyrrolidinedithiocarbamate complexes into methyl isobutyl ketone. The emulsions are more stable than the extracts, and the standards can be prepared from aqueous solutions by emulsification, but without extraction.
Evaluation of Diethyl Carbonate and Methyl Isobutyl Ketone as Entrainers for the Separation of 1-Hexene and n-Hexane
2017
Diethyl carbonate and methyl isobutyl ketone are tested as possible entrainers for separating 1-hexene and n-hexane by extractive distillation. For this purpose, isobaric vapor–liquid equilibrium (VLE) data at 100 kPa have been obtained for the two ternary systems formed by the two hydrocarbons and one of the selected solvents: 1-hexene + n-hexane + diethyl carbonate and 1-hexene + n-hexane + methyl isobutyl ketone. VLE data for the following constituent binary systems have also been determined: 1-hexene + diethyl carbonate, n-hexane + diethyl carbonate, 1-hexene + methyl isobutyl ketone, and finally n-hexane + methyl isobutyl ketone. All binary systems present moderate positive deviations …
Direct synthesis of methyl isobutyl ketone in gas-phase reaction over palladium-loaded hydroxyapatite
2005
Several compositions of palladium-loaded calcium hydroxyapatite Pd(x)/CaHAp were prepared and characterized by XRD, IR, and UV–visible spectroscopy and temperature-programmed reduction (TPR). The acid–base properties of the samples were studied with the use of butan-2-ol conversion and IR spectroscopy coupled with lutidine adsorption/desorption. Calcium hydroxyapatite bears Lewis acid sites of moderate strength and a limited number of Bronsted acid sites, which produce butenes by dehydration. The selectivity of the dehydrogenation reaction (formation of methyl ethyl ketone) is very limited in the absence of oxygen but indicates the existence on the surface of phosphate of basic sites that a…
Isobaric Vapor−Liquid Equilibria for Binary and Ternary Mixtures with Cyclohexane, Cyclohexene, and Methyl Isobutyl Ketone at 100 kPa
2010
Consistent vapor−liquid equilibrium (VLE) data at 100 kPa have been determined for the ternary system cyclohexane + cyclohexene + methyl isobutyl ketone and two constituent binary systems: cyclohexane + methyl isobutyl ketone and cyclohexene + methyl isobutyl ketone. Both binary systems show positive deviations from ideal behavior and do not present an azeotrope. The VLE data have been correlated by the Wilson, UNIQUAC, and NRTL equations. The ternary system does not present an azeotrope and is well predicted from binary interaction parameters. Prediction with the UNIFAC method has also been obtained.