Quantitative Gas Liquid Chromatographic Estimation of Volatile Fatty Acids in Aqueous Media.

Ackman, R. G.; Burgher, R. D.

doi:10.1021/ac60199a045

Cited by 70 publications

(16 citation statements)

References 33 publications

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“…A. was 30,500 ,ug/100 ml compared ' O to a mean fasting level of 58 4 ysis on feces revealed no significant elevaand the interpretation are described in tions. a-Ketocaproic acid was measured by the text.…”

mentioning

confidence: 68%

Isovaleric acidemia: a new genetic defect of leucine metabolism.

Tanaka¹,

Budd²,

Efron³

et al. 1966

Proc. Natl. Acad. Sci. U.S.A.

308

139

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At present, leucine-induced hypoglycemia and maple-syrup urine disease are the only inborn errors of leucine metabolism recognized in man. In the former disorder, recurrent hypoglycemia is the result of leucine-induced hyperinsulinism.1 In maple-syrup urine disease there is a block in the oxidative decarboxylation of leucine, isoleucine, and valine resulting in the accumulation of the amino acids themselves as well as their a-keto derivatives.2 We have recently obtained evidence for a new genetic disorder of leucine metabolism in which there is a defect in the catabolism of leucine resulting in the accumulation of isovaleric acid.This disease has been observed in two siblings, aged 21/2 and 4, who since the early months of life had a persistent odor to their breath and body fluids described as "cheesy" or "like sweaty feet." In addition, these children experienced recurrent episodes of vomiting often progressing to metabolic acidosis and either stupor or coma. These episodes were usually precipitated by protein ingestion or intercurrent infections; the children actually had a pronounced aversion to dietary proteins. During attacks of acidosis the peculiar odor of the children usually intensified. Since the odor resembled that of short-chain fatty acids, the blood and urine were analyzed for these acids by gas-liquid chromatography (GLC) and mass spectrometry. These studies resulted in the demonstration of markedly increased amounts of isovaleric acid in the body fluids of these patients and evidence for a block in the utilization of this branched-chain fatty acid. The complete clinical details of this syndrome will be presented in full detail elsewhere.Materials and Methods.-Patient material: Biochemical studies were performed on blood, urine, and feces of the two patients, B. A. (male, 21/2 yr) and S. A. (female, 4 yr) during attacks of acidosis and after recovery from such attacks. Comparable determinations were performed on specimens from four adults and four children without known metabolic abnormalities.Gas-liquid chromatography (GLC): An improved GLC method for short-chain fatty acids was used (detailed description to be published). Serum samples were acidified with 0.2 vol of 1.0 N H2SO4, then extracted with 20 vol of chloroform-methanol (v/v 2: 1), and subsequently filtered. Mixing with 0.2 vol of 0.1 N NaOH at 0-5O resulted in the formation of a two-phase system. The upper layer was evaporated to dryness and acidified with o-phosphoric acid and steam-distilled.3 The evaporated residue of the lower layer was hydrolyzed with 1.0 N KOH in methanolwater (v/v 4:1) for 4 hr at 650, and similarly steam-distilled. Preliminary experiments indicated that virtually all (>99%) of short-chain fatty acids (straight and branched) (C2-C8) recovered were in the upper layer, and greater than 96% of neutral lipids (tributyrin, tricaproin, trioctanoin) were present in the lower layer. Urine specimens were alkalinized, evaporated to dryness, then acidified and steam-distilled. Alkalinized distillates were evaporated to dryne...

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mentioning

confidence: 68%

Isovaleric acidemia: a new genetic defect of leucine metabolism.

Tanaka¹,

Budd²,

Efron³

et al. 1966

Proc. Natl. Acad. Sci. U.S.A.

308

139

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“…(7), VFAs become more volatile at pH <7.0. Formic acid has also been reported to prevent peak tailing and ghosting in gas chromatography of VFAs (18). The use of formic acid in this study was questioned, when separations of a calibration series involving mixtures of VFA standards, performed in the absence of formic acid, showed no obvious, immediate difference in peak area or height.…”

Section: Resultsmentioning

confidence: 99%

Preliminary Studies into the Characterization of Chemical Markers of Decomposition for Geoforensics*

Swann

Chidlow

Forbes

et al. 2010

Journal of Forensic Sciences

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In this paper, we report the results of our preliminary studies into chemical characterization of the fluids produced during decomposition in the absence of a soil matrix. Pig (Sus domestica) carcasses were used to model the human decomposition process in two separate locations, Western Australia (Perth) and Canada (Oshawa). Analysis involved simple dilution and filtration of the decomposition fluids followed by gas chromatography-mass spectrometry. Several previously unreported compounds were detected in the decomposition fluid samples during the trials, including benzeneacetic acid, benzenepropionic acid, 2-piperidone, and isocaproic acid. Possible biosynthetic pathways for some of the compounds produced are proposed. Further research trials are required, particularly in the presence of soil matrices.

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“…In 1975, Cochrane (1) stated that esters of C-2 through C-6 acids could not be analyzed quantitatively by GC. He recommended the method of Ackman and Burgher (2). Our procedure required the quantitative analyses of butanoic and hexanoic acids, so Cochrane's statements interested us.…”

Section: Introductionmentioning

confidence: 99%

“…Our procedure required the quantitative analyses of butanoic and hexanoic acids, so Cochrane's statements interested us. Ackman and Burgher (2) first reported that when a GC was modified to allow formic acid vapors in the carrier gas to pass into the injection port, C-2 through C-6 acids were separated, and ghosting and peak tailing were not problems. Cochrane (3) applied Ackman and Burgher's method for the quantitative analysis of C-2 through C-12 acids.…”

Section: Introductionmentioning

confidence: 99%

Functional analysis of gas chromatographic data for C‐4 through C‐18:2 fatty acids

Wulff

Duthie

Wulff

1980

J Americ Oil Chem Soc

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The problem of finding a functional relationship between concentration and output data from GC has been considered for a series of fatty acids (FA). The concentrations used are relative values, i.e., the actual concentration of a FA divided by that for an internal standard. The GC output used is relative peak areas, i.e., the integrated chromatograrn area of the FA divided by that for the internal standard. Five functions have been investigated, each in reasonable accord with the concept of relative response factors being constant for a homologous series of compounds. We conclude that one of the five, C i = aAib, is clearly superior and recommend its use in agreement wRh a liferature report for different compound types (5). In the equation above, "C" and "A" are the relative concentrations and areas, respectively, and "a" and "b" are fitting constants determined from the data by least-squares minimization. We found it was impossible to deal with a matrix of 10 acids and 9 concentrations in a manner that would reproduce the data within the experimental uncertainty (6%), and we concluded that an acid-by-acid analysis was preferable.

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Quantitative Gas Liquid Chromatographic Estimation of Volatile Fatty Acids in Aqueous Media.

Cited by 70 publications

References 33 publications

Isovaleric acidemia: a new genetic defect of leucine metabolism.

Isovaleric acidemia: a new genetic defect of leucine metabolism.

Preliminary Studies into the Characterization of Chemical Markers of Decomposition for Geoforensics*

Functional analysis of gas chromatographic data for C‐4 through C‐18:2 fatty acids

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