DETERMINATION OF VOLATILE ACID PRODUCTION OF CLOSTRIDIUM BY GAS CHROMATOGRAPHY

1967 ◽  
Vol 13 (8) ◽  
pp. 1033-1040 ◽  
Author(s):  
Vester J. Lewis ◽  
C. Wayne Moss ◽  
Wallis L. Jones
Keyword(s):  
Liquid Chromatography ◽  
Acid Production ◽  
Volatile Fatty Acid ◽  
Volatile Acid ◽  
Gas Liquid Chromatography ◽  
Experimental Conditions ◽  
Fatty Acid Production ◽  
Pure Cultures

Gas–liquid chromatography was used to determine volatile fatty acid production by pure cultures of 15 species of Clostridium. Acetic acid was detected from each of the 39 strains examined, although only in trace amounts from C. bulyricum. Butyric acid was detected in considerable amounts from all organisms except the three strains of C. sporogenes tested. In addition, several species produced one or more of the following acids: valeric, isovaleric, isobutyric, and isocaproic. The technique of gas–liquid chromatography proved to be both reliable and rapid for the characterization of volatile acids produced by the bacteria under the experimental conditions employed.

scholarly journals Characterization of Flavobacterium Species by Analysis of Volatile Fatty Acid Production

Microbiology ◽  
1986 ◽  
Vol 132 (10) ◽  
pp. 2723-2732
Author(s):  
D. RASOAMANANJARA ◽  
F. PELADAN ◽  
J. C. TURLOT ◽  
H. MONTEIL ◽  
C. RICHARD
Keyword(s):  
Fatty Acid ◽  
Acid Production ◽  
Volatile Fatty Acid ◽  
Fatty Acid Production

Effects of Oil Contamination on Cotton Quality: Methods of Analysis and Characterization of Contaminants

1977 ◽  
Vol 47 (4) ◽  
pp. 271-276 ◽  
Author(s):  
Henry H. Perkins ◽  
Charles K. Bragg
Keyword(s):  
Liquid Chromatography ◽  
Quantitative Determination ◽  
Oil Contamination ◽  
Gas Liquid Chromatography ◽  
Infrared Spectrophotometry ◽  
Simple Method ◽  
Yarn Strength ◽  
Problem Severity

Oil contamination of cotton is a recurring problem that adversely affects cotton quality. Processing problems occur in carding through spinning, and both yarn strength and appearance are lowered. Problem severity increases as the level of contamination increases. A simple method is described for quantitative determination of contamination. Contaminants are characterized and differentiated from each other and from the natural constituents of cotton by use of infrared spectrophotometry and gas-liquid chromatography.

Determination of Curcuminoids by Liquid Chromatography with Diode Array Detection: Application to the Characterization of Turmeric and Curry Samples

2020 ◽  
Vol 16 (2) ◽  
pp. 95-105 ◽  
Author(s):  
Òscar Vidal ◽  
Xavier Castilla ◽  
Núria Aliaga-Alcalde ◽  
Ana M. López-Periago ◽  
Concepción Domingo ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Reversed Phase ◽  
Diode Array ◽  
Diode Array Detection ◽  
Experimental Conditions ◽  
Gradient Based ◽  
Peak Areas ◽  
Array Detection

Background: A simple, rapid and efficient method for the determination of curcumin and other polyphenols in turmeric and curry samples was here developed. The method relied on sample extraction with methanol and extract analysis by liquid chromatography with diode array detection (HPLC-DAD). Methods: The separation of components was carried out in reversed-phase mode using an elution gradient based on 0.1% (v/v) formic acid aqueous solution and acetonitrile as the components of the mobile phase. Chromatograms were recorded at 420 nm for specific monitoring of curcumin and related compounds. Results: Extraction and separation conditions were optimized by experimental design and multicriteria response functions. Figures of merit were established under the selected experimental conditions. In general, repeatability of peak areas were better than 0.4%, detection limits were below 0.006 mg L-1 and quantitative recoveries expressed as a percentage were about 100 ± 2. The method was applied to quantify curcuminoids in commercial samples. It was found that apart from curcumin, demethoxycurcumin and bisdemethoxycurcumin, other related molecules also occurred in the samples. In this regard, a tentative elucidation of possible unknown curcuminoids was attempted by liquid chromatography coupled to mass spectrometry. Conclusion: Differences in the compositional profiles among samples were encountered to be relevant, so that the resulting HPLC-DAD data was exploited for chemometric characterization of turmeric and curry samples. Samples were successfully discriminated according to matrix types, species varieties and origins.

Separation and Micro Quantitative Determination of Dipterex and DDVP by Gas-Liquid Chromatography

1965 ◽  
Vol 48 (2) ◽  
pp. 374-379
Author(s):  
Abdel Rahman (Ali) El-Refai ◽  
Laura Giuffrida
Keyword(s):  
Liquid Chromatography ◽  
Simple Procedure ◽  
Gas Liquid Chromatography ◽  
Experimental Conditions ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of ◽  
Gas Chromatographic Separation ◽  
Sensitive Method ◽  
General Method

Abstract A simple, rapid, and sensitive method was required for the determination of Dipterex and DDVP in water and insecticidal formulations. Existing methods were found to he unsatisfactory. This paper describes a rapid method for the gas chromatographic separation and estimation of Dipterex and DDVP in macro and micro amounts. The sodium thermionic detector (STD) was used, and the GLC conditions are described. A general method for extraction of the two compounds from water solutions was developed and applied in studying the rate of hydrolysis of Dipterex and DDVP in river water. A simple procedure has been developed for analysis of formulations of Dipterex and DDVP. Several commercial formulations have been analyzed by this method with a precision of 1–2% obtained under experimental conditions.

GASCHROMATOGRAPHIC DETERMINATION OF STEROIDS IN THE URINE OF PATIENTS WITH CUSHING'S SYNDROME

1971 ◽  
Vol 67 (2) ◽  
pp. 303-315 ◽  
Author(s):  
A. J. Moolenaar ◽  
A. P. van Seters
Keyword(s):  
Liquid Chromatography ◽  
Cushing’S Syndrome ◽  
Normal Subjects ◽  
Diagnostic Value ◽  
Cushing's Syndrome ◽  
Gas Liquid Chromatography ◽  
Obese Subjects

ABSTRACT The 17-oxosteroids were estimated in the urine of 27 patients with Cushing's syndrome by gas-liquid chromatography (G. L. C.). The values of the various steroid fractions are compared with those of normal subjects, patients with thyrotoxicosis and obese subjects. The effect of the age of the patients on the diagnostic value of the invidual 17-oxosteroids and their ratios is discussed.

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