Thin Layer and Gas-Liquid Chromatography of Cholesterol in Fats and Oils. I. Development of Method

1969 ◽  
Vol 52 (4) ◽  
pp. 774-778
Author(s):  
C W Thorpe ◽  
Linda Pohland ◽  
D Firestone
Keyword(s):  
Liquid Chromatography ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Unsaponifiable Matter ◽  
Fats And Oils ◽  
Cholesterol Content ◽  
Gas Liquid Chromatography ◽  
Animal Fat ◽  
Low Levels ◽  
Layer Chromatography

Abstract A inethod is described for analysis of sterols by thin layer chromatography-gas liquid chromatography (TLC-GLC). Sterols are isolated from other components of unsaponifiable matter by preparative TLC. The sterols are quantitatively removed from the TLC plate, extracted from the silica gel, and analyzed by GLC. This method has been used to detect low levels (2–3%) of animal fat in vegetable oil by measuring the cholesterol content of the animal fatvegetable oil admixtures.

ANALYSIS OF CHLORORGANIC COMPOUNDS IN FODDER FOR BROILERCHICKENS BY THE METHOD OF GAS-LIQUID CHROMATOGRAPHY WITH MASSSPECTROMETER DETECTOR

2020 ◽  
Vol 1 (2) ◽  
pp. 205-208
Author(s):  
A.A. Parshutina ◽  
◽  
A.A. Solovyova ◽  
L.P. Satyukova ◽  
E.G. Shubina ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Organochlorine Pesticides ◽  
Mass Spectrometer ◽  
Broiler Chickens ◽  
Gas Liquid Chromatography ◽  
Layer Chromatography

The article shows the importance of the study of feed for broiler chickens on the content of organochlorine pesticides. These substances in significant concentrations can disrupt the development of birds and cause mass poisoning. The study of formula feed for broiler chickens «prestart» and «start» by two methodswas conducted: a certified method for the determination of organochlorine pesticides in feed and formula feed (thin layer chromatography) and a method for detecting pesticides not certified for feed (gas-liquid chromatography with mass spectrometer detector). During the experiment, the presence of organochlorine pesticides in several formulafeed samples was revealed.

Additional Cleanup of Samples on GLC Column for TLC Determination of Pesticide Residues

1967 ◽  
Vol 50 (3) ◽  
pp. 615-623
Author(s):  
Kenneth T Hartman
Keyword(s):  
Liquid Chromatography ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Pesticide Residues ◽  
Gas Liquid Chromatography ◽  
Rf Values ◽  
Layer Chromatography

Abstract Gas-liquid chromatography (GLC) following conventional isolation procedures has been used to clean up pesticide residues for confirmation by thin layer chromatography (TLC). This procedure is more rapid and efficient than present cleanup procedures and permits the determination of pesticide residues that do not survive these rigorous acid or alkali treatments. The method also permits TLC confirmation of pesticide residues that have similar Rf values but different GLC retention times. Recoveries ranged from 85 to 105% for 25 of 28 pesticides tested

Comparison of Postcolumn Derivatization-Liquid Chromatography with Thin-Layer Chromatography for Determination of Aflatoxins in Naturally Contaminated Corn

1990 ◽  
Vol 73 (4) ◽  
pp. 579-581 ◽  
Author(s):  
Rodney W Beaver ◽  
David M Wilson ◽  
Mary W Trucksess
Keyword(s):  
Liquid Chromatography ◽  
Detection Limit ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Correlation Coefficient ◽  
Low Levels ◽  
Aflatoxin B2 ◽  
Layer Chromatography ◽  
Postcolumn Derivatization

Abstract Quantitation of aflatoxins by liquid chromatography with postcolumn iodine derlvatization (LC-PCD) and fluorescence detection was compared with quantitation by the AOAC CB method, 968.22. Thirty-seven naturally contaminated corn samples were ground and then divided. One portion was extracted, and the extract was cleaned up and analyzed by thin-layer chromatography according to the CB method. The second portion was extracted and cleaned up In a similar fashion, but quantitation was by the LC-PCD method. For aflatoxin B1, concentrations ranging from 0 to 150 ng/g, results obtained by the 2 methods were fitted to a linear equation with the LC-PCD results as the dependent variable. The correlation coefficient was 0.99, the Intercept was near 0, and the slope was near 1. For aflatoxin B2, the correlation coefficient was 0.97, and the Intercept was near 0. However, the slope of the equation relating LC-PCD concentration to TLC concentration was only 0.5. We believe that this lack of equivalence between the methods for determination of aflatoxin B2 is due to overestlmatlon by the TLC method because the low levels present are near the TLC detection limit for B2.

Steroids in Aged Whisky

1973 ◽  
Vol 56 (6) ◽  
pp. 1357-1361
Author(s):  
Robert A Black ◽  
Arthur A Andreasen
Keyword(s):  
Liquid Chromatography ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Gas Liquid Chromatography ◽  
Infrared Spectrophotometry ◽  
Layer Chromatography

Abstract Steroids were isolated from aged whisky and identified as β-sitosterol-D-glucoside, β-sitosterol, stigmasterol, and campesterol. Only β-sitosterol-D-glucoside has been reported in whisky. These steroids were characterized by gas-liquid chromatography, thin layer chromatography, and infrared spectrophotometry. They are extracted from the barrel during maturation and can contribute to clarity instability in finished whisky products.

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