Gas-Liquid Chromatography and Liquid Chromatography of Ethylenethiourea in Fresh Vegetable Crops, Fruits, Milk, and Cooked Foods

1977 ◽  
Vol 60 (5) ◽  
pp. 1105-1110 ◽  
Author(s):  
John H Onley ◽  
Laura Giuffrida ◽  
N Fred Ives ◽  
Randall R Watts ◽  
Robert W Storherr
Keyword(s):  
Liquid Chromatography ◽  
Aluminum Oxide ◽  
Thin Layer ◽  
Gas Liquid Chromatography ◽  
Vegetable Crops ◽  
Photometric Detection ◽  
Fresh Vegetable ◽  
Flame Photometric Detection ◽  
Aluminum Oxide Column ◽  
Layer Chromatography

Abstract The Onley-Yip procedure for determining ethylenethiourea (ETU) in milk and crops was modified to reduce interferences by the ethylenebisdithiocarbamates (EBDCs). A 20 g cropmethanol extract is cleaned up by adsorbing the sample onto Gas-Chrom S, desorbing ETU, and eluting ETU from aluminum oxide with chloroform containing ethanol. ETU is converted to the S-butyl derivative for gas-liquid chromatography (GLC) and flame photometric detection (sulfur mode). For liquid chromatography (LC), ETU is cleaned up on another aluminum oxide column and injected directly. LC and GLC results are confirmed by thin layer chromatography. A cooking procedure based on conversion of EBDCs to ETU is included for surveying crops for possible EBDC content. Recoveries from 8 crops and milk fortified at 0.05 ppm ETU ranged from 73 to 100%.

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

Identification of the Photoalteration Products Formed from Parathion by Ultraviolet Light

1974 ◽  
Vol 57 (2) ◽  
pp. 408-415
Author(s):  
Ronald L Joiner ◽  
Karl P Baetcke
Keyword(s):  
Gas Chromatography ◽  
Infrared Spectroscopy ◽  
Thin Layer ◽  
Ultraviolet Light ◽  
High Intensity ◽  
Percentage Composition ◽  
Photometric Detection ◽  
Flame Photometric Detection ◽  
Time Periods ◽  
Layer Chromatography

Abstract A comparison of the effects of various time periods of ultraviolet light on the formation of rearrangement products of parathion is presented. Twelve products were separated and identified by thin layer chromatography in 4 systems, and were confirmed by infrared spectroscopy, when possible. The effect of 2 solvents, methanol and acetone, on the formation and percentage composition of photoalteration products of parathion from high-intensity ultraviolet light is also discussed. Retention times are given for each component from gas chromatography by electron capture and flame photometric detection.

Gas-Liquid Chromatography and Flame Photometric Detection of Phosphine in Wheat

1978 ◽  
Vol 61 (4) ◽  
pp. 829-836 ◽  
Author(s):  
Thomas W Nowicki
Keyword(s):  
Liquid Chromatography ◽  
Screening Method ◽  
Gas Liquid Chromatography ◽  
Gas Chromatograph ◽  
Aluminum Phosphide ◽  
Photometric Detection ◽  
Residual Aluminum ◽  
Flame Photometric Detection ◽  
Rubber Septa ◽  
Electronic Integrator

Abstract A screening method using gas-liquid chromatography with flame photometric detection has been developed for determining phosphine in wheat. Phosphine is measured as the sum of physically bound intact phosphine and that derived from residual aluminum phosphide. Wheat is extracted in a closed, partially evacuated glass system by refluxing with 10% sulfuric acid. Liberated gases are swept into a gas-collection flask fitted with rubber septa to permit gas sampling. Aliquots of collected gas are injected into a gas chromatograph. Phosphine is quantitated by peak area as determined by an electronic integrator. Recoveries varied with concentration: 67% was recovered at 0.10 ppm and 98% was recovered at 19 ppm. For concentrations less than 1.5 ppm, the coefficient of variation was 9.95%. Using flame photometric detection, phosphine concentrations as low as 0.04 ppm were easily determined in wheat.

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.

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