Gas Chromatographic Determination of Ethylene Thiourea Residues

1973 ◽  
Vol 56 (2) ◽  
pp. 333-337 ◽  
Author(s):  
Linwood D Haines ◽  
Irving L Adler
Keyword(s):  
Gas Chromatography ◽  
Sodium Borohydride ◽  
Chromatographic Determination ◽  
Food Crops ◽  
Alumina Column ◽  
Flame Photometric Detector ◽  
Photometric Detector ◽  
Ethylene Thiourea

Abstract Residues of ethylene thiourea on food crops are determined by extracting the sample with methanol, partially purifying the extract on an alumina column, and derivatizing the ethylene thiourea extracted with 1-bromobutane in the presence of dimethylformamide and sodium borohydride. The resulting derivative is measured by gas chromatography, using a flame photometric detector. The method is suitable for routine use and is sensitive to 0.01 ppm.

Herbicidal Carbamates: Extraction, Cleanup, and Gas Chromatographic Determination by Thermionic, Electron Capture, and Flame Photometric Detectors

1971 ◽  
Vol 54 (6) ◽  
pp. 1366-1370 ◽  
Author(s):  
John H Onley ◽  
George Yip
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Chromatographic Determination ◽  
Food Crops ◽  
Water Mixture ◽  
Flame Photometric Detector ◽  
Photometric Detector ◽  
Electron Capture Detectors ◽  
Cellulose Column

Abstract Extraction, cleanup, and gas chromatographic procedures have been developed for the determination of carbamate herbicides in food crops. Each sample is extracted with ethanol or an ethanol-water mixture and then cleaned up on a MgO-cellulose column. Determinations are made by gas chromatography, using thermionic and electron capture detectors; a flame photometric detector may also be used to quantitate and confirm those carbamates containing sulfur. Recoveries from apples, potatoes, alfalfa, corn, and soybeans at fortification levels of 0.01 to 10 ppm exceeded 80%.

Gas Chromatographic Determination of Ametryn and Its Metabolites in Tropical Root Crops

1984 ◽  
Vol 67 (2) ◽  
pp. 280-284
Author(s):  
Promode C Bardalaye ◽  
Willis B Wheeler
Keyword(s):  
Anhydrous Sodium Sulfate ◽  
Residue Analysis ◽  
Gel Permeation Chromatography ◽  
Chromatographic Determination ◽  
Solvent System ◽  
Complete Separation ◽  
Flame Photometric Detector ◽  
Root Crops ◽  
Photometric Detector

Abstract Residue analysis of the herbicide ametryn (2-methyIthio-4-ethylamino-s-isopropylamino-s-triazine) is widely known but an analytical method for determining its metabolites has not yet been reported in the literature. A method has been developed for the extraction and determination of ametryn and 3 metabolites, 2-methylthio-4-amino-6-isopropylammo- s-triazine (GS-11354), 2-methylthio-4,6-diamino-.s-triazine(GS- 26831), and 2-methylthio-4-amino-6-ethylamino-s-triazine (GS-11355) in taniers, yams, cassava. Residues were extracted from crops with ethyl acetate-toluene (3 + 1 v/v), using a Polytron homogenizer and anhydrous sodium sulfate added for drying. The extracts were cleaned up by automated gel permeation chromatography on Bio-Beads SX-3 gel in the same solvent system. Quantitative determination was performed by gas chromatographic (GC) analysis on a column packed with 5% DEGS-PS on 100-120 mesh Supelcoport using either an N-P detector or a flame photometric detector (FPD) in the sulfur mode. Minimum detection by the flame photometric detector is 10 ng each for ametryn, GS-11354, and GS-11355 and 21 ng for GS-26831; by the N-P detector, 0.3 ng of each component gives easily quantitatable peaks. On a parts per million basis, starting with 25 g sample, the FPD detected a minimum level of 0.04 p.g/g each for ametryn, GS-11354, and GS-11355, and 0.08 p.g/g for GS-26831. The N-P detector could detect 0.0024 p.g/g for all 4 compounds. In addition to superior sensitivity, instrumental conditions allowed the complete separation of components in 10 min, for the N-P detector; more than 30 min was required for the FPD. Recoveries from fortified crops ranged from 67 to 111% at levels of 0.1-1.0 μg/g.

Gas-Liquid Chromatographic Determination of Sodium Bisulfite in Complex Matrices

1979 ◽  
Vol 62 (1) ◽  
pp. 15-18
Author(s):  
John J Czarnecki ◽  
Walter R Koehler ◽  
Aaron D Cooper
Keyword(s):  
Chromatographic Determination ◽  
Sodium Bisulfite ◽  
Experimental Conditions ◽  
Flame Photometric Detector ◽  
Photometric Detector ◽  
Specificity And Sensitivity ◽  
Combined Use ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A gas-liquid chromatographic (GLC) headspace technique is described for determining sodium bisulfite in a dermatological cream. The sample is dispersed in an aqueous medium and acidified to convert sulfite to volatile sulfur dioxide which partitions into the headspace. An aliquot of the headspace vapor is analyzed by GLC using the sulfur-selective flame photometric detector. Advantages of the method include the facility of sample preparation, the specificity and sensitivity resulting from the combined use of the headspace technique and the flame photometric detector, and the applicability of the method to various types of sample matrices. Recoveries ranged from 95 to 102% for spiked samples containing 200—2000 ppm sodium bisulfite. For the sample size and experimental conditions used in this application, the detection limit is 0.02 mg sodium bisulfite.

Determination of sulfur-containing drugs by gas chromatography with flame photometric detector

1983 ◽  
Vol 6 (2) ◽  
pp. 103-108
Author(s):  
Kyoung Ho Kim ◽  
Yung Hyun Cho ◽  
Man Ki Park ◽  
Wang Kyu Lee
Keyword(s):  
Gas Chromatography ◽  
Flame Photometric Detector ◽  
Photometric Detector ◽  
Sulfur Containing
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