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 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.

Gas Chromatographic Determination of N-Butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine and α,α,α-Trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine in Formulations

1971 ◽  
Vol 54 (3) ◽  
pp. 711-712
Author(s):  
Martha Fuzesi
Keyword(s):  
Gas Chromatography ◽  
Quantitative Determination ◽  
Electron Capture ◽  
Chromatographic Method ◽  
Chromatographic Determination ◽  
Electron Capture Detector ◽  
Reference Solution ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method is described for the quantitative determination of N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-tolindine and α,α,α-trifluoro-2,6-dinitro-N,N-dipropyI-p-toluidine herbicides in formulations. The sample is extracted with benzene, and equal amounts of sample and reference solution in the same concentration range are analyzed by gas chromatography, using an electron capture detector and an SE-30/Diatoport S column. The method has been applied successfully to laboratory-prepared and commercial samples.

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 Chromatographic Determination of Captan, Folpet, and Captafol Residues in Tomatoes, Cucumbers, and Apples Using a Wide-Bore Capillary Column: Interlaboratory Study

1991 ◽  
Vol 74 (5) ◽  
pp. 830-835 ◽  
Author(s):  
Dalia M Gilvydis ◽  
Stephen M Walters
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Capillary Column ◽  
Chromatographic Determination ◽  
Interlaboratory Study ◽  
Electron Capture Detection ◽  
Coefficients Of Variation ◽  
Capillary Column Gas Chromatography ◽  
Ppm Level

Abstract An interlaboratory study of the determination of captan, folpet, and captafol in tomatoes, cucumbers, and apples was conducted by 4 laboratories using wide-bore capillary column gas chromatography with electron capture detection. The 3 fungicides were determined using the Luke et al. multlresidue method modified to Include additional solvent elutlon in the optional Florisll column cleanup step used with this method. The crops were fortified with each fungicide at 3 levels per crop. Mean recoveries ranged from 86.2% for a 25.1 ppm level of captan in apples to 115.4% for a 0.288 ppm level of captafol In apples. Interlaboratory coefficients of variation ranged from 3.4% (24.7 ppm folpet) to 9.7% (0.243 ppm captafol) for tomatoes; from 2.8% (2.0 ppm captafol) to 8.2% (24.8 ppm captan) for cucumbers; and from 1.5% (0.234 ppm folpet) to 22.1% (0.266 ppm captafol) for apples.

Gas Chromatographic Determination of Pentachlorophenol in Gelatin

1984 ◽  
Vol 67 (2) ◽  
pp. 275-277
Author(s):  
Arnold P Borsetti ◽  
Lee S Thurston
Keyword(s):  
Gas Chromatography ◽  
Liquid Phase ◽  
Electron Capture ◽  
Limit Of Detection ◽  
Direct Determination ◽  
Chromatographic Determination ◽  
Gelatin Matrix ◽  
Limit Of Quantitation ◽  
Acetate Derivative

Abstract A method is described for the determination of pentachlorophenol (PCP) in gelatin. The method employs acid and heat to hydrolyze the gelatin matrix, a base partition and wash for separation and cleanup, and a reacidification and extraction with hexane for direct determination of PCP, without preparation of a derivative, using gas chromatography (GC) with a 1% SP-1240DA liquid phase and a 63Ni electron capture detector. Recoveries averaged 106% for fortifications between 0.02 and 1.0 ppm. The limit of quantitation is 20 ppb. The limit of detection is 4-6 ppb. The method, which has undergone a successful intralaboratory trial, is simple and rapid, and requires only general laboratory reagents and equipment. GC of the acetate derivative of PCP is used for confirmation of identity.

scholarly journals Determination of Malathion, Coumaphos, and Fluvalinate Residues in Honey by Gas Chromatography with Nitrogen–Phosphorus or Electron Capture Detectors

2000 ◽  
Vol 83 (1) ◽  
pp. 178-182 ◽  
Author(s):  
Urania Menkissoglu-Spiroudi ◽  
Grigorios C Diamantidis ◽  
Vassiliki E Georgiou ◽  
Andreas T Thrasyvoulou
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
High Selectivity ◽  
Order Model ◽  
First Order ◽  
Quantitation Limit ◽  
Coefficients Of Variation ◽  
Electron Capture Detectors ◽  
Nitrogen Phosphorus

Abstract A rapid, reliable, and inexpensive extraction method was developed to determine acaricide residues in honey by gas chromatography (GC) with nitrogen–phosphorus (NP) or electron capture (EC) detectors. Because of the high selectivity of the NP detector, no interfering peaks were present and no cleanup was necessary. A simple cleanup step is proposed for the GC–ECD analysis. Recoveries from spiked honey samples ranged from 79 to 94.4%, with coefficients of variation of 0.3–18.5%. The quantitation limit obtained was 0.015 mg/kg for malathion, 0.020 mg/kg for coumaphos, and 0.005 mg/kg for fluvalinate. The method was used to determine the disappearance of malathion and coumaphos residues from honey samples collected from beehives treated with these acaricides. The disappearance of both acaricides was rapid and followed a first-order model for the duration of the experiment.

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