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.

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.

scholarly journals Determination of Fluvalinate Residues in Beeswax by Gas Chromatography with Electron-Capture Detection

2000 ◽  
Vol 83 (5) ◽  
pp. 1225-1228 ◽  
Author(s):  
Angeliki Tsigouri ◽  
Urania Menkissoglu-Spiroudi ◽  
Andreas T Thrasyvoulou ◽  
Grigorios C Diamantidis
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Diethyl Ether ◽  
Capillary Gas Chromatography ◽  
Diatomaceous Earth ◽  
Accurate Method ◽  
Electron Capture Detection ◽  
Limit Of Determination ◽  
Coefficients Of Variation

Abstract A simple, rapid, and accurate method is described for the determination of residual fluvalinate in beeswax. The procedure consists of partitioning on a disposable column of diatomaceous earth (Extrelut®), followed by chromatographic cleanup on a Florisil cartridge. The final extract is analyzed by capillary gas chromatography with electron-capture detection (GC–ECD). Briefly, wax samples were dissolved in n-hexane, and the solutions were sonicated and transferred to Extrelut columns. The fluvalinate was extracted with acetonitrile, and a portion of the extract was cleaned up on a Florisil cartridge. The fluvalinate was eluted with diethyl ether–n-hexane (1 + 1) and directly determined by GC–ECD. Recoveries from wax samples spiked at 5 fortification levels (100–1500 μg/kg) ranged from 77.4 to 87.3%, with coefficients of variation of 5.12–8.31%. The overall recovery of the method was 81.4 ± 3.2%, and the limit of determination was 100 μg/kg.

scholarly journals Determination of Organochlorine, Organophosphorus, and Triazine Pesticide Residues in Wine by Gas Chromatography with Electron Capture and Nitrogen–Phosphorus Detection

1996 ◽  
Vol 79 (6) ◽  
pp. 1423-1427 ◽  
Author(s):  
Rosario Garcia-Repetto ◽  
Isabel Garrtoo ◽  
Manuel Repetto
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Pesticide Residues ◽  
Solid Phase ◽  
Electron Capture Detection ◽  
Gel Chromatography ◽  
Phase Extraction ◽  
Silica Gel Chromatography ◽  
Nitrogen Phosphorus

Abstract A multiresidue analytical method is described for determining 6 pesticides in wine: chlorpyrifos, dimethoate, quinalphos, simazine, tetradifon, and endosulfan. Wine (200 mL) is extracted with dichloromethane (50 mL, 3 times), and the evaporated extracts are purified by silica gel chromatography. Pesticide residues are eluted with n-hexane, n-hexane-benzene (1 + 1), benzene, benzene–acetone (1 + 1), and acetone. Residues are determined by gas chromatography with nitrogen–phosphorus and electron capture detection, using CPSH-5CB, Carbo wax-20M, and CPSH-19CB columns. Recoveries of pesticides added at 0.025 μg/L were 83–97%, with standard deviations of 0.01–0.05%. Detection limits were 0.13–8.9 ng/L, except for simazine (36.7 μg/L). Results are compared with those obtained with a solid-phase extraction (C18) purification and with different eluant series.

Determination of clovoxamine concentration in human plasma by electron capture gas chromatography.

1981 ◽  
Vol 27 (7) ◽  
pp. 1210-1212 ◽  
Author(s):  
H E Hurst ◽  
D R Jones ◽  
C H Jarboe ◽  
H deBree
Keyword(s):  
Clinical Trial ◽  
Gas Chromatography ◽  
Human Plasma ◽  
Electron Capture ◽  
Plasma Concentrations ◽  
Antidepressant Drug ◽  
Internal Standard ◽  
Early Clinical Trial ◽  
Coefficients Of Variation

Abstract The antidepressant drug clovoxamine can be specifically and sensitively quantitated in human plasma by electron capture gas chromatography. Clovoxamine and the internal standard fluvoxamine are extracted into ethyl acetate from plasma at pH 12, back-extracted into phosphoric acid, and hydrolyzed at 90 degrees C to form ketone derivatives, which are then re-extracted into hexane for injection into the chromatograph. As little as 1 microgram of clovoxamine per liter of plasma can be measured. The coefficients of variation (CV) for th analysis at concentrations of 10 and 100 micrograms/L are respectively: within-run, 5.4% and 2.7%; between-run, 17.5% and 7.0%. When this assay was applied to plasma from individuals involved in an early clinical trial of clovoxamine, steady-state plasma concentrations ranged from 50 to 77 micrograms/L 3 h after a 50-mg oral dose of clovoxamine fumarate.

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