Clean-up and confirmation procedures for gas chromatographic determination of pesticide residues in contaminated waters. Part I

1993 ◽  
Vol 655 (2) ◽  
pp. 285-292 ◽  
Author(s):  
E. Viana ◽  
J.C. Moltó ◽  
J. Mañes ◽  
G. Font
1981 ◽  
Vol 64 (3) ◽  
pp. 743-748 ◽  
Author(s):  
Árpád Ambrus ◽  
Éva Hargitai ◽  
Gabriella Károly ◽  
András Fülöp Ambrus ◽  
János Lantos Ambrus

Abstract o-Tolidine plus KI, p-nitrobenzene-diazoniumfluoroborate, bioassay with fungi and enzyme sources, AgNO3 plus UV radiation, and p-dimethyl-aminobenzaldehyde modes of detection have been selected for TLC screening of pesticide residues in extracts of samples of unknown origin. Single solvents were used for the elution. Coefficients of variation of Rf values were studied as a function of Rf and eluants. Indicator compounds were used for controlling the proper conditions of detection. The detectability of 188 pesticide compounds was tested, and the minimum detectable amounts were determined.


2006 ◽  
Vol 89 (1) ◽  
pp. 196-200 ◽  
Author(s):  
Frank J Schenck ◽  
Lynda V Podhorniak ◽  
James Hobbs ◽  
John Casanova ◽  
Dan Donoghue

Abstract A reversed-phase liquid chromatographic (LC) method is presented for the analysis of N-methyl carbamate pesticide residues and piperonyl butoxide in eggs at levels as low as 2 gkg (ppb). The study was undertaken to provide data for dietary exposure estimates used in risk analysis. The method uses an acetonitrile extraction followed by liquidliquid partitioning and normal-phase aminopropyl solid-phase extraction column cleanup. Determination of residues is by reversed-phase LC with an inline postcolumn reaction followed by fluorescence detection. The average recoveries of 21 fortified (most at 2.0 and 20.0 ppb) N-methyl carbamate pesticide residues and the carbamate metabolite 1-naphthol from eggs ranged from 70 to 107%. Recoveries of the pesticide synergist piperonyl butoxide ranged from 63 to 106%. Single-comb White Leghorn hens were treated with the carbamate carbaryl, and the eggs subsequently produced were analyzed for carbaryl and 1-naphthol residues.


2007 ◽  
Vol 90 (2) ◽  
pp. 544-549 ◽  
Author(s):  
Nuria Vela ◽  
Gabriel Prez ◽  
Gins Navarro ◽  
Simn Navarro

Abstract A method for the simultaneous determination of 9 pesticides (dinitroanilines, organophosphorus, triazoles, and pyrimidines) in several products (malt, spent grains, wort, and beer) of the beer industry is reported. Solid samples (malt and spent grains) are extracted by homogenization with a waterhexane mixture, and the pesticides are partitioned with dichloromethane. Liquid samples (wort and beer) are extracted by sonication with a hexanedichloromethane mixture. Determination of pesticide residues was made by capillary gas chromatography with an electron capture detector (ECD). Confirmation of the compounds was performed by gas chromatography/ion trap mass spectrometry in the selected ion monitoring mode. Detection limits for GCECD varied from 0.2 to 5.5 pg for trifluralin and malathion, respectively. Recoveries of the pesticides from spiked samples ranged from 81.2 to 113.7% with a relative standard deviation between 3.47.5%. The method presents good linearity over the studied range (0.0052 g/mL). The proposed method is rapid and reliable and can be useful for routine monitoring during brewing.


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