Analysing organophosphorus pesticides in wines using graphitized carbon black extraction cartridges.
A quick and simple method was developed to determine the residues of 15 organophosphorus pesticides of different polarity in grape wine, based on liquid-solid extraction with graphitized carbon black cartridges and capillary gas chromatography. Aliquots of diluted wine (10 ml wine + 40 ml deionized water) and 250 mg graphitized carbon black cartridges were used to extract the analytes. The pesticides were eluted with 2 x 0.5 ml acetone and 3 x 2.5 ml ethyl acetate/acetone (80:20). The eluates were then dried with anhydrous sodium sulphate and concentrated to 1 ml under a nitrogen current. After adding triphenylphosphate internal standard (i.s.), this extract was analysed by capillary gas chromatography using a nitrogen-phosphorus detector (GC-NPD). Pesticide recovery percentages at levels of 0.01 and 0.02 microgram/ml were between 74% and 111%, with a 2-13% relative standard deviation interval. The chromatograms of extracts had few co-extracted species peaks, with no analytical interference. Dilution of the grape wine samples removed most of the pigments, thus producing clear extracts. The results indicate that liquid-solid extraction from wine samples using graphitized carbon is fast (25 min per sample), efficient and reproducible for analysing organophosphorus pesticides of different polarity.
Prieto
A
A
Departamento de Química, Facultad de Agronomía, Universidad del Zulia, Maracaibo, Venezuela.
Ettiene
G
G
Medina
D
D
Buscema
I
I
González
G
G
Araujo
L
L
D002849:Chromatography, Gas / Q000379:methods; D005506:Food Contamination; D006108:Graphite; D006801:Humans; D007306:Insecticides / Q000032:analysis*; D009943:Organophosphorus Compounds; D010573:Pesticide Residues / Q000032:analysis*; D014920:Wine / Q000032:analysis*
D007306:Insecticides; D009943:Organophosphorus Compounds; D010573:Pesticide Residues; D006108:Graphite