Determination of residues of endosulfan and five pyrethroid insecticides in virgin olive oil using gas chromatography with electron-capture detection.
A simple, fast and economical method has been developed for the determination of endosulfan and five pyrethroid insecticides, cypermethrin, deltamethrin, fenvalerate, lambda-cyhalothrin and permethrin, in virgin olive oil. The method uses a Sep-Pak alumina-N column cleanup after a liquid-liquid extraction or low-temperature precipitation step, and gas chromatography (GC) with electron-capture detection. The matrix effect was assessed for the GC systems used. Recoveries were 71-91% with RSD values of 6-17%. The method was applied to 338 virgin olive oil samples for monitoring of residues of these pesticides. Cypermethrin and lambda-cyhalothrin were detected at the limit of quantification in one sample each, while 22% of samples contained endosulfan residues, mostly at very low levels ranging from 0.02 to 0.57 mg/kg.
Lentza-Rizos
C
C
National Agricultural Research Foundation, Athens, Greece. rizos@internet.gr
Avramides
E J
EJ
Visi
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E
D002849:Chromatography, Gas / Q000379:methods*; D004726:Endosulfan / Q000032:analysis*; D007306:Insecticides / Q000032:analysis*; D000069463:Olive Oil; D010573:Pesticide Residues / Q000032:analysis*; D010938:Plant Oils / Q000737:chemistry*; D011722:Pyrethrins / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D007306:Insecticides; D000069463:Olive Oil; D010573:Pesticide Residues; D010938:Plant Oils; D011722:Pyrethrins; D004726:Endosulfan