Multiresidue method for determination of 90 pesticides in fresh fruits and vegetables using solid-phase extraction and gas chromatography-mass spectrometry.
A multiresidue method for analysis of 90 pesticides with different physico-chemical properties in fruits and vegetables was developed. The method involves a rapid and small-scale extraction procedure with acetone using vortex mixing. Solid-phase extraction (SPE) on a highly cross-linked polystyrene divinylbenzene column (LiChrolut EN) was used for clean-up and pre-concentration of the pesticides from the water-diluted acetone extracts. For most fruit and vegetable samples this partial clean-up was sufficient, but some of them with more co-extracting substances need further clean-up (cereals, spinach, carrots, etc.). Diethylaminopropyl (DEA) modified silica was used for efficient removal of interferences caused by various organic acids, sugars, etc. The pesticide residues were determined by gas chromatography with a mass selective detector (GC-MS). The majority of pesticide recoveries for various fruits and vegetables were >80% in the concentration range from 0.01 to 0.50 mg/kg, except for the most polar pesticides (methamidophos, acephate, omethoate) which cannot be determined by this method. The limit of quantitation for most of the pesticides was 0.01 mg/kg with majority of relative standard deviations (R.S.D.s) below 10%.
Public Health Institute, Environmental Protection Institute, Prvomajska 1, 2000 Maribor, Slovenia. darinka.stajnbaher@zzv-mb.si
Darinka
D
Stajnbaher
Lucija
L
Zupancic-Kralj
D002138:Calibration; D005638:Fruit / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D010573:Pesticide Residues / Q000032:analysis*; D012015:Reference Standards; D015203:Reproducibility of Results; D014675:Vegetables / Q000737:chemistry*
D010573:Pesticide Residues