Determination of chlorpyrifos residues in water,cabbage and soil by GC-FPD

Using gas chromatography-flame photometric detection(GC-FPD),a method was developed for the analysis of organophosphorus pesticide chlorpyrifos in water,soil and cabbage.The chlorpyrifos residue in water was extracted and purified by petroleum ether and liquid-liquid extraction.The chlorpyrifos residue in cabbage was extracted with acetone and the chlorpyrifos residue in soil was extracted by the Soxhlet method with acetone.After clean up by liquid-liquid distribution,it was determinated by GC-FPD equipped with OV-101(100% dimethyl polysiloxane)column(30 m×0.53 mm×1.0 μm).The retention time of chlorpyrifos was 1.74 min;the linearity range of chlorpyrifos was between 1.0×10-11 and 1.0×10-8 g;the correlation coefficient was 0.9998;the limits of detection was 2.0×10-12 g.Average recovery rates of chlorpyrifos in these samples ranged from 80% to 120% with coefficient of variation from 1.19% to 4.40%.The method is sensitive and operated easily to detect low levels of chlorpyrifos in the water,cabbage and soil.