Determination Of Organochlorines And Pyrethroid Pesticide Residues In Vegetable And Fruit By GC With Solid-phase Extraction

Synthetic pesticides are widely used in fruit and vegetables because of their susceptibility to insects and decease attacks. Organochlorine has been banned using in agricultural products since 1983. However, there are still some trace level residues in the plants and environment. The pyrethroids pesticides are used especially on vegetable, fruits, and other foodstuff. Although lower residuary, some adverse impacts still expose upon the environment and the human health. The method for control of pesticide residues in food has been paid great attention in the last decades and a number of analytical techniques have been developed for determination of pesticide residues in food and environment.Sophisticated analytical techniques such as gas chromatography with electron capture or mass spectrometry detection have been used for the determination of organochlorine and pyrethroids residues. Due to the trace levels of the compounds and the complex matrix, sample pretreatment, such as extraction, clean-up and concentration influence the reliability and accuracy of the result greatly. It is necessary to exploit efficient technology for samples pre-treatment and sensitive methods in multi-pesticide residues detections.SPE has been developed in these years due to its advantage of simplicity and economy in terms of time and solvent needs. The present study tried to develop the determination methods by gas chromatography with electron capture detector (ECD) on the multi-pesticide residues in vegetable and fruits. Study focus on sample pre-treatment comparing with that of the traditional methods. Ultrasonic wave assisted extraction and solid-phrase extraction were used instead of the traditional liquid-liquid extraction and chromatographic technique.Comparison was made within several kinds of sample extraction technique. The most efficient one is ultrasonic extraction. Concerning the involvement of SPE for the sample cleanup and enrichment, the type of eluents and the materials of cartridges should be considered according to the polar of target analysts. The mixture of petroleum ether-ethylacetate (9:1) and employment of the train with the Florisil and activated carbon cartridge gave a more satisfactory result than others.The average recoveries of the three spiked levels of 12 pesticides were 70-120% in vegetable and fruits. The Coefficient of variation (CV) is less than 20%. Method detection limits ranges from 0.15 to 2.36μg/kg. The result is reliable for determination of Organochlorine and pyrethroids residues by GC with solid-phase extraction simultaneously.