Study On Developing A Systemic Multi-residue Method For Detecting Pesticide Residues In Vegetables,Fruits And Foods

The use of pesticides provides unquestionable benefits in increasing agricultural production. However, it has the drawback of pesticide residues which remain in fruit and vegetables, constituting a potential risk to consumers.In this paper a review concerning the determination of pesticide residues in fr-uit,vegetables and foods is presented. The basic principles of pesticide residues analysis are summarized, it's evulution is brought forword.It is impossible to establish one method to applying for all of pesticides and samples, so different methods are introduced to analysis different categories of pesticides, according to different physico-chemical properties.11 Organochlorine Pesticides are detected by GC-ECD and extracted with 50ml acetone and 100ml petroleum aether in Solxhlet's extractor clean-up with oil of vitriol. Recoveries of majority of pesticides from spiked samples at fortification levels of 0.005-2.0 mg/kg ranged from 92.4% — 103.7%, mean recovery≥80%. Relative standard deviations (RSD) ranged from 1.16 — 9.16%.6 Pyrethrines are detected by GC-ECD followed by extracted with petroleum aethe and clean-up with Florisil column chromatography. The recoveries of 6 pyrethroid ranged from 84.8% —107.2%, the average recoveries were ≥80%, RSD were 0.43-14.87%.19 Organophosphorus Pesticides are analysised by GC-FPD followed by extracted with acetonitrile without further clean-up, The majority of pesticide Recoveries for various fruits, vegetables foods were 70-110%. relative standard deviations (RSD) ranged from ≤20% except for DDVP.6 Methyl Carbamates are extracted by acetonitrile in combination with a normal-phase aminopropyl bonded silica SPE column cleanup and HPLC postcolumn fluorogenic determination. The recoveries of 6 Methyl Carbamates ranged from 67.8-99.4%,the average recoveries were 78.4-84.8%, RSD were 2.83-17.73% but the recoveries of ethyl para-nitro-pheny in youmucai and wheat were very low.For the conformation purpose a method for analysis of 36 pesticides determined by GC-MS in selective ion mode is also developed .