Determination of 8 Organophosphorus Pesticides in Xinhui Dried Orange Peel and Its Products by Gas Chromatography with Solid Phase Extraction

KeyWord:organophosphorus pesticides  pesticide residues  homemade double solid phase extraction column  gas chromatography(GC)  xinhui dried orange peel

Abstract:

      A method of gas chromatography(GC) coupled with solid phase extraction was established for the simultaneous determination of 8 kinds of organophosphorus pesticide residues£¬including ethopropophos,sulfotep,terbufos,monocrotophos,parathion methyl,fenitrothion,isofenphos methyl and isocarbophos in xinhui dried orange peel and its products.The factors affecting extraction£¬purification and detection efficiency were optimized£¬and the optimal conditions were as follows£ºthe samples were extracted with ethyl acetate£¬and purified on a homemade double solid phase extraction column packed with N-propylethylenediamine and multi-walled carbon nanotubes.The separation of target compounds were performed on a film thickness of Shimadzu Rtx-1701 capillary column(30 m¡Á0.25 mm¡Á0.25 ¦Ìm)£¬and the quantitative analysis of organophosphorus pesticides was carried out by GC with flame photometric detector and the external standard method.Under the optimized conditions£¬the calibration curves of 8 organophosphorus pesticides were linear in the range of 0.020-1.0 ¦Ìg/mL with correlation coefficients of 0.997 0-0.999 2£®The detection limits(S/N=3)were in the range of 3.6-8.8 ¦Ìg/kg£®The recoveries of the pesticides in Xinhui dried orange peel and its products at three spiked levels ranged from 72.5%to 106%£¬with relative standard deviations of 2.8%-8.7%. With the advantages of accuracy,sensitivity£¬easy operation and rapidness,the method is applicable in the simultaneous determination of 8 kinds of organophosphorus pesticides in Xinhui dried orange peel and its products.The homemade column is worthy of popularization and application as it is inexpensive,and could largely reduce the detection cost.