Study On Clean Up Technology Of Complex Matrix Based On Detection Of Orgnaophosphorus Residues In Chinese Chive

The matrix of Chinese chive is very complex.It is difficult to obtain good cleaning-up effect by traditional preprocess technologies.Therefore,the phenomenon called interference of base would be caused in the determination of pesticides and then the detection results would be inaccuracy.This paper studied the composition of Chinese chive and the cleaning ability of several absorptive materials.And methods of cleaning-up and detection of 11 orgnaophosphorus pesticides in Chinese chive samples based on solid-phase extraction(SPE) and matrix solid-phase dispersion(MSPD) was established.The main research results are presented as follows:1.The ability of several different solvents to extract sample was compared and ethyl acetate was chosen as the extraction solvent in the detection of pesticides finally.The main substances including sulfur compounds,fatty acids and some sterols were identified by GC/MS.Micro-wave had good effect on removing the interferencing substances while it could influence the pesticides.2.The cleaning-up effects on matrix of samples with four kinds of SPE columns including Envi-carb,Florisil,Lc-Si and N-Aliumn were compared.The results showed that Envi-carb column has good absorption affinity for pigments but weak for the other substances.The Florisil column,Lc-Si column and N-Aliumn column had weak absorption for pigments and the absorption effect on the other matrix by Florisil column was the best. 3.A method for double column series solid-phase extraction on purification of samples was described.The samples were extracted by ethyl acetate and the interferencing substances were removed by double column series SPE composed of Envi-carb column and Florisil column.The optimization conditions of elution were presented as following:the volume of n-hexane as elution solvent in Envi-carb cleaning-up was 8mL,and the volume of n-hexane mixed with ethyl acetate as elution solvent in Florisil cleaning-up was 5mL whose volume ratio was 9:1.11 kinds of orgnaophosphorus pesticides were cleaned up by this method and detected by GC/MS/SIM.The results indicated that the method of double column series solid-phase extraction was effective.4.A method for matrix solid-phase dispersion on purification of samples was described.The sampling weight was 0.5g.Pesti Carb and Lc-Florisil were used as absorbents whose weight was 0.1g and 0.4g respectively.The washing solvents were composed of n-hexane and ethyl acetate whose volume ratio and volume was 9:1 and 8mL respectively.11 kinds of orgnaophosphorus pesticides were cleaned up by this method and detected by GC/MS/SIM.The average recovery was 80%～110%,while the RSD was 0.3%～3.0%.Compared with SPE,MSPD was a rapid,high effective and environmental friendly method which could be available in the determination of pesticide residues of complex matrix.