Study On The Determination Of Organophosphorus Multiresidue In Bamboo-shoot

Bamboo-shoot is traditional export product of our country.However, Organophosphorus pesticides are used widely.It is very important to establish the analytic method for organophosphorus multiresidue determination in bamboo-shoot.In this paper, we established the analytic method for 14 organophosphorus multiresidue determination in bamboo-shoot,refers to method of QuEchERS,and we investigated bamboo-shoot in which anhui produced for contaminated by organophosphorus pesticides.The main results were summarized as follows:The determination condition of 14 organophosphorus pesticide by GC with HP-5 capillary column:0.25 mm(i.d.)×30mm.Detecter:FPD.Calefactive program of column: the column temperature was set at 60℃(hold 1 min),then increased at 30℃/min to 180℃(hold 5 min),then increased at 20℃/min to 200℃(hold 9min),at last raised 40℃/min until 240℃(hold 9 min).Inet:200℃,Detecter temperature:250℃flow of N2:1.5mL/min;and injector volume:2μL.1.The process of sample preparation was optimized and developed.Extracting method:This experiment compared the method of extracted by ultrasonic and swirling,and the average recoveries were respectively 63.9%～87.2%and 79.7%～110.4%.The optimal method was ultrasonic method.Extracting time:The average recoveries from fortifed bamboo-shoot extracted with ultrasonic method by 3min,5min and 10min were respectively 63.9%～87.2%,63.9%～87.2%and 63.9%～87.2%,the optimal extracting time was 3min.Volume of extracting solvent:The volume of extracting solvent were respectively 10mL,15mLand 20mL,and the average recoveries were respectively 80.7%～112.4%,78.6%～115.3%and 74.3%～113.7%,the optimal volume of extracting solvent was 10mL.Amount of PSA:When the amount of PSA were added respectively 50mg,80mg, 100mg and 150mg,the average recoveries were respectively 52.3%～98.3%,81.3%～106.8%,79.6%～109.4%and 83.4%～121.7%,and the optimal amount of PSA was 80～100mg.The average recoveries of organophosphorus in bamboo-shoot was 60.2%～93.1%,when use anhydrous Na₂SO4 instead of anhydrous MgSO₄.The average recoveries of organophosphorus in bamboo-shoot was 45.4%～83.7%,when wipe off the system of buffer.3.The method entails extracting the pesticide residues from 10g of sample by wortex mixing with 10mL of acetonitrile which containing 1%acetic acid and adding 4g anhydrous magnesium sulfate plus 1g sodium acetate,carried out by ultrasonic shaking a centrifuging tube.The tube is then centrifuged for 10min,and a portion of the extract is transferred to a tube containing 80mg primary secondary amine and 300mg anhydrous magnesium.Then,the extract is centrifuged and transferred 1mL to 1mL volumetric flask,blow to dry,waiting for detecting.The recovery experiment indication:By using the established method,when the fortified concentration were 0.05mg·kg^-1～0.1mg·kg^-1,0.1mg·kg^-1～0.2mg·kg^-1and 0.5mg·kg^-1～1mg·kg^-1,the average recoveries of 14 organophosphorus pesticides ranged between 60.1%and 79.2%,71.6%and 89.5%,84.3% and 96.3%respectively,the CV were respectively 4.2%～8.7%,3.2%～7.9%and 2.1%～7.6%.The results are all according with the requirement of residual analysis.The minimum detected concentration are 0.0042mg/kg～0.0208mg/kg.This experiment also compared the optimized method according to QuEchERS with other three typical sample preparations.The result indicated that three typical sample preparations which selected was not according with the requirement of residual analysis, moreover,the consume of solvent was greatness.But the optimized method is of accurate identification and quantity,simple operation and economy.4.We investigated bamboo-shoot which anhui produce contaminated by organophosphorus pesticides on the basis of the optimized method.The result of investigation indicated that bamboo-shoot which lingguo and huangshan of anhui provence were detected,the both pesticides was ddv,concentration were 0.051 mg/kg,0.041 mg/kg respectively.