Study On Detecting Pesticide Multiresidues In Apple

A new rapid method for detecting the pesticide multiresidues in fruits was developed.The sensitivity and accuracy of the method were investigated.And the applicability in different fruits matrixes,practicality and applicability of the method were also studied.The main results were summarized as following:Firstly 3 methods for sample parathion were compared,and choose the compatiable one for next study,then we optimized the method as follow aspects:the orthogonal regression design were used to compare with different sorbents,elute solvents,their dosage,and ultrasonic extracting time to establish the optimized method.The first orthogonal regression design were used to compare with Florisil,silica gel:Aluminium oxide neutral(g/g,1:1),Florisil:silica gel(g/g,1:1) and the dosage of them were 2g,2.5g,3g respectively.Under the condition:2g Florisil and acetone:Hexane(v/v,2:8),the pesticides' recoveries have a range from 65.1%to 110.0 %,and RSD were all below 20%.We also compare with different volomn of elute solvents,25mL acetone:Hexane (v/v,2:8) were used to set up wash curve.When the volomn of elute solvents were 15mL the recoveries attain more than 90%.So 15mL acetone:Hexane(v/v,2:8) can fit to the experiment's require.The second orthogonal regression design were used to choose extract solvent,they were acetonitrile,ethyl acetate,and acetone:Hexane(v/v,1:1),the volomn were 10mL,15mL,20mL respectively.Ultrasonic extracting time were 5min,8min,10min respectively.Though analyzing the results when use 20mL acetonitrile and the ultrasonic extracting time is 10min,the average recoveries have a range from 74.1 %～130.1%,RSD all below 20%,can fit to the experiment's require.The applicability of the optimized method were studyed in different matrixes apple,pear and so on.The recoveries of organochlorines and pyrethroids pesticides in pear matrix were 88.7%～118.34%,and RSD were 0.36%～19.22%.Use this method to detecting 19 organophosphorus pesticides,the average recoveries have a range from 71.6%to 123.3%,and the RSD have a range from 0.002%to 12.8%.And lastly we investigated samples of pesticides contaminated by Anhui roduce on the basis of the optimized method.The results show that the method could be easily detecting pestiside residues in fruits.