Method for detecting systemic pesticide dimethoate residue

[0035] In this embodiment, petroleum ether is selected from analytically pure petroleum ether supplied by Sinopharm Chemical Reagent Co., Ltd., diethyl ether is selected from analytically pure diethyl ether supplied from Sinopharm Chemical Reagent Co., Ltd., and disodium hydrogen phosphate is selected from analytically pure hydrogen phosphate supplied from Sinopharm Chemical Reagent Co., Ltd. Disodium, citric acid selects 99% citric acid supplied by Sinopharm Chemical Reagent Co., Ltd., chloroform selects analytical pure chloroform supplied by Sinopharm Chemical Reagent Co., Ltd., and 33% diethylamine aqueous solution selects Sinopharm Chemical Reagent Co., Ltd. to supply Analytical pure 33% diethylamine aqueous solution, hydrogen peroxide chooses analytical pure 30% hydrogen peroxide supplied by Sinopharm Chemical Reagent Co., Ltd., and anhydrous dipotassium hydrogen phosphate chooses analytical pure anhydrous phosphoric acid supplied by Sinopharm Chemical Reagent Co., Ltd. Dipot

[0044] A method for detecting systemic pesticide dimethoate residues of the present invention comprises the following:

[0045] Step a, weighing 100g of the vegetable sample to be tested in a homogenizer, pulverizing to obtain the first sample, for use;

[0046] Step b, weigh 5g of the first sample into a 50ml first centrifuge tube, add 10ml of pH 6.0 sodium salt solution, fully shake and mix for 2 minutes, add 5ml of chloroform, shake and mix for 2 minutes, then put it in the centrifuge , centrifuge at 10000rpm for 3min until the solution in the first centrifuge tube is clearly stratified, take 4.5ml of the lower chloroform phase solution into the 15ml second centrifuge tube to obtain the first sample solution, the sodium salt solution of pH6.0 is disodium hydrogen phosphate solution and the mixed solution of citric acid solution;

[0047] Step c, put the second centrifuge tube into the air concentrator, and dry the first sample liquid with air at 65°C to obtain the first analy

[0053] A method for detecting systemic pesticide dimethoate residues of the present invention comprises the following:

[0054] Step a, weighing 100g of the fruit sample to be tested in a homogenizer, pulverizing to obtain the first sample, for use;

[0055] Step b, weigh 5g of the first sample into a 50ml first centrifuge tube, add 10ml of pH 6.0 sodium salt solution, fully shake and mix for 2 minutes, add 5ml of chloroform, shake and mix for 2 minutes, then put it in the centrifuge , centrifuge at 10000rpm for 3min until the solution in the first centrifuge tube is clearly stratified, take 4.5ml of the lower chloroform phase solution into the 15ml second centrifuge tube to obtain the first sample solution, the sodium salt solution of pH6.0 is disodium hydrogen phosphate solution and the mixed solution of citric acid solution;

[0056] Step c, put the second centrifuge tube into the air concentrator, and dry the first sample liquid with air at 65°C to obtain the first analyte;