Determining pretreatment method for sample containing 3,5,6-trichloro-2-pyridinol pesticide residue

[0028] Extraction: Accurately weigh 20g of crushed leek sample (accurate to 0.01g) into a 250mL Erlenmeyer flask, add 10mL of water, 0.2mL of glacial acetic acid and 40mL of ethyl acetate, shake and extract for 1 hour, collect the extract in a 100mL stoppered measuring cylinder, Add 5g of sodium chloride, shake and mix well, then let it stand for 30 minutes, absorb 10mL of supernatant, concentrate to dryness, dissolve with 2mL of acetonitrile, and wait for purification.

[0029] Purification: Add 2mL of the solution to be purified to a graphitized carbon amino column activated by 10mL of acetonitrile, and after it is drained, rinse with 5mL of acetonitrile and 5mL of 0.2% formic acid acidified acetonitrile solution, and then use 40mL of 0.5% formic acid Elute with acidified acetonitrile solution and collect all eluate. It was evaporated to dryness at 40°C, dissolved in 4 mL of methanol-0.1% formic acid water (50+50, V+V), and passed through a 0.22 μm filter membrane for testing.

[0031] Extraction: Accurately weigh 10g of crushed leek sample (accurate to 0.01g) into a 250mL Erlenmeyer flask, add 20mL of water, 0.25mL of glacial acetic acid and 50mL of ethyl acetate, shake and extract for 0.5h, collect the extract in a 100mL stoppered measuring cylinder , add 10g of sodium chloride, shake and mix well and let it stand for 30 minutes, absorb 10mL of the supernatant, concentrate it, dissolve it with 2mL of acetonitrile, and wait for purification.

[0032] Purification: Add 2mL of the solution to be purified to a graphitized carbon amino column activated by 10mL of acetonitrile, and after it has drained dry, rinse with 5mL of acetonitrile and 5mL of 0.5% formic acid acidified acetonitrile solution, and then use 40mL of 0.3% formic acid Elute with acidified acetonitrile solution and collect all eluate. It was evaporated to dryness at 40°C, dissolved in 2 mL of methanol-0.1% formic acid water (50+50, V+V), and passed through a 0.22 μm filter membrane for testin

[0034] Extraction: Accurately weigh 20g of crushed leek sample (accurate to 0.01g) into a 250mL conical flask, add 20mL of water, 0.2mL of glacial acetic acid and 40mL of ethyl acetate, shake and extract for 2 hours, collect the extract in a 100mL stoppered measuring cylinder, Add 10g of sodium chloride, shake and mix well, then let stand for 15 minutes, absorb 10mL of supernatant, concentrate to dryness, dissolve with 2mL of acetonitrile, and wait for purification.

[0035] Purification: Add 2mL of the solution to be purified to a graphitized carbon amino column activated by 10mL of acetonitrile, and after it is drained, rinse with 5mL of acetonitrile and 5mL of 0.5% formic acid acidified acetonitrile solution, and then use 40mL of 0.5% formic acid Elute with acidified acetonitrile solution and collect all eluate. It was evaporated to dryness at 40°C, dissolved in 4 mL of methanol-0.1% formic acid water (50+50, V+V), and passed through a 0.22 μm filter membrane for testing. Fin