Method for determinating glyphosate, aminomethylphosphonic acid and glufosinate pesticide residues in tea leaves

Abstract

The invention discloses a method for determinating glyphosate, aminomethylphosphonic acid and glufosinate pesticide residues in tea leaves. By a liquid chromatography tandem mass spectrometry, the method is characterized by comprising the following steps: 1), weighing a test sample, adding 5-20mL of methanol water, whirling thoroughly, adding 5-20mL of dichloromethane, whirling, uniformly mixing,performing ultrasonic treatment, taking out, centrifuging, and taking a supernatant for purification; 2), taking 2mL of the supernatant, eluting with a CAX eluent in an activated CAX purifying small column, collecting by using 10ml of a round-bottom plastic tube, performing nitrogen blowing till a nearly dry state, adding 1mL of a boric acid buffer solution with the concentration of 1-5% for lateruse; 3), taking the stock solution, uniformly mixing, adding 200[mu]L of an FMOC-Cl derivatization reagent, uniformly mixing by whirling for 1min, derivatizing overnight at normal temperature, centrifuging at the speed of 4500r / min for 5min, then filtering by using a 0.22[mu]m organic filtration membrane, and applying to a machine for detection. By the method, the detection limit is 0.010mg / kg.

Description

technical field [0001] The invention relates to a determination method, in particular to a determination method of glyphosate, aminomethylphosphonic acid and glufosinate-ammonium pesticide residues in tea leaves. Background technique [0002] The existing standard SN / T1923-2007 uses liquid chromatography-mass spectrometry to detect glyphosate residues in imported and exported foods, which is applicable to soybeans, wheat, rice, corn, sugar cane, oranges, perilla, chestnuts, tea detection and confirmation of residues of glyphosate (PMG) and its metabolite aminomethylphosphonic acid (AMPA) in ginseng, shrimp, fish, livestock and poultry meat, honey, spices, ginseng, but glyphosate and aminomethylphosphonic acid (AMPA) in tea The detection limit of phosphonic acid is too high, not reaching the organic detection standard of 0.010mg / kg. Contents of the invention [0003] In order to solve the problems in the above-mentioned background technology, the object of the present inve...

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Problems solved by technology

[0002] The existing standard SN / T1923-2007 uses liquid chromatography-mass spectrometry to detect glyphosate residues in imported and exported foods, which is applicable to soybeans, wheat, rice, corn, sugar cane, oranges, perilla, chestnuts, tea detection and confirmation of residues of glyphosate (PMG) and its metabolite aminomethylphosphonic acid (AMPA) in ginseng, shrimp, fish, livestock and poultry meat, honey, spices, ginseng, but glyphosate and aminomethylphosphonic acid (AMPA) in tea The detection limit of phosphonic acid is too high, not reaching the organic detection standard of 0.010mg / kg

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