▎ 摘　　要

NOVELTY - Method for detecting content of food preservative involves randomly taking samples from food to be tested, adding the samples into a test tube, injecting hydrochloric acid solution, shaking, centrifuging the test tube, performing precipitation, filtering to obtain filtrate, dding adsorbent to the filtrate, vortexing with ethanol, analyzing, combining the analytical solutions, blow drying with nitrogen, then dissolving in ethanol to obtain sample solution, separating the sample solution and purification agent into solid-liquid mixture, collecting the supernatant, mixing the standard preservative, then dissolving in methanol to obtain the preservative standard mixed stock solution, using methanol to dilute the preservative standard mixed stock solution, injecting supernatant into the injection valve of the liquid chromatography-mass spectrometer using a pipette, performing liquid chromatography-mass spectrometry analysis and detecting the type and content of preservatives. USE - The method is useful for detecting content of food preservative, preferably dimethyl fumarate, dehydroacetic acid, benzoic acid, dimethyl p-hydroxybenzoate, diethyl p-hydroxybenzoate and diisopropyl p-hydroxybenzoate (claimed). ADVANTAGE - The method is safe and simple, has wide detection range and high detection efficiency, removes impurities that affect the detection result and improves accuracy of detection results. DETAILED DESCRIPTION - Method for detecting content of food preservative involves (a) randomly taking samples from 5 different parts of the food to be tested, adding the samples into a test tube, injecting 10-20 ml hydrochloric acid solution into the test tube, shaking for 1-2 minutes, centrifuging the test tube in a centrifuge for 3-5 minutes, performing precipitation and filtering to obtain filtrate, (b) adding adsorbent to the filtrate obtained in step (a), vortexing with ethanol 2-3 times for 2-5 minutes (each time), analyzing for 1-2 minutes (each time), combining the analytical solutions, blow drying with nitrogen, and then dissolving in ethanol to obtain sample solution, (c) separating the sample solution obtained in step (b) and purification agent into solid-liquid mixture and collecting the supernatant, (d) mixing the standard preservative, then dissolving in methanol to obtain the preservative standard mixed stock solution and then using methanol to dilute the preservative standard mixed stock solution to obtain the preservative standard mixed solution and (e) injecting 20 mu l supernatant obtained in step (c) into the injection valve of the liquid chromatography-mass spectrometer using a pipette, performing liquid chromatography-mass spectrometry analysis and detecting the type and content of preservatives.