Detection method and application of 2-methylimidazole and 4-methylimidazole in baked food

Abstract

The invention discloses a detection method of 2-methylimidazole and 4-methylimidazole in baked food. A mixed solution of trichloroacetic acid and methyl alcohol is added to a baked food sample to make protein, colloid and other impurities subside, supersonic extraction is conducted, a solution to be detected is obtained through centrifugation and filtering, a CAPCELL CR (1:4) chromatographic column (5 microns, 2.0 mm*150 mm) is adopted for separation, and the 2-methylimidazole and the 4-methylimidazole are subjected to qualitative and quantitative analysis through an isotope dilution ultra high performance liquid chromatography tandem mass spectrometry method. The method is free of solid phase extraction and other complex sample pre-processing procedures, three types of isomeride of the methylimidazole can be effectively separated, the ion inhibition effect is effectively lowered, sensitivity is improved, and the detection method has the advantages of being low in detection limit and good in accuracy.

Description

technical field [0001] The invention relates to a detection method and application of 2-methylimidazole and 4-methylimidazole in baked food. Background technique [0002] Methylimidazole is a nitrogen-containing heterocyclic compound. Methylimidazoles containing a methyl group include 1-methylimidazole (1-MEI), 2-methylimidazole (2-MEI) and 4-methylimidazole (4 -MEI) three isomers, of which 2-MEI and 4-MEI have a strong convulsive effect, and the US National Toxicology Program (NTP) has proved that 2-MEI and 4-MEI are carcinogenic through animal toxicology experiments , the International Agency for Cancer (IARC) lists it as a Group 2B "probable human carcinogen". The California Office of Environmental Health Risk Assessment (OEHHA) recommends that the daily intake of 4-methylimidazole should be less than 29 μg. The caramel color produced by ammonia method and ammonium sulfite method is the main source of 2-MEI and 4-MEI. The national standard GB8817-2001 of the People's R...

AI Technical Summary

Problems solved by technology

Generally speaking, thin-layer chromatography has many operational steps and is inaccurate in quantification; spectrophotometry is seriously interfered by the matrix, and the measurement results have large deviations; the sample pretreatment of GC and GC-MS methods is cumbersome and requires derivatization; Susceptible to the interference of impurities, prone to false positives; LC-MS / MS and UPLC-MS / MS methods, sample pretreatment methods mainly include QuEChERS kit, ion pair extraction, solid phase extraction, supercritical fluid extraction, cation exchange Adsorption, etc. Although these purification methods can reduce interference and improve sensitivity, they increase the detection workload and test cost, and the current methods do not take into account the possible interference of the isomer 1-MEI on the detection

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