Simultaneous Determination of 2-Methylimidazole and 4-Methylimidazole in Various Foods by Ultrahigh Performance Liquid Chromatography-Tandem Mass Spectrometry
Simultaneous Determination of 2-Methylimidazole and 4-Methylimidazole in Various Foods by Ultrahigh Performance Liquid Chromatography-Tandem Mass Spectrometry[J]. 2016,35(8):943-948.
Simultaneous Determination of 2-Methylimidazole and 4-Methylimidazole in Various Foods by Ultrahigh Performance Liquid Chromatography-Tandem Mass Spectrometry[J]. 2016,35(8):943-948.DOI:
An ultrahigh performance liquid chromatography-tandem mass spectrometric(UPLC-MS/MS) method was developed for the simultaneous determination of 2-methylimidazole(2-MEI) and 4-methylimidazole(4-MEI) in various foods.Most of foods could be injected directly after ultrasonic extraction.Solid phase extraction was needed for extremely complex sample matrix(such as sauce,coffee and tea),and the target analytes were quantified by isotope internal standard.Under the optimized conditions,the limits of detection for 2-MEI and 4-MEI were up to 0.5 ng/g and 1.4 ng/g,respectively,the recoveries of the method ranged from 82.6%to 98.1%for 2-MEI and 89.5%to 108.1%for 4-MEI.The intraday RSDs of 2-MEI and 4-MEI were 1.3%-4.5%and 1.0%-5.0%,while their inter-day RSDs were 2.0%-5.4%and 1.9%-6.5%,respectively.The results indicated that the method was suitable for simultaneous determination of 2-MEI and 4-MEI in food matrices.This method was applied in more than 90 kinds of foods,in which 2-MEI was only observed in several samples and the contents were relatively low,whereas 4-MEI was detected in most of the tested foods,including dark soy sauce(3 224.20-18 795.93 ng/g),coffee(0-5 554.35 ng/g),cookie(63.48-584.78 ng/g),biscuit(containing caramel,373.12-1 899.60 ng/g),cola(44.13-342.77 ng/g) and barley tea(3 131.05-3 335.60 ng/g).This study also reported the contents of 4-MEI in different varieties of tea(16-761.89 ng/g) for the first time.