Determination of three methylimidazole compounds in food flavors by solid phase extraction coupled with ultra-performance liquid chromatography-mass spectrometry

Abstract

Objective: This study aimed to establish a method for quick determination of 3 kinds ofmethylimidazole compounds in food flavor. Methods: The food flavor was extracted with 5% trichloroacetic acid solution and purified with PCX mixed cationic solid phase extraction column. Finally, the qualitative and quantitative analysis was carried out by ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS) and internal standard method. Results: The linear relationship between the three methyl imidazole compounds was good in the range of 5.0~400.0 ng/mL, with correlation coefficient R2≥0.997. The limits of detection were 0.030~0.450 μg/kg and the limits of quantification (LOQ) were 0.10~1.50 μg/kg. The recoveries of three methylimidazole ranged from 82.8% to 111.7%, and the relative standard deviations (RSDS) ranged from 1.3% to 9.3%. Conclusion: The method is simple, efficient and accurate, and can be used for the quantitative determination of 1-methylimidazole, 2-methylimidazole, 4-methylimidazole in food flavor.

Keywords

• solid phase extraction
• ultra performance liquid chromatography-tandem mass spectrometry
• methylimidazole compounds
• food flavor