The present study has established a laboratory method for the determination of three methylimidazoles (N-methylimidazole, 2-methylimidazole and 4-methylimidazole) in oyster sauce based on ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The samples were extracted by water, enriched and purified with MCX solid-phase extraction column and assayed with UPLC-MS/MS. In addition, separated on HILIC column with electrospray ionization in a positive mode (ESI+), the samples were monitored with multiple reaction monitoring (MRM) and the target substances were quantified based on the internal standard method. The three methylimidazoles showed good linearity (R2＞0.996) within the range of 5-200 ng/mL, with the detection limit of 5 μg/kg and the quantification limit of 10 μg/kg for all the three substances. At three spiked levels, the recovery rate of all three methylimidazoles were within the range of 82.9%-113.1%,and the relative standard derivation was below 10%. This method features quick detection and high stability while enabling simultaneous determination of three methylimidazoles in oyster sauce, hence is suitable for application in risk monitoring of oyster sauces on the market.
[1] GB 1886.64—2015,食品安全国家标准食品添加剂焦糖色[S].北京:中国标准出版社,2015.
[2] GROSSE Y,BAAN R,SECRETAN-LAUBY B,et al.Carcinogenicity of chemicals in industrial and consumer products,food contaminants and flavourings,and water chlorination by products[J].Lancet Oncol,2011,12:328-329.
[3] BAAN R, GROSSE Y, SECRETAN-LAUBY B,etal.Carcinogenicity of radiofrequency electromagnetic fields[J].Lancet Oncol,2011,12(7): 624-626.
[4] 孟颖.焦糖色素着色食品中甲基咪唑测定方法的研究及应用[D].太原:山西大学,2014.
[5] CHAN P,MAHLER J,TRAVLOS G,et al.Induction of Thyroid lesions in 14-week toxicity studies of 2 and 4-methylimidazole in fischer 344/N rats and B6C3F1 mice[J].Archives of Toxicology,2006,80(3):169-180.
[6] CHAN P C,HILLS G D,KISSLING G E,et al.Toxicity and carcinogenicity studies of 4-methylimidazole in F344/N rats and B6C3F1 mice[J]. Archives of Toxicology,2008,82 (1):45-53.
[7] GB 2760—2014 食品安全国家标准食品添加剂使用标准[S].北京,中国标准出版社,2014.
[8] 杨朦,韩倩,王雨萌,等.磁性分子印迹聚合物联合HPLC快速富集和检测酱油中4-甲基咪唑[J].甘肃科学学报,2019,31(2):40-45.
[9] 李建平,渠志华,王辰,等.固相萃取-超高效液相色谱-串联质谱法测定啤酒中4-甲基咪唑的含量[J].中国食品卫生杂志,2016,28(5):610-613.
[10] FMNG T T, WU J H, LIANG X, et al. Isotope dilution determination for the trace level of 4(5)-methylimidazole in beverages using dispersive liquid-liquid microextraction coupled with ESI-HPLC–MS/MS[J]. Food Chemistry, 2018, 245:687-691.
[11] 于淑娟,刘定波,徐献兵,等.离子色谱-质谱联用法测定4-甲基咪唑的含量[J].华南理工大学学报(自然科学版),2015,43(2):8-12.
[12] 吴翠华,郑学殷,李巧琪,等.QuEChERS结合高效液相色谱-串联质谱法测定酱油中的4-甲基咪唑[J].当代化工,2018,47(3):653-656.
[13] 庞美蓉,林钦,戴明,等.超高效液相色谱-串联质谱法同步检测食品中的2-甲基咪唑及4-甲基咪唑[J].分析测试学报,2016,35(8):943-948.
[14] 刘芸,丁涛,费晓庆,等.高效液相色谱-四极杆/静电场轨道阱高分辨率质谱检测酱油中的4-甲基咪唑与2-甲基咪唑[J].分析测试学报,2015,34(4):381-387.
[15] 陈小曼,陈漾,李攻科,等.表面增强拉曼光谱法测定饮料中4-甲基咪唑和2-甲基咪唑[J].分析化学,2016,44(5):816-821.
[16] 周菊峰,刘文奇,李河冰,等.分光光度法测定酱油中4-甲基咪唑[J].粮食科技与经济,2015,40(5):45-47.
[17] 黄志勤,屈海云.分光光度法测定焦糖色中4-甲基咪唑[J].中国调味品, 2005(6): 52-54.
[18] 陈岩,赵宇明. 紫外可见光谱法测定食醋中4-甲基咪唑含量[J]. 食品研究与开发, 2016, 37(24): 128-131.
[19] 荣维广,宋宁慧,阮华,等.固相萃取-高效液相色谱法测定焦糖色素中副产物2-甲基咪唑、4-甲基咪唑和2-乙酰基-4-(1,2,3,4-四羟基丁基)咪唑[J].分析化学,2015,43(5):742-747.
[20] 王淼,陈海珍.高效液相色谱法测定焦糖中4-甲基咪唑的含量[J].中国处方药,2015,13(10):25-26.
[21] SCHLEE C, MARLOVA M, SCHRANK J,et al.Determination of 2-methylimidazole,4-methylimidazole and 2-acetyl-4-(1,2,3,4-tetrahydro -xybutyl)imidazole in caramel colours and cola using LC/MS/MS[J].Journal of Chromatography B,2013,927:223-226.
[22] 李锦清,綦艳,郦明浩,等.固相萃取-高效液相色谱-串联质谱法测定酱油中4-甲基咪唑[J].中国调味品,2016,41(1):132-135;143.
[23] 王丽英,任贝贝,杨立新,等.同位素稀释超高效液相色谱-串联质谱法测定酱油、醋和饮料中的4-甲基咪唑[J].食品安全质量检测学报,2015,6(3):962-967.
[24] 赵文素.毛细管气相色谱法检测调味料中4-甲基咪唑[J].天津科技,2014,41(8):5-6;12.
[25] 彭向前,冯玮,石海英,等.气相色谱法同时检测焦糖色素中的2-甲基咪唑和4-甲基咪唑[J].中国调味品,2012,37(8):83-85.
[26] CUNHA C,SENRA L,FERNANDES J O,et al.Gas chromatography-mass spectrometry analysis of 4-methylimidazole in balsamic vinegars and processed sauces[J].Food Analytical Methods,2014,7 (7):1 519-1 525.
[27] CHOI S J, JUNG M Y. Simple and fast sample preparation followed by gas chromatography-tandem mass spectrometry (GC-MS/MS) for the analysis of 2- and 4-methylimidazole in cola and dark beer[J]. Journal of Food Science, 2017, 82(4):1 044-1 052.
[28] WIECZOREK M N,PRZYGON′SKI K,JELEN′ H H.Determination of 4-methylimidazole in ammonia caramel using gas chromatography-tandem mass spectrometry (GC-MS/MS)[J]. Journal of Food Quality, 2018, 2018:1-5.
