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

Determination of 4-methylimidazole in Soy Sauce Using Solid-phase Extraction and High Performance Liquid Chromatography-Tandem Mass Spectrometry

建立固相萃取-高效液相色谱-串联质谱／质谱法（SPE-HPLC—MS／MS）测定酱油中4-甲基咪唑的分析方法。试样经水稀释提取，LC-SCx固相萃取柱净化后，以乙腈和5mmol／L乙酸铵溶液（含0．1％甲酸，V／V）作为流动相，C18色谱柱分离，采用电喷雾离子源，正离子扫描多反应监测（MRM）模式进行检测。4-甲基咪唑在5-500μg／L浓度范围内呈良好线性关系，相关系数（r。）大于0．99，加标回收率为83．6％-95．1％，相对标准偏差为7．3％～8．2％，方法检出限为5μg／kg，定量限为10g／kg。方法简单快速、准确灵敏，适用于酱油中4·甲基咪唑的测定。

A method is established for the determination of 4-methylimidazole in soy sauce using solid-phase extraction （SPE） and high performance liquid chromatography-tandem mass spectrometry （HPLC-MS/MS）. The sample is diluted and extracted by water, and then purified by LC-SCX SPE column. The target compound is separated on a reversed phase column by acetonitrile and 5 mmol/L ammonium acetate solution （containing 0. 1% formic acid, V/V）, and then detected by positive electrospray ionization under multiple reaction monitoring （MRM） mode. Under the optimal conditions, the calibration curves for 4-methylimidazole is linear in the range of 5-500 μg/L with correlation coefficients （r2） greater than 0. 99. The average recoveries of blank matrix sample is 83.6%-95.1%, and the relative standard deviation （RSD） is 7.3-8.2%. The limit of detection （LOD） and quantitation （LOQ） of 4-methylimidazole is 5, 10 μg/kg in soy sauce respectively. The developed method is simple, rapid, accurate and sensitive for the detection of 4-methylimidazole in soy sauce.