摘要
乳粉、米粉样品经0.1%(体积分数,下同)甲酸溶液提取,加入乙腈去除蛋白质,正己烷去除脂肪等基质,所得溶液用0.1%甲酸溶液稀释10倍后用孔径0.22μm聚四氟乙烯针式过滤器(Pall)过滤,滤液采用超高效液相色谱-串联质谱法(UHPLC-MS/MS)测定;功能饮料样品直接用0.1%甲酸溶液稀释1 000倍后采用UHPLC-MS/MS测定。在色谱分析中,采用ACQUITY UPLC?HSS T3色谱柱作为固定相,不同体积比的0.1%甲酸溶液和含0.1%甲酸的甲醇溶液的混合溶液进行梯度洗脱;在质谱分析中,采用电喷雾离子源正离子模式电离,多反应监测模式检测,外标法定量。结果表明,甘氨酸和其余19种氨基酸的质量浓度分别在5~50 mg·L^(-1)和0.05~0.5 mg·L^(-1)内和定量离子峰面积呈线性关系,检出限(3S/N)分别为7.50 mg·kg^(-1)和0.006 00~0.300 mg·kg^(-1)。以2种乳粉、1种米粉和3种功能饮料样品为基质进行3个浓度水平的加标回收试验,回收率为78.4%~136%,测定值的相对标准偏差(n=6)为0.10%~14%。方法用于4种乳粉、1种米粉和3种功能饮料的分析,均未检出半胱氨酸,其余氨基酸均有不同程度检出。
Milk powder and rice flour samples were extracted with 0.1%(volume fraction,the same below)formic acid solution,proteins in which were removed by the addition of acetonitrile,and fats and other matrices were removed by n-hexane.The solution obtained was diluted 10 times with 0.1%formic acid solution and then passed through a Pall polytetrafluoroethylene syringe filter with pore size of 0.22μm.The filtrate was determined by ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS).Functional beverage samples were directly diluted 1000 times with 0.1%formic acid solution and then determined by UHPLC-MS/MS.In the chromatographic analysis,an ACQUITY UPLC®HSS T3 column was used as the stationary phase,and a mixture of 0.1%formic acid solution and methanol solution containing 0.1%formic acid at different volume ratios was used for gradient elution.In the mass spectrometry analysis,electrospray ionization positive ion mode was used for ionization,and multiple reaction monitoring mode was used for detection,with external standard method for quantification.It was shown that linear relationships of values of the mass concentrations and quantitative ion peak areas were kept in the ranges of 5-50 mg·L^(-1) for glycine and 0.05-0.5 mg·L^(-1) for other 19 amino acids,with detection limits(3S/N)of 7.50 mg·kg^(-1) and 0.00600-0.300 mg·kg^(-1),respectively.Recovery tests at three concentration levels were conducted using two types of milk powder,one type of rice flour,and three types of functional beverage samples as matrices,giving recoveries in the range of 78.4%-136%,and RSDs(n=6)of the determined values in the range of 0.10%-14%.The proposed method was applied to the analysis of four types of milk powder,one type of rice flour,and three types of functional beverages,and no cysteine was detected in any of them,while the remaining amino acids were detected at varying levels.
作者
王奕婷
罗艳
李杰
WANG Yiting;LUO Yan;LI Jie(College of Chemistry and Chemical Engineering,Donghua University,Shanghai 201620,China;Shanghai Institute of Measurement and Testing Technology,Shanghai 201203,China)
出处
《理化检验(化学分册)》
北大核心
2025年第5期506-516,共11页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
基金
上海市计量测试技术研究院科研项目(I00RY2406)。
作者简介
王奕婷,硕士,主要研究方向为色谱-质谱分析技术;通信作者:李杰,正高级工程师,博士,主要研究方向为标准物质研制、色谱-质谱联用技术及其在食品安全检测中的应用,lijie@simt.com.cn。
