高效液相色谱-串联质谱法测定稻米和米糠中γ-氨基丁酸含量及相关性分析

Determination ofγ-aminobutyric acid in rice and rice bran by HPLC-MS/MS and its correlation analysis

通过高效液相色谱-串联质谱法(HPLC-MS/MS),建立测定稻米和米糠中γ-氨基丁酸(GABA)含量的分析方法,并研究不同品种不同生长季精米、糙米和米糠中GABA含量的相关性。结果表明:最佳测定条件为以乙醇-水(体积比4∶1)溶液为提取剂,重复提取2次,以乙腈-体积分数0.1%甲酸水溶液为流动相,选择正离子模式进行外标法定量。在此条件下,测得GABA在5~1000μg/L范围内,线性关系较好(r为0.9997);精米中GABA平均回收率为84.9%~93.4%,相对标准偏差(RSD)≤3.5%;糙米中GABA平均回收率为84.0%~90.2%,RSD≤3.7%;不同水稻部位GABA含量为米糠>糙米>精米,3个部位中GABA含量间均有显著的相关性。检测方法简便快捷,准确度和精密度均满足相关检测要求。

High performance liquid chromatography tandem mass spectrometry(HPLC-MS/MS)was established for the determination of trace elements in rice and rice branγ-aminobutyric acid(GABA).The content of GABA in milled rice,brown rice and rice bran of different varieties in different growing seasons was studied.The results showed that the optimum determination conditions were as follows:ethanol water(volume ratio 4∶1)solution was used as extracting agent,repeated extraction twice,acetonitrile-volume fraction of 0.1%formic acid aqueous solution was used as mobile phase,and positive ion mode was selected for external standard quantitative method.Under this condition,GABA was measured in the range of 5-1000μg/L,the linear relationship was good(r was 0.9997).The average recovery of GABA in milled rice was 84.9%-93.4%,and the relative standard deviation(RSD)≤3.5%.The average recovery of GABA in brown rice was 84.0%-90.2%,RSD≤3.7%.The content of GABA in different parts of rice was rice bran>brown rice>milled rice,and there was significant correlation between the content of GABA in the three parts.The detection method was simple and fast,and the accuracy and precision meet the relevant detection requirements.