GC-FID测定黄酒中17种游离氨基酸

建立以N-(特丁基二甲基硅烷)-N-甲基三氟乙酰胺(MTBSTFA)为衍生试剂测定黄酒中17种游离氨基酸的气相色谱(GC)方法。比较了衍生温度、时间、及辅助试剂等对衍生效率的影响,确定N,N-二甲基甲酰胺(DMF)为辅助衍生试剂,衍生温度80℃,衍生时间60 min,可以定量检测黄酒中主要的游离氨基酸。各氨基酸在50～500 mg/L内线性良好(相关系数均大于0.99)。对黄酒样品的测定结果与高效液相色谱测定结果相比皮尔逊相关系数为0.998,样品的平均加标回收率为87.11%～119.47%。结果表明:GC-FID方法操作简便、准确、重现性好,适用于黄酒中17种游离氨基酸的分离检测。该测定方法将为开发气相-燃烧-同位素比率质谱(GC-C-IRMS)测定黄酒中氨基酸13C稳定同位素丰度以及分析黄酒酿造过程中的代谢实验提供研究基础。

Determination of 17 Free Amino Acids in Rice wine by Gas Chromatography-flame Ionization Detector (GC-FID)

Methods were developed to quantitatively analyze 17 free amino acids in rice wine by Gas Chromatography-Flame Ionization Detector(GC-FID).The derivative reagent used in this study was N-tertbutyldimethylsily-N-methytrifluroacetamide(MTBSTFA).Conditions for derivatization(reagent,temperature,and time) were optimized to give high efficiency.Conditions were identified as N,N-dimethylformamide(DMF) as second derived reagents at 80℃for 60 min.Analysis of pure amino acid standards showed good linearity(R2≥0.99) within the ranges of 50 to 500 mg/L.Free amino acids in rice wine sample were quantified by the developed methods and the results were comparable to those analyzed by HPLC.The Pearson correlation coefficient was 0.998.Recoveries of amino acids were 87.11%~119.47% ranges for spiked rice wine.The results show that the developed GC-FID method is simple,accurate and reproducible.This experiment will provide fundamental for the detection of free amino acids abundance of 13C stable isotopes in rice wine by Gas Chromatography-Combustion-Isotope Ratio Mass Spectrometry(GC-C-IRMS) and further the metabolic experiment of rice wine brewing process.