超高效液相色谱串联质谱法测定豆类食品中的游离神经递质类氨基酸

本文建立了超高效液相色谱串联三重四极杆质谱（UPLC-MS/MS）测定豆类食品中神经递质类氨基酸的分析方法。样品经超纯水超声提取，Zorbax SB-Aq RRHT色谱柱（3.0 mm×100 mm, 1.8 μm）分离，以甲醇和0.5 mmol/L乙酸铵溶液为流动相梯度洗脱，流速为0.3 mL/min。采用电喷雾离子源（ESI）正离子模式扫描，多反应监测（MRM）模式进行检测，外标法定量。结果表明，神经递质类氨基酸在各自浓度范围内线性良好，相关系数（r）为0.991~0.999，检出限（LOD, S/N≥3）为2~8 μg/kg，定量限（LOQ, S/N≥10）为8~40 μg/kg；在3个不同浓度加标水平下的平均回收率为80.30%~109.97%，相对标准偏差（RSD, n=6）为0.12%~7.20%；稳定性、精密度、重复性在峰面积上的RSD值分别为4.74%~6.98%、0.63%~7.27%、0.46%~5.17%，说明该方法简单、高效、灵敏，适用于豆类食品的快速定量检测。

Determination of Free Neurotransmitter Amino Acids in Legume Food by Ultra High Performance Liquid Chromatography-Tandem Mass Spectrometry

A method was developed for the determination of neurotransmitter amino acids in legume food by ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). The samples were ultrasonically extracted with ultra pure water. The target compounds were separated on a Zorbax SB-Aq RRHT column(3.0 mm×100 mm, 1.8 μm) by gradient elution using methanol and 0.5 mmol/L ammonium acetate solution as mobile phase at a flow rate of 0.3 mL/min. Qualification was achieved by positive electro-spray ionization using multiple reaction monitoring(MRM), and the external standard method was used for quantitation. The calibration curves for neurotransmitter amino acids were linear in their corresponding range with their correlation coefficients(r) between 0.991 and 0.999. The limits of detection(LOD, S/N≥3) were 2~8 μg/kg while the limits of quantitation(LOQ, S/N≥10) were 8~40 μg/kg. The recoveries for neurotransmitter amino acids at three different spiked levels were in the range of 80.30%~109.97%, with relative standard deviations(RSD, n=6) of 0.12%~7.20%. The RSDs of stability, precision and reproducibility were 4.74%~6.98%, 0.63%~7.27% and 0.46%~5.17%, respectively. Owing to easy, high efficiency and sensitivity, the method was suitable for rapid analysis of neurotransmitter amino acids in legume food.