高效液相色谱法测定发芽糙米中γ-氨基丁酸含量

HPLC Analysis of γ-Amino Butyric Acid in Germinated Brown Rice

建立一种简单快速的邻苯二甲醛柱前衍生,紫外检测反相高效液相色谱测定发芽糙米中γ-氨基丁酸含量的方法。色谱柱为Intertsil ODS-C18柱,梯度洗脱,紫外吸收波长为332 nm,线性方程为Y=9.26×106X+2 093.79,r=0.999 5。方法线性范围为0.005~0.06 mg/mL,检出限为2.927 ng,峰面积的相对标准偏差为0.57%,回收率范围为98.85%~100.94%。该方法易于操作、反应时间短、精密度高。用该方法测定了20种发芽糙米中γ-氨基丁酸含量(22.68~88.36 mg/100 g,以干质量计),结果表明,发芽糙米中γ-氨基丁酸含量随品种不同而不同,其中中嘉早17和浙福802明显高于其他品种(P<0.05),故在实际生产中可尝试作为发芽糙米副产品的原料。

A simple and fast high performance chromatography(HPLC) with UV detection method for determination of γ-amino butyric acid(GABA) in germinated brown rice was developed by pre-column derivatization of GABA with orthophthalaldehyde(OPA). GABA was separated on intertsil ODS-C18 column(4.6 mm × 250 mm, 5 μm) and detected with UV detector at 332 nm. Good linearity was observed within the range from 0.005 to 0.06 mg/mL from the calibration equation: Y = 9.26 × 106X + 2 093.79(r = 0.999 5), and the limit of detection was 2.927 ng. The relative standard deviation(RSD) of peak area was 0.57%, and the recoveries were 98.85%–100.94% for GABA. The method is easy to operate, time-saving and highly precise. GABA contents in 20 cultivars of germinated brown rice were 22.68–88.36 mg/100 g on a dry weight basis as determined by the method. The result showed that GABA content in germinated brown rice varied with cultivar and Zhongiazao 17 and Zhefu 802 contained significantly more GABA than the other cultivars tested(P < 0.05). Thus, attempt can be made to use germinated brown rice products from the two cultivars as raw materials in practical production.