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研究建立了高效液相色谱-蒸发光散射法(HPLC-ELSD)测定黑茶中单糖和双糖的含量。采用XBridge Amide 5μm(4.6 mm×250 mm)色谱柱,柱温40℃,流动相0.02%氨水-乙腈(体积比25︰75)且流速0.5 mL/min进行等度洗脱,雾化管温度30℃,漂移管温度70℃,空气流速2.5 mL/min。鼠李糖、阿拉伯糖、果糖、甘露糖、葡萄糖、蔗糖和麦芽糖在0.004 8~4.32 mg/mL范围内线性关系良好,回收率在94.34%~99.92%之间,最低检测限0.792~25.052 ng/mL,精密度、稳定性的标准偏差分别不超过1.74%和2.83%。该方法具有快速简便、回收率高、精密度和稳定性好等优点。应用此方法分析6种黑茶,得出除未检测出相应糖的黑茶外,黑茶中还含有鼠李糖3.17~3.42mg/g,阿拉伯糖2.82~4.73 mg/g,果糖2.93~3.55 mg/g,葡萄糖4.05~10.35 mg/g,蔗糖4.31~6.36 mg/g,麦芽糖7.17~8.13 mg/g。
The content of monosaccharides and disaccharides in black tea was determined by HPLC-ELSD. An isocratic elution was performed on an XBridge Amide 5 μm (4.6 mm × 250 mm) column with a column temperature of 40 ° C and a mobile phase of 0.02% ammonia-acetonitrile (25:75 by volume) at a flow rate of 0.5 mL / ℃, drift tube temperature 70 ℃, air flow rate 2.5 mL / min. The linear ranges of rhamnose, arabinose, fructose, mannose, glucose, sucrose and maltose ranged from 94.34% to 99.92% in the range of 0.004 8 ~ 4.32 mg / mL with the detection limits of 0.792 ~ 25.052 ng / mL, the standard deviation of precision and stability did not exceed 1.74% and 2.83% respectively. The method has the advantages of fast and easy, high recovery, good precision and good stability. Six kinds of black tea were analyzed by this method. The black tea also contained rhamnose 3.17 ~ 3.42mg / g, arabinose 2.82 ~ 4.73 mg / g, fructose 2.93 ~ 3.55 mg / g, glucose 4.05 ~ 10.35 mg / g, sucrose 4.31 ~ 6.36 mg / g, maltose 7.17 ~ 8.13 mg / g.