药食两用铁皮石斛中水溶性多糖测定方法的优化及验证

Analysis of Water-soluble Polysaccharides in an Edible Medicinal Plant Dendrobium officinale Kimura et Migo:Method Development,Validation

水溶性多糖是铁皮石斛植物中重要的组成成分,具有很好的保健功效。为了确定一种特异性、准确性、可重复、灵敏性好的苯酚-硫酸法来定量分析铁皮石斛的多糖含量。试验以D-葡萄糖作为标准单糖,确定490 nm处为检测波长。通过单因素和L9（34）正交试验获得最优反应条件为：温度30℃,6%的苯酚0.3 m L,浓硫酸4.5 m L,保温时间25 min,试剂的添加顺序：苯酚-样品-浓硫酸。校正曲线在8.00~104.00μg/m L范围内呈线性关系,相关系数为0.999 8。检出限与定量限估算值分别为1.1μg/m L和3.33μg/m L。样品溶液在显色反应后2 h内表现出高稳定性。精密度和回收率分别为3.27%和96.9%~102.5%。

Water-soluble polysaccharides are important constituents with evident health benefits in Dendrobium officinale Kimura et Migo. To establish a specific, accurate, reproducible, and sensitive phenol-sulfuric acid method for the quantitative assay ofDendrobium officinale polysaccharides. This test uses D-Glucose to adopt as the standard monosaccharide, and 490 nm is chosen as the detection wavelength. The optimal conditions for the color reaction are obtained using single factor experiments and a L9（3^4） orthogona/test： temperature 30 ℃, amount of 6% phenol 0.3 mL, amount of concentrated sulfuric acid 4.5 mL, incubation time 25 rnin, and addition sequence of phenol-sample-sulfuric acid. The calibration curve is linear within the range 8.00-104.00 μg/mL, and the correlation coefficient of the regression equation is 0.999 8. LOD and LOQ are 1.1 and 3.33 μg/mL, respectively. The colored sample solution after chromogenic reaction exhibits high stability within 2 h. Precision and recovery are 3.27% and 96.9%-102.5%, respectively.