3,5-二硝基水杨酸法测定铁皮石斛中多糖的含量

目的:建立铁皮石斛中多糖的含量测定方法。方法:对3,5-二硝基水杨酸法(DNS法)测定方法的各影响因素进行考察,确定最佳条件,测定铁皮石斛中的还原糖和水溶性总糖的含量,并计算出多糖的含量。结果:检测波长520nm,显色剂用量6.0mL,沸水浴中保持15min。样品经DNS试剂显色后于520nm处测定吸收度,在此波长处溶液的吸光度与葡萄糖含量呈良好线性关系,线性范围:0.1～0.8mg·mL-1(r=0.9997),加样回收率为98.05%～103.18%。铁皮石斛总多糖含量17.76%～29.19%。结论:经过系统的方法学考察,所建立的方法具有操作简便、稳定、可重复的特点,可用于铁皮石斛药材及其多糖类保健品的质量控制。

Determination of Polysacharide in Dendrobium Officinale by 3,5-Dinitrosalicylic Acid Colorimetry

Objective：To establish the method of 3,5-dinitrosalicylic acid （DNS） for detecting the polysaccharide in Dendrobium officinale. Methods： Using Thermo Helios 3＇ detected the absorption of the solution of reference solution and sample solution reacted with 3,5-dinitrosalicylic acid, and calculated the content of mono-sugar and total sogar. Results ：It was suggested that the best suitable wavelengths for determination is 520 nm, and the best suitabale amount of color reagent is 6.0mL, and duration for color development in water bathe is 15 rain. The calibration curve was in good linearity over the range of 0.1-0.8 mg·mL-1 （r=0.999 7）, the average recovery was 98.05%-103.18%. The polysaccharides measured in 5 batches of samples were 17.76%-29.19%. Conclusion：The established method has been proven to be simple, stable an repeatable, and can be applied for quality control of crude Dendrebium officinale and medical Care preparations containing polysaccharide extracted from Dendrobium officinale.