苯酚-硫酸法测定紫山药多糖含量的条件优化

建立苯酚-硫酸法测定紫山药中多糖含量的方法。以吸光度A为指标,对最大吸收波长、显色温度、显色时间、浓硫酸用量、苯酚用量5个因素进行优化。并对该方法的精密度、加标回收率等进行考察。结果表明,最优检测条件为最大吸收波长488 nm、浓硫酸用量5.0 mL、6%的苯酚用量0.7 mL、显色温度80℃、显色时间20 min。该方法线性范围为0~54μg/mL,相对标准偏差为1.19%,加标回收率为97.26%~102.63%,可作为紫山药中多糖的测定方法。

Optimization of Analytical Conditions for the Determination of Polysaccharides Contents in Purple Yam by Phenol-Sulfuric Acid Method

The phenol-sulfuric acid method to determine the concentration of polysaccharides in purple yam was established.Taking absorbance A as an index,the experimental conditions were optimized from 5 aspects:determination wavelength,amount of sulfuric acid,amount of phenol,reaction time,reaction temperature,and the precision and sample recovery of the method were investigated.The experimental results showed that the optimum conditions were absorption wavelength 488 nm,sulfuric acid 5.0 mL,6%phenol 0.7 mL,reaction temperature 80℃,reaction time 20 min.According to the results,the line of range was from 0 to 54μg/mL,the relative standard deviation was 1.19%,and the recoveries were from 97.26%to 102.63%.The results proved that this method could be used for the determination of polysaccharides in purple yam.