黄蜀葵多糖的分子质量测定及单糖组成分析

采用凝胶渗透色谱法测定了4种黄蜀葵多糖的相对分子质量;选用糖分离柱(CarboPacPA200,3×250 mm),以10 mmol.L-1NaOH溶液为流动相、Au为工作电极、Ag/AgCl为参比电极的脉冲积分安培离子色谱法分离测定了4种多糖水解产生的单糖成分及相对含量.结果表明:凝胶渗透色谱法测定4种黄蜀葵多糖的重均分子量分别为4.23×103、6.11×105、4.47×103、6.01×105Da;离子色谱法检出4种多糖均含有半乳糖、葡萄糖、甘露糖以及极少量的阿拉伯糖,其中半乳糖、葡萄糖和甘露糖的物质量之比分别为0.29∶1.00∶0.41、0.56∶0.13∶1.00、0.10∶1.00∶0.11和0.55∶0.17∶1.00;检出限在1.63～2.80μg.L-1范围,相对标准偏差在2.55%～4.67%之间,样品加标回收率为95.8%～107.9%.

Determination of molecular weights and monosaccharide compositions in abelmoschus manihot polysaccharides

The molecular weights of four kinds of purified Abelmoschus manihot polysaccharides were characterized by gel permeation chromatography(GPC),and monosaccharides produced via hydrolysis of them were separated and detected on a CarboPac PA200(3×250 mm) column using 10 mmol·L-1 NaOH as the mobile phase and determined by ion chromatography(IC) with integrated pulsed amperometric detection using gold as the working electrode and Ag/AgCl as the reference electrode.The results showed that the average molecular weights(Mw) of the polysaccharides were 4.23×103 Da,6.11×105 Da,4.47×103 Da and 6.01×105 Da respectivly.Four kinds of samples all contained galactose,glucose,mannose and arabinose;and the molar ratios of galactose,glucose and mannose were 0.29∶1.00∶0.41,0.56∶0.13∶1.00,0.10∶1.00∶0.11 and 0.55∶0.17∶1.00,respectivly.Their detection limits ranged from 1.63 μg·l-1 to 2.80 μg·l-1.Relative standard deviations for these monosaccharides were 2.55% to 4.67% and recoveries ranged from 95.8% to107.9%.