采用高效阴离子交换色谱一脉冲安培法,建立了不同作物中支链淀粉糖链长分布的分析方法。通过异淀粉酶水解支链淀粉糖分枝点的a-1,6糖苷键,形成不同长度的葡萄糖链。比较了不同色谱柱和不同色谱条件对支链淀粉糖链长分布测定结果的影响,优化了测定方法。以水、0.1mol/LNaOH和1mol/LNaAc+0.1moL/LNaOH溶液为淋洗液进行梯度淋洗,通过CarboPacPA20阴离子交换柱分离,实现了对聚合度(DP)大于80的支链淀粉糖葡萄糖链的测定。分别选取玉米、木薯、马铃薯与水稻的淀粉进行支链淀粉糖链长分布的研究,并用于其分子构型的判断。实验结果表明该方法简便、检测范围广、重现性良好,连续5次进样,在聚合度小于65时,各峰面积的相对标准偏差小于5%,可为进一步的淀粉糖理化特性研究和品种改良提供有效的实验依据。
A high performance ion exchange chromatographic method coupled with pulsed amperometric detection was established for the analysis of amylopeetin chain-length distribution. The amylopectin was hydrolysised into unit chain under the function of isoamylase which can broke the, 6 chain of glucan. The determination method was optimized by comparing different chromatographic columns and elution conditions. Water, 100 mmol/L NaOH and 1 mol/L NaAc + 100 mmol/L NaOH aqueous solution were used as mobile phase, and the analysis of degree of polymerization (DP) more than 80 could be achieved by using CarboPac PA20 anion exchange column. Maize, cassava, potato and rice starch were selected as the example for the determination of chain-length distribution, which could be used to judge their molecular configurations. This method was proved to be simple, extensive and reproducible, and the RSD was less than 5% when the DP was under 65. The method could provide the basis for further research of physical and chemical properties of starch and breed improvement.