双波长法测定人参中淀粉含量

Determination of Starch Content in Ginseng by Dual-wavelength Specrophotometry

目的:建立双波长测定人参中直链淀粉和支链淀粉两类淀粉含量的方法。方法:以人参中直链淀粉和支链淀粉为研究对象,测定不同生长年限林下山参和园参中直链淀粉和支链淀粉含量并分析其分布规律,以碘比色法中双波长法为检测方法,对测定条件和方法进行优化,最后通过方法学验证最佳方法的准确性。结果:根据双波长法的测定原理和扫描光图谱,确定直链淀粉的测定波长和参比波长分别为600、471 nm;支链淀粉测定波长和参比波长分别为540、702 nm。直链淀粉和支链淀粉质量浓度分别在0.004~0.060(r=0.9998)、0.02~0.16 mg·mL^(-1)(r=0.9997)时具有良好的线性关系。平均加样回收率分别为100.03%和101.84%,RSD分别为1.29%和1.92%。结论:该方法操作简便,准确性、稳定性和重复性均良好,适用于人参中直链淀粉和支链淀粉含量的测定,可为人参的质量控制提供参考。

Objective:To determine the content of amylose and amylopectin in ginseng by dual-wavelength spectrophotometry.Methods:Amylose and amylopectin in ginseng were taken as the main research objects.The content of amylose and amylopectin in ginseng from forests and gardens in different years was determined,and the distribution pattern was analyzed.The determination conditions and methods were optimized by using the dual-wavelength spectrophotometry in iodine colorimetry,and finally,the accuracy of the best method was verified by methodology.Results:According to the principle of the dual-wavelength method and the scanning photograms,the determined wavelengths and reference wavelengths of amylose were 600 nm and 471 nm,and those of amylopectin were 540 nm and 702 nm,respectively.There was a good linear relationship(r=0.9998,r=0.9997)between amylose and amylopectin concentrations in the ranges of 0.004-0.060 mg·mL^(-1) and 0.02-0.16 mg·mL^(-1).The average spiked recoveries were 100.03%and 101.84%,and the RSDs were 1.29%and 1.92%,respectively.Conclusion:The method is easy to operate,with good accuracy,stability,and reproducibility,and it is suitable for the determination of amylose and amylopectin content in ginseng.