四种测定直链淀粉和支链淀粉方法的比较

对常用的直链和支链淀粉的四种测定方法进行比较分析,筛选出更适宜的方法。对单标单波长法(方法1)、单标双波长法(方法2)、双标单波长法(方法3)、双标双波长法(方法4)进行验证、精密度、回收率及样品测定试验。结果表明,根据直、支链淀粉-碘复合物吸收光谱分别确定测量波长(638、536 nm)及参比波长(430、768 nm)建立四种方法,得到回归方程,其在各浓度范围内符合比尔定律。直链淀粉中方法2、3、4较精确,方法4的相对标准偏差0.29%,回收率103.25%~103.48%;支链淀粉中方法2、3较精确,方法3的相对标准偏差最小(1.54%),回收率94.52%~94.85%。由此选择混合标准溶液,直链淀粉测定波长638、430 nm,支链淀粉测定波长536 nm,依据回归方程可求出直、支链淀粉及总含量。

Comparison of Four Methods for the Determination of Amylose and Amylopectin

Four methods for the determination of commonly used linear and amylopectin were compared for better methods. The accuracy,recovery and sample test were performed on single standard single wavelength determination(method 1),single standard double wavelength determination(method 2),double standard single wavelength determination(method 3),double standard double wavelength determination(method 4). Results showed that:The measurement wavelength(638,536 nm)and the reference wavelength(430,768 nm)were determined based on the absorbance spectra of the amylose and amylopectin-iodine complexes respectively. The regression equation was established,and the Bill’s law was found within the range of concentration. Method 2,3,and 4 were more accurate in amylose determination,the relative standard deviation of Method 4 was 0.29%,the recovery rate was 103.25% to 103.48%. Method 2 and 3 of amylopectin determination were more accurate,the relative standard deviation of method 3 was the smallest(1.54%),the recovery rate was 94.52%~94.85%. In combination with the two methods,the mixed standard solution was selected,the measurement wavelength of amylose was 638,430 nm,and the measurement wavelength of amylopectin was 536 nm. The contents of straight and amylopectin was determined according to the regression equation.