一种新的连续流动注射分析法快速测定食品及葡萄酒中的总糖

Rapid determination of total sugar in food by air segment-continuous flow injection analysis

采用空气气泡间隔-连续流动注射分析的新技术建立了一种快速测定食品总糖的方法。88℃条件下用HCl使样品水解成单糖,水解后的单糖经过透析器净化,除去颗粒物、蛋白质或者生成有色基团的大分子,然后在碱性条件下新亚铜复合物Ⅱ被还原性单糖(果糖、葡萄糖)在88℃热浴中还原形成新亚铜螯合物Ⅰ,在450nm波长处测定吸光度。分析速率可达40样/小时。方法以果糖、葡萄糖混合标准溶液做工作曲线,该法在0～5g/L范围内线性范围良好,相关系数r^2=0.999,方法相对标准偏差在0.008%～0.64%之间,食品基质总糖测定结果与GB 5009.8-2016相比结果相对标准偏差在1.24%～3.32%之间,葡萄酒基质测定结果与国标GB/T 15038-2006相比,相对标准偏差在0.8%～5%之间。本法测定结果与国标测定方法无显著性差异。因此该方法适合于食品中总糖的快速测定,大大缩短了分析时间,减少了手工滴定带来的人为操作误差。

The samples were hydrolyzed into monosaccharides by HCl at 88℃.Then the monosaccharides after hydrolysis were purified by the dialyzer to remove particles,protein,or macromoleculars with colored groups.Neocuproine complex Ⅱwas reduced to Neocuproine chelateⅠin alkaline condition in hot bath（88℃）,and the absorbance was measured at the wavelength of 450 nm.The analysis rate can be up to 40 samples per hour.Fructose and glucose were selected as standard solution.This proposed method has a good linerity of range from 0 g/L to 5 g/L with coefficient of 0.999,the relative standard deviation was from 0.008% to 0.64%.The relative standard deviation of total sugar in foods determined by this method was between 1.24%to 3.32%compared with the method of GB 5009.8-2016.For wine matrix,the relative standard deviation was in the range of 0.8% to 0.64% compared with the method of GB/T15038-2006.There is no significant difference between this method and national standard methods.This method is suitable for rapid determination of total sugar in foods and wine.