摘要
本文报导了用磷钼酸、钨酸钠作显色剂,与啤酒花中鞣酸生成深蓝色物质,以吸光光度法测定啤酒花中鞣酸的适宜条件及操作方法。实验结果表明:在NaOH介质中,蓝色物质的最大吸收波长为750nm;在750nm处,蓝色物质的摩尔吸光系数为7.2×10~41·mol^(-1)·cm^(-1);鞣酸浓度在O.5～7μg·ml^(-1)范围内,遵守Beer定律;鞣酸的回收率在96.00～109.2%之间;多次平行测定的变动系数为1.6%。利用磷钼酸、钨酸钠作显色剂,进行吸光光度法测定啤酒花中鞣酸含量,方法灵敏,操作简便,准确度、精密度较好。
The optimum conditions and method to determine tannic acid in hops by visibleabsorptiometry with a formed deep-blue matter of two colour reagents-phosphomolybdicacid and sodium tungstate were studied. The results showed that in medium sodiumhydroxide, the maximum absorbing wavelength of the matter was at 750nm. At this point,the molar absorptivity of the matter was 7.2×10^(-4)l. mol^(-1)·cm^(-1). The rate of recovery oftannic acid with Beer's law was between 0.5~7g. ml^(-1). The concentration of fannic acidwas between 96.00 and 109.2 percent and the coefficient of variation determined in severalparallel tests 1.6 percent. It may be considered as a sensitive, accurate, and simple methodfor determination of tannic acid content in hops.
出处
《山东农业大学学报（自然科学版）》
CSCD
1990年第1期63-66,共4页
Journal of Shandong Agricultural University：Natural Science Edition
关键词
吸光光度法
啤酒花
鞣酸
测定
hop
tannic acid
phosphomolybdic acid
sodium tungstate
absorbance
