石榴籽经盐酸脱水反应后,向样品溶液中加入溴水使还原性葡萄糖氧化,与蔗糖和果糖分离;根据蔗糖难溶于乙醇,利用乙醇使蔗糖与果糖分离,据此提出了用紫外分光光度法直接测定石榴籽中葡萄糖、蔗糖和果糖含量的方法。葡萄糖、蔗糖和果糖的最大吸收波长均在285 nm处。葡萄糖、蔗糖和果糖的质量浓度在30 mg·L-1以内服从比耳定律。方法用于石榴籽中葡萄糖、蔗糖和果糖含量的测定,测定值分别为0.203 9,0.188 6,0.373 1 mg·g-1。测定值的相对标准偏差(n=6)均小于1.0%;加标回收率在99.4%~100.1%之间。

After adding bromine water to the sample solution obtained by dehydration of pomegranate seed with HCl, reductive glucose was oxidized and separated from sucrose and fructose. Due to the in-solubility of sucrose in ethanol, sucrose was separated from fructose by adding ethanol. Based on these facts, a method of UV-spectrophotometry for the direct determination of glucose, sucrose and fructose in pomegranate seeds was proposed. Linear relationships between values of absorbance measured at the absorption maximum of 285 nm and mass concentration of glucose, sucrose and fructose were kept in the range of within 30 mg·L-1. The proposed method was used in the determination of glucose , sucrose and fructose in a sample of pomegranate seeds, giving values of 0.203 9, 0.188 6, 0.373 1 mg·g-1 respectively. Values of RSD′s (n=6) were found less than 1.0%, and values of recovery obtained by standard addition method were in the range of 99.4%-100.1%.