摘要
采用紫外分光光度法测定山梨酸钾。在253 nm处有最大吸收峰,而且在较大范围内具有良好的线性关系,但饮料中含有的维生素C在紫外区也有吸收,直接测定会有很大误差,将山梨酸钾转化成山梨酸,用氯仿萃取,再用碳酸氢钠溶液反萃取,而后用紫外分光光度法测定。
Potassium sorbate is determined by UV-spectrophotometric, which has maxmum observition λ at 253 nm, and its excellent linear relationship at relative wide wavelengths makes the UV-spectrophotometer feasible. But vitamin C also has evident absorbance at UV band, which makes that the direct determination inevitably brings unsatisfactory error. So the conversion of potassium sorbate into sorbic acid, which is followed by extraction with chloroform and back-extraction with sodium bicarbonate and makes the UV-spectrophotometer effective.
出处
《南阳师范学院学报》
CAS
2007年第6期47-48,共2页
Journal of Nanyang Normal University
关键词
山梨酸钾
饮料
紫外分光光度法
potassium sorbate
drinks
UV-spectrophotometric