国标测定白酒中甲醇含量的方法改进研究

Study on the Improvement of the Method for Determining Methanol Content in Liquor by National Standard

为了更准确、便捷的测定白酒中甲醇含量,我们对国标中测定白酒中甲醇含量的的方法进行了条件优化,文章首先对品红-亚硫酸法测定原理进行分析,然后以高锰酸钾-磷酸、品红-亚硫酸、草酸-硫酸溶液等作为原材料,在测量中调整测量波长、草酸-硫酸的用量、显色时间、显色温度等条件,进而得到当测量波长在590nm,草酸-硫酸的加入量在0.5mL,显色时间在0.5h,显色温度介于20~25℃时,为最佳的测量条件,并且精密度和回收率符合要求。

In order to reduce the harm of methanol in liquor to human body,a national standard method for determination of methanol content by fuchsin-sulfite with optimized conditions was proposed. In this paper,the principle of fuchsin-sulfurous acid method is analyzed firstly.Then,potassium permanganate-phosphoric acid,fuchsin-sulfurous acid and oxalic acid-sulfuric acid solution are used as raw materials.The measuring wavelength,the dosage of oxalic acid-sulfuric acid,the developing time and the developing temperature are adjusted in the measuring process.Then,when the measuring wavelength is 590 nm, the dosage of oxalic acid-sulfuric acid is 0.5 ml and the developing time is 0.5.When the color rendering temperature is between 20 and 25 ℃,it is the best measurement condition,and the combination of precision and recovery is required.