重铬酸钾法测定生物柴油副产物粗甘油中甲醇含量

摘要

A potassium dichromate method for determination of methanol in crude glycerine was established,the influence factors on experiment such as CH+,heating time were studied. Under the condition of CH+=11.04 mol·L-1 and 25min heat-ing time,methanol can be quantitative oxidized to carbon dioxide by potassium dichromate,the excess of potassium dichro-mate was titrated by ammonium ferrous sulfate. For this method,the recovery rate ranged from 97.3%to 102.5%,the rela-tive standard deviation of detection results was less than 2%.%建立了重铬酸钾测定粗甘油中甲醇含量的方法,研究了H+浓度、加热时间对实验的影响.结果表明,在H+浓度为11.04 mol·L-1,加热回流25min,甲醇可被重铬酸钾定量的氧化成二氧化碳,用硫酸亚铁铵滴定过量的重铬酸钾.加标回收率在97.3%—102.5%,样品测定结果的相对标准偏差低于2%.