摘要
采用电位滴定法改进了测定甲醛含量的中性亚硫酸钠法,并对其准确度和影响因素进行了探讨.用改进的中性亚硫酸钠法测定栲胶中单宁胺甲基化产物的甲醛含量的实验结果表明,反应体系甲醛测得率93.82%,r=0.999,空白实验回收率97.74%,r=0.999,温度控制在15～20℃,反应后放置时间在1 h之内稳定,该方法可以克服单宁溶液有色、浑浊无法用指示剂指示终点的缺陷,电位突跃范围宽,数据误差小,重复性好.实现了快速、简便、准确地滴定栲胶中单宁胺甲基化反应产物剩余甲醛的含量.
In this paper a potentiometric titration was used to improve the neutral sodium sulfite method for determining the content of formaldehyde, and the accuracy and influential factors were discussed. The results of quantitative determination of formaldehyde in the aminomethylated product of tannin showed that the mensurative rate of formaldehyde in reaction system was 93.82 %, r =0.999, the recovery rate of the blank test was 97.74 %, r = 0.999 , temperature was controlled at 15-20 ℃, laying time was between 1 h for stabilization. This method eliminated the defects of coloured and cloudy liquor which blurred the end point of titration by indicator. The range of electric potential was wide, the repetition and accuracy of data were perfect. This method is quick, simple and easy to control.
出处
《林产化学与工业》
EI
CAS
CSCD
2005年第2期103-106,共4页
Chemistry and Industry of Forest Products
基金
引进国际先进农业科学技术"948"2002-42
东北林业大学院士启动基金(无编号)
关键词
电位滴定法
单宁
甲醛含量
胺甲基化反应
potentiometric titration
tannin
formaldehyde content
aminomethylation
