工业氰基乙酸乙酯酸度测定方法的对比  

Comparative Study on Methods for the Determination of Acidity of Industrial Ethyl Cyanacetate

作　　者：王芳珠[1] 刘秋菊[1] 王勤[1] 

机构地区：[1]中国石油大学化学化工学院,东营257061

出　　处：《理化检验（化学分册）》2007年第11期916-919,共4页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

摘　　要：碱滴定法测定工业氰基乙酸乙酯的方法通常有3种方法的变化,其一滴定中用指示剂目测滴定终点;其二,用电位法指示滴定终点,滴定中采用自动电位滴定仪;其三,先用水或饱和氯化钠水溶液将试样中的酸萃取入水相中,然后用碱滴定法在水溶液中测定其酸度。对此3种方法的变化作了对比试验,结果表明,在第一种变化中,在所试验的10种指示剂中只有甲基红在终点时有明显的颜色变化,但作为整个方法,测定结果的误差较大;对第二种方法变化,即采用电位滴定法,在终点到达时其滴定曲线中产生明显的突跃,而且按此方法所测得结果精密度和准确度都很好,方法操作方便而快速;对第三种方法变化,经试验用饱和氯化钠溶液作萃取剂的效果较好。经分离后的测定结果与电位滴定法的结果基本吻合,但此方法操作过程长而繁琐。A comparative study on the results obtained by 3 alternative alkalimetric titration of acidity of ethyl cyanacetate was made and discussed.The 3 alternations are: ① visual detection of end point with indicators;② detection of end-point by potential change,that is,the titration performed by an automatic potentiometric titrator;and ③ acid in the sample was separated by extraction with water or saturated sodium chloride solution and the acidity determined by alkalimetric titration in the aqueous solution.As sh...

关 键 词：碱滴定法 氰基乙酸乙酯 酸度 

分 类 号：TQ225.24[化学工程—有机化工]