用溴酚蓝法测定有机阳离子的讨论

Discussion on determination of organic cation with bromophenol blue.

介绍了用溴酚蓝法定性、定量测定有机阳离子及带有阳离子基团聚合物的原理、操作程序及结果.本法用溴酚蓝(BPB)作两相指示剂,二氯乙烷作分相溶剂,用待测有机阳离子溶液滴定阴离子标准溶液,至下层溶剂层显蓝色为终点.本方法适用于测定十二个碳原子以上阳离子化合物及带阳离子基团聚合物的有效成分,含量测定值为97%～99%,平均相对偏差为0.14%～0.44%,而且无机阳离子对阳离子表面活性剂有效含量的测定没有影响,结果表明操作简便的溴酚蓝化学分析法对十二碳原子以上的有机阳离子聚合物的测定终点明确,结果准确可靠,可在油田化学剂中推广应用.

This paper presented the theory,operational procedure and testing results of Bromophenol Blue Test by which the organic cation and polymer containing organic cation groups can be measured qualitatively and quantitatively.In the test,Bromophenol Blue(BPB) used as a two-phase indicator and ethylene dichloride as a phase splitting solvent,anion standard solution was titrated with organic cation solution to the end point when the lower solvent layer became blue.The effective constituent of organic cation compound containing more than 12 carbon atoms and polymer containing cation groups can be measured by this test.The content value tested is 97%～99%,the relative average error is 0.14%～0.44%.In addition,the inorganic cation had no effect on the measurement of cationic surfactant effective content.It was indicated that Bromophenol Blue Test for measuring organic polymer containing more than 12 carbon atoms is simple,the titration end point was clear and the results were accurate.So this test can be spreaded and applied in oil field chemicals analysis.