摘要
提出用硝酸镧电位滴定格氏作图法测定含氟量的方法,并讨论氯离子干扰和离子强度对测定的影响.在50%乙醇-水体系中测定下限为1×10^(-4)mol/l,相对偏差≤3%,回收率为96%-107%,完成一次滴定约需20min用离子选择电极法进行了对照实验.
This Paper discusses the method for determining flurine content with potentiometric titration of lanthanum nitrate by using Cran's plot and also studies the influence of the interference of chloride ion and ionic strength on the determination.Under the condition of 50 percent alcohol-water system, the experiment has the characteristics of a recovery from 96 percent to 107 percent, a lowermost limit of 0.0001 moles/liter and a relative average deviation less than 3%. It takes about twenty minutes to complete the whole titration. Compared with the method of ion-selective electrode, this new method appears to have better reproducibility and higher accuracy.
关键词
废水
格氏作图法
电位滴定法
含氟量
flurine
potentiometric titration
Gran's plot
waste water
