摘要
采用交流示波极谱滴定法研究海水中硫酸盐的直接测定法。在pH8的乙二胺—盐酸底液中,以标准K_2Cr_2O_7溶液滴定适当过量的钡,由微过量的Cr_2O_7^(2-)(或CrO_4^(2-))在交流示波极谱图上产生的切口指示滴定终点。方法准确快速.测定标准海水和卤水中的SO_4^(2-)的回收率分别为98.11±0.67和100.03±1.1％。相对标准偏差小于1％。
A procedure is described for the determination of sulfate in seawater by using the Oscillopolarographic titration.A suitable excess of BaCl2 solution is added to seawater samples containing ethylenediamine-HCl with pH 8 and then the excess of BaCl2 can be titrated directly with K2Cr2O7 using the appearance of CrO42-incision to indicate the endpoint of titration.The method is very simple,rapid and accurate.The rates of recovery of sulfate in seawater and salty brine samples are 98.11±0.67% and 100.03±1.1% respectively.The relative standard deviation is less than 1 %.
关键词
海水
硫酸盐
极谱滴定
交流示波
oscillopolarographlc titration
sulfate
seawater analysis
