钙镁和极弱酸的二次微分示波极谱滴定  

SECONDARY DIFFERENTIAL OSCILLOGRAPHIC CHRONOPOTEN-TIOMETRIC TITRATION OF Ca,Mg AND VERY WEAK ACIDS

作　　者：翁筠蓉[1] 陈新文[1] 袁晓健 高鸿[1] 

机构地区：[1]南京大学化学系,南京210008

出　　处：《应用化学》1990年第5期83-85,共3页Chinese Journal of Applied Chemistry

摘　　要：示波极谱滴定法有它独特的优点,但在某些测定中,终点指示的灵敏度尚有待进一步提高。例如,用EGTA(乙二醇二乙醚二胺四乙酸)和HEDTA(N-β羟基乙基乙二胺三乙酸)滴定Ca^(2+)、Mg^(2+)时,过量滴定剂的切口变化不够敏锐。用强碱中和滴定极弱酸时,作为相应于pH≈11的指示剂的苯胺的切口变化不易判断。高次微分及电流反馈技术能克服这些缺陷。在(d^2E/dt^2)～E图上终点切口观察灵敏得多,Ca:Mg的比例可提高到100:1。在硼酸和苯酚测定中,测定下限较一次微分法降低了一个多数量级。The secondary differential oscillographic chronopotentiometric titration has been carriedout for Ca, Mg, boric acid and phenic acid determenition. The incision on the d^2E/dt^2-Ecurves produced by the depolarizers is more sharp than that on the dE/dt-E curver. Theindication of the end point of titration has been greatly improved.

关 键 词：钙 镁 苯酚 硼酸 微分示波极谱 

分 类 号：O614.231[理学—无机化学]