络合体系中的相对滴定法及其应用于铝的测定

The Relative Titration in Complexing Systems and Its Application to the Determination of Aluminium

本文提出了络合体系中的相对滴定分析法，它以滴定到一定的状态时，滴定剂体积与被测物的基之间的线性关系为定量基础，用仪器分析的定量方法进行定量，适应于所有类型的络合体系，即使对滴定突跃很小或根本无突跃的体系也同样适用。用氟离子滴定铝离子的实验结果表明本方法的精密度很高。一般相对误差小于0．1％。即使对于铝离子的量小到10-7mol／L时，在最佳实验条件下的相对误差也不大于0．2％。该方法既具有滴定分析法的高精密度，又具有仪器分析法可以测量微量物质的优点，并且设备和方法简单。

The relative titration in complexing systems is based on the linear relation between the amount of analyte and the volume of titrant consumed to reach a certain titration state. The determination of Al3+ by F- demonstrates the high accuracy of the method. Generally the relative error of measurements is less than 0. 1% and does not exceed 0. 2% even when the concentration of Al3+ is as small as 10-7 mol/L. This method has both the advantage of high accuracy in titration and the capacity of determining trace amount of analyte in instrumental analysis. The experimental apparatus and procedure are simple.