在一般极谱法及阳极溶出伏安法中,通常采用标准加入法。该法是先定量移取待测溶液,测定一次扩散(或溶出)电流;然后定量加入已知浓度且含量相近的标准溶液,再测定一次扩散(或溶出)电流,根据标准加入法的计算式即可求出未知浓度c_x。此法的优点是操作方便,加入一次标准溶液即可算出c_x,计算程序的设计也较容易。但在实际工作中发现,由于扩散电流的测量误差(特别是在溶出分析法时),若仅根据加入一次标准溶液进行计算,则结果不够准确。一般要求加入一定量标准溶液后,扩散电流增加一倍左右时测定精密度较高。但实际上由于试样中待测元素量是未知数,因而无法确定加入标准溶液的量,而 In general polarography and anodic stripping voltammetry, usually using standard addition method. In this method, the solution to be measured is firstly quantitatively measured and the diffusion (or dissolution) current is measured once. Then, a standard solution of known concentration and similar content is quantitatively added, and then a diffusion (or dissolution) current is measured again. You can find the unknown concentration c_x. Advantages of this method is easy to operate, can be calculated by adding a standard solution c_x, the calculation of the program design is also easier. However, it has been found in practical work that due to the measurement error of the diffusion current (especially in the case of dissolution analysis), the result is not accurate enough if the calculation is made only by adding a standard solution. Generally require the addition of a certain amount of standard solution, the diffusion current measured doubled higher precision. In fact, however, the quantity of the element to be measured in the sample is unknown and thus the amount of the standard solution can not be determined,