This chapter describes the general approach for the determination of elemental impurities in medicinal products or substances for pharmaceutical use. As the chemical composition of the considered samples and the specification limits for the element(s) of interest vary considerably, it is not possible to describe all suitable sample preparation and measurement methods. Therefore, any method that fulfils the requirements described in this chapter may be used.
The results of the analysis are acceptable only if the system suitability has been demonstrated by a suitable test. Before the initial use of a method, the analyst must ensure that the method is appropriate for the samples and instruments used. This is accomplished by applying a validation procedure to methods not described in the individual monograph or by a system suitability test for methods which are described in the monograph. Decision trees for the choice of the sample preparation and the measurement procedures are presented in Figures 2.4.20.-1 and 2.4.20.-2.