Background

XRF has been considered as a useful method for impurity analysis for its short measurement time and few spectral overlaps even for multi-element matrices. In addition, analysis by TXRF has the advantage that only a small amount of sample is required compared to other methods. The analysis of pharmaceutical products is carried out in both the development phase and quality control of the final products. In particular, in the development stage, rapid and simple analytical method such as the confirmation of active compound tags and residual catalysts has been required. TXRF can meet these requirements. In TXRF, the glass substrate on which 10 μL of the liquid sample is dropped and dried is measured. It is possible to perform qualitative analysis with simple sample preparation. For example, screening elemental analysis of intermediates can be performed in a short time. Furthermore, by using the internal standard addition method, it is possible to easily perform quantitative analysis of trace elements in aqueous solutions. Congeners those are chemically similar in nature, such as Ni-Pd-Pt or Cl-Br, can also be measured separately. The qualitative spectra of ppm level Pd and 10 ppb of Br in aqueous solution have low background and good SN ratio. ICP-MS has issues such as waste water treatment, and therefore another simple analytical technique has been desired for the analysis of intermediate. Since TXRF can perform highly sensitive measurement with simple pretreatment, it is an applicable technique for screening analysis.