Ultra-sensitive speciation analysis of inorganic platinum-chloride complexes in platinum-based drugs by HPLC-ICP-MS

Abstract

This work establishes a hyphenated methodology coupling HPLC with ICP-MS for the determination of platinum chloride complexes as synthetic impurities of platinum-based drugs for the first time. The separation of inorganic platinum-chloride complexes was accomplished in less than 3 min on an anion exchange column with a mobile phase containing 2 mmol L⁻¹ (v : v) HCl. The detection limits were found to be 0.2 μg L⁻¹ and 0.3 μg L⁻¹ for potassium hexachloroplatinate (K₂PtCl₆) and potassium chloroplatinate (K₂PtCl₄), respectively. Method precision and accuracy were satisfactory at <3% relative standard deviations (RSDs) for 10 μg L⁻¹ of K₂PtCl₆ and K₂PtCl₄, and >90% recoveries for real samples. The method has the advantages of simplicity, rapidity and sensitivity, and provides a basis for quality control of trace impurities in the production process of platinum-based drugs.