ICP-MS method for the determination of platinum in suspensions of cells exposed to cisplatin

Abstract

This paper describes an inductively coupled plasma–mass spectrometric (ICP-MS) method for rapid and sensitive determinations of concentrations of Pt contained in cells exposed to cisplatin. The cells are sonicated, digested with nitric acid, a dilution is made and the suspension is introduced to the plasma. The whole sample is analysed as a suspension. The absence of filtration steps eliminates the potential for shortfalls in the recovery of Pt which may result from incomplete digestion and losses during filtration. Interferences caused by reagents that are normally used to effect digestion of this material, e.g., NaOH, are also eliminated. These benefits, combined with the high sensitivity of ICP-MS analysis, yielded a method detection limit for Pt of less than 1 ng ml^–1. When the concentrations of Pt contained in the samples were at least 20 ng ml^–1, good agreement was obtained between repeats. The method was used in an investigation concerned with mechanisms of platinum accumulation in mouse lymphoma cell lines exposed to cisplatin. This paper describes one of the analytical methods used, but does not discuss the results of the investigations into mechanisms of Pt accumulation.