HPLC-ICP-MS Determination of Carboplatin and Chloroplatinic Acid

A portion of the sample (0.100 0 g) was dissolved in water and diluted to an appropriate volume according to the concentration of the analyte in sample. The ion-exchange column PRP-X100 was chosen as separation column, which was proved to have high efficiency in separation of chloroplatinic acid and carboplatin, due to bonding of polymer of divinylbenzene/triethylamine on the stationary phase. 60 mmol·L^-1 NH₄NO₃ solution (pre-adjusted its acidity to pH 5.5 with dil. NH₃·H₂O or dil. HNO₃) was used as mobile phase in the gradient elution program. Analyte in respective eluate was then determined by ICP-MS according to the prescribed procedure. As shown by the results, linearity ranges for chloroplatinic acid and carboplatin were found between 1.00 and 100 μg·L^-1 and between 500.0 and 1 000 μg·L^-1 with detection limits (3S/N) of 0.1 μg·L^-1 and 0.01 μg·L^-1respectively. Testes for recovery were performed by standard addition method using a substantial sample as matrix, giving values of recovery of 90.0%-98.8% for chloroplatinic acid and of 98.5%-99.2% for carboplatin. Values of RSDs (n=6) found was 2.7%-3.4% for chloroplatinic acid and 2.1%-2.8% for carbonplatin. It was found that in the analysis of a substantial sample by the proposed method, as the concentration of carboplatin found was 1 mg·L^-1, H₂PtCl₆ was not inspected in the same sample. Hence, inspection of traces of platinum(Ⅳ) was attained directly in the sample solution without any enrichment manipulation.