VALIDATED METHOD FOR THE DETERMINATION OF CARBOPLATIN IN BIOLOGICAL-FLUIDS BY ZEEMAN ATOMIC-ABSORPTION SPECTROMETRY

We have developed and validated a rapid, simple and sensitive analytical method, based on Zeeman atomic absorption spectrometry, for the quantitative analysis of carboplatin in human plasma, plasma-ultrafiltrate (UF), saliva and urine. The sample pretreatment is simple and only involves dilution of the samples with a solution containing 0.15 mol/L NaCl and 0.2 mol/L HCl in water (diluent). The carboplatin concentrations in the different biological matrices could be quantified using a standard curve constructed in plasma UF: diluent (1:10; v/v). The validated range of determination was 0.24 to 242 mu mol/L of carboplatin in plasma UF, 0.84 to 242 mu mol/L in plasma, 0.12 to 3.64 mu mol/L in saliva, and 2.02 mu mol/L to 12.1 mmol/L in urine. Matrix-effects were not observed. The stability of carboplatin (determined as Pt) in biological samples stored at - 20 degrees C was checked for a period of 8 months; no losses occurred during this period. The performance of the method, in terms of accuracy and precision, fitted well within the generally accepted criteria for validation of analytical methodologies. The proposed method was utilized in a pharmacokinetic study in one patient to demonstrate the usefulness of the assay.