Quantification of intact carboplatin in human plasma ultrafitrates using hydrophilic interaction liquid chromatography–tandem mass spectrometry and its application to a pharmacokinetic study

Carboplatin is a platinum agent that is used for treatment of non-small-cell lung cancer and ovarian cancer. A sensitive and selective analytical method for the quantification of carboplatin in human plasma ultrafiltrates using liquid chromatography–tandem mass spectrometry was developed. Human plasma ultrafiltrates were precipitated by acetonitrile containing carboplatin-d4 as an internal standard and were further diluted with acetonitrile. Chromatographic separation was performed on a Accucore HILIC (50 mm × 2.1 mm i.d., 2.6 μm) column using mobile phase (acetonitrile–water–acetic acid = 90:10:0.1, v/v/v) at the flow rate of 0.2 mL/min. Detection was performed on electrospray ionization triple quadrupole tandem mass spectrometer using low-energy collision induced dissociation (CID-MS/MS) analysis operating in the selected reaction monitoring (SRM) scan mode. The lower limit of quantification for carboplatin was 0.025 μg/mL. This method covered a linearity range of 0.025–50 μg/mL. The intra-day precision and inter-day precision (R.S.D.) ranged from 1.5 to 4.3%, and the accuracy (R.E.) was within ±2.9%. The present method was applied to a clinical pharmacokinetic study of carboplatin in a cancer patient.