Quantitative determination of platinum derived from cisplatin in human plasma ultrafiltrate using derivatization with diethyldithiocarbamate and liquid chromatography coupled with electrospray ionization tandem mass spectrometry

This paper describes a method for the determination of platinum derived from cisplatin in human plasma ultrafiltrate using liquid chromatography tandem mass spectrometry (LC-MS/MS). Cisplatin and the internal standard trans-diamminedichloropalladium(II) (TDPD) were chelated with diethyldithiocarbamate (DDTC) and separated with an isocratic elution on a C18 column. The method was validated with intra-/inter-batch accuracy and precision (relative standard deviation, RSD, %), matrix effect, specificity, limit of quantification (LOQ), linearity and stability. The linear range was 1.0–100.0 ng mL⁻¹ and the LOQ was 1.0 ng mL⁻¹. The intra-/inter-batch accuracy and precision were 92.2–111.0%/94.7–106.0% and 3.9–8.8%/2.1–9.3%, respectively. This sensitive and interference-free method can permit reliable and accurate analysis of platinum derived from cisplatin in human plasma ultrafiltrate.