Selective, sensitive and simple LC-APCI-MS method for the quantitation of Alpha-Tocopheryl Nicotinate in human plasma

A sensitive and specific method using liquid chromatography with atmospheric pressure chemical ionization mass spectrometry (LC-APCI-MS) has been developed and validated for the identification and quantification of Alpha-Tocopheryl Nicotinate in human plasma. A simple liquid-liquid extraction procedure was followed by injection of the extracts onto a C₁₈ column with isocratic elution and detection using a single quadrupole mass spectrometer in selected ion monitoring (SIM) mode. The method was tested using six different plasma batches. Linearity was established for the concentration range 2-1500 ng/ml, with a coefficient of determination (r) of 0.9998 and good back-calculated accuracy and precision. The intra- and inter-day precision values were less than 15% and the deviations were within ± 5.0%. The lower limit of determination was reproducible at 0.5ng/ml with 0.5 ml plasma. The proposed method enables the unambiguous identification and quantification of Alpha-Tocopheryl Nicotinate for pre-clinical and clinical studies.