Simultaneous Determination of Medicinal Ingredients in So-called Health-promoting Food Using Liquid Chromatography Tandem Mass Spectrometry with a Pentafluorophenyl Stationary Phase

Abstract

An analytical method using liquid chromatography tandem mass spectrometry equipped with electrospray ionization (ESI) was demonstrated for the determination of medicinal ingredients, such as fenfluramine (FF), N- nitrosofenfluramine (NFF), sibutramine (SIB), sildenafil (SDF), vardenafil (VDF), tadalafil (TDF) and xanthoan- thrafil (XAF), in so-called health-promoting food. These analytes were clearly separated with acetonitrile-water (40: 60) containing 4 mM formic acid and 8 mM ammonium formate used in the mobile phase on a pentafluo- rophenyl (PFP) column under isocratic conditions. The retention times of FF, SIB, SDF and VDF on the PFP column were longer than those on the C18 column under the same mobile phase conditions. Within wide ranges, all peaks were proportional and the coefficient of determination (r2) showed more than 0.9950 in a linear regression analysis. The limit of quantification (LOQ) of the developed method was 0.8-42.2 g/l (S/N = 10). The recoveries of analytes admixed with commercially available health-promoting food ranged from 80.2 to 113.3% and were acceptable for quantitative analysis. Analytes of more than 2 g in a health-promoting food sample (0.5 g) were able to be identified by the European Communities (EC) criteria.