Determination of naphthalene metabolites in human urine by liquid chromatography-mass spectrometry with electrospray ionization

The use of a liquid chromatography-electrospray mass spectrometry system wa s investigated for the quantitative analysis of naphthalene metabolites (al pha-naphthol, alpha-naphthylglucuronide and beta-naphthylsulphate) in untre ated urine samples. Chromatography was carried out under ion-suppressed rev ersed-phase conditions, by using high-speed (3 cm, 3 mu m) columns and form ic acid (2 mM) as a modifier in the mobile phase. The ionization was obtain ed in the negative-ion mode. Linearity, sensitivity and precision of the me thod were explored by operating in selected-ion monitoring mode. The method was applied to the quantitative analysis of naphthalene metabolites in unt reated urine samples from workers in a naphthalene producing plant. Solid-p hase extraction was used for sample clean-up and trace enrichment. Liquid c hromatography-tandem mass spectrometry experiments were performed for confi rmation purposes. (C) 1999 Elsevier Science B.V. All rights reserved.