The use of chemical derivatization to enhance liquid chromatography/tandem mass spectrometric determination of 1-hydroxypyrene, a biomarker for polycyclic aromatic hydrocarbons in human urine.

This article presents an analytical approach that used chemical derivatization to enhance mass spectrometric (MS) response in electrospray ionization (ESI) mode of 1-hydroxypyrene (1-OHP), a commonly used biomarker to monitor human exposure to polycyclic aromatic hydrocarbons (PAHs). The enhancement successfully enabled the desired detection of 50 pg/mL in human urine. The introduction of an MS-friendly dansyl group to 1-OHP enhanced both ionization efficiency in the ESI source and collision-activated dissociation (CAD) in the collision cell. The response increase was estimated to be at least 200-fold, and enabled the reduction of sample size to only 100 microL. The selective MS detection also facilitated a fast (run time 3 min) liquid chromatography (LC) method which successfully resolved the analyte and interferences. The sample processing procedure included enzymatic hydrolysis of glucuronide and sulfate conjugates, liquid-liquid extraction, derivatization with dansyl chloride and a final liquid-liquid extraction to generate clean extracts for LC/MS/MS analysis. This approach has been validated as sensitive, linear (50-1000 pg/mL), accurate and precise for the quantitation of 1-OHP in human urine. This is the first report of using chemical derivatization to enhance MS/MS detection with fast chromatography in the determination of 1-OHP in human urine.