ABSTRACT
We developed and validated a method using high performance liquid chromatography ( HPLC ) coupled with electrospray ionization tandem mass spectrometry ( ESI_MS/MS ) to simultaneously quantify 11 urinary volatile organic compound ( VOC ) metabolites. The frozen urinary samples were unfrozen at room temperature and centrifuged to remove settled precipitate. 100 μL of the supernatant and 50 μL of internal standard were added and then diluted by 850μL of water so as to be analyzed by LC_MS/MS. The compounds were separated on a XSELECT HSS T3 column using acetonitrile as mobile phase A and 15 mmol/L ammonium acetate as mobile phase B at a flow rate of 250μL/min. The analytes were determined qualitatively and quantitatively under multi_reaction monitoring ( MRM) and negative polarity mode. The limits of detection ranged from 0 . 5-30 μg/L and the spiked recoveries of the analytes ranged from 89 . 8%-123 . 8% with RSDs of 3 . 1%-14 . 4%. This method was applied to 22 h urine samples collected from 16 smokers and 6 non_smokers. The results showed that the contents of the metabolites in smokerˊs urine were higher than those of nonsmokers, especially, smoking more than 25 cigarettes per day.