Simultaneous Determination of Trace Monochlorophenols in Water by Ion Chromatography Atmospheric Pressure Chemical Ionization Mass Spectrometry

A novel, sensitive, and accurate method has been successfully developed for the simultaneous determination of 3 monochlorophenols (MCPs) in drinking water samples by ion chromatography (IC) coupled with atmospheric pressure chemical ionization mass spectrometry in the negative mode. Drinking water was preconcentrated by solid-phase extraction (SPE). The IC separation was carried out with an IonPac® AS18 analytical column (250 mm × 4.0 mm) and an IonPac® AG18 guard column (50 mm × 4.0 mm) using 15 mmol l−1 KOH containing 10% acetonitrile as mobile phase in the isocratic mode at a constant flow rate of 1.0 ml min−1. The molecular ion m/z 127 [M-H] was selected for the quantification in the selected ion monitoring (SIM) mode. Within-the-day and day-to-day relative standard deviations were less than 8.6 and 10.5%, respectively. The limits of quantification (LOQs) in water samples were 0.02, 0.01, and 0.01 μg l−1 for 2-MCP, 3-MCP, and 4-MCP, respectively. The method allows the three target compounds in water samples to be determined at a level of ng ml−1, and it has been successfully applied to the routine analyses.