HPLC-ICPMS/MS shows a significant advantage over HPLC-ICPMS for the determination of perchlorate in ground, tap, and river water

Abstract

Perchlorate is an environmental contaminant that originates from anthropogenic as well as natural sources. The health effects of perchlorate with respect to the thyroid function are well known. The capabilities of the inductively coupled plasma mass spectrometry (ICPMS) has been recently expanded by coupling with tandem mass spectrometry. The advantages of HPLC-ICPMS/MS has not yet been thoroughly assessed for chlorine speciation analysis. We report a rapid and simple method for perchlorate determination in ground, tap, and river water and we show that the ICPMS/MS offers as a chromatographic detector at least 10-fold improvement in the detection limit relative to single quadrupole ICPMS. The achieved limit of detection was 0.3 μg Cl L−1 perchlorate and could be yet improved by simple freeze-drying (down to ca. 50 ng Cl L−1, based on the river water matrix), which is comparable with HPLC-ESIMS/MS, with the advantage of eliminating the need for the 18O-perchlorate isotopically labeled internal standard. The method was validated in the various water matrices in terms of recovery at levels 5.0–250 μg Cl L−1 (±10%), repeatability (RSD<5%), and linearity (r2 = 0.9999), and revealed the presence of trace levels in the Mur river water (0.33 ± 0.04 μg Cl L−1). Carbon was found to significantly decrease signal response for chlorine, and we shed light on the general effects of carbonate on chlorine speciation in hard water analysis.