A combined sampling approach for simultaneous detection of volatile organic compounds and heavy metal ions in water using vacuum ultraviolet photoionization time-of-flight mass spectrometry

Volatile organic compounds (VOCs) and heavy metal ions significantly threaten human health. Hence, there is an urgent need to develop a faster and simpler method to detect these pollutants in water. Vacuum ultraviolet photoionization time-of-flight mass spectrometry (VUP-TOF-MS) shows an advantage in detecting these pollutants. The VUP-TOF-MS offers a wide detection range due to its ability to ionize analytes using photons and energetic photoelectrons. In this study, we report the first-ever simultaneous detection of VOCs and heavy metal ions in water using a single TOF-MS. We designed a novel combined sampling, which extracted the analytes from water into the gas phase. This was followed by photoionization by the VUP ion source with switched ionization modes. We also investigated ionization mechanisms to explain the characteristic peaks. The detection limits of these analytes ranged from 5.4 × 10−2 to 36.8 μg L−1. We monitored the river water and observed recoveries in the range of 94–118%. Thus, the proposed method provides a new possibility for the simultaneous online detection of VOCs and heavy metal ions by mass spectrometry. [Display omitted] •Simultaneous detection of VOCs and heavy metal ions in water was first achieved on a single mass spectrometry.•A novel sampling system for simultaneous extraction of VOCs and heavy metal ions from water to the gas phase was constructed.•This strategy provides new insights for the online water quality monitoring.