Simultaneous and Rapid Analysis of Multiclass Emerging Contaminants Using a Column-Switching LC-MS Method

Contaminants of emerging concern (CECs) in aquatic environments have attracted a considerable amount of attention from the public and regulatory groups. Due to their wide variety of chemical properties, simultaneous analysis of multiclass CECs presents a great challenge. This study develops an innovative liquid chromatography-mass spectrometry (LC-MS) method that integrates both large volume injection (LVI) and online solid phase extraction to quantify 102 CECs. The method utilizes three columns: a reversed phase (RP) column, a custom-built mixed weak cation/anion exchange trap column, and a mixed-mode ion exchange (MMIE) column. With valve switching, highly polar/ionic CECs that are not retained by the RP column are captured by the trap column while other CECs are separated by the RP column. Subsequently, the trapped highly polar/ionic CECs are transferred to the MMIE column for further separation. Matrix effects from sewage effluent and urine samples were assessed, and the method accuracy and precision were also determined using spike recovery. LVI notably enhanced the method sensitivity, with the method quantification limits for 93 of the 102 CECs in various water matrices being –1. Overall, this novel column-switching LC-MS method enables the rapid and simultaneous determination of multiclass CECs in diverse aqueous samples.