OPTIMIZING LVDI-LC-HRMS SENSITIVITY FOR NON-TARGETED ENVIRONMENTAL ANALYSIS BY DESIGN OF EXPERIMENTS

Non-targeted analytical approaches based on liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) are gaining attention for the comprehensive detection and identification of chemicals of environmental concern (CECs) occurring in environmental samples, alleviating the need for reference standards. LC-HRMS non-targeted approaches are playing a relevant role in monitoring CEC occurrence in surface waters and effluents from wastewater treatment plants, in both of which transformation products (TPs) can occur after chemical, photochemical, and biological degradation processes. Consequently, non-targeted approaches tend to lower selectivity by reducing sample handling, without drastically affecting sensitivity often performing large-volume direct injection (LVDI) [2]. On this basis, a Design-of-Experiment (DoE) optimization workflow is here presented for increasing the sensitivity of a LVDI-LC-HRMS method, performed using a training set of 42 CECs (e.g., PFASs and estrogens) and TPs from 2013-2020 regulations and watch lists, covering a wide range of physicochemical properties, being thus characterized by different chromatographic and ionization behaviours.