In addition to extraction, and keeping anionic selectivity as the focus, the instrumental analysis requires similar levels of consideration. Consensus regarding the limitations of reversed-phased liquid chromatography (RPLC) for NTA of very polar and ionic compounds has resulted in new methods employing hydrophilic interaction liquid chromatography , mixed-mode RP-anion exchange-cation exchange and supercritical fluid extraction . For NTA, a carefully optimised data-processing workflow is also critical. Several studies have highlighted the marked difference in output of different algorithms for peak detection . Consensus is also growing in the scientific community about the importance of feature reduction to eliminate unnecessary workload and reduce false positives. In particular, blank and repeatability filters are increasingly becoming integrated in data-processing NTA workflows. Additionally, several studies have characterised natural dissolved organic matter (DOM) by LC-HRMS including relatively harmless fulvic and humic acids. The concentration of DOM in UK tap water is generally in the range of a few parts per million . By applying a concentration factor during sample preparation, a large number of DOM mass spectral features will be generated. Therefore, a means to reduce or remove such features in silico would reduce the NTA/SS workload and likelihood of generating false positives (while retaining the option to reassess the data for such substances post-hoc if required).