Interferents in the sample ...

... (such as dissolved organic matter (DOM), salts, ...)

may hamper the quality of the environmental analysis for several reasons

1.	Interferents may damage the chromatographic separation system (e.g., DOM may adsorb to the stationary phase, which leads to deterioration of column quality or even complete clogging of the column)
2.	Interferents may co-elute with analyte(s) from the chromatographic system into the detector unit (e.g., an interferent may generate a signal that completely masks the signal of a co-eluting analyte).
3.	Interferents may raise the background signal of the detector and/or create noise in the background signal. Both effects increase the lowest analyte concentration that can be detected (i.e., the so-called limit of detection) and quantified (i.e., the so-called limit of quantitation).

Sample pre-treatment therefore aims at (at least partial) removal of the interferents from the sample
prior to chromatographic separation and detection of the analyte(s)