Non-target screening and prioritization of organic contaminants in seawater desalination brine using comprehensive two-dimensional gas chromatography-mass spectrometry

Abstract

With the expansion of seawater desalination, the impact of desalination brine on the marine environment attracts increasingly concerning globally. Salinity is generally accepted as the major environmental factor in desalination concentrate. However, more and more studies have shown people cannot ignore the influence of organic contaminants in brine. This study developed a non-targeted screening method based on comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry combined with EPI Suite™ Toolbox 4.11 for identifying and prioritizing organic contaminants in the desalination brine. A total of 55 compounds were tentatively identified, including two polycyclic aromatic hydrocarbons, three engineering plastic ingredients, nine pesticides, eight plasticizers, two disinfection by-products, four phosphate ester flame retardants, two chlorophenols, and 25 other industry intermediates. We prioritize these chemicals by persistence (P), bioaccumulation (B), and toxicity (T) to determine whether they are harmful and need to be further analyzed. In addition, we found that four chemicals (caprolactam, N-phenyl-formamide, 2,4,6-tribromophenol, and tribromomethane) were possibly introduced from the desalination process. The method and results given in this study provide us with a new idea to identify the environmental impact factors of brine.