A time-updated review on the identification of emerging disinfection byproducts in drinking water: Revealing the role of chromatography

Since the identified disinfection byproducts (DBPs) do not fully explain the overall toxicity of disinfected drinking water, accurately identifying highly toxic unknown DBPs is essential for understanding the adverse effects of water disinfection. Analytical methods are selected based on the distinct properties of DBPs. A literature search was conducted in the PubMed, Embase, Web of Science, Google Scholar, and CNKI databases to identify emerging DBPs first reported in the past five years, collecting data on their identification and occurrence. While earlier studies primarily employed gas chromatography (GC) related methods, recent years have seen a substantial shift toward liquid chromatography (LC) related methods. Among the emerging DBPs reported over the past five years, GC related methods have identified four classes, whereas LC related methods have identified 26 classes. Furthermore, innovative techniques such as supercritical fluid chromatography-quadrupole-time of flight-tandem mass spectrometry (SFC-Q-TOF-MS/MS) have been introduced to enhance DBP identification. The reported concentrations of individual emerging DBPs are mostly in the range of 10¹ ng/L, typically only one-thousandth to one-tenth of those of regulated and priority DBPs, which generally exist at μg/L levels. This review also discusses future developments in the accurate identification of unknown DBPs and explores strategies to enhance drinking water safety, informed by insights gained from the emerging DBPs identified in the past five years.