Green detection of trace cyanuric acid and free chlorine together via ion chromatography

Abstract

Chlorinated cyanurates (CCAs) are a type of disinfectants currently used worldwide for fight of Coronavirus. However, CCAs upon dosed into water can release not only free chlorine (FC), a strong disinfectant, but also cyanurate (CYA), a persistent compound potentially harmful to human and environment. Therefore, detecting CYA and FC in water are very important not only for ensuring sufficient disinfection but also for monitoring the impacts of FC and CYA on receiving watershed. However, conventional analytical methods for them are mostly based on colorimetric methods, which have high method detection limits (MDLs) and rely on chemical reactions that are likely sensitive to coexisting chemicals. To overcome these issues, we herein proposed a facile and reaction-free method to detect CYA and FC together in just one run by ion chromatography (IC) equipped with both conductivity and ultraviolet absorbance detectors. The method features obvious advantages over colorimetric methods in being lower MDLs (3.6 μg/L for CYA and 9.0 μg/L for FC), environmental-friendly (i.e., no organic solvent involved), and more resistant to alkaline solution. With this method, trace levels of CYA (i.e., 34–44 μg/L), which were nondetectable by conventional method, were found in two river water samples, implying that the local environment was already polluted by CCAs during the pandemic period. Overall, this study demonstrates a robust tool that may assist better understanding and monitoring the fate and transport of trace CCA derivatives in water.

Study on the health risk of cyanuric acid in swimming pool water and its prevention and control measures

“…The concentration of cyanuric acid in pool water is determined using various methods: liquid chromatography-mass spectrometry (LC–MS) ( 37 ), ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) ( 11 ), and gas chromatography–mass spectrometry (GC–MS) ( 38 ). These techniques utilize chromatography to separate the compounds and mass spectrometry to identify and quantify cyanuric acid based on its unique molecular characteristics.…”