Chloronitramide Anion: A New DBP Detected in Drinking Water

Drinking Water
Oral Presentation

Prepared by Y. Li
Eurofins Eaton Analytical, 110 South Hill Street, South Bend, Indiana, 46617, United States


Contact Information: [email protected]; 574-472-5562

ABSTRACT

A recent breakthrough discovery by Fairey et al. confirmed the presence of chloronitramide anion in chloraminated drinking waters as a previously unidentified decomposition product of chloramine disinfectants. This pivotal study published in Science (https://www.science.org/doi/10.1126/science.adk6749) revealed that chloronitramide anion was at concentration levels of up to 120 µg/L in the studied samples. Chloramines are widely used, in place of chlorine or combined with other disinfectants, to minimize the formation of regulated disinfection byproducts (DBPs) such as total trihalomethanes (TTHMs) with a maximum contaminant level (MCL) of 80 µg/L and total haloacetic acids (HAA5) with an MCL of 60 µg/L. In the United States, approximately one-third of the public water systems (PWSs), particularly in California, use chloramination as a primary or secondary disinfection process. While its impact on human health remains under investigation, chloronitramide anion shares structural similarities with some highly toxic compounds, which raises important questions about its associated potential risks.

Eurofins Eaton Analytical, in collaboration with Dr. Julian Fairey from the University of Arkansas, has developed a cutting-edge LC/MS/MS method to analyze chloronitramide anion in drinking water. With the use of 15N-labeled chloronitramide as the internal standard, this method provides great sensitivity, accuracy, precision, and compensation for matrix interferences. This new method was to analyze more than two dozens of drinking water samples collected from different PWSs across the United States. Chloronitramide anion was at concentrations of 1.1 to 115 µg/L in all the chloraminated samples and at concentrations of 0.3 to 36 µg/L in several chlorinated waters. This presentation will provide more details of the findings and demonstration of capability. It will also discuss the impacts of disinfection conditions, such as chlorine levels, chlorine-to-nitrogen ratios, pH values, other disinfectants, etc., on the formation of chloronitramide anion.