When Disinfection Meets Detection: Modern Approaches for DBPs and Anions Analysis by EPA 300.1 and 326.0

Drinking Water
Oral Presentation

Prepared by y. jiang1, A. Savka2, E. Ando1, A. Tanabe1
1 - Shimadzu Scientific Instruments, 1, Nishinokyo Kuwabara-cho, Nakagyo-ku, kyoto, Kyoto, 6048511, Japan
2 - Shimadzu Scientific Instruments, 7102, Riverwood Drive, Columbia, Maryland, 21046, United States


Contact Information: [email protected]; 07015713230

ABSTRACT

Reliable determination of inorganic anions in drinking water is essential for regulatory compliance and protection of public health. Disinfection byproducts (DBPs) such as chlorite, bromate, and nitrate, nitrite and fluoride, are regulated contaminants due to potential health risks.
In this study, EPA method 300.1 was validated using a Shimadzu Nexera IC with an electrodialytic suppressor (ICDS-Ai) and a conductivity detector. Method 326.0 was demonstrated using a Shimadzu Nexera lite inert system equipped with a post-column system and UV detector for trace bromate analysis. Calibration curves for all target anions had correlation coefficients exceeded 0.999. MDLs for the target anions ranged from 0.0004 to 0.003 mg/L, values well below the corresponding Maximum Contaminant Level (MCL) for fluoride, nitrate and nitrite. For bromate analysis by Method 326.0, the LOQ was calculated as 0.3 µg/L, >30 times lower than the MCL.
Various drinking water samples by method 300.1 were analyzed using dichloroacetic acid (DCA) as a surrogate. DCA recoveries fell within the QC acceptable criteria (90–115%). All spike recovery tests showed excellent recoveries (97~104% for conductivity detector, 97~103% for UV detector) with low percent relative standard deviations (%RSD <0.87). The continuing calibration checks standards described in Method 300.1 remained within 100±10% over the period of this study.
This presentation reports accuracy, precision, and stability data from the validation of EPA Method 300.1 and 326.0. These methods deliver high sensitivity, robust recoveries and reliable chromatography with stable retention times across runs (%RSD<0.05, n=7), improving the productivity in water quality laboratories in need to routinely report “short holds” samples, address emerging requirements as the analysis of fluoride as surrogate of PFAS, or require routine monitoring low concentrations of bromide and bromate, critical parameters in utilities relying on oxidation for achieving their treatment goals.