High-Throughput RPLC-MS/MS Analysis of Bromate, Chlorate, Dalapon, and Haloacetic Acids in Drinking Water Samples by Shimadzu LCMS-8065XE

Drinking Water
Oral Presentation

Prepared by V. Zerda-Pinto1, R. Marfil-Vega2, E. Hain1, L. Wiest1
1 - Shimadzu Scientific Instruments, 7102 Riverwood Dr, Columbia, Maryland, 21046, United States
2 - Shimadzu Corporation Japan, 1-3, Kanda Nishiki-cho, Tokyo, , Japan


Contact Information: [email protected]; 202-819-7655

ABSTRACT

Drinking water treatment plants that use chlorination or bromination for disinfection can create disinfection byproducts (DBPs), such as bromate, chlorate, and several haloacetic acids. The EPA established maximum contaminant levels for bromate and the sum of five haloacetic acids. Dalapon is an herbicide with a similar structure to the HAAs and is also enforced under the National Primary Drinking Water Regulations (NPDWRs). These DBPs and dalapon can be analyzed using EPA Method 557, which utilizes ion chromatography electrospray ionization tandem mass spectrometry; however, the runtime is 56 minutes. A reverse-phase liquid chromatography tandem mass spectrometry (RPLC-MS/MS) method was developed to analyze bromate, chlorate, dalapon, and the individual haloacetic acids known as the HAA9 at NPDWR-relevant concentrations with approximately 4× the throughput than the regulated methods.
Analytes were separated by a Nexera HPLC and quantified by a Shimadzu LCMS-8065XE with a runtime of 15 minutes. Gradient elution on a Shim-pack Scepter C18-120 (3 µm; 150×2.1 mm) was used for this analysis with 0.05% formic acid in water and 0.3% formic acid in 4:1 methanol:water. Neat standards for calibration were prepared from 1-100 ppb. Reagent water, tap water, and laboratory synthetic sample matrix (LSSM) described in EPA Method 557 were used for testing recovery and method detection limits (MDLs). Accuracy of calibration standards was between 70-130% for all standards and controls. Other quality criteria were within acceptable ranges. Recovery of the analytes in reagent water, tap water, and the LSSM were between 70-130%. This presentation will demonstrate the method development that was conducted towards this method for measuring these contaminants at levels that meet regulatory criteria, but with higher throughput.