Simultaneous LC-MS/MS Analysis of Haloacetic Acids, Bromate, Chlorate, and Dalaponin Water Samples

Significance of the Topic

Disinfection of drinking water generates halogenated byproducts including haloacetic acids, bromate, chlorate and dalapon that are linked to adverse health effects. Monitoring these compounds at trace levels is essential to ensure compliance with regulatory limits and to protect public health.

Objectives and Overview of the Study

This study aimed to develop a rapid, direct injection LC-MS/MS method using a triple quadrupole instrument for simultaneous quantification of nine haloacetic acids, bromate, chlorate and dalapon in water. The method was benchmarked against established EPA protocols and designed to reduce analysis time and sample preparation.

Methodology

A mixed stock solution containing target analytes was prepared in LCMS grade water to generate calibration standards spanning the required concentration range. Laboratory fortified blanks and a synthetic sample matrix were employed to evaluate method precision, accuracy and matrix effects. Real water samples were collected, quenched with ammonium chloride and spiked with isotope labeled internal standards prior to analysis.

Used Instrumentation

• Shimadzu LC-30 Nexera HPLC system
• Shimadzu LCMS-8060NX triple quadrupole mass spectrometer with electrospray ionization in negative mode
• Capcell Pak C18 reverse phase column (150 × 3 mm, 3 µm)

Main Results and Discussion

The method achieved limits of quantitation of 0.1 to 1 µg/L for all analytes with calibration linearity coefficients of determination above 0.99. Recoveries in fortified blanks ranged from 80 to 120% with relative standard deviations below 15%. Minimal matrix effects were observed in synthetic matrix and real water samples. Analysis of six environmental water samples confirmed analyte concentrations well below regulatory maximum contaminant levels for haloacetic acids (60 µg/L), bromate (10 µg/L) and dalapon (200 mg/L).

Benefits and Practical Applications

The direct injection LC-MS/MS method significantly reduces run time compared to EPA 557, eliminates extensive sample preparation and enables simultaneous quantification of multiple regulated byproducts. This approach supports high throughput water quality monitoring laboratories and aids compliance with drinking water regulations.

Future Trends and Opportunities

Further expansion of analyte scope to include emerging disinfection byproducts, integration with automated sample handling and application to diverse water matrices represent promising directions. Advances in high resolution mass spectrometry may enhance selectivity and lower detection limits.

Conclusion

The presented LC-MS/MS method on the Shimadzu LCMS-8060NX delivers rapid, sensitive and reliable quantification of key halogenated disinfection byproducts in water with performance comparable to or exceeding existing EPA methods.

References

1. United States Environmental Protection Agency Method 557 Determination of Haloacetic Acids, Bromate and Dalapon in Drinking Water by Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry September 2009
2. World Health Organization Chlorite and Chlorate in Drinking Water 2005
3. United States Environmental Protection Agency Technical Factsheet on Dalapon National Primary Drinking Water Regulations
4. United States Environmental Protection Agency Envirofacts Information Collection Rule
5. Tap Water Safety Center Haloacetic Acids Information