Analysis of Haloacetonitriles in Tap Water Using Triple Quadrupole LC/MS/MS

Importance of the Topic

Haloacetonitriles are halogenated compounds formed during chlorination of water and are recognized as toxic disinfection byproducts regulated in drinking water. Their monitoring is critical for ensuring compliance with water quality standards and protecting public health.

Objectives and Study Overview

This study demonstrates a rapid method for simultaneous determination of three haloacetonitriles—dichloroacetonitrile, bromochloroacetonitrile, and dibromoacetonitrile—in tap water using the Shimadzu LCMS-8060 triple quadrupole LC/MS/MS system without sample preparation.

Analytical Methodology

Separation was achieved on an Inertsil Ph-3 HP phenyl column (150 mm x 2.1 mm, 3 μm) with a water (A)–methanol (B) gradient (10% to 75% B over 8 min, held at 100% B until 10 min, then returned to 10% B by 13 min) at 0.3 mL/min and 40°C. Detection used negative APCI with MRM transitions 108.35>34.90 for dichloroacetonitrile, 151.80>78.85 for bromochloroacetonitrile, and 195.75>78.85 for dibromoacetonitrile. Key parameters: 50 μL injection, probe voltage –4.0 kV, interface 400°C, DL and block heater at 200°C, nebulizing gas 3 L/min, drying gas 5 L/min.

Instrumentation Used

• Shimadzu LCMS-8060 triple quadrupole LC/MS/MS
• Inertsil Ph-3 HP phenyl column

Main Results and Discussion

MRM chromatograms showed clear separation of the three analytes within a 13-min run time. Calibration curves from 1 to 20 μg/L exhibited excellent linearity (R2 > 0.999). Spike-and-recovery tests at 5 and 10 μg/L in tap and dechlorinated tap water yielded recoveries between 91.0% and 103.1% with RSDs below 8%, demonstrating the method’s accuracy and precision. Direct analysis without sample extraction proved effective.

Advantages and Practical Applications

• Simultaneous quantification of three haloacetonitriles in 13 min
• No sample preparation required for tap water
• Simple interchange between APCI and ESI ionization sources

Future Trends and Opportunities

Future developments may include on-site and high-throughput monitoring platforms, expansion to additional disinfection byproducts, enhanced ionization techniques for challenging analytes, and integration with automated sample handling for routine water quality surveillance.

Conclusion

The presented LC/MS/MS method using the LCMS-8060 enables rapid, accurate, and precise determination of key haloacetonitriles at or below provisional target levels in tap water without sample preparation, supporting efficient water quality assessment.

Reference

No literature references were cited in the source document.