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

Significance of the Topic

Acrylamide contamination in tap water poses a health risk due to its classification as a Class 1 designated chemical in Japan and its inclusion in drinking water quality standards. Trace-level detection is essential to ensure compliance with the target limit of 0.5 μg/L and to monitor potential exposure from water treatment processes that use polyacrylamide flocculants.

Objectives and Study Overview

This study aimed to develop a rapid, reliable method for quantifying acrylamide in tap water without the need for sample concentration or extensive cleanup. Using the Shimadzu LCMS-8060NX triple quadrupole system coupled with Nexera X3 UHPLC, the work assessed detection limits, calibration linearity, precision, and recovery in dechlorinated tap water samples.

Methodology and Instrumentation

• Sample preparation: Direct injection of tap water; dechlorination with 0.02 g/L sodium ascorbate to prevent acrylamide degradation.
• Instrumentation:
  • Liquid chromatography: Nexera X3 UHPLC with CAPCELL PAK C18 AQ column (150 mm×2.0 mm, 3 μm).
  • Mobile phases: 0.01% formic acid in water (A) and acetonitrile (B); gradient from 2% to 100% B over 9 min, re-equilibration to 2% B by 15 min; flow rate 0.2 mL/min; column at 40 °C.
  • Mass spectrometry: LCMS-8060NX ESI in positive mode; MRM transitions m/z 72.10>55.15 for acrylamide and 75.10>58.15 for 13C3 internal standard; interface 350 °C; heat block 500 °C; desolvation gas flows: nebulizing 3 L/min, drying 10 L/min, heating 10 L/min.
• Calibration: Standards from 0.025 to 0.5 μg/L with 0.1 μg/L 13C3-acrylamide internal standard; weighted (1/C) linear regression.
• Precision and recovery tests: Five replicate analyses at 0.05 μg/L; spike-and-recovery in Kanagawa tap water.

Main Results and Discussion

• Acrylamide was detectable at 0.025 μg/L with clear MRM peaks and no significant background interference.
• Calibration exhibited linearity across 0.025–0.5 μg/L with R² > 0.999 and accuracy within 80–120%.
• Repeatability at 0.05 μg/L achieved an RSD of 1.9% (n=5), demonstrating high precision at one-tenth of the regulatory limit.
• Spike-and-recovery in dechlorinated tap water yielded 100.3% recovery and 2.5% RSD, confirming method robustness in real samples.

Benefits and Practical Applications

• Elimination of pre-concentration steps simplifies workflow and reduces analysis time.
• High sensitivity allows monitoring at levels twenty times lower than the 0.5 μg/L target.
• Suitable for routine water quality surveillance in public health and environmental laboratories.

Future Trends and Potential Applications

Integration of microflow LC, online sample cleanup, and automated data processing may further enhance sensitivity and throughput. Expanding the method to other polar contaminants and coupling with high-resolution MS or machine learning algorithms could support comprehensive water quality screening and real-time monitoring.

Conclusion

The LCMS-8060NX platform enables direct, ultra-trace analysis of acrylamide in tap water with excellent linearity, precision, and recovery. The method meets and exceeds regulatory requirements without complex sample preparation, providing a robust tool for water quality assessment.

Reference

• Japan Water Works Association. Standard Methods for the Examination of Water, 2020 Edition, III. Organic Compounds, 16. Acrylamide.