US EPA Method 524.3 - Atomx XYZ and Agilent 7890B GC/5977A MS

Significance of the Topic

The analysis of volatile organic compounds in drinking water using purge and trap gas chromatography–mass spectrometry is essential for regulatory compliance and safeguarding public health. Monitoring trace-level contaminants ensures water safety and informs remediation efforts.

Objectives and Study Overview

This study evaluated the Teledyne Tekmar Atomx XYZ purge and trap system coupled with an Agilent 7890B GC/5977A MS under US EPA Method 524.3. The aims included establishing calibration linearity, determining method detection limits (MDLs), assessing accuracy and precision at 1 ppb, and confirming minimum reporting levels (MRLs) at 10 ppb for 75 target VOCs in water.

Methodology and Instrumentation

• Calibration standards were prepared from Restek® mixes at concentrations spanning 0.2 to 50 ppb, with internal standards (1,4-difluorobenzene, chlorobenzene-d5, 1,4-dichlorobenzene-d4) and surrogate standards added at 12.5 ppb.
• The Atomx XYZ P&T system featured optimized trap cooling, a moisture control system to reduce water vapor interference by up to 60%, and an 84-position autosampler for increased throughput.
• GC/MS analysis used an Rtx-VMS capillary column (20 m × 0.18 mm, 1 µm film) with helium carrier gas, an oven program from 35 °C to 225 °C, a 120:1 split inlet at 180 °C, and a mass spectrometer scanning 35–260 m/z.

Main Results and Discussion

All compounds exhibited excellent linearity (r² ≥ 0.995) over 0.2–50 ppb. MDLs ranged from 0.13 to 0.73 ppb. At 1 ppb, average recoveries were within ±20% and precision did not exceed 20% RSD. MRL confirmation at 10 ppb yielded recoveries between 50% and 150%. Chromatographic runs showed clear peaks with minimal water interference, demonstrating robust system performance.

Benefits and Practical Applications

• Achieves low detection limits and high sensitivity for trace-level VOC monitoring in drinking water.
• Reduced cycle times and advanced moisture control improve sample throughput and instrument longevity.
• Compliance with US EPA Method 524.3 supports routine environmental analysis and regulatory reporting.

Future Trends and Possibilities

Further advances in rapid GC temperature programming, enhanced automation, and real-time data analysis will shorten run times and expand applicability to complex matrices. Integration with online monitoring platforms could facilitate continuous water quality surveillance.

Conclusion

The Atomx XYZ P&T system together with Agilent 7890B GC/5977A MS successfully met US EPA Method 524.3 requirements for VOC analysis in drinking water. Demonstrated linearity, sensitivity, accuracy, and precision confirm the method’s reliability for high-throughput environmental testing.

Reference

• Munch J W Measurement of Purgeable Organic Compounds in Water by Capillary Column Gas Chromatography/Mass Spectrometry US EPA Method 524.3 Revision 1.0 June 2009