Uninterrupted analysis of volatile organic compounds in drinking water using single quadrupole GC-MS

Importance of the topic

Monitoring and quantitation of volatile organic compounds (VOCs) in drinking water are essential to protect public health and ensure compliance with environmental regulations. VOCs arise from industrial processes and can contaminate water sources, necessitating sensitive, reliable, and high‐throughput analytical methods.

Objectives and study overview

The study demonstrates a routine analytical method conforming to U.S. EPA Method 524.2 using a Teledyne Tekmar Atomx XYZ purge and trap system coupled with a Thermo Scientific ISQ 7610 single quadrupole GC-MS and TRACE 1610 GC. Key performance metrics including linearity, method detection limits (MDLs), precision, accuracy, and robustness were evaluated.

Methodology and instrumentation

The method employs purge and trap sample preparation with internal and surrogate standards, followed by split-mode injection onto a TraceGOLD TG-VMS capillary column and analysis in full-scan mode on the ISQ 7610 mass spectrometer controlled by Chromeleon CDS. Instrumental features include:

• Teledyne Tekmar Atomx XYZ P&T with efficient trap cooling and moisture control.
• Thermo Scientific ISQ 7610 MS equipped with NeverVent VPI and ExtractaBrite ion source for rapid source and column changes without venting.
• TRACE 1610 GC operated in split mode (50:1) with a 20 m × 0.18 mm, 1 µm TG-VMS column.
• Chromeleon CDS for unified control of GC-MS and P&T workflow.

Main results and discussion

All 81 target VOCs were resolved within a 15-minute run time with minimal water interference, preserving sharp peak shapes across low-level samples. Calibration curves spanning 0.2–50 ppb achieved correlation coefficients >0.99 and relative standard deviations <20%. MDLs were typically 0.01–0.1 ppb. At 10 ppb, recoveries ranged from 90% to 130% and precision satisfied method criteria. A 197-injection sequence over three days exhibited RSDs below 30%, demonstrating system stability and negligible maintenance needs.

Benefits and practical applications

• Increased throughput via rapid trap cooling and short analysis times.
• Enhanced moisture management for extended column life and reduced downtime.
• Extended dynamic range allowing broad calibration spans on a single detector.
• Unified instrument control streamlines operations and reporting.

Future trends and opportunities

Developments may include selected ion monitoring for improved selectivity, high-resolution MS integration for comprehensive screening, advanced sorbent materials for broader analyte coverage, and deeper automation in data processing. The approach can expand to other environmental matrices and emerging contaminants.

Conclusion

The combined Teledyne Tekmar Atomx XYZ P&T with TRACE 1610 GC and Thermo Scientific ISQ 7610 GC-MS system provides a sensitive, robust, and regulatory-compliant solution for routine VOC analysis in drinking water under U.S. EPA Method 524.2.

References

1. U.S. EPA Method 524.2. Measurement of Purgeable Organic Compounds in Water by Capillary Column Gas Chromatography/Mass Spectrometry. U.S. Environmental Protection Agency, 1995.
2. Thermo Scientific Application Note 65632: Routine Analysis of Volatile Organic Compounds in Drinking Water Using the Thermo Scientific ISQ 7000 MS System. Thermo Fisher Scientific.