US EPA Method 524.3 with the Teledyne Tekmar Atomx XYZ and the Thermo Scientific™ TRACE™ 1310 GC and ISQ™ LT MS System

Importance of the Topic

This summary describes the application of US EPA Method 524.3 for the determination of volatile organic compounds (VOCs) in drinking water matrices. Accurate VOC analysis is vital for regulatory compliance, safeguarding public health, and monitoring environmental quality. The integration of a modern purge and trap system with gas chromatography–mass spectrometry offers enhanced sensitivity, reproducibility, and throughput for routine laboratory workflows.

Study Objectives and Overview

The primary goal of the study was to validate the performance of the Teledyne Tekmar Atomx XYZ purge and trap system coupled to the Thermo Scientific TRACE 1310 GC and ISQ LT mass spectrometer under US EPA Method 524.3. Key tasks included generating a nine-point calibration curve (0.2–40 ppb), determining method detection limits (MDLs), assessing accuracy and precision at 0.5 ppb, and confirming minimum reporting levels (MRLs) at 20 ppb for a suite of 74 target VOCs.

Methodology

Calibration standards were prepared from Restek® MegaMix and Gas Calibration Mix at 10 ppm and 50 ppm in methanol, yielding a nine-point linear range with r² ≥ 0.995. Internal standards (1,4-Difluorobenzene, Chlorobenzene-d5, 1,4-Dichlorobenzene-d4) and surrogates (MTBE-d3, 4-Bromofluorobenzene, 1,2-Dichlorobenzene-d4) were spiked to each 5 mL water sample at 12.5 ppb. Seven replicates at 0.5 ppb and at 20 ppb were used for MDL, accuracy/precision, and MRL confirmation. Atomx XYZ P&T conditions included a 5 mL purge volume, 80 mL/min purge flow at 20 °C, a 2 min thermal desorb at 250 °C, and moisture control to minimize interference. GC parameters featured an Rtx-VMS capillary column, helium carrier, and a temperature program from 35 °C to 225 °C in under 11 minutes. MS detection was performed in scan mode from 35 to 260 amu.

Instrumental Setup

• Teledyne Tekmar Atomx XYZ purge and trap system with 84-position autosampler and moisture control system.
• Thermo Scientific TRACE 1310 gas chromatograph with Rtx-VMS 20 m × 0.18 mm, 1 µm column.
• Thermo Scientific ISQ LT single quadrupole mass spectrometer in full scan mode (35–260 amu).

Key Results and Discussion

Calibration linearity for all compounds met or exceeded r² ≥ 0.995. MDLs ranged from 0.02 to 0.32 ppb. Accuracy across seven 0.5 ppb replicates fell within 73–119% of true values, and precision (RSD) remained below 20%. MRL confirmation at 20 ppb showed lower and upper percent interval ranges of 50–150%. A representative total ion chromatogram of a 20 ppb standard demonstrated well-resolved peaks and negligible water interference, affirming the system’s robustness.

Benefits and Practical Applications

The Atomx XYZ P&T system with the TRACE 1310 GC/ISQ LT MS provides:

• High sensitivity allowing sub-ppb detection of a broad VOC panel.
• Efficient moisture removal extending column and system lifetime.
• Reduced cycle times (14% faster) and compact footprint for enhanced throughput (up to four samples per hour).
• Reliable performance for regulatory monitoring, QA/QC testing, and environmental surveillance.

Future Trends and Potential Applications

Advancements may include further optimization of GC temperature programs to reduce analysis time, integration with high-resolution or tandem MS for improved compound identification, and coupling to automated sampling for near real-time water quality monitoring. Broader adoption of multi-matrix purge and trap systems will support diverse environmental and industrial applications.

Conclusion

The combined Teledyne Tekmar Atomx XYZ and Thermo Scientific TRACE 1310 GC/ISQ LT MS system meets US EPA Method 524.3 requirements, delivering excellent linearity, sensitivity, accuracy, and precision for VOC analysis in drinking water. Its efficient design and robust moisture control enable high throughput and minimal interference, making it well-suited for routine environmental and regulatory laboratories.

References

• 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.