US EPA Method 524.2: Successful Measurement of Purgeable Organic Compounds in Drinking Water by Agilent 8860/5977B GC/MSD

Importance of the Topic

Volatile organic compounds (VOCs) are common contaminants in drinking water and pose significant health risks. The US EPA Method 524.2 outlines procedures for quantifying purgeable organics by GC/MS, ensuring compliance with regulatory standards to protect potable water supplies.

Study Objectives and Overview

This application note evaluates the performance of an Agilent 8860/5977B GC/MSD system, coupled with a Teledyne Tekmar Lumin purge-and-trap concentrator and AQUATek LVA autosampler, to meet or exceed US EPA Method 524.2 requirements for VOC analysis in drinking water. Key goals include verifying calibration linearity, achieving low method detection limits (MDLs), and demonstrating real-sample applicability.

Methodology and Instrumentation

We used an Agilent 8860 GC with split/splitless inlet, UI DB-624 column, and a 5977B MSD autotuned via BFB Autotune. The Tekmar Lumin P&T concentrator with Moisture Control System minimized water transfer to the MSD. A six-compound surrogate/internal standard mix was added via the AQUATek LVA. Calibration spanned 0.25–50 µg/L over seven levels. MDLs were determined using eight replicate injections at the lowest calibration levels. Key operating parameters include:

• Carrier gas: helium at constant flow (0.663 mL/min)
• Inlet split ratio 150:1, inlet temperature 250 °C
• Oven program: 35 °C hold 4 min, ramp 15 °C/min to 240 °C
• Purge and trap: trap purge at 20 °C, water purge 11 min at 40 mL/min
• MSD scan range m/z 35–260

Main Results and Discussion

Calibration results showed <20% RSD for 79 of 80 target VOCs over two orders of magnitude dynamic range. Iodomethane required quadratic fitting due to stability issues. Calculated MDLs were in the low ng/L (ppt) range, meeting EPA guidelines. Application to finished tap water samples from multiple Pennsylvania municipalities identified and quantified several VOCs—including chloroform, bromodichloromethane, toluene, tetrachloroethylene, and tribromomethane—at concentrations from 0.3 to 14 µg/L. MassHunter Unknowns Analysis provided reliable spectral deconvolution at low analyte levels (=3× MDL).

Benefits and Practical Applications

• High-throughput and reproducible VOC quantitation at regulatory compliance levels
• Robust moisture control reduces maintenance and downtime
• Automated tuning and spectral deconvolution improve method reliability
• Suitable for routine drinking water monitoring and QA/QC in environmental laboratories

Future Trends and Applications

Advancements may include enhanced software-driven automation, miniaturized P&T modules for portable field analysis, and integration with high-resolution mass spectrometry for improved selectivity. Expanding spectral libraries and AI-powered data processing can further streamline unknown VOC identification in complex matrices.

Conclusion

The Agilent 8860/5977B GC/MSD with Teledyne Tekmar purge-and-trap and AQUATek LVA meets US EPA Method 524.2 requirements for VOCs in drinking water, offering excellent sensitivity, precision, and robustness. The approach demonstrates applicability for regulatory monitoring and public health protection.

References

1. US EPA Method 524.2 Measurement of Purgeable Organic Compounds in Water by Capillary Column GC/MS (Revision 4.1)
2. Hollis J. S.; Prest H. Volatile Organic Compound Analysis Using Purge and Trap with Agilent 5975C MSD; Agilent Technologies Application Note 5991-0029EN