US EPA Method 524.3 with the Tekmar Lumin P & T Concentrator and Agilent 7890B GC and 5977A MSD System

Significance of the Topic

Monitoring trace levels of volatile organic compounds in drinking water is essential for public health protection and regulatory compliance. US EPA Method 524.3 is widely adopted by environmental laboratories to detect and quantify VOCs at sub-ppb concentrations. Effective moisture management during purge and trap sample preparation is critical to maintain chromatographic performance and reduce instrument maintenance due to water vapor loading.

Objectives and Overview of the Study

This application note evaluates the performance of the Tekmar Lumin purge and trap concentrator, featuring an integrated moisture control system, in conjunction with an Agilent 7890B gas chromatograph and 5977A mass spectrometer. The primary goal is to demonstrate reduced water transfer to the GC-MS system while maintaining method performance criteria defined in US EPA 524.3.

Methodology

Calibration standards from 0.2 to 50 ppb were prepared in deionized water with required preservatives. Internal standards and surrogates were added to calculate relative response factors. Seven replicate standards at 0.5 and 5 ppb were used to determine method detection limits, accuracy, and precision. Analytical trap cooling improvements were implemented to shorten cycle times.

Instrumentation

• Tekmar Lumin purge and trap concentrator with moisture control system
• AQUATek 100 autosampler
• Agilent 7890B gas chromatograph with DB-624 UI column
• Agilent 5977A mass selective detector

Main Results and Discussion

Linearity across all target compounds yielded correlation coefficients of at least 0.995. Method detection limits ranged from 0.05 to 0.18 ppb, meeting regulatory requirements. Accuracy values were between 82 and 108 percent, and precision (RSD) remained below 12 percent. Chromatograms of 0.2 ppb and 5 ppb standards showed well defined peaks with minimal baseline noise or water interference, confirming effective moisture reduction by the Lumin concentrator.

Benefits and Practical Applications of the Method

The integrated moisture control system significantly lowers water vapor entering the GC-MS, reducing column and source fouling and maintenance downtime. Enhanced trap cooling shortens analysis cycles, increasing sample throughput. This approach provides reliable detection of VOCs in drinking water at regulatory levels.

Future Trends and Opportunities

Advancements in moisture management and trap design will further improve sensitivity and speed of VOC analysis. Integration with high-throughput autosamplers and remote monitoring will streamline laboratory workflows. Emerging applications include on-site water quality screening and coupling with advanced detectors for broader analyte coverage.

Conclusion

The Tekmar Lumin purge and trap concentrator, combined with the Agilent GC-MS system, meets or exceeds all US EPA Method 524.3 requirements while significantly reducing water vapor transfer. This configuration enhances analytical performance, reduces maintenance, and supports high-throughput environmental testing.

References

1. Munch JW Measurement of Purgeable Organic Compounds in Water by Capillary Column Gas Chromatography Mass Spectrometry US EPA Method 524.3 Revision 1.0 June 2009.