US EPA Method 8260 with the Tekmar Lumin P&T Concentrator and Thermo Scientific™ TRACE™ 1310 GC and ISQ™ MS

Significance of the topic

The accurate measurement of trace volatile organic compounds (VOCs) in water and wet soils is critical for environmental monitoring and regulatory compliance. Traditional purge and trap systems often introduce water vapor into GC-MS instruments, compromising chromatographic resolution for early eluting compounds. The Tekmar Lumin purge and trap concentrator with its moisture control system (MCS) addresses this challenge by removing water vapor prior to GC-MS transfer, enhancing data quality and laboratory throughput.

Objectives and Study Overview

This application note evaluates the performance of the Tekmar Lumin combined with the AQUATek 100 purge-and-trap system in conjunction with EPA Method 8260 (and 5030 for sample preparation), interfaced to a Thermo Scientific TRACE 1310 GC and ISQ LT MS. The study aims to assess water vapor reduction, detection limits, linearity, precision, accuracy, and sample cycle times under no-dry-purge conditions.

Methodology and Instrumentation

Calibration standards spanning 0.5 ppb to 200 ppb (extended ranges for ketones and t-butanol) were prepared with multiple internal and surrogate standards. Key instrument settings included:

• Tekmar Lumin P&T MCS with 11 min purge at 20 °C, no dry purge step, rapid trap cooling and bake cycles.
• AQUATek 100 conditions for sample transfer.
• Thermo TRACE 1310 GC: Rtx®-VMS column, helium carrier, optimized oven program (35 °C start, ramp to 225 °C), 15.5 min runtime.
• ISQ LT MS: transfer line 230 °C, source 300 °C, scan 35–260 amu.

Key Results and Discussion

Linearity across all compounds showed RF RSDs below 16% with method detection limits typically below 0.3 ppb. Seven replicate injections at 0.5 ppb yielded accuracy between 90–115% and precision within 15% RSD. A 0.5 ppb standard chromatogram demonstrated no water interference on early eluters. A 30 ppb TIC showed consistent peak shapes. Internal and surrogate standards over 29 injections (9.5 h) exhibited low drift (<6% RSD internal, <4% RSD surrogate), confirming system stability.

Benefits and Practical Applications

The Lumin MCS enables EPA 8260 and 5030 compliance without dry purge, reducing cycle times and increasing sample throughput in 12-hour shifts. Improved water management preserves chromatographic resolution and minimizes maintenance associated with moisture.

Future Trends and Opportunities

Advances may include accelerated GC temperature programs, integration of high-resolution and tandem MS for enhanced selectivity, real-time method optimization via machine learning, and miniaturized purge-and-trap modules for field deployable systems. Expansion to more complex matrices and automated quality control workflows will further streamline environmental VOC analysis.

Conclusion

The Tekmar Lumin P&T concentrator with MCS coupled to AQUATek 100 and a Thermo TRACE 1310 GC-ISQ LT MS system effectively meets or exceeds EPA Method 8260/5030 requirements for VOC analysis in aqueous samples. The system’s superior moisture removal without dry purge yields robust chromatography, low detection limits, high precision and accuracy, and enhanced laboratory productivity.

Used Instrumentation

• Tekmar Lumin Purge and Trap Concentrator with Moisture Control System
• Teledyne Tekmar AQUATek 100 Sample Handling System
• Thermo Scientific TRACE 1310 Gas Chromatograph
• Thermo Scientific ISQ LT Mass Spectrometer

References

• US EPA SW-846 Method 8260B, Revision 2, December 1996
• US EPA SW-846 Method 8260C, Revision 3, August 2006
• US EPA SW-846 Method 5030B, Revision 2, December 1996
• US EPA SW-846 Method 5030C, Revision 3, May 2003