US EPA Method 8260 with the Tekmar Atomx XYZ P&T System and Agilent 7890B GC/5977A MS

Significance of the Topic

The determination of volatile organic compounds in water and soil is critical for environmental monitoring, regulatory compliance and contamination assessment. Reliable analysis supports public health protection and informed decision making in remediation projects.

Objectives and Study Overview

This application study evaluates US EPA Method 8260 combined with purge and trap Methods 5030 and 5035 for quantifying 91 target VOCs in water and soil. The work establishes calibration performance, method detection limits and demonstrates improved water removal using an advanced purge and trap system.

Methodology

Sample Preparation

• Preparation of two working standards at 50 ppm and 100 ppm in methanol covering 91 compounds
• Dilution to calibration levels from 0.5 ppb to 200 ppb
• Addition of four internal standards and four surrogate standards to each 5 mL sample to achieve 25 ppb spiking
• Seven replicates at 0.5 ppb for water and seven at 1.0 ppb for soil to determine detection limits, accuracy and precision

Analytical Protocol

• Purge and trap sampling under optimized temperature and flow conditions
• GC separation using a 20 m Restek VMS column with temperature ramp from 35 to 225 degrees Celsius
• Mass spectral detection from m/z 35 to 260 with autotune gain factor 10

Instrument Used

The Teledyne Tekmar Atomx XYZ purge and trap concentrator equipped with an 84-position autosampler system for soil and water samples. Key features include a moisture control system for enhanced water vapor removal and precision valve manifold. Coupled to an Agilent 7890B gas chromatograph and 5977A mass selective detector operated in full scan mode.

Main Results and Discussion

Calibration exhibited excellent linearity across the range with relative standard deviations of response factors typically below 10 percent. Method detection limits ranged from 0.08 ppb to 0.53 ppb for water and 0.08 ppb to 0.53 ppb for soil compounds. Accuracy for water and soil replicates remained within 80 to 127 percent, and precision was below 25 percent RSD. Chromatographic overlays confirmed that the Atomx XYZ moisture control system removed excess water more effectively than the prior model, yielding sharper peaks and minimal interference at a 50 ppb standard level.

Benefits and Practical Applications

This method enables reliable quantitation of low level VOCs in environmental matrices. Key advantages include:

• Increased sample throughput due to reduced cycle time and 84-position autosampler
• Enhanced GC column life through effective moisture control
• Compliance with established EPA method requirements for accuracy, precision and detection limits
• Scalable workflow for routine monitoring in water treatment, soil remediation and industrial quality control

Future Trends and Potential Applications

Further development may include optimization of GC temperature programs to shorten run times and integration with high resolution mass spectrometry for trace identification. Automation of data processing and coupling with predictive analytics platforms will enhance real-time monitoring. Portable or field deployable purge and trap systems could extend analysis to on site screening.

Conclusion

The combination of US EPA Method 8260 with the Atomx XYZ purge and trap system and Agilent GC/MS delivers robust performance for VOC analysis in water and soil. The system meets method requirements for linearity, sensitivity, precision and accuracy while offering improved water removal and higher throughput.

References

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