Method 8260C by Purge and Trap Gas Chromatography Mass Spectrometry using the Clarus SQ 8

Importance of the Topic

Volatile organic compounds (VOCs) represent a broad class of environmental pollutants that require sensitive, reliable, and rapid analytical methods for monitoring air, water, soil, and waste matrices. EPA Method 8260C using purge and trap gas chromatography–mass spectrometry (GC/MS) remains a cornerstone for regulatory and research laboratories worldwide. Advancements in detector technology and instrument design can further enhance throughput, sensitivity, and data quality in routine VOC analysis.

Study Goals and Overview

This application note evaluates the performance of the PerkinElmer Clarus SQ 8 GC/MS system equipped with a Teledyne Tekmar Atomx purge and trap sample introduction module. The objectives were to verify compliance with EPA Method 8260C performance criteria, demonstrate calibration linearity over a wide concentration range (0.5–200 µg/L), and assess method detection limits (MDLs), precision, and accuracy for 84 target VOC analytes.

Instrumentation

• GC/MS System: PerkinElmer Clarus SQ 8C with electron ionization mode
• Purge and Trap Module: Teledyne Tekmar Atomx with #9 trap
• Column: Elite 624 MS, 30 m × 0.25 mm i.d. × 1.4 µm film
• Carrier Gas: Helium at 1.0 mL/min
• MS Transfer Line Temp: 220 °C; Ion Source Temp: 300 °C; Scan Range: m/z 35–270

Methodology

Samples (5 mL) were purged at 40 mL/min for 11 min, trapped, desorbed at 200 °C, and introduced to the GC/MS. The oven program ramped from 40 °C to 200 °C to achieve baseline separation within a 20-min runtime. Calibration standards spanning nine concentration levels (0.5 to 200 µg/L) were prepared from certified multi-component mixes, including surrogate and internal standards. MDLs were calculated from seven replicates at 0.5 µg/L and 1.0 µg/L, while precision and accuracy were assessed at 25 µg/L through four replicates.

Results and Discussion

Calibration curves for most analytes exhibited excellent linearity (R² > 0.99), meeting or exceeding EPA criteria. MDLs ranged from 0.05 to 0.38 µg/L, with method precision (%RSD) below 5% and recoveries between 90–110%. High-speed oven cooling via the Clarus 680’s dual-walled design reduced cycle times, achieving injection-to-injection intervals under 30 min. Repeatability at low levels was highlighted by seven overlaid TICs of naphthalene (25 µg/L), yielding a 3.8% RSD in extracted ion chromatograms at m/z 128.

Benefits and Practical Applications

• High sensitivity allowing full-scan library searchable spectra at low µg/L levels
• Wide dynamic range with robust linearity across regulatory concentration limits
• Fast cooling and short runtimes increase sample throughput
• Flexible split flow control to optimize detection limits for priority analytes

Future Trends and Potential Applications

Emerging detector enhancements such as SIFI™ and SIM modes promise further improvements in detection limits and selectivity. Automation of purge and trap workflows and integration with advanced data processing algorithms will support expanded monitoring of trace VOCs in complex matrices. The Clarifî detector’s stability may enable longer intervals between tune procedures, benefiting high-volume laboratories.

Conclusion

The PerkinElmer Clarus SQ 8 GC/MS paired with an Atomx purge and trap system meets and surpasses EPA Method 8260C requirements for VOC analysis. The system delivers excellent sensitivity, precision, and accuracy across a broad concentration range while offering high throughput and operational ease.

References

• U.S. Environmental Protection Agency. Method 8260C: Volatile Organic Compounds by Purge and Trap GC/MS (2006).