Reducing the helium consumption without compromising performance using the HeSaver-H2Safer technology for PCBs analysis

Significance of the topic

Polychlorinated biphenyls (PCBs) are persistent organic pollutants that bioaccumulate through food chains and pose serious environmental and health risks. Reliable GC-MS analysis is essential for regulatory compliance and monitoring. However, helium shortages and rising costs threaten routine operations. The HeSaver-H2Safer technology addresses this challenge by decoupling inlet pressurization from carrier gas supply, enabling dramatic helium savings without sacrificing chromatographic performance.

Study objectives and overview

This study aimed to evaluate the HeSaver-H2Safer inlet upgrade on a TRACE 1610 GC coupled to a TSQ 9610 triple quadrupole MS for PCB analysis. Key goals included:

• Assessing retention time reproducibility and peak shape for 28 PCB congeners.
• Comparing linearity, detection limits, and precision against a standard split/splitless (SSL) injector.
• Demonstrating robustness during prolonged sequences of complex environmental extracts.
• Estimating helium consumption and cost savings using a dedicated calculator tool.

Methodology and instrumentation

TRACE 1610 GC with dual iConnect injectors (one standard SSL, one modified to HeSaver-H2Safer mode) and TSQ 9610 MS were used. A five-point calibration (0.20–2000 ng/mL) of 28 PCB congeners was prepared in nonane. The HeSaver-H2Safer inlet used nitrogen for pressurization and helium limited to column supply, maintaining typical GC flow rates. MS conditions: emission current 10 µA, selected reaction monitoring for each PCB. Robustness tests included 100 injections of environmental extracts interspersed with QC standards (1.0 ng/mL).

Main results and discussion

Retention times for all congeners matched the SSL injector within ±0.03 min, and recoveries averaged >97% at 0.2 ng/mL. Chromatographic resolution for critical pairs (e.g., PCB-123/PCB-118) remained high (Rs >7%), and peak asymmetry (As) was ≤1.0. Linearity coefficients (R2) exceeded 0.9999 across the calibration range for both injector modes. Instrument detection limits were ∼0.02 ng/mL, and repeatability at the lowest level had peak area RSD <4.5%. Robustness testing showed QC RSD <10% over 100 injections of complex matrices without inlet or MS maintenance. The Gas Saver Calculator predicted a 4.5-fold extension of helium cylinder life using EPA Method 1668C.

Benefits and practical applications

• Seamless method transfer: no need for re-optimization or changes to existing protocols.
• Substantial reduction in helium consumption and operating costs.
• Improved inlet cleanliness by limiting septum and matrix contaminants.
• Continuous column flow during inlet maintenance.
• Immediate compatibility with regulatory methods for PCBs and other analytes.

Future trends and applications

As helium supply uncertainties persist, technologies like HeSaver-H2Safer will gain broader adoption in environmental, food safety, and petrochemical analysis. Integration with automated gas management software and expansion to hydrogen carrier gas workflows can further enhance sustainability. Ongoing development may include real-time consumption monitoring and dynamic flow optimization.

Conclusion

The HeSaver-H2Safer inlet upgrade provides a cost-effective, performance-equivalent solution for GC-MS analysis of PCBs, delivering significant helium savings and ensuring robust, high-quality data. This technology supports sustainable laboratory operations without method requalification.

References

1. Thermo Fisher Scientific. Technical Note 001218: Addressing gas conservation challenges when using helium or hydrogen as GC carrier gas.
2. Thermo Fisher Scientific. Application Note 000561: Reproducible trace analysis of PCBs in environmental matrices using triple quadrupole GC-MS/MS.
3. Thermo Fisher Scientific. Helium Saver Calculator tool.
4. US EPA. Method 1668C: Chlorinated Biphenyl Congeners in Water, Soil, Sediment, Biosolids, and Tissue by HRGC/HRMS, April 2010.