High-Performing Restek PAL SPME Fibers

Significance of the Topic

Solid phase microextraction SPME has become an essential sample preparation technique in analytical chemistry due to its solvent-free operation, minimal sample handling and compatibility with a wide range of analytes and matrices. High-performance SPME fibers can streamline workflows in environmental monitoring, food safety, clinical diagnostics and quality control by offering rapid extraction, high sensitivity and excellent reproducibility.

Objectives and Study Overview

This application note presents the performance characteristics of Restek PAL SPME fibers. It aims to summarize the fiber offerings, demonstrate their versatility across target analyte classes and benchmark their quantitative performance against a leading competitor in residual solvent analysis of cannabis extracts following the USP 467 headspace SPME approach.

Methodology and Instrumentation

A standardized headspace SPME method was applied to 6 mL aqueous samples containing residual solvents spiked at 10 µg/mL. Samples were prepared with sodium chloride in amber vials and agitated at 1 000 rpm. Extraction was performed in the headspace for 2 minutes at 30 °C using 80 µm DVB/Carbon WR/PDMS fibers. Thermal desorption occurred at 250 °C for 10 seconds and analytes were separated on an Rxi-624 Sil MS capillary column with a programmed oven ramp from 30 °C to 250 °C. GC-MS detection used an Agilent 7890 gas chromatograph coupled to a 5977B HES mass spectrometer.

Used Instrumentation

• PAL CTC RTC autosampler for automated SPME handling
• Agilent 7890 GC with split/splitless inlet
• Agilent 5977B HES mass spectrometer
• Rxi-624 Sil MS column, 30 m × 0.25 mm × 1.40 µm

Main Results and Discussion

Quantitative comparison of Restek SPME fibers versus a popular brand showed equivalent or superior area counts for key residual solvents in cannabis matrices. The triple-phase DVB/Carbon WR/PDMS fibers exhibited robust extraction efficiency and low carryover. Performance metrics confirmed that Restek fibers meet or exceed industry benchmarks, providing consistent results across replicates.

Practical Benefits and Applications

Restek PAL SPME fibers are optimized for PAL autosamplers and compatible with most GC inlets. Their aluminum hubs enhance durability compared to plastic alternatives. A variety of stationary phases and fiber thicknesses cover nonpolar, polar, volatile and semivolatile analytes. Additional accessories such as manual injection kits, Topaz inert inlet liners and Merlin microseal septa support seamless integration and extended operational life in routine analytical workflows.

Future Trends and Potential Applications

Emerging developments include SPME Arrow formats for increased phase volume, expanded fiber chemistries for challenging analytes and further automation of sample preparation. Integration of SPME with high-resolution mass spectrometry and online coupling in environmental and metabolomics studies will broaden applicability. Continuous improvement in inlet liners and septa deactivation will enhance trace analysis reliability.

Conclusion

Restek PAL SPME fibers deliver reliable, high-throughput sample preparation with performance matching or exceeding competing products. Their robust design, broad analyte compatibility and comprehensive accessory support make them a valuable choice for diverse GC-MS applications in research, industry and regulatory laboratories.