Automated SPME - analysis Multi Fiber EXchange MFX

Significance of the Topic

Solid Phase Micro-Extraction (SPME) is a versatile, solvent-free technique for isolating and concentrating trace organic analytes from a wide range of sample matrices. Its importance in analytical chemistry stems from rapid sample preparation, minimal matrix interference, and compatibility with gas and liquid chromatographic methods. Automation of SPME enhances reproducibility, reduces manual labor and enables high-throughput screening in research, quality control and environmental monitoring.

Objectives and Study Overview

This article reviews the integration of SPME into an automated workflow using the GERSTEL MultiPurpose Sampler (MPS), the Multi Fiber Exchange (MFX) accessory and MAESTRO control software. The goal is to demonstrate how these modules collectively streamline method development, fiber switching, derivatization and analysis scheduling to achieve reliable, 24/7 operation.

Methodology and Instrumentation

SPME fibers coated with various adsorbent phases extract analytes from either the headspace or direct immersion in liquid samples. The MPS robot automates vial handling, fiber conditioning, extraction and transfer steps. MFX enables automatic selection and replacement of up to 25 fibers mid-sequence, facilitating multi-phase extractions and recalibration without interruption. Thermal desorption occurs in the GERSTEL Cooled Injection System (CIS) fitted with a septumless head and narrow bore liner to prevent septum coring and maintain peak shape. MAESTRO software orchestrates the entire process, including sample prep overlap (PrepAhead), priority sample insertion and email alerts for sequence interruptions.

Results and Discussion

The automated SPME setup provides significant gains in throughput by overlapping extraction and GC/MS analysis, allowing continuous operation even when different chromatographic methods are used. MFX minimizes mechanical stress on fibers, extending their lifespan and reducing consumable costs. The CIS septumless design eliminates particle buildup to lower background signals and carry-over. Parallel processing ensures optimized productivity and reproducibility, while on-fiber derivatization supports water-sensitive reagents for aqueous samples.

Benefits and Practical Applications

• High throughput: unattended analysis of large sample series including overnight and weekend runs
• Flexible method development: rapid testing of multiple fiber coatings and phases
• Enhanced selectivity: sequential use of different fibers for a broad analyte polarity range
• Extended fiber life: reduced mechanical wear during automated exchange and stirring
• Minimal carry-over: automated fiber bake-out and septumless injection avoid sample cross-contamination
• Efficient software control: single sequence table manages sample prep and GC/MS workflows

Future Trends and Applications

• Expansion of fiber chemistries to target emerging contaminants and polar analytes
• Integration with LC/MS and ambient ionization techniques for broader applicability
• AI-driven method optimization within control software for self-tuning workflows
• Miniaturized, field-deployable SPME robotics for on-site environmental and forensic sampling
• Further automation of derivatization and multi-dimensional chromatography coupling

Conclusion

The combination of the GERSTEL MPS with MFX and MAESTRO software elevates SPME to a fully automated, high-throughput platform. This system delivers robust, reproducible analyses with enhanced selectivity and minimal maintenance, meeting the demanding needs of modern analytical laboratories.