SPME Portable Field Sampler with Carboxen/PDMS Fiber

Significance of the Topic

The Supelco SPME Portable Field Sampler with Carboxen/PDMS fiber offers an efficient and cost-effective solution for field collection, storage, and transport of volatile and semivolatile organic compounds. This approach simplifies on-site sampling, eliminates solvent use, and preserves analyte integrity for subsequent laboratory analysis.

Objectives and Overview

This document details the design, operation, and performance of the portable field sampler. Key goals include demonstrating analyte retention during storage, establishing sampling procedures for gas and liquid matrices, and ensuring compatibility with gas chromatography (GC) analysis.

Methodology and Instrumentation

Sampling is performed by exposing a 75 µm Carboxen/PDMS fiber to the sample matrix. The fiber adsorbs target compounds and retracts into a protective needle housed in an aluminum nosepiece with a replaceable Thermogreen™ LB-2 septum. Precise depth control is achieved via a needle guide/depth gauge with five insertion slots. After collection, fibers can be:

• Immediately desorbed in a GC injection port at 300 °C for 30 minutes to remove impurities (conditioning).
• Stored in the sealed sampler at ambient or subambient temperature for up to 3 days without significant analyte loss.

Instrumentation Used

• SPME Portable Field Sampler assembly (polymer body, aluminum nosepiece)
• 75 µm Carboxen/PDMS SPME fiber
• Thermogreen™ LB-2 septa, 5 mm diameter
• SPME septum tool for septum replacement
• Magnetic stirrer and stir bar for liquid headspace sampling
• Gas chromatograph with temperature-controlled injection port

Main Results and Discussion

Analyte stability was evaluated by storing US EPA Method 624 compounds and naphthalene (20 ppb each) on fiber at –4 °C for 3 days. Table 1 data indicate:

• Mean change in response: 0.2 %
• Individual analyte variations: –4.8 % to +7.0 %

These negligible shifts confirm that the Carboxen/PDMS fiber retains target compounds effectively during short-term storage. Indoor air experiments detected common solvents at 2–20 ppb levels within 5 minutes of exposure.

Benefits and Practical Applications

• Solvent-free sampling reduces costs and environmental impact.
• On-site concentration and storage capability allows remote sampling.
• Reusability of fiber (50–100 cycles) enhances operational economy.
• Adaptable to vials, sampling bombs, and Tedlar® bags for air analysis.

Future Trends and Potential Applications

Advances may include custom fiber coatings for broader analyte classes, integration with portable GC or mass spectrometry systems, and automated field samplers for real-time monitoring in environmental, industrial, and indoor air quality applications.

Conclusion

The Supelco SPME Portable Field Sampler with Carboxen/PDMS fiber provides a robust, user-friendly platform for field sampling of volatile and semivolatile compounds. Its effective analyte retention, ease of operation, and compatibility with standard GC methods make it a valuable tool for analytical chemists across environmental and industrial settings.

References

• US EPA Method 624: Purgeable Organic Compounds in Water by Capillary Column Gas Chromatography/Mass Spectrometry