ORBO Solvent Desorption Tubes

Importance of Solvent Desorption Tubes in Analytical Chemistry

Solvent desorption tubes are essential tools for trapping volatile and semi-volatile compounds from air samples, enabling accurate quantification in environmental monitoring, occupational hygiene, and indoor air quality assessment. Their reliable performance and compatibility with solvent extraction and gas chromatography workflows make them indispensable in analytical laboratories worldwide.

Project Objectives and Overview

This product specification outlines the range of ORBO solvent desorption tubes designed by Sigma-Aldrich (Supelco) to accommodate diverse sampling needs. The document lists adsorbent materials, bed weights, tube dimensions, equivalent SKC catalog numbers, and available packaging. It also highlights custom tube manufacturing capabilities for specialized requirements.

Methodology and Provided Instrumentation

Sampling methodology relies on drawing a known air volume through a packed adsorbent tube. After collection, analytes are desorbed with a suitable organic solvent and injected into a gas chromatograph or other detection system. Provided instrumentation and materials include:

• ORBO desorption tubes packed with various adsorbents
• Sorbent bed configurations (A/B options and retaining plugs)
• Glass or metal holders and precleaned plugs for Polyurethane Foam (PUF) cartridges
• Custom tube fabrication service to meet method or regulatory specifications

Main Features and Discussion

The ORBO series covers a wide spectrum of adsorbent classes:

• Charcoal variants: activated coconut, petroleum, low-nickel, treated with oxidizers or alkali
• Carbon molecular sieves: Carboxen, Carbosieve, Carbotrap series
• Silica gel: activated, acid-coated, glass-fiber enhanced, DNPH derivatization
• Florisil and Hopcalite for inorganic or polar compound capture
• Porous polymers: Supelpak, Tenax TA, Amberlite XAD, Chromosorb, Porapak families
• Polyurethane foam cartridges for large-volume sampling and specialized matrices
• Custom tubes tailored to OSHA/NIOSH methods or unique project timelines

Key parameters such as bed weight (50–600 mg), tube diameter (6–11 mm), and length (20–150 mm) are carefully matched to sorbent characteristics and target analyte profiles.

Benefits and Practical Applications

ORBO desorption tubes offer:

• High adsorption capacity and analyte recovery for a broad chemical range
• Standardized dimensions for seamless integration with thermal or solvent desorption units
• Compatibility with regulatory sampling methods and routine QA/QC protocols
• Availability in multiple pack sizes and rapid access to custom production

These attributes support applications in environmental air monitoring, workplace exposure assessment, and research into volatile organics.

Future Trends and Potential Applications

Emerging directions include the development of new hybrid sorbents with enhanced selectivity, miniaturized micro-sampling tubes for on-site real-time analysis, and integration with automated sampling systems. Advances in sorbent chemistry may further extend tube lifetimes and reduce solvent consumption during desorption.

Conclusion

The ORBO Solvent Desorption Tube portfolio provides a versatile and reliable foundation for quantitative air sampling workflows. With a comprehensive selection of adsorbents, customizable formats, and global technical support, these tubes address diverse analytical challenges in environmental and occupational monitoring.

References

No references were provided in the original specification.