Air Sampling with the CAM 5000

Application Note Summary: Air Sampling with CAM 5000 and Polymer Analysis via GPC-IR

Significance of the Topic:
Air quality assessment and polymer mixture characterization are critical in environmental monitoring and materials development. Reliable sampling of volatile organic compounds (VOCs) ensures compliance with regulatory limits and protects human health, while hyphenated techniques such as GPC-IR enable detailed profiling of complex polymer formulations used in industrial inks and coatings.

Objectives and Overview of Studies:
Two complementary case studies are presented. The first evaluates the CDS Analytical CAM 5000 purge-and-trap system for ambient air VOC monitoring under varying ventilation scenarios and accidental release of petroleum solvents. The second demonstrates the capability of gel-permeation chromatography coupled with infrared detection (GPC-IR) to separate and identify individual polymer components in a silver-based ink paste.

Methodology and Used Instrumentation:

• Air Sampling Study: CAM 5000 continuous air monitoring system interfaced to a Varian 3700 gas chromatograph with flame ionization detector (FID). Samples drawn at 40 mL/min for 4 min onto a Tenax-silica gel-charcoal trap (EPA 502.2) at 35 °C, thermally desorbed at 280 °C, and separated on a 30 m × 0.53 mm ID SE54 GC column (40 °C hold 2 min, ramp 8 °C/min to 180 °C).
• Polymer Analysis Study: GPC-IR hyphenated system (DiscovIR-LC) for separation of polymer mixtures, using infrared spectral libraries for component identification.

Main Results and Discussion:

• Ventilation Impact: Early-morning air samples showed VOCs from building materials. After running exhaust fans for two hours, total volatile component levels declined markedly, demonstrating the importance of continuous ventilation for indoor air quality.
• Accidental Solvent Release: A 2 mL petroleum naptha spill produced easily detectable VOC peaks within minutes, highlighting the CAM 5000’s sensitivity to sudden emissions and its capacity to warn of fugitive releases.
• Detection Limits: By extending sampling times, the CAM 5000 approach can attain part-per-trillion sensitivity for trace pollutants.
• Polymer Mixture Separation: GPC-IR successfully resolved three main components from a silver ink paste: Polymer A (aliphatic polyester resin, Amoco-type), Polymer B (aliphatic polyurethane Spensol L-53), and Additive C (ketoxime-blocked HDI trimer, inert at room temperature but deblocking at >130 °C to form tri-isocyanate cross-linker).

Benefits and Practical Applications:

• CAM 5000: Simplifies ambient VOC monitoring without separate sorbent tube sampling; provides flexible operation (continuous, timed or manual) for indoor air quality management, regulatory compliance, and rapid leak detection.
• GPC-IR Analysis: Offers direct infrared structural information on separated polymer fractions, aiding in quality control, formulation troubleshooting, and supplier verification of complex ink or coating systems.

Future Trends and Potential Applications:
Advancements are expected in trap materials and pump designs to lower detection limits further, integration of mass spectrometric detectors for enhanced selectivity, and real-time GPC-IR data processing with full-range FTIR capabilities. Expanded use in environmental forensics, process monitoring, and intellectual property defense is anticipated.

Conclusion:
The CAM 5000 coupled to GC-FID provides a robust platform for routine and event-driven VOC monitoring, while GPC-IR hyphenation unlocks detailed compositional insights in polymer mixtures. Together, these techniques enhance analytical capabilities across environmental and materials science applications.

Reference:

• Measurement of Toxic and Related Air Pollutants. Proceedings of the 1990 EPS/A&WMA International Symposium.
• J.J. Keller & Associates, Inc. (1990). Federal Regulations on Air and Water Pollution.