Rapid and Sensitive Determination of Airborne N-Nitrosamines Using the Agilent Capillary Trap Sampler, Thermal Separation Probe, and an Agilent 5975T LTM GC/MS

Importance of the Topic

The reliable monitoring of airborne N-nitrosamines is critical due to their well-documented carcinogenic potential and widespread occurrence in industrial emissions, tobacco smoke, and environmental reactions. Rapid and highly sensitive detection methods enable better exposure assessment, regulatory compliance, and timely intervention to protect public health.

Objectives and Study Overview

This study presents a streamlined analytical workflow for the quantitation of six common N-nitrosamines in ambient air. The key goals were to reduce sampling time, minimize solvent usage, and improve method detection limits compared to established protocols such as NIOSH 2522.

Methodology and Instrumentation

Airborne nitrosamines were sampled directly in the field using the Agilent Capillary Trap Sampler (CTS) fitted with six PoraPLOT Q capillaries. Sample volumes ranged from tens of milliliters up to several hundred milliliters, enabling flexibility for high- or low-concentration environments. Desorption was achieved via the Agilent Thermal Sample Probe (TSP) inserted into a split/splitless inlet of the Agilent 5975T LTM GC/MS. The low thermal mass (LTM) column modules and a controlled temperature program (60 °C initial hold, ramping to 200 °C) ensured efficient separation of N-nitrosamines without thermal degradation.

Main Results and Discussion

• Calibration and Linearity: Six standards spanning 48–1,600 ng showed excellent correlation coefficients (R2 ≥ 0.990).
• Sensitivity: A presumed method detection limit (MDL) below 1 ng per injection was achieved by capturing analyte from up to 500 mL of air (equivalent to 4 ng in the final extract).
• Signal Quality: Extracted ion chromatograms exhibited sharp peaks without significant interferences, highlighting the selectivity of capillary trapping.
• Recovery: Liquid-injection calibration yielded recoveries of 100% for NDBA and 105–125% for other analytes, compensating for slight losses of more volatile species.

Benefits and Practical Applications

The CTS–TSP–GC/MS system offers:

• Rapid field sampling in seconds to minutes.
• Reduced solvent consumption and simpler workflows.
• High sensitivity suitable for trace-level monitoring.
• Portability and ease of use for environmental screening and compliance testing.

Future Trends and Potential Applications

Ongoing developments may include integrating automated sampling protocols, expanding analyte scope to other volatile and semi-volatile contaminants, and coupling with real-time monitoring platforms. Miniaturized GC/MS systems and enhanced data processing algorithms will further support on-site decision-making and high-throughput environmental surveillance.

Conclusion

The combination of the Agilent Capillary Trap Sampler, Thermal Sample Probe, and 5975T LTM GC/MS delivers a fast, sensitive, and cost-effective solution for the determination of airborne N-nitrosamines. This approach addresses limitations of existing methods by reducing sampling times, lowering detection limits, and simplifying sample preparation, thereby improving analytical capabilities for environmental and occupational health applications.