Capillary thermal desorption unit for near real-time analysis of VOCs at sub-trace levels. Application to the analysis of environmental air contamination and breath samples.
A capillary microtrap thermal desorption module is developed for near real-time analysis of volatile organic compounds (VOCs) at sub-ppbv levels in air samples. The device allows the direct injection of the thermally desorbed VOCs into a chromatographic column. It does not use a second cryotrap to focalize the adsorbed compounds before entering the separation column so reducing the formation of artifacts. The connection of the microtrap to a GC-MS allows the quantitative determination of VOCs in less than 40 min with detection limits of between 5 and 10 pptv (25 degrees C and 760 mm Hg), which correspond to 19-43 ng m(-3), using sampling volumes of 775 cm(3). The microtrap is applied to the analysis of environmental air contamination in different laboratories of our faculty. The results obtained indicate that most volatile compounds are easily diffused through the air and that they also may contaminate the surrounding areas when the habitual safety precautions (e.g., working under fume hoods) are used during the manipulation of solvents. The application of the microtrap to the analysis of VOCs in breath samples suggest that 2,5-dimethylfuran may be a strong indicator of a person's smoking status.
Department of Chemistry, University of Girona, Girona, Spain.
Mónica
M
Alonso
Mar
M
Castellanos
José
J
Martín
Juan M
JM
Sanchez
D000327:Adsorption; D000393:Air Pollutants / Q000737:chemistry*; D001944:Breath Tests; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D012137:Respiratory System / Q000737:chemistry*; D055549:Volatile Organic Compounds / Q000737:chemistry*
D000393:Air Pollutants; D055549:Volatile Organic Compounds