Schematic diagram for the Peltier-assisted cooling assembly for CMV
Florida International University (FIU) is pursuing a business partner interested in commercializing Device and Methods for the Cryofocused Sampling of Volatile Organic Compounds from Ambient Air. The sampling of volatile compounds from air using the previously described capillary extraction of volatiles (CMV) is enhanced by as much as by a factor of 4 times by cryofocusing the volatiles directly onto the CMV at -10 C. This device allows sampling of the headspace of indoor air, with many potential applications including forensic chemical analysis.
The analysis of VOCs in ambient air is currently performed with sorbent tubes following the guidelines from the EPA method TO-17. Some of the limitations observed for the analysis of VOCs with sorbent tubes include: long headspace extraction times (about an hour) with low flow rates and the use of expensive thermal desorption units coupled to gas chromatography-mass spectrometry (GC-MS) through the use of transfer lines that can result in poor recoveries.
FIU inventors have developed a CMV sampling device, which includes a thermoelectric cooler, a vacuum pump,
Peltier cooling assembly detail illustration the placement of the CMV tube within the Peltier-cooled assembly
at least one holder for a capillary microextractor of volatiles (CMV) tube, and at least one CMV tube. The thermoelectric cooler thermally contacts the holder and the CMV tube, and the vacuum pump is fluidly connected to the CMV tube. The CMV tube can have a polydimethylsiloxane (PDMS) gel on glass fibers within a glass tube. The thermoelectric cooler can be a single-stage, dual-stage, or multi-stage Peltier cooler. The CMV tube is cooled with an air stream being drawn through the CMV tube for a prescribed period of time. Air flow and cooling can be maintained for a period of 1 to 10 minutes at a temperature of -15 to 5°C. After sampling, the CMV with the absorbed diagnostic volatiles can be placed in an ionized gas beam and introduced into a mass spectrometer or placed in a thermal desorption unit (TDU), where, upon heating, the diagnostic volatiles are released to an inlet port of an analytical instrument. Analytical instruments that can be used include gas chromatographs and ion mobility spectrometers for separation and mass spectrometers for unambiguous identification of the diagnostic volatiles. This CMV sampling device and methods permit rapid extraction of VOCs in ambient air, and have superior performance relative to the performance according to the reported guidelines of the EPA method TO-17.
- Detection of illicit drugs, explosives, and dangerous chemicals in public places such as airports, public transportations, recreational facilities
- Diagnosis and monitoring of diseases by detecting VOCs in lungs
- Indoor air quality management for residential and non-residential spaces
- Detection of marijuana smokers’ breath for impaired driver management
- Detection of gunshot residues on swab samples from the hands of shooters
- Cost-efficient and disposable
- Offers dynamic and rapid sampling of volatile organic compounds
- Thermally stable at 300˚C
- Offers 5000x increase in surface area improvement in capacity over the static sampling single-fiber SPME