CMV device a) overview b) detailed close up
Florida International University (FIU) is pursuing a business partner interested in commercializing a Capillary Microextractor of Volatiles (CMV). This device allows the sampling of volatile organic compounds (VOCs) such as an explosive, explosive taggant, drug, poison, decomposition products thereof, a mixture of chemicals comprising an odor signature determined from detector dog trials, or VOCs indicative of a disease or other medical condition.
The analysis of VOCs in ambient air is currently performed with sorbent tubes following the guidelines from the EPA method TO-17. The commercially available sorbent tubes consist of a thin cylinder that can be made out of glass or stainless steel. The interior of the tubes is packed with sorbent material, which is selected depending on the target compounds, specifically the volatility or vapor pressure of the molecule of interest. Each sorbent material is classified according to its strength, which is described as the affinity of the compounds to the sorbent. Some of the limitations observed for the analysis of VOCs with sorbent tubes include: long headspace extraction times ( about 1 hour) with low flow rates and the use of thermal desorption units (TDU) 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 portable dynamic flow extraction device for sampling. The CMV has a thermally stable housing with orifices to allow the contact of a gas that contains one or more diagnostic volatiles with an absorbent that extracts and concentrates the diagnostic volatiles. After sampling, the CMV with the absorbed diagnostic volatiles can be directly introduced into the injection port of a GC using a low-cost thermal separation probe, thereby reducing sample loss and allowing faster elution relative to other thermal desorption units that use a transfer line. Alternatively the CMV can be placed in a 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. With a total surface area of about 0.05 m2 in the sampling device and a phase volume of 100 mm3 for the CMV, this device offers greater absorption capacity compared to SPME where the surface area is 10-5 m2 and phase volume is only 0.612 mm3 , improving the capacity of CMV over SPME by 5,000 times.
- 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
- Provides a cost-efficient, disposable, and thermally stable sampling device (up to 300˚C)
- Offers 5000x increase in surface area improvement in capacity over the static sampling single-fiber SPME
- Reduces contamination and loss of target compounds