High volume sampling trap thermal extraction device
Inventors
Assignees
US Department of Homeland Security
Publication Number
US-11237083-B1
Publication Date
2022-02-01
Expiration Date
2041-01-29
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Abstract
In an example, a thermal extraction apparatus includes: a housing having a gas inlet and a gas outlet to receive a gas flow through the housing from the gas inlet to the gas outlet, and a side opening to receive a sample collector, having a sample collector adsorbent containing a vapor sample, into a sample collector location; a pump to generate the gas flow; a heater to heat the sample collector adsorbent of the sample collector to a temperature sufficient to release the vapor sample; a thermal desorption (TD) tube connected with the gas outlet of the housing to receive the gas flow downstream of the sample collector and collect the vapor sample released from the sample collector adsorbent of the sample collector; and a cooling member in heat exchange with the TD tube to cool the TD tube.
Core Innovation
The invention relates to a thermal extraction apparatus and methods for thermally extracting vapor samples collected with a sample trap such as a high volume sampling trap (HVST). The apparatus includes a housing with a gas inlet and outlet and a side opening to receive a sample collector containing a sample adsorbent with vapor sample. A pump generates gas flow through the housing. Heaters upstream and downstream of the sample collector heat the sample collector adsorbent to a temperature sufficient to release the vapor sample. A thermal desorption (TD) tube connected downstream collects the vapor sample released from the sample collector adsorbent. A cooling member exchanges heat with the TD tube to cool it during collection.
The problem being solved addresses limitations in current sampling devices used for screening substances such as explosives and narcotics in high-volume contexts. Existing methods using liquid preparations are time-consuming and inefficient for large volume sampling. Other systems require large chambers or are hindered by tethered sampling wands limiting operator mobility. Vapor deposition systems often do not enable simultaneous extraction and sequestration of solid and liquid phase samples. The invention improves efficiency and sample recovery by enabling thermal extraction of vapor-phase and particle samples collected on a sample trap, and subsequent concentrated collection of analytes in a cooled TD tube for direct analysis.
The apparatus is adapted to handle large volumes of air samples from sources such as cargo container freight, palletized cargo, and security checkpoints to trap illicit organic volatile materials. The sample trap can be removably inserted into the housing via a side opening and heated to about 200° C. to vaporize collected particles and analytes. The gas flow directs the vapor-phase sample toward a polymer adsorbent TD tube cooled to about 0-10° C. for collecting vapors and analytes. The TD tube can be directly inserted into thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS) systems for analysis, providing a one-step process with improved sample recovery and portability.
Claims Coverage
The claims include three main independent claims detailing the structure and method of the thermal extraction apparatus and process, focusing on specific heating, cooling, and gas flow features.
Thermal extraction apparatus with dual heating members and cooling for TD tube
An apparatus having a housing with a gas inlet, outlet, and side opening to receive a sample collector with adsorbent. A pump generates gas flow through the housing. The heater includes separate upstream and downstream heating members on either side of the sample collector location, with a temperature control unit managing differing temperatures (upstream higher than downstream). A thermal desorption tube downstream collects vapor samples released from the sample collector adsorbent, and a cooling member exchanges heat with the TD tube to cool it during collection.
Thermal extraction apparatus with heating means creating temperature gradient
An apparatus comprising a housing with a gas inlet, outlet, and insertion port for a sample collector. A pump generates gas flow through the housing. Heating means heat the sample collector adsorbent to release vapor sample, where the heating means create a temperature gradient: upstream portion heated to a higher temperature than the downstream portion. A TD tube downstream collects the vapor sample released.
Thermal extraction method with heating and cooling steps for vapor sample collection
A method comprising placing a sample collector with adsorbent containing vapor sample in a housing via a side opening; heating the sample collector adsorbent to facilitate vapor release by heating upstream and downstream regions of the housing to different temperatures (downstream lower than upstream); directing gas flow through the sample collector toward a TD tube downstream; cooling the TD tube to about 0-10° C. to collect vapors; and inserting the TD tube with collected vapor sample into a TD-GC/MS for analysis.
The independent claims collectively describe a thermal extraction system and method characterized by a housing adapted for a removable sample collector, controlled dual-zone heating to vaporize samples, a cooled TD tube to collect released vapors downstream, and directed gas flow to facilitate efficient sample transfer and analysis. The apparatus and method focus on improving sample recovery, handling high volume air samples, and integrating with analytical systems.
Stated Advantages
Facilitates large volume air sample collection efficiently from various security and cargo screening areas.
Enables simultaneous extraction and collection of vapor-phase and particle samples, improving sample recovery.
Portable and lightweight device adaptable for field and checkpoint use, enhancing operator mobility.
Facilitates one-step sample analysis by enabling direct insertion of the TD tube into TD-GC/MS systems.
Allows precise temperature control with upstream and downstream heating members to optimize sample vaporization while preventing sample loss downstream.
Documented Applications
Air sampling from cargo container freight, palletized cargo, and security checkpoints to trap illicit organic volatile materials.
Sample collection at airports and other checkpoints involving smaller air volumes.
Field use for chemical and biological warfare agent sampling.
Industrial toxic chemical detection.
Explosives particle and vapor sample detection.
Sampling of drugs or hazardous waste materials.
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