Thermal extraction apparatus with high volume sampling trap
Inventors
Assignees
US Department of Homeland Security
Publication Number
US-11543333-B2
Publication Date
2023-01-03
Expiration Date
2041-01-29
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
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 designed to thermally extract vapor samples collected by a high volume sampling trap (HVST) using a thermal desorption (TD) collector such as a TD tube. The thermal extraction device (TED) heats a sample trap containing an adsorbent resin to release vapor-phase samples, which are then carried by a gas flow to a TD tube for collection. This TD tube may be cooled and subsequently inserted directly into a mass spectrometer for analysis, facilitating a one-step sample recovery and identification process.
The apparatus comprises a housing with a gas inlet and outlet and a side opening to receive a removable sample collector containing the vapor sample adsorbent. Heating members positioned upstream and downstream of the sample collector heat the adsorbent to about 200° C. to vaporize the samples. The vapor sample passes through the housing and is collected in a TD tube downstream, which is cooled by a coil with circulating fluid to about 0-10° C. The housing includes frustoconical cavities upstream and downstream of the sample collector to optimize gas flow cross-sectional areas. Temperature control units regulate the heating elements to maintain temperature gradients for efficient thermal extraction.
The problem being solved is the inefficient sampling and detection of vapor-phase and particle-phase volatile compounds over large volumes, especially in high-volume situations such as cargo inspection, security checkpoints, and screening for explosives or hazardous substances. Existing methods rely on liquid preparations, encapsulating chambers, or tethered handheld devices, which suffer from inefficiencies, large footprints, or limited operator mobility. The disclosed system enables efficient collection and thermal extraction of vapor samples from large volumes of air with improved sample recovery, transport, and direct analysis capability, addressing limitations of prior art systems.
Claims Coverage
The patent includes multiple independent claims focused on thermal extraction apparatuses and methods, covering structural components and operational features. The main inventive features are extracted from these claims.
Integrated thermal extraction apparatus with controlled heating and cooling
The apparatus comprises a housing with gas inlet and outlet and a side opening to receive a sample collector containing vapor sample adsorbent. It includes a pump generating gas flow, upstream and downstream heating members positioned around the sample collector to heat it to at least about 200° C., and a thermal desorption (TD) tube downstream connected to the outlet to collect vapor sample. A cooling member exchanges heat with the TD tube, cooling it to about 0-10° C., and a temperature control unit regulates the heating members to maintain different upstream and downstream temperatures, such as 200° C. and 190° C., respectively. Upstream and downstream frustoconical cavities in the housing manage cross-sectional gas flow.
Thermal extraction apparatus with heating means and cooling means
The apparatus includes a housing with an insertion port for a sample collector adsorbent, heating means for heating the housing adjacent to the sample collector adsorbent to at least about 200° C., a TD tube downstream connected with the gas outlet to receive gas flow and collect vapor sample, and cooling means to cool the TD tube to about 0-10° C. The housing features upstream and downstream frustoconical cavities that respectively increase and decrease in cross-sectional area around the sample collector location for optimized flow.
Method for thermal extraction of vapor samples
The method includes placing a sample collector with vapor sample adsorbent into a housing via a side opening, heating the housing region adjacent to the adsorbent to at least about 200° C. to release vapor sample, and directing gas flow through the housing from inlet, through the sample collector, to outlet connected to a cooled TD tube downstream to collect vapor sample. The method includes controlling the TD tube cooling to about 0-10° C., maintaining upstream and downstream temperature gradients around 200° C. and 190° C., measuring these temperatures with feedback control, and controlling gas flow at about 50-100 cc/minute for 2-4 minutes to collect vapor sample. The TD tube can then be inserted into a TD-GC/MS for analysis.
The claims cover apparatuses and methods featuring a housing with a side insertion port for sample collectors, controlled heating elements upstream and downstream of the sample, a TD tube downstream cooled to low temperatures for vapor sample collection, and temperature-controlled thermal extraction facilitating efficient recovery and analysis of vapor samples from various environments.
Stated Advantages
Improved sample recovery on the TD tube through controlled heating and cooling.
Facilitates one-step direct analysis of trapped samples by allowing the TD tube to be inserted directly into a mass spectrometer.
Efficient collection and thermal extraction of large volumes of vapor-phase and particle samples from air samples at security checkpoints, cargo containers, and other screening areas.
Portable and lightweight device suitable for various applications including chemical, biological warfare agents, explosives, toxic chemicals, and drugs sampling.
Documented Applications
Large volume air sample collection from cargo container freight, palletized cargo, and security checkpoints to trap illicit organic volatile materials.
Sample collection at airports or other checkpoints involving smaller volumes of air sampling.
Chemical and biological warfare agent sampling, industrial toxic chemicals, explosives particle samples, and drugs or hazardous waste sampling.
Screening and detection of explosives, vapor residues including high volatile organic compounds such as MNT, NG, EGDN, and DMNB taggant in security and military contexts.
Interested in licensing this patent?