Apparatus and method for thermal assisted desorption ionization systems
The present invention is directed to a method and device to desorb an analyte using heat to allow desorption of the analyte molecules, where the desorbed analyte molecules are ionized with ambient temperature ionizing species. In various embodiments of the invention a current is passed through a mesh upon which the analyte molecules are present. The current heats the mesh and results in desorption of the analyte molecules which then interact with gas phase metastable neutral molecules or atoms to form analyte ions characteristic of the analyte molecules.
1. A method of analyzing an analyte comprising:
contacting a plastic with an analyte;
introducing the plastic in proximity to a mesh positioned between a source and an entrance of a spectrometer;
heating the mesh with a supply;
directing a plurality of ionizing species formed by the source at the plastic, where analyte molecules desorbed from the plastic interact with the plurality of ionizing species to form one or more analyte ions which pass through the entrance of the spectrometer and are analyzed.
2. The method of analyzing an analyte of claim 1 , further comprising inserting a gas ion separator between the mesh and the entrance to improve efficiency of sampling.
3. The method of analyzing an analyte of claim 1 , where the one or more analyte ions are formed at approximately atmospheric pressure.
4. The method of analyzing an analyte of claim 1 , where the plurality of ionizing species are formed at approximately atmospheric pressure.
5. The method of analyzing an analyte of claim 1 , where the source is selected from the group consisting of a direct analysis real time (DART), Plasma Assisted Desorption/Ionization ( PADI ), Dielectric Barrier Discharge ionization source (DBDI or DCBI), Desorption Atmospheric Pressure Chemical Ionization (DAPCI), Desorption Sonic Spray Ionization (DeSSI), Desorption Atmospheric Pressure Photoionization (DAPPI), and Flowing Atmospheric-Pressure Afterglow (FAPA) and a desorption electrospray ionization (DESI), an atmospheric laser desorption ionization, a Corona discharge, an inductively coupled plasma (ICP) and a glow discharge source.
6. The method of analyzing an analyte of claim 1 , where the supply passes power to the mesh of between:
a lower limit of approximately 10.sup.-2 Watts; and
an upper limit of approximately 10.sup.3 Watts.
7. The method of analyzing an analyte of claim 1 , where a first potential is applied to the mesh.
8. The method of analyzing an analyte of claim 7 , where the first potential is approximately the same as a potential applied to the entrance of the spectrometer.
9. The method of analyzing an analyte of claim 1 , where the analyte is a solution.
10. The method of analyzing an analyte of claim 1 , further comprising where an auto sampler contacts the plastic with the analyte.
11. The method of analyzing an analyte of claim 1 , where the plastic is a sponge.
12. The method of analyzing an analyte of claim 1 , where the plastic is a foam.
13. A method of analyzing an analyte of ionizing an analyte comprising: contacting an analyte onto a plastic with an auto sampler; introducing the plastic in proximity to a mesh; heating the mesh with a supply; directing a plurality of ionizing species at the plastic, where analyte molecules desorbed from the plastic interact with the plurality of ionizing species to form one or more analyte ions.
14. The method of analyzing an analyte of claim 13 , where the plurality of ionizing species is generated by a method selected from the group consisting of a direct analysis real time (DART), Plasma Assisted Desorption/Ionization ( PADI ), Dielectric Barrier Discharge ionization source (DBDI or DCBI), Desorption Atmospheric Pressure Chemical Ionization (DAPCI), Desorption Sonic Spray Ionization (DeSSI), Desorption Atmospheric Pressure Photoionization (DAPPI), and Flowing Atmospheric-Pressure Afterglow (FAPA) and a desorption electrospray ionization (DESI), an atmospheric laser desorption ionization, a Corona discharge, an inductively coupled plasma (ICP) and a glow discharge source.
15. The method of analyzing an analyte of claim 13 , where the plurality of ionizing species is formed from a carrier gas.
16. The method of analyzing an analyte of claim 15 , where the carrier gas can be heated.
17. A method of ionizing an analyte comprising: contacting a plurality of analytes onto a plurality of formed plastic pieces with an auto sampler; introducing sequentially one or more of the plurality of formed plastic pieces in proximity to a mesh; heating the mesh with a supply; directing a plurality of ionizing species at the one or more of the plurality of formed plastic pieces, where analyte molecules desorbed from the one or more of the plurality formed plastic pieces interact with the plurality of ionizing species to form one or more analyte ions.
18. The method of ionizing an analyte of claim 17 , where the plurality of ionizing species are formed at approximately atmospheric pressure.
19. The method of ionizing an analyte of claim 17 , where one or more of the plurality of analytes comprise a solution containing the analyte.
20. The method of ionizing an analyte of claim 17 , where one or more of the plurality of formed plastic pieces comprise teflon.