Practical ion mobility spectrometer apparatus and methods for chemical and/or biological detection
This invention describes an ion mobility spectrometer and operational methods for chemical analysis. The ion mobility spectrometer allows for continuous operation and rapid temperature control to reach designed operational conditions, as well as analysis under a temperature gradient.
1. An ion mobility spectrometer (IMS) apparatus comprising:
a) components including an inlet accepting samples; an ionization source ionizing some of the samples; a drift tube separating ions based on ion mobility; an ion detector detecting ions;
b) dielectric materials that have thermal conductivity at least that of aluminum nitride (AIN) in the construction of the drift tube, and
c) a heat pump that adds or removes heat from the components for heating and/or cooling the apparatus.
2. The IMS apparatus of claim 1 , further comprises one or more low thermal mass components.
3. The IMS apparatus of claim 2 , wherein the low thermal mass structure is a resistance coil, a resistive material affixed on a thin dielectric structure, or a metalized thin dielectric structure.
4. The IMS apparatus of claim 1 , wherein the heat pump comprising heating elements in physical connection and/or in fluid communication with the IMS for rapid temperature increase.
5. The IMS apparatus of claim 1 , wherein the heat pump comprising a heat sink and related cooling apparatus in physical connection and/or in fluid communication with the IMS for rapid temperature decrease.
6. The IMS apparatus of claim 1 , wherein the heat pump further comprises a controlled temperature fluid.
7. The IMS of claim 6 , wherein the controlled temperature fluid is a gas.
8. The IMS apparatus of claim 1 , wherein the dielectric material is aluminum nitride (AlN) or beryllium oxide (BeO).
9. The IMS apparatus of claim 1 , further comprises a resistance coil or a resistive material affixed on the dielectric material.
10. The IMS apparatus of claim 1 , wherein the drift tube comprises a plurality of high thermal conductivity metal drift rings and alternating high thermal conductivity dielectric spacers.
11. A method for operating an IMS comprising: adjusting an IMS temperature to the first starting operating temperature; ramping the temperature to the ending operating temperature at a designed rate using a heat pump that adds or removes heat from the IMS; and obtaining ion mobility spectra while ramping the temperature.
12. The method of claim 11 , further comprises ramping temperature of a thermal desorber that is in fluid communication with a sample inlet of the IMS wherein the design rate of the IMS temperature ramping is substantially equal to or higher than the desorber temperature ramping rate.
13. The method in claim 11 , wherein the heat pump comprises heating elements in physical connection and/or in fluid communication with the IMS for rapid temperature increase.
14. The method in claim 11 , wherein the heat pump comprising a heat sink and related cooling apparatus in physical connection and/or in fluid communication with the IMS for rapid temperature decrease.