Ion mobility spectrometer
View Patent ↗The invention relates to the material, design and manufacture of a drift tube with an ion source region, particularly a miniaturized drift tube, for an ion mobility spectrometer to measure mobility spectra, particularly at atmospheric pressure. The invention proposes to use a high-performance plastic which can be injection-molded for the insulating main body for the drift tube and the ion source region. Polyphenylene sulfide (PPS) can be used for this purpose, for example.
1. An ion mobility spectrometer comprising a drift tube and an upstream ion source region, wherein at least one of the drift tube and the ion source region have a main body which is made at least in part of a polyaryl whose aromatic rings are linked via sulfur atoms or SO 2 groups, and
wherein a desorber chamber upstream of the ion source region has a main body which comprises the polyaryl and which is connected to a main body of the ion source region or which forms a shared main body with a main body of the ion source region.
2. The ion mobility spectrometer according to claim 1 , wherein the polyaryl is a polyphenylene sulfide (PPS).
3. The ion mobility spectrometer according to claim 1 , wherein the polyaryl can be injection-molded.
4. The ion mobility spectrometer according to claim 1 , wherein the main body comprises two joined half-shells with internal grooves and the drift tube has conductive electrodes which are inserted into the grooves.
5. The ion mobility spectrometer according to claim 4 , wherein the conductive electrodes comprises metal rings.
6. The ion mobility spectrometer according to claim 4 , wherein a gating element or a screening grid is inserted into one of the internal grooves in each half-shell.
7. The ion mobility spectrometer according to claim 1 , wherein the main body comprises two joined half-shells, whose interior surfaces are coated with a pattern of conductive layers.
8. The ion mobility spectrometer according to claim 7 , wherein said conductive layers are metal layers.
9. The ion mobility spectrometer according to claim 1 , wherein the main body or a segment of it comprises a single plastic component which is injection molded around inner conductive electrodes to form a full-mold unit.
10. The ion mobility spectrometer according to claim 1 , wherein a wall of the main body contains longitudinal channels to guide a gas and/or to accommodate heating elements.
11. A method for the manufacture of an ion mobility spectrometer, wherein at least one of a main body of a drift tube and a main body of an ion source region is formed by injection molding of a polyaryl, whose aromatic rings are linked sulfur atoms or SO 2 groups, and
wherein a desorber chamber upstream of the ion source region has a main body which comprises the polyaryl and which is connected to a main body of the ion source region or which forms a shared main body with a main body of the ion source region.
12. The method according to claim 11 , wherein the polyaryl is a polyphenylene sulfide.
13. The method according to claim 11 , wherein the main body is injection molded around inner electrodes to form a full-mold unit.
14. A method for the operation of an ion mobility spectrometer comprising a drift tube and an ion source region, wherein at least one of the drift tube and the ion source region have a main body which is made at least in part of a polyaryl whose aromatic rings are linked via sulfur atoms or SO 2 groups, and at least one of the drift tube and the ion source region are operated at a temperature of between 100° Celsius and 220° Celsius.
15. The method according to claim 14 , wherein the at least one of the drift tube and the ion source region are operated at a temperature of between 150° Celsius and 220° Celsius.