Integrated ion separation spectrometer

Abstract

An apparatus including an ion injector having an inlet and an outlet and a micro-corona ionizer positioned between the inlet and the outlet of the ion injector. The micro-corona ionizer includes a planar electrode and a sharp knife-edged electrode spaced apart from the planar electrode and positioned with the sharp knife edge pointing toward the planar electrode. A drift and separation channel having a first end and a second end is positioned with the first end coupled to outlet of the ion injector, and an ion detector is coupled to the second end of the ion separation and drift channel. Other embodiments are disclosed and claimed.

1 . An apparatus comprising:
 an ion injector having an inlet and an outlet;   a micro-corona ionizer positioned between the inlet and the outlet of the ion injector, the micro-corona ionizer including:
 a planar electrode; and 
 a sharp knife-edged electrode spaced apart from the planar electrode and positioned with the sharp knife edge pointing toward the planar electrode; 
   a drift and separation channel having a first end and a second end, the first end being coupled to outlet of the ion injector; and   an ion detector coupled to the second end of the ion separation and drift channel.   
     
     
         2 . The apparatus of  claim 1 , further comprising a voltage source coupled to the planar electrode and the sharp knife-edged electrode. 
     
     
         3 . The apparatus of  claim 1  wherein the ion injector comprises:
 a first pair of injection electrodes; and 
 a second pair of injection electrodes spaced apart from the first pair of injection electrodes. 
 
     
     
         4 . The apparatus of  claim 3  wherein the micro-corona ionizer is positioned between the first pair of injection electrodes and the second pair of injection electrodes. 
     
     
         5 . The apparatus of  claim 3 , further comprising a voltage source coupled between the first pair of injection electrodes and the second pair of injection electrodes. 
     
     
         6 . The apparatus of  claim 1  wherein the drift and separation channel comprises:
 a first channel wall having a first set of separation electrodes thereon; and 
 a second channel wall having a second set of separation electrodes thereon, wherein the second set of separation electrodes is spaced apart from the first set of separation electrodes. 
 
     
     
         7 . The apparatus of  claim 6 , further comprising:
 a voltage source coupled to the first set of separation electrodes; and   a voltage source coupled to the second pair of separation electrodes.   
     
     
         8 . The apparatus of  claim 7  wherein the voltage applied to the first set of separation electrodes is different than the voltage applied to the second set of separation electrodes. 
     
     
         9 . The apparatus of  claim 6  wherein the spacing between the first set of separation electrodes and the second set of separation electrodes is constant. 
     
     
         10 . The apparatus of  claim 6  wherein the spacing between the first set of separation electrodes and the second set of separation electrodes varies from the first end of the channel to the second end of the channel. 
     
     
         11 . The apparatus of  claim 1  wherein the ion detector comprises an array of at least two sensor electrodes positioned about a centerline of the drift and separation channel. 
     
     
         12 . The apparatus of  claim 11 , further comprising a reading circuit and logic coupled to the array of sensor electrodes to sense and read signals generated by each sensor electrode. 
     
     
         13 . The apparatus of  claim 12 , further comprising a conditioning circuit and logic coupled to the reading circuitry to condition signals received from the reading circuit. 
     
     
         14 . A process comprising:
 ionizing chemicals in a gas sample using a micro-corona ionizer, wherein ionizing chemicals comprises:
 directing the gas sample into a space between a planar electrode and a sharp knife-edged electrode spaced apart from the planar electrode, wherein the sharp knife-edged electrode is positioned with the sharp knife edge pointing toward the planar electrode, and 
 applying a voltage between the planar electrode and the sharp knife-edged electrode; 
   injecting the ionized chemicals into a drift and separation channel;   time-domain separating the chemical ions from each other in the drift and separation channel; and   detecting the separated chemical ions.   
     
     
         15 . The process of  claim 14  wherein injecting the ionized chemicals comprises:
 positioning the ionized chemicals between a first pair of injection electrodes and a second pair of injection electrodes spaced apart from the first pair of injection electrodes; and 
 applying a voltage between the first pair of injection electrodes and the second pair of injection electrodes. 
 
     
     
         16 . The process of  claim 14  wherein time-domain separating the chemical ions from each other comprises:
 injecting the chemical ions into a drift and separation channel between a first set of separation electrodes and a second set of separation electrodes spaced apart from the first set of separation electrodes; and 
 applying a voltage to the first set of separation electrodes and to the second set of separation electrodes. 
 
     
     
         17 . The apparatus of  claim 16  wherein the voltage applied to the first set of separation electrodes is different than the voltage applied to the second set of separation electrodes. 
     
     
         18 . The process of  claim 14  wherein detecting the separated chemical ions comprises:
 receiving the time-domain separated chemical ions at an array of at least two sensor electrodes; and 
 generating a signal in each electrode indicative of the ions received at that electrode. 
 
     
     
         19 . The process of  claim 18 , further comprising reading the signals generated by the sensor electrodes. 
     
     
         20 . The process of  claim 19 , further comprising conditioning signals read from the sensor electrodes. 
     
     
         21 . A system comprising:
 a gas chromatograph having an inlet and an outlet;   a detector coupled to the outlet of the gas chromatograph, the detector comprising:
 an ion injector having an inlet and an outlet, wherein the inlet of the ion injector is coupled to the outlet of the gas chromatograph; 
 a micro-corona ionizer positioned between the inlet and the outlet of the ion injector, the micro-corona ionizer comprising:
 a planar electrode, and 
 a sharp knife-edged electrode spaced apart from the planar electrode and positioned with the sharp knife edge pointing toward the planar electrode; 
 
 an ion separation and drift channel having a first end and a second end, the first end being coupled to outlet of the ion injector; and 
 an ion detector coupled to the second end of the ion separation and drift channel. 
   
     
     
         22 . The system of  claim 21 , further comprising a voltage source coupled to the planar electrode and the sharp knife-edged electrode. 
     
     
         23 . The system of  claim 21  wherein the ion injector comprises:
 a first pair of injection electrodes; and 
 a second pair of injection electrodes spaced apart from the first pair of injection electrodes. 
 
     
     
         24 . The system of  claim 23  wherein the micro-corona ionizer is positioned between the first pair of injection electrodes and the second pair of injection electrodes. 
     
     
         25 . The system of  claim 23 , further comprising a voltage source coupled between the first pair of injection electrodes and the second pair of injection electrodes. 
     
     
         26 . The system of  claim 21  wherein the drift and separation channel comprises:
 a first channel wall having a first set of separation electrodes thereon; and 
 a second channel wall having a second set of separation electrodes thereon, wherein the second set of separation electrodes is spaced apart from the first set of separation electrodes. 
 
     
     
         27 . The system of  claim 26 , further comprising:
 a voltage source coupled to the first set of separation electrodes; and   a voltage source coupled to the second pair of separation electrodes.   
     
     
         28 . The system of  claim 27  wherein the voltage applied to the first set of separation electrodes is different than the voltage applied to the second set of separation electrodes. 
     
     
         29 . The system of  claim 26  wherein the spacing between the first set of separation electrodes and the second set of separation electrodes is constant. 
     
     
         30 . The system of  claim 26  wherein the spacing between the first set of separation electrodes and the second set of separation electrodes varies from the first end of the channel to the second end of the channel. 
     
     
         31 . The system of  claim 21  wherein the ion detector comprises an array of at least two sensor electrodes positioned about a centerline of the drift and separation channel. 
     
     
         32 . The system of  claim 31 , further comprising a reading circuit and logic coupled to the array of sensor electrodes to sense and read signals generated by each sensor electrode. 
     
     
         33 . The system of  claim 31 , further comprising a conditioning circuit and logic coupled to the reading circuit to condition signals received from the reading circuit. 
     
     
         34 . The system of  claim 33 , further comprising a processing circuit and logic coupled to the conditioning circuitry to process the conditioned signals. 
     
     
         35 . The system of  claim 34 , further comprising a control circuit and logic coupled to the ion sensor, the gas chromatograph, and the processing circuit. 
     
     
         36 . The system of  claim 21 , further comprising a pre-concentrator coupled to the inlet of the gas chromatograph.