Apparatus and method for ion mobility spectrometry and sample introduction

Abstract

The IMS apparatus and methods described in this invention involve setting the ion detector at the highest potential of the drift tube and setting the ionization source at ground or near ground potential. The methods allow significantly simple sample introduction without the limitation of the high potential (voltage) concern of the front end sample delivery. The invention also describes bringing samples directly into the ion mobility drift tube. The invention further describes using single syringe for sample introduction via an electrospray ionization method.

1 . An ion mobility based spectrometer apparatus comprising:
 a) an ionization source that is set at a low potential of the spectrometer;   b) an ion detector that is set at a high potential of the spectrometer; and   c) an ion mobility based analyzer that is in fluid communication with the ionization source on one end and the ion detector on the other end.   
     
     
         2 . The ion mobility based spectrometer apparatus of  claim 1 , wherein the low potential is the lowest potential for the spectrometer at ground or near ground potential. 
     
     
         3 . The ion mobility based spectrometer apparatus of  claim 1 , wherein the high potential is the highest potential for the spectrometer. 
     
     
         4 . The ion mobility based spectrometer apparatus of  claim 1 , wherein the high potential is either positive or negative potential. 
     
     
         5 . The ion mobility based spectrometer apparatus of  claim 1 , further comprises a sample inlet. 
     
     
         6 . The ion mobility based spectrometer apparatus  claim 5 , wherein the sample inlet is set at the lowest potential. 
     
     
         7 . The ion mobility based spectrometer apparatus of  claim 1 , wherein the ionization source is an electrospray ionization source. 
     
     
         8 . The ion mobility based spectrometer apparatus of  claim 7 , wherein the electrospray ionization source comprises a syringe needle that is used for sampling and as the spray needle. 
     
     
         9 . The ion mobility based spectrometer apparatus of  claim 7 , further comprises a curtain gas section which has at least two plates with an opening in the center. 
     
     
         10 . The ion mobility based spectrometer apparatus of  claim 9 , wherein the plates are positioned to administrator gas flow as such: a low temperature cooling gas flow enters the center hole of the first plate on the needle side; a high temperature desolvation gas flow enters the center hole of the second plate on the desolvation section side; both gas flows are exhausted at a gas exit located between the two plates. 
     
     
         11 . The ion mobility based spectrometer apparatus of  claim 9 , wherein the plates are set at different potentials that guide ions entering the first plate toward the second plate. 
     
     
         12 . The ion mobility based spectrometer apparatus of  claim 10 , wherein the gas exit could be used as a gas inlet for the cooling gas flow and exhaust both cooling gas flow and the desolvation gas flow from the center hole of the first plate. 
     
     
         13 . An ion mobility based spectrometer method comprises:
 operating an ion mobility based analyzer that is in fluid communication with an ionization source on one end and an ion detector on the other end; setting the ionization source at a low potential of the spectrometer; and setting the ion detector at a high potential of the spectrometer.   
     
     
         14 . The ion mobility based spectrometer method of  claim 13 , wherein the low potential is set at the lowest potential for the spectrometer at ground or near ground potential. 
     
     
         15 . The ion mobility based spectrometer method of  claim 13 , wherein the high potential is set at the highest potential for the spectrometer. 
     
     
         16 . The ion mobility based spectrometer method of  claim 13 , wherein the high potential is set at either positive or negative potential. 
     
     
         17 . The ion mobility based spectrometer method of  claim 13 , further comprises setting a sample inlet at the lowest potential. 
     
     
         18 . The ion mobility based spectrometer method of  claim 13 , further comprises electrospraying a sample from a syringe needle. 
     
     
         19 . The ion mobility based spectrometer method of  claim 18 , further comprises using the needle for sampling and spraying. 
     
     
         20 . The ion mobility based spectrometer method of  claim 13 , further comprises administering gas flows in the curtain gas section as such: a low temperature cooling gas flow enters a center hole of a first plate on the needle side; a high temperature desolvation gas flow enters the center hole of a second plate on the desolvation section side; both gas flows are exhausted at a gas exit between the first and second plate.