Chemical analyzer with membrane

Abstract

A system for analyzing an analyte is described herein. The system includes a chamber having an inlet and a semi-permeable membrane arranged to seal the inlet. The semi-permeable membrane includes a cross-linked mixture of a first compound and a second compound. The system can also include a radiation source arranged in the vacuum chamber, the radiation source spaced apart from the semi-permeable membrane and adapted to irradiate the semi-permeable membrane with electromagnetic radiation at a frequency at least partially absorbed by the semi-permeable membrane.

1 . A system for analyzing an analyte, comprising:
 a) a chamber having an inlet; and   b) a semi-permeable membrane arranged to seal the inlet, the semi-permeable membrane comprising a cross-linked mixture of a first compound and a second compound,   c) wherein the first compound includes:
 i) 55.0-75.0 wt. % of Dimethyl siloxane, dimethylvinyl-terminated; 
 ii) 15.0-35.0 wt. % of Silica, amorphous; 
 iii) 5.0-10.0 wt. % of Dimethyl siloxane, hydroxy-terminated; and 
 iv) 3.0-7.0 wt. % Dimethyl, methylvinyl siloxane, dimethylvinyl-terminated; and 
   d) wherein the second compound includes:
 i) 55.0-75.0 wt. % Dimethyl siloxane, dimethylvinyl-terminated; 
 ii) 15.0-35.0 wt. % Silica, amorphous; 
 iii) 5.0-10.0 wt. % Dimethyl siloxane, hydroxy-terminated; 
 iv) 3.0-7.0 wt. % Dimethyl, methylvinyl siloxane, dimethylvinyl-terminated; and 
 v) 1.0-5.0 wt. % Dimethyl, methylhydrogen siloxane. 
   
     
     
         2 . The system of  claim 1 , further comprising a detector. 
     
     
         3 . The system of  claim 2 , wherein the chamber is a vacuum chamber and the detector is a mass spectrometer. 
     
     
         4 . The system of  claim 3 , further comprising an ion source arranged in the chamber. 
     
     
         5 . The system of  claim 1 , wherein the membrane comprises a specific gravity at 25° C. substantially equal to 1.15. 
     
     
         6 . The system of  claim 1 , wherein the membrane comprises a Shore A durometer of approximately 50. 
     
     
         7 . The system of  claim 1 , wherein the chamber comprises a plurality of inlets and wherein the system further comprises:
 a supply for providing the analyte;   a plurality of semi-permeable membranes arranged to seal respective one of the plurality of inlets; and   a connector adapted to selectively provide the analyte from the supply to each of the plurality of membranes.   
     
     
         8 . The system of  claim 7 , wherein the analyte comprises a chemical and wherein two of the plurality of semi-permeable membranes comprises respective different permeabilities to the chemical. 
     
     
         9 . The system of  claim 7 , wherein the inlets comprise aperture pairs and wherein the system further comprises:
 a plurality of tubes having respective semi-permeable sidewalls, each tube passing into and out of the chamber via a respective one of the aperture pairs; and   a detector arranged in the chamber and adapted to detect properties of a substance that passes through a sidewall of one of the tubes.   
     
     
         10 . A chemical-analysis system, comprising:
 a vacuum chamber having an inlet;   a semi-permeable membrane sealing the inlet; and   a radiation source arranged in the vacuum chamber, the radiation source spaced apart from the semi-permeable membrane and adapted to irradiate the semi-permeable membrane with electromagnetic radiation at a frequency at least partially absorbed by the semi-permeable membrane.   
     
     
         11 . The chemical-analysis system of  claim 10 , further comprising a supply adapted to provide an analyte to an exterior side of the semi-permeable membrane, wherein the radiation source is to heat the membrane before the analyte reaches the membrane. 
     
     
         12 . The chemical-analysis system of  claim 10 , wherein the radiation source is adapted to heat the semi-permeable membrane in a non-contact manner. 
     
     
         13 . The chemical-analysis system of  claim 10 , wherein the radiation source comprises a laser diode. 
     
     
         14 . The chemical-analysis system of  claim 13 , wherein the laser diode is adapted to heat the semi-permeable membrane by emitting a wavelength preferentially absorbed by the semi-permeable membrane. 
     
     
         15 . The system of  claim 10 , wherein the radiation source comprises a plurality of laser diodes.