Supporting substrate used for the deposition, automated recognition and spectroscopic identification of particles

Abstract

A supporting substrate for the deposition, automated recognition and spectroscopic identification of particulate impurities in liquid or gaseous media, comprising a filter membrane of polymer materials of a defined pore width, wherein the surface of the filter membrane is coated with metal which in the selected wavelength range for spectroscopic identification has no spectral features and at the selected excitation wavelength absorbs no or only little of the laser energy which is radiated in, and has a very smooth structure.

What is claimed is:  
     
         1 . A supporting substrate for the deposition, automated recognition and spectroscopic identification of particulate impurities in liquid or gaseous media, comprising: 
 a filter membrane of polymer materials of a defined pore width,    wherein the filter membrane has a surface coated with a metal layer that has no spectral features in a wavelength range selected for spectroscopic identification and that absorbs no or only little of the laser energy which is radiated in at a selected excitation wavelength, the surface coating having a thickness of between about 50 and 200 nm, and having a very smooth structure with a roughness of <1 μm.    
     
     
         2 . The substrate of  claim 1 , wherein: 
 the metal layer is selected from the group of metals consisting of: nickel, aluminum, palladium, platinum, tungsten, iron, tantalum, rhodium, cadmium, copper, gold, silver, indium, cobalt, tin, silicon, germanium, tellurium, selenium and alloys thereof.    
     
     
         3 . The substrate of  claim 2 , wherein: 
 the metal layer is vapor-deposited.    
     
     
         4 . The substrate of  claim 3 , wherein: 
 the filter membrane comprises polycarbonate, polytetrafluoroethylene or cellulose acetate.    
     
     
         5 . The substrate of  claim 4 , wherein: 
 the defined pore width is between about 0.2 and 1.2 μm.    
     
     
         6 . The substrate of  claim 5 , wherein: 
 spectroscopic identification is effected by Raman spectroscopy.    
     
     
         7 . The substrate of  claim 1 , wherein: 
 the metal layer is vapor-deposited.    
     
     
         8 . The substrate of  claim 3 , wherein: 
 the filter membrane comprises polycarbonate, polytetrafluoroethylene or cellulose acetate.    
     
     
         9 . The substrate of  claim 7 , wherein: 
 the filter membrane comprises polycarbonate, polytetrafluoroethylene or cellulose acetate.    
     
     
         10 . The substrate of  claim 1 , wherein: 
 the defined pore width is between about 0.2 and 1.2 μm.    
     
     
         11 . The substrate of  claim 8 , wherein: 
 the defined pore width is between about 0.2 and 1.2 μm.    
     
     
         12 . The substrate of  claim 9 , wherein: 
 the defined pore width is between about 0.2 and 1.2 μm.    
     
     
         13 . The substrate of  claim 5 , wherein: 
 spectroscopic identification is effected by Raman spectroscopy.    
     
     
         14 . The substrate of  claim 1 , wherein: 
 spectroscopic identification is effected by Raman spectroscopy.    
     
     
         15 . The substrate of  claim 10 , wherein: 
 spectroscopic identification is effected by Raman spectroscopy.    
     
     
         16 . The substrate of  claim 11 , wherein: 
 spectroscopic identification is effected by Raman spectroscopy.    
     
     
         17 . The substrate of  claim 12 , wherein: 
 spectroscopic identification is effected by Raman spectroscopy.