Closed loop automated matrix removal

Abstract

An automated matrix removal module is configurable to automatically withdraw a portion of sample containing an interfering matrix. The module is further configurable to mix the portion of sample with a reagent selected to react with the matrix to form a precipitant and then filter the mixture of sample and precipitant reagent through a filter. Finally, the module is further configurable to flush the precipitant from the filter.

1 . An apparatus for the automated removal of a matrix from a solution containing an analyte of interest, comprising: 
 at least one analytical instrument operable to measure a concentration of the matrix in a sample of the solution;    a source of reagent, the reagent being reactive with the matrix to form a precipitate;    a reaction vessel; and    a filter, wherein the apparatus has a filtering configuration in which a volume of the solution and a volume of the reagent react in the reaction vessel to form a reaction mixture that is filtered through the filter, the volume of the reagent being based upon the matrix concentration measurement, the apparatus having a flushing configuration in which the filter is back flushed with a solvent.    
     
     
         2 . The apparatus of  claim 1 , wherein the reaction vessel comprises a syringe pump.  
     
     
         3 . The apparatus of  claim 1 , wherein the reaction vessel is a mixing tee.  
     
     
         4 . The apparatus of  claim 2 , wherein the syringe pump includes a side port, and wherein the apparatus is configured in the flushing configuration such that the contents of the syringe pump are flushed into the side port.  
     
     
         5 . The apparatus of  claim 4 , further comprising a source of inert gas configurable to pump the inert gas into the side port if the apparatus is in the mixing configuration such that the inert gas bubbles through the reaction mixture.  
     
     
         6 . The analytical apparatus of  claim 2 , wherein the apparatus is configured in the filtering configuration such that the syringe pump may pump solvent into a body of syringe pump to mix with the reaction mixture.  
     
     
         7 . The analytical apparatus of  claim 1 , wherein the apparatus is responsive to electronic commands for controlling whether the apparatus is in the mixing or flushing configuration.  
     
     
         8 . The analytical apparatus of  claim 1 , wherein the at least one analytical instrument comprises an optical spectroscopy module.  
     
     
         9 . The analytical apparatus of  claim 8 , wherein the at least one analytical instrument further comprises an ion selective electrode.  
     
     
         10 . The analytical apparatus of  claim 1 , wherein the reagent source is a source of aqueous barium hydroxide.  
     
     
         11 . The analytical apparatus of  claim 10 , wherein the matrix comprises copper sulfate and sulfuric acid.  
     
     
         12 . The analytical apparatus of  claim 1 , further comprising a chemical metrology instrument for analyzing the reaction mixture filtered through the filter.  
     
     
         13 . The analytical apparatus of  claim 1 , wherein the chemical metrology instrument is a mass spectrometer.  
     
     
         14 . An apparatus, comprising: 
 a sample extraction module operable to extract sample from a selected one of a plurality of process solution baths;    at least one dilution and spiking module operable to spike and dilute extracted sample to form a processed solution;    a source of reagent solution reactive with a matrix in the processed solution to form a precipitate;    a plurality of matrix removal modules, each matrix removal module operable in a mixing cycle to mix the processed solution with the reagent solution to form a reaction mixture having the precipitate and to filter the precipitate from the reaction mixture through a filter to form a filtered solution, each matrix removal module operable in a flushing cycle to flush the filter; and    a control system to control the mixing and flushing cycles of the plurality of matrix removal modules such that as one matrix removal module is in the mixing cycle another matrix removal module is in the flushing cycle.    
     
     
         15 . The apparatus of  claim 14 , further comprising: 
 a mass spectrometer operable to process the filtered solution from each matrix removal module to form a ratio response, wherein the control system is further operable to measure the amount of at least one analyte based upon the ratio response.    
     
     
         16 . The apparatus of  claim 15 , further comprising: 
 at least one analytical instrument operable to measure a concentration of the matrix, wherein the control system controls each matrix removal module in the mixing cycle to mix the processed solution with a volume of reagent solution based upon the measured concentration from the analytical instrument.    
     
     
         17 . An apparatus for the automated removal of a matrix from a solution containing an analyte of interest, comprising: 
 at least one analytical instrument operable to periodically measure a concentration of the matrix;    a source of reagent, the reagent being reactive with the matrix to neutralize the matrix; and    a reaction vessel, wherein the apparatus has a neutralizing configuration in which a volume of the solution and a volume of the reagent react in the reaction to form a neutralized mixture, the volume of the reagent being based upon a most-recent matrix concentration measurement by the analytical instrument.    
     
     
         18 . The apparatus of  claim 17 , further comprising: 
 a chemical metrology instrument operable to analyze a concentration of at least one analyte in the neutralized mixture.    
     
     
         19 . The apparatus of  claim 17 , wherein the analytical instrument comprises an optical spectrometer.  
     
     
         20 . The apparatus of  claim 17 , wherein the analytical instrument comprises a mass spectrometer.