Simultaneous determination of multiple analytes in industrial water system

Abstract

A multi-purpose reagent composition is used for simultaneously determining concentrations of at least two analytes in a water sample. The two analytes are selected from the group consisting of free chlorine, pH, anionic polymer, and phosphates. In one embodiment, the multi-purpose reagent composition is for simultaneously determining the concentration of free chlorine and pH and comprises a free chlorine sensitive dye and pH indicator. In another embodiment, the reagent composition is for simultaneously determining of free chlorine and anionic polymer and includes a free chlorine sensitive dye, a pH buffer, cationic dye, and organic co- solvent. Thus, the pairs of free chlorine and pH or free chlorine and anionic polymer are determined using a single reagent composition. The reagent composition can also be the main reagent for one analyte analysis when it is used alone and also function as an ancillary reagent when it is combined with a second reagent composition for the determination of another analyte.

What is claimed is:  
     
         1 . A multi-purpose reagent composition for simultaneously determining concentrations of at least two analytes in a water sample, wherein the two analytes are selected from the group consisting of free chlorine, pH, anionic polymer, and phosphates. 
     
     
         2 . The multi-purpose reagent composition of  claim 1  wherein the reagent composition is for simultaneously determining the concentration of free chlorine and pH and comprises a free chlorine sensitive dye and pH indicator. 
     
     
         3 . The composition of  claim 2  where said co-solvent is ethylene glycol and methanol. 
     
     
         4 . The multi-purpose reagent composition of  claim 2  wherein said free chlorine sensitive dye includes one or more coloring reagents selected from the group consisting of infrared dyes. 
     
     
         5 . The multi-purpose reagent composition of  claim 1  wherein said pH indicator is a colorimetric pH indicator. 
     
     
         6 . The multi-purpose reagent composition of  claim 1  wherein the reagent composition is for simultaneously determining of free chlorine and anionic polymer and comprises a free chlorine sensitive dye, cationic dye, organic co-solvent and a pH buffer to obtain a pH in the range of 2.85 to 4.5. 
     
     
         7 . The composition of  claim 6  wherein said free chlorine sensitive dye is a tetraalkyl benzidine compound. 
     
     
         8 . The composition of  claim 6  wherein said free chlorine sensitive dye is N-(3-sulfopropyl)-3,3′,5,5′-tetramethylbenzidine (TMB-PS). 
     
     
         9 . The composition of  claim 6  wherein said cationic dye is selected from the group consisting of Dimethyl Methylene Blue (DMMB), Basic Blue 17, and New Methylene Blue (NMB). 
     
     
         10 . The composition of  claim 6  wherein said co-solvent is a water-soluble ketone. 
     
     
         11 . A multi-functional reagent composition that can be used for determining at least one analyte when it is used alone and has other functionality to assist the determination of other analytes in an online analyzer system comprising an analyte-sensitive reagent, solvent, and ancillary reagent. 
     
     
         12 . The composition of  claim 11  wherein said functionality is to act as a reagent for the determination of another analyte along with a second reagent composition. 
     
     
         13 . The composition of  claim 11  wherein said functionality is to act as a buffer for the determination of another analyte along with a second reagent composition. 
     
     
         14 . The composition of  claim 11  wherein said functionality is to act as a cleaning agent to clean the residual left from the analysis of other analytes. 
     
     
         15 . The composition of  claim 11  wherein said functionality is to act as a calibration solution that can be to calibrate the reagents in said online system.