Patent ID: 6214627
Filing Date: 2001-04-10
Classification: G01N,Y10S,Y10T

Abstract:
A method for measuring the concentration of an anionically charged polymer in an aqueous solution that comprises the steps of:(a) providing a reagent solution comprisingi) water,ii) Nile Blue Dye; andiii) chelant, with said chelant being selected from the group consisting of the alkali metal or ammonium salts of phosphonobutane tricarboxylic acid;(b) using a suitable device to measure the absorbance of said reagent solution by itself and using this absorbance measurement to zero said suitable device at the level of 0 ppm polymer concentration;(c) providing a sample of an aqueous solution containing at least one anionically charged polymer to be tested;(d) combining said reagent solution and said sample to create a mixture;(e) measuring the absorbance of the mixture using the same suitable device used in step (b); and(f) comparing the absorbance of the mixture with the absorbance of samples containing known concentrations of the anionically charged polymers and determining the concentration of anionically charged polymer in the sample therefrom;wherein the method is conducted without adjusting the pH of said sample and wherein the method further comprises the step of waiting a time period of less than about 7 minutes for said reagent solution and said anionically charged polymer to react between the (d) combining step and the (e) measuring step.