MXPA01006593A - Rapid colorimetric method for measuring polymers in aqueous systems - Google Patents

Abstract

A method for measuring the concentration of an anionically charged polymer in an aqueous solution.

Description

QUICK COLORIMETER METHOD FOR MEASURING POLYMERS IN AQUEOUS SYSTEMS FIELD OF THE INVENTION The present invention generally concerns the detection of water-soluble polymers in industrial water systems such as cooling water systems and water systems of steam generators. More specifically, the present invention concerns a method of determining the concentration or availability of anionic water-soluble polymers in industrial water systems wherein said polymers are employed to prevent the formation of scale and / or deposits. BACKGROUND OF THE INVENTION Water is used as a cooler in a number of industrial processes, as well as in steam generation. However, undistilled or untreated water contains a number of impurities that can affect heat transfer, fluid flow or cause corrosion of process equipment. Therefore, when municipal or untreated water is used for cooling or steam formation, the water must be treated with the appropriate chemicals in order to inhibit the formation of scale on the industrial equipment. Typically, problematic impurities in water are metallic cations, such as calcium, barium, magnesium and Ref: 130462 sodium as well as anions, such as bicarbonate, carbonate, sulfate, phosphate, silicate and fluoride. When the water contains an excess of these precipitated anions and cations, they are known to form on the surfaces of the equipment in the form of scale or deposits. The presence of deposits or deposits adversely affects the rate of heat transfer and consequently, the efficiency of the system. In addition, the cleaning or removal of such deposits or deposits is expensive, because typically it requires a stoppage of the system. A number of chemicals have been provided to reduce or inhibit the formation of scale or deposits in industrial water systems. More specifically, aqueous-soluble polymers, which are anionically charged, have proved useful. A water-soluble polymer, particularly useful is polyacrylic acid and modified polyacrylic acid; although other water-soluble polymers that are at least partially anionically charged are also in use. However, the use of water-soluble polymers in industrial water systems presents its own adjustment problems, because the concentration of the polymers in the water must be carefully monitored. For example, if too high a polymer concentration is used, then the operating cost / efficiency of the system is adversely affected. In contrast, if too little polymer is used, fouling and / or depositing and / or corrosion may occur. Along with another chemical treatment of aqueous systems, there is an optimum concentration that should be conserved. Methods for determining the concentration of water-soluble polymers in aqueous systems are available. For example, there is a patented fluorometric method for the determination of polyelectrolytes, which uses fluorochromatic dyes, see US Pat. No. 5,389,548, which is incorporated herein by reference. Other current methods for determining the concentration of water-soluble polymers in aqueous systems depend, in part, on the formation of turbidity, with the principles of said processes described in the reference, "Turbidity Science", by Michael J. Sader, Technical Information Series-Booklet No. 11, from the HACH Technical Center for Applied Analytical Chemistry. One such method is the TRANSPORT-PLUS® DR / 2000 Procedure from Nalco Chemical Company. The TRANSPORT-PLUS® DR / 2000 Procedure is a turbidimetric method based on the absorbance in multiple stages that takes approximately 20 minutes to determine the level of polymer by TRANSPORT-PLUS®. A colorimetric method is Hach's polyacrylic acid method (Meted 8107 from Hach, telephone no. (800) 227-4224). Hach's polyacrylic acid method uses the chelation of iron thiocyanate to detect polymers with calibrations based on polyacrylic acid products. The known turbidi etric methods and the Hach method suffer from extensive absorption / desorption / washing process steps with multiple reagents and long reaction times. There is another colorimetric analytical method, described in US Patent No. 4,894,346, (hereinafter the "346 patent"). The method described in the '346 patent is relatively complicated and difficult to snow out in the field. When driving the method described in the patent 346, the pH of the water sample must be adjusted, at the beginning, before the combination of the sample with the reagent containing the dye. A data sheet describing this colorimetric method (based on the European patent application corresponding to the patent? 346) includes in the procedure a waiting period of 30 minutes to complete the reaction necessary to complete the analysis. Under field conditions 30 minutes is a waiting time too long for the method to be practical. Accordingly, there is a need for an improved colorimetric method for measuring the concentration of aqueous-soluble polymers in aqueous systems that is easier, safer, more selective and faster to drive than currently available methods. Yet another drawback associated with currently available turbidimetric and colorimetric measurement methods is their intolerance to ions and other contaminants commonly present in industrial and municipal water systems. For example, currently available colorimetric methods such as those described in the '346 patent are susceptible to insecurity in highly alkaline systems, highly acidic systems or where the presence of ions or other impurities exceed certain concentrations. Turbidimetric methods are also more susceptible to inaccuracies caused by the presence of ions and other contaminants than colorimetric methods. Accordingly, there is a need for an improved method for measuring the concentration of polymers in aqueous systems that is more tolerant of common contaminants and other properties common to municipal and industrial waters. BRIEF DESCRIPTION OF THE INVENTION The first aspect of the present invention is a method for measuring the concentration of an anionically charged polymer in an aqueous solution comprising the steps of: (a) providing a reactive solution comprising i) water, ii) Nile blue coloring; and iii) sequestering agent, with said sequestering agent selected from the group consisting of the ammonium or alkali metal salts of phosfonobutane tricarboxylic acid; (b) using a suitable device to measure the absorbance of said reactive solution by itself and using this absorbance measurement for zero, in 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 examined, (d) combining said reactive solution and said sample to create a mixture, (e) measuring the absorbance of the mixture using the same device suitable used in step (b); and (f) comparing the absorbance of the mixture with the absorbance of the samples containing known concentrations of the anionically charged polymers and determining the concentration of anionically charged polymer in the sample thereof; wherein the method is conducted without adjusting the pH of said sample and wherein said method further comprises the step of waiting for a period of time of less than about 7 minutes for said reactive solution and said anionically charged polymer to react between the combining step (d) and the measurement stage (e). The second aspect of the present invention is a method for measuring the concentration of an anionically charged polymer in an aqueous solution comprising the steps of: (a) providing a reactive solution comprising i) water, ii) Nile Blue Dye; and iii) sequestering agent, which is phosphobutan tricarboxylic acid; (b) using a suitable device to measure the absorbance of said reactive solution by itself and using this absorbance measurement for zero of said suitable device, at the level of 0 ppm of polymer concentration; (c) providing a sample of an aqueous solution containing at least one anionically charged polymer to be examined, (d) combining said reactive solution and said sample to create a mixture, (e) measuring the absorbance of the mixture using the same device suitable used in step (b); and (f) determining the concentration of anionically charged polymer, which contains a measurable amount of at least one strongly acidic portion; wherein the method is conducted without adjusting the pH of said sample and wherein the method further comprises the step of waiting for a period of time of less than about 7 minutes for said reactive solution and said anionically charged polymer to react, between the step of combine and the stage of measuring. The third aspect of the present invention is a reactive solution comprising: (i) water, (ii) Nile Blue Dye; and (iii) sequestering agent, with said sequestering agent being selected, from the group consisting of the ammonium or alkali metal salts of the phosphonobutane tricarboxylic acid. The fourth aspect of the present invention is a reactive solution comprising: (i) water, (ii) Nile Blue Dye; and (iii) sequestering agent, which is phosphonobutane tricarboxylic acid. BRIEF DESCRIPTION OF THE FIGURES Figure 1 illustrates, graphically, a calibration curve of absorbance difference versus polymer concentration (in mg / liter) at 635 nanometers (hereinafter "nm") for Polymer A using a DR spectrophotometer 2010. Polymer A, is a terpolymer of acrylic acid (approximately 60 to 70 mol%), acrylamide (approximately 9 to 27 mol%) and sodium salt of acrylamidomethanesulfonic acid, (approximately 13 to 21 mol%) with an average molecular weight between approximately 14,000 and approximately 25,000 Daltones. One of the lines is a graph of the current measurements taken, the other line was sketched using a least squares adjustment of the data. Figure 2 graphically illustrates a calibration curve of absorbance differences versus polymer concentration (in mg / liter) at 635 nm for Polymer B using a DR 2010 spectrophotometer. Polymer B is a terpolymer of acrylic acid (approximately 40 50% molar), acrylamide (about 15 to 35 mol%) and sodium salt of acrylamidomethanesulfonic acid, (about 25 to 35 mol%), said terpolymer having an average molecular weight of between about 20,000 and 35,000 Daltones. One of the lines is a graph of the current measurements taken, the other line was sketched using a least squares adjustment of the data. Figure 3 illustrates, graphically, a calibration curve of absorbance difference versus polymer concentration (in mg / liter) at 635 nm for Polymer C, using a 2010 DR spectrophotometer. Polymer C is a polyacrylic acid, salt homopolymer sodium, with an average molecular weight between about 2500 and about 4000 Daltones. One of the lines is a graph of the current measurements taken, the other line was sketched, using a least squares data adjustment. Figure 4 illustrates, graphically, a calibration curve of absorbance difference versus polymer concentration (in mg / liter) at 610 nm for the Polymer D using the DR / 890 Colorimeter. Polymer D is a copolymer of acrylic acid (approximately 90 mol%) and the sodium salt of styrenesulfonic acid, (about 10 mol%) with an average molecular weight of between about 25,000 and about 50,000 Daltones. One of the lines is a graph of the current measurements taken, the other line was sketched using a least squares data fit. Figure 5 illustrates, graphically, a calibration curve of absorbance differences versus polymer concentration (in mg / liter) at 610 nm for Polymer E, using a DR / 890 Colorimeter. Polymer E is a copolymer of acrylic acid (about 99 mol%) and styrenesulfonic acid, sodium salt (about 1 mol%) with an average molecular weight of between about 7000 and about 10,000 Daltons. One of the lines is a graph of the current measurements taken, the other line was sketched by least squares data adjustment. Figure 6 illustrates graphically a calibration curve of absorbance differences versus polymer concentration (in mg / liter) at 610 nm for Polymer A, using a DR / 890 Colorimeter. One of the lines is • a graph of the current measurements taken, the other line was sketched using a least squares data fit. Figure 7 graphically illustrates a calibration curve of absorbance differences versus polymer concentration (in mg / liter) at 610 nm for Polymer B, using a DR / 890 Colorimeter. One of the lines is a graph of the current measurements taken, the other line was sketched using a least squares data fit. DETAILED DESCRIPTION OF THE PREFERRED MODALITIES The present invention provides an improvement to previous methods in the art, in that the method is carried out essentially in three simple steps: the absorbance of the reactive solution is measured, a specific amount of the sample of water to the coloring solution, and then the absorbance of the mixture of the reactive solution / polymer solution is measured. When creating the reactive solution necessary to conduct this analysis, it can be used as a coloring reagent either Blue NiloA (Chemical Abstract Service Reg. No. 3625-57-8) or Nile Blue chloride (CAS Reg. No. 2381-85-3 ). Both the Blue Nile A and Nile Blue chloride are available from Aldrich Chemical Company, P.O. Box 2060, Milwaukee, Wisconsin 53201, telephone numbers 414-273-4979 or 1-800-558-9160. hereinafter, the phrase "Nile Blue Dye" will be used to mean either Nile Blue or Nile Blue chloride or a mixture of Nile Blue A and Nile Blue chloride. Likewise, although it is possible to use Blue Nile by itself or in combination with Blue Nile A, the preferred coloring reagent is Blue Nile Colorant by itself. The appropriate amount of Nile Blue Dye present in the reactive solution is from about 4.7 ppm to 9.0 ppm, preferably from about 5.3 ppm to about 8.5 ppm and more preferably about 6.9 ppm. The sequestering agent used in the reaction solution is an ammonium or alkali metal salt of phosphonobutane tricarboxylic acid. The preferred phosphonobutane tricarboxylic acid is 2-phosphonobutan-1,2,4-tricarboxylic acid. The alkali metal salts include, but are not limited to, the sodium salt, the potassium salt and the lithium salt. The preferred sequestering agent is the sodium salt of 2-phosphonobutan-1,2,4-tricarboxylic acid. 2-Phosphonobutan-1,2,4-tricarboxylic acid is available from Bayer, 100 Bayer Road, Pittsburg, PA 15205-9741, telephone number: (800) 662-2927. One way to create the sodium salt of phosfonobutan acid The tricarboxylic acid is to contact the phosphonobutane tricarboxylic acid, with a suitable reagent such as sodium hydroxide. The concentration of sequestering agent in the reactive solution is from about 55 ppm to about 1100 ppm, preferably from about 500 ppm to about 600 ppm and more preferably about 550 ppm. The reactive solution with approximately 550 ppm of sequestering agent will be hereafter referred to as "JARGON". The reactive solution with more than about 550 ppm of sequestering agent will be referred to hereafter as "super-JARGON". The reactive solution with less than about 550 ppm of sequestering agent will be referred to hereafter as "lite-JARGON". It is also possible to create a reactive solution using sequestering agent, which is phosphonobutane tricarboxylic acid. A reactive solution using sequestering agent which is phosphonobutane tricarboxylic acid will be hereafter referred to as JARGON-A. The amount of phosphonobutane tricarboxylic acid present in JARGON-A is preferably from about 300 ppm to about 2200 ppm, more preferably from about 500 ppm to about 600 ppm and more preferably about 550 ppm. It is possible to create A-JARGON containing as little as 55 ppm phosphonobutane tricarboxylic acid, however, in order to use any JARGON-A containing less than about 300 ppm of phosphonobutane tricarboxylic acid, the pH of JARGON-A should be adjusted to less of about 3 using a suitable reagent. Reagents suitable for this purpose include, but are not limited to, hydrochloric acid, sulfuric acid or nitric acid. The reactive solution with approximately 550 ppm of phosphonobutane tricarboxylic acid will hereafter be referred to as "JARGON-A-normal". The reactive solution with more than about 550 ppm of phosphonobutane tricarboxylic acid will be hereinafter referred to as "super-JARGON-A". The reactive solution with less than about 550 ppm of phosphonobutane tricarboxylic acid will hereinafter be referred to as "lite JARGON-A". The JARGON-A, is useful only to detect polymers that contain strongly acidic portions. These strongly acidic portions include but are not limited to, sulfonate, sulfate, phosphonate and phosphate moieties. The remnant of the reactive solution is water that has been either distilled or deionized or otherwise treated to remove possible contaminants. In order to make a reactive solution, it was found preferable to first make a "mother" aqueous solution of Nile Blue Dye and a separate "mother" solution of sequestering agent. In the following, the aqueous "mother" solution of sequestering agent will be mentioned as the "Sequestering Agent" stock solution, if the sequestering agent is an ammonium or alkali metal salt of phosphonobutane tricarboxylic acid. If the sequestering agent is phosphonobutane tricarboxylic acid, then the stock solution of sequestering agent will be mentioned as a stock solution of "Sequestering Agent-A". The concentration of Nile Blue Dye in the stock solution is from about 43 ppm to about 81 ppm, preferably from about 48 ppm to about 76 ppm and more preferably about 62 ppm. The concentration of sequestering agent in the sequestering stock solution is from about 500 ppm to about 10,000 ppm, preferably from about 4500 ppm to about 5000 ppm and more preferably about 5000 ppm. The concentration of phosphonobutane tricarboxylic acid in the stock of sequestrant-A is from about 500 ppm to about 10,000 ppm, preferably from about 4500 ppm to about 5000 ppm and more preferably about 5000 ppm. In practice, it has been found that the Nile Blue Dye stock solution, the Sequestering Agent stock solution and the Sequestrant A stock solution are all stable for many months, thus ensuring that they can be made in advance and used as needed. Once the appropriate amounts of Nile Blue Dye stock solution and Sequestering Agent or Sequester Agent-A stock solution are added to the appropriate amounts of water to make JARGON or super-JARGON or lite-JARGON or JARGON-A or super JARGON-A or JARGON-A lite, the absorbance of the reactive solution, by itself, is measured in order to calibrate the instrument used to zero. Absorbances can be measured using any suitable device known in the art to measure abrorbancy. Such suitable devices include, but are not limited to, colorimeters, spectrophotometers, color wheels and other types of known color comparison meter instruments. The preferred suitable devices are spectrophotometers and colorimeters. Preferred spectrophotometers include the currently available DR / 2010 spectrophotometer, which is available from Hach Company, 5600 Lindbergh Drive, P.O. Box 389, Loveland, Colorado 80539-0389; telephone numbers: (800) 227-4224 or (970) 669-3050. To use the DR / 2100 spectrophotometer for this work, it is set to a wavelength of 635 nm, with a cell path length of 1 inch . Preferred colorimeters include the currently available DR / 890 Colorimeter, which is also available from Hach Company. To use the DR / 890 Colorimeter for this work, it is adjusted to a wavelength of 610 nm, with a round cell path of 2.5 centimeters. In order to determine the concentration or amount of anionic polymer available in an industrial water system it is necessary first to generate "calibration curves", for each polymer of interest. Calibration curves are generated by preparing water samples containing known amounts of polymer, making an appropriate reactive solution and measuring the absorbance of the sample using the reactive solution. For the purposes of this paper, absorbance is being reported as a difference in absorbance. The difference in absorbance is the difference between the absorbance of the reactive solution by itself and the absorbance of the reactive solution mixture and the water sample is being examined. The calibration curve then graphs this absorbance difference versus the known concentration of the polymer in the sample. Once the calibration curve is created, it can be used to tell how much polymer is present in a sample by comparing the measured absorbance difference of the sample with the curve and reading the amount of polymer present from the curve. In order to use a calibration curve, the reactive solution used to examine the sample must have the same type and concentration of sequestrant as is present in the reactive solution that was used to create the curve. In addition, in order to use a calibration curve, the appropriate device to measure absorbance must also be the same as the appropriate device that was used to create the calibration curve. Figure 1, Figure 2, Figure 3, Figure 4, Figure 5, Figure 6 and Figure 7, all illustrate the calibration curves for certain anionic polymers. All these calibration curves were generated using JARGON's reactive solution. Once created, the calibration curves can be used repetitively to determine the desired anionic polymer concentration in the water sample that is examined. In order to determine the concentration of anionic polymer in the water sample using this method, 1 ml of the water sample is combined with 25 ml of the reaction solution. Before the water sample is combined with the reactive solution, it is preferred that the water sample be filtered. The preferred filter is a 0.45-micron filter. The sample of 1 ml of water and 25 ml of reactive solution can be measured using conventional pipettes. It is possible to conduct the method claimed herein by adding the 25 ml of reactive solution to 1 ml of filtered water sample, however it is preferred that 1 ml of the filtered water sample be added to 25 ml of the reactive solution because this facilitates the measurement. The anionic polymer in the sample is then maintained to react with the reaction solution for not more than 7 minutes, preferably less than 2 minutes, more preferably less than 1 minute and more preferably for about 30 seconds. It was found that the reaction is usually complete in about 30 seconds, making any absorbance measurement taken at about 30 seconds and thereafter, accurate. It was found that this exact absorbance measurement remains essentially stable for the first seven minutes of time, with minor fluctuations occurring after the first seven minutes. Once the absorbance of the sample and the reaction solution is measured (usually as the absorbance difference described above), it is compared to the calibration curves showing the standard absorbances of solutions containing known quantities of the specific anionic polymer. In this way, the amount of anionic polymer present in the sample can be determined. Figure 1, Figure 2, Figure 3, Figure 4, Figure 5, Figure 6 and Figure 7, all illustrate calibration curves for certain anionic polymers using either a spectrophotometer or a colorimeter. The calibration curves are easily generated, as previously described, and can be fixed on site or electronically stored to determine the concentration of the desired anionic polymer in the water sample being examined. Polymers capable of being detected by the method of the invention claimed herein include, but are not limited to polymers with polyacrylic acid moieties with functional groups that result in at least a partial anionic charge for the polymer, and polysulfonated polymers and polymers of maleic anhydride. Polymers with portions of acrylic acid include homopolymers, copolymers, terpolymers and tetrapolymers. Functional groups that result in at least a partial anionic charge include carboxylates, sulfonates, organic sulfonate, phenolic, phosphonate, organic phosphate and mixtures thereof. The polymer can also be amphoteric, or a mixture of anionic and cationic charged, as long as there is a sufficient predominance of anionic charge in the polymer. Polysulfonated polymers include, but are not limited to, polymers of polystyrene sulfonic acid and polymers of polyvinyl sulfonic acid. Examples of polymers that can be detected using the method of the invention claimed herein can be found in US Patent Nos. 4,752,443; 4,756,881; 4,801,388; 4,869,828; 4,898,686; 4,929,425; 4,963,267; 4,973,428; and 5,128,419. Preferred polymers in cooling water treatment include, but are not limited to polyacrylic acid homopolymers, acrylic acid and acrylamide copolymers and terpolymers derived from post-polymerization of acrylamide / acrylic acid and either acrylamide ethane sulphonic acid or acrylamide acid sulphonic methane. These preferred polymers include, but are not limited to, terpolymer of acrylic acid (about 60 to 70 mol%), acrylamide (about 9 to 27 mol%) and sodium salt of acrylamidomethanesulfonic acid (about 13 to 21) % mol) with an average molecular weight of between about 14,000 and about 25,000 Daltones; a terpolymer of acrylic acid (about 40 to 50 mol%), acrylamide (about 15 to 35 mol%) and sodium salt of acrylamido methanesulfonic acid (about 25 to 35 mol%), said terpolymer having an average molecular weight of between about 20,000 and 35,000 Daltones; a homopolymer of the sodium salt of polyacrylic acid, with an average molecular weight of between about 2500 and about 4000 Daltons; a copolymer of acrylic acid (about 90 mol%) and sodium salt of styrenesulfonic acid (about 10 mol%) with an average molecular weight of between about 25,000 and about 50,000 Daltones; and a copolymer of acrylic acid (about 99 mol%) and sodium salt of styrenesulfonic acid (about 1 mol%) with an average molecular weight of about 7,000 and about 10,000 Daltones. The copolymers of acrylic acid and acrylamide are available from Nalco Chemical Company under the brand name Transport Plus®. The terpolymers of acrylamide / acrylic acid and acrylamido methanesulfonic acid are available from Nalco Chemical Company under the trademark PRISM®. The remainder of these polymers are known to those skilled in the art. The method claimed herein is capable of detecting polymers up to a level of about 0.6 ppm to about 20 ppm. It is possible to extend this range by modifying the size of the sample and the reactive solution. These modifications would be within the reach of an expert in the field. It is understood that whether the size of the sample or the size of the reactive solution will be modified, then the calibration curve will have to be generated again for the new sample sizes. For example, all calibration curves included in this patent application were generated using a water sample size of 1 ml and a reactive solution size of 25 ml. When the method of the invention claimed here was conducted, it was found that when JARGON was used the method is still feasible (feasibility defined as measured values obtained in ± 10% of the current polymer concentrations) also when the species listed in the Table 1 are present in the sample at or below the indicated concentrations. The method is still feasible when the sample has a pH in the indicated pH range. It is also understood that these operating ranges can be adjusted by changing the ratio of the reactive solution to water sample or adjusting the level of the sequestrant in the reactive solution. This tolerance of contaminants is a huge advantage over known turbidimetric and colorimetric analysis methods, which can not tolerate such contaminant levels.

Table 1 Alkalinity (HC03 as CaCO3) 1800 ppm Alkalinity (C03 ~ 2 as CaC03) 600 ppm Aluminum (as Al + 3) 120 ppm Barium (as Ba2 +) 770 ppm Benzotriazole (as BZT) 1500 ppm Bisulfate (as HS04) 1800 ppm Boron (as B) 280 ppm Bromide (as Br) 3300 ppm Calcium (as CaC03) 1700 ppm Chloride (as Cl ") 3000 ppm Chromate (as Cr04) 600 ppm Chromium (as Crd +) 270 ppm Conductivity 6000 ppm Copper (as Cu2 +) 660 ppm Chlorine (free as Cl2) 10 ppm H glaze (as P04) 4 ppm HEDP (as P04) 1400 ppm Iron (as Fe3 +) 4 ppm Iron (as Fe2 +) 90 ppm Magnesium as CaC03) 1700 ppm Manganese (as Mn + 2) 860 ppm Molybdate (as Mo042 ~) 870 ppm PH 4.5-11.0 Hexametaphosphate (as P04) 4 ppm Tripolyphosphate (as P04) 300 ppm Nickel (as Ni2 +) 200 ppm Nitrate (as N03) 1600 ppm Nitrite (as N02) 2300 ppm Orthophosphate (as P04) 2100 ppm Pyrophosphate (as PO 370 ppm Silicate (as Si02) 530 ppm Sodium (as Na +) 2000 ppm Strontium (as Sr2 +) 80 ppm Sulphate (as S0 ~ 2) 1700 ppm Sulfite (as S03 ~ 2) 1300 ppm Toliltriazole (as TT) 1100 ppm Turbidity ( after filtration) 120 ppm Zinc (as Zn + 2) 400 ppm The following examples are intended to be illustrative of the present invention and to teach those skilled in the art how to make and use the invention These Examples are not intended to limit the invention. or its protection, in any way EXAMPLES Example 1 Preparation and Verification of JARGON The Mother of Blue Nile A solution is made by adding 0.619 grams of Nile Blue Dye at 82% to one liter of distilled water.

The sequestering solution is prepared by diluting to 1 liter, 10 grams of a 50% aqueous solution of 2-phosphobutan-1,2,4-tricarboxylic acid. Sufficient sodium hydroxide is then added to create the sodium salt of phosphobutan tricarboxylic acid. The pH of the sequestering solution ranges from 7 to about 9, and preferably from about 7.5 to about 8.5. The sequestering solution is then brought to the desired volume of 1 liter by the addition of sufficient distilled water. The resulting sequestering solution contains 5000 ppm of the sodium salt of phosphobutane tricarboxylic acid. The next step is to take 111 ml of the sequestering solution and combine it with 111 ml of Nile Blue A stock solution and approximately 300 ml of distilled water. This combined solution is then completed to 1 liter using distilled water and mixed thoroughly to provide a reactive solution with a sodium salt level of phosphonobutane tricarboxylic acid, of approximately 550 ppm, ie JARGON. The absorbance of the JARGON is then measured using a DR 2010 spectrophotometer, adjusted to 635 nm with a cell path extension of 1 inch and this absorbance value is then used as "zero" of the instrument.

The next step is to add 1 ml of filtered water sample to 25 ml of JARGON. After waiting 30 seconds, the absorbance is measured. The measured absorbance value is compared to the calibration curves showing the absorbance of samples containing known amounts of polymer. The following measurements were taken, using the same DR 2010 spectrophotometer, adjusted to 635 nm with a cell path length of 1 inch over water samples from four different pilot cooling towers, containing specific anionic polymer quantities. Once the measurements were obtained, they were compared with the calibration curve in Figure 1 (using the line for current data) for those samples containing Polymer A and with the calibration curve in Figure 2 (using the line for current data) for those samples containing Polymer B: Sample Polymer Difference of active polymer Absorbance (ppm) 1 A -0.452 12.3 2 A -0.156 3.2 3 B -0.467 14.9 4 B -0.455 14.6 Example 2 Elaboration and Verification of JARGON- A The reaction solution is made in the same manner as in Example 1, except for the fact that sodium hydroxide is not added to the sequestering solution, which means that the sequestering solution prepared is SEQUESTRANT AGENT-A. The created JARGON-A had a pH of about 2.8. A standard of 10 ppm of Active Polymer A and a standard of 10 ppm of Active F-Polymer (acrylic acid copolymer / acrylamide, molar ratio, 70:30 and average molecular weight of about 25,000 to about 40,000) were analyzed using the JARGON elaborated as in Example 1 and JARGON-A, created according to the previous description. The spectrophotometer was used DR / 2010 with a cell path length of 1 inch set at 635 nm, to measure polymer concentration. Then, the calibration curves for each polymer examined were consulted to determine the amount of polymer present in each sample. The results are: SAMPLE Quantity of Polymer Found using JARGON Polymer A of 10 ppm 10.9 ppm Polymer F of 10 ppm 10.8 ppm A similar set of experiments was conducted with Polymers A and F, using JARGON-A. The same DR / 2010 spectrophotometer was used to measure the polymer concentration based on the amount of the sulfonate portion present in the polymer. Polymer F, had a proportion of 0 mol% of sulfonate portion and Polymer A, had a proportion of ~ 20 mol% of acrylic acid to sulfonate portion When the JARGON-A was used, as a reactant, the sulfonate portion will be measured; but not the acrylate portion. The polymer concentration, observed and expected, in relation to the results obtained using JARGON are shown in the following table: SAMPLE CONCENTRATION OF CURRENT SULPHONATE CONCENTRATION DETERMINED USING SULFONATE JARGON-A Polymer A 10 ppm 1. ppm ~ 2.0 ppm Polymer A 20.6 ppm 3.4 ppm - .1 ppm Polymer F 10 ppm 0.0 ppm 0.0 ppm The results of JARGON-A reflect exactly that Polymer F (acrylic acid copolymer / acrylamide), did not have a sulfonate (or other strongly acidic) portion present and the Polymer A had a sulfonate content of ~ 20% mol based on polymer composition considerations. It will be understood that various changes and modifications to the preferred embodiments of the present, described above will be obvious to those skilled in the art. Such changes and modifications can be made, without departing from the spirit and scope of the present invention and without diminishing its expected benefits. It is intended, however, that such changes and modifications be covered by the appended claims. It is noted that in relation to this date, the best method known by the applicant, to carry out the aforementioned invention, is the conventional one for the manufacture of the objects or products to which it refers.

Claims (10)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. A method for measuring the concentration of an anionically charged polymer in an aqueous solution, which is characterized in that it comprises the steps of: (a) providing a reactive solution comprising i) water, ii) Nile Blue Dye; and iii) sequestering agent, with said sequestering agent selected from the group consisting of ammonium or alkali metal salts of phosfonobutane tricarboxylic acid; (b) using a suitable device to measure the absorbance of said reactive solution on its own and use this absorbance measurement for zero of said suitable device at the polymer concentration level of 0 ppm; (c) providing a sample of an aqueous solution containing at least one anionically charged polymer to be verified; (d) combining said reactive 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 thereof; wherein the method is conducted without adjusting the pH of said sample and wherein the method further comprises the step of waiting for a period of time of less than about 7 minutes for said reactive solution and said anionically charged polymer to react between the combining step (d) and the stage of measuring (e).
2. 2. A method of claim 1, characterized in that the sequestering agent is phosphonobutane tricarboxylic acid.
3. 3. A reactive solution that is characterized in that it comprises: (i) water, (ii) Nile Blue Dye; and (iii) sequestering agent, with said sequestering agent, selected from the group consisting of ammonium or alkali metal salts of phosphonobutane tricarboxylic acid.
4. 4. A reactive solution of claim 3, characterized in that said sequestering agent is phosphonobutane tricarboxylic acid.
5. 5. The method of claim 1, characterized in that said sequestering agent is the sodium salt of 2-phosphonobutan-1,2,4-tricarboxylic acid.
6. 6. The reactive solution of claim 3, characterized in that said sequestering agent is the sodium salt of 2-phosphonobutan-1,2,4-tricarboxylic acid. The method of claim 2, characterized in that said sequestering agent is 2-phosphonobutan-1,2,4-tricarboxylic acid. The reactive solution of claim 4, characterized in that said sequestering agent is 2-phosphonobutan-1,2,4-tricarboxylic acid. The method of any of claims 1, 2, 5 or 7, which is characterized in that said Nile Blue Dye is Nile Blue A. The reactive solution of any of claims 3, 4, 6 or 8, which is characterized in that said Blue Nile Colorant in Blue Nile A.