Hach Company

Angella Nicholle Greenawalt

Darren Kent MacFarland

Melanie Ann Roth

Amit Das

Brendan Easley Young

Daniel Gustav Mieritz

Darren Kent Macfarland

An embodiment a method for measuring an amount of manganese in an aqueous sample, including: reducing, using a dechlorination reagent, wherein the dechlorination reagent comprises iron(II) and potassium iodide; oxidizing, under an alkaline condition using sodium hydroxide, Mn(II) to Mn(IV) in the aqueous sample, and chelating, using etidronic acid (HEDP), Fe(II) and Fe(III) in the aqueous sample, oxidizing an amount of 3,3',5,5′-tetramethylbenzidine (TMB) with Mn(IV); and measuring, using a colorimetric indicator, the amount of manganese within the aqueous sample, by measuring an absorbance intensity at a wavelength of the oxidized amount of 3,3′,5,5′-tetramethylbenzidine (TMB). Other aspects are described and claimed.

Manganese detection

An embodiment provides a method for measuring zinc in a solution, including: preparing an indicator solution; introducing the indicator solution to a solution, wherein the solution contains an amount of zinc and the introducing causes a change in fluorescence of the solution in response to the indicator solution reacting with the zinc; and measuring the amount of zinc in the solution by measuring a change in intensity of the fluorescence. Other aspects are described and claimed.

Zinc measurement

An embodiment provides a method for measuring peracetic acid concentration in an aqueous solution, including: combining, in a reactive solution, 4-(methylthio)aniline and at least one reactive species to produce a chromophore, wherein the at least one reactive species comprises a chromotropic acid disodium salt; placing the chromophore in an aqueous solution, wherein the aqueous solution comprises peracetic acid, wherein peracetic acid within the aqueous solution reacts with the chromophore; and measuring a concentration of peracetic acid within the aqueous solution, wherein the measuring comprises quantifying a colorimetric change of the aqueous solution caused by the peracetic acid reacting with the chromophore. Other embodiments are described and claimed.

Aqueous peracetic acid detection

An embodiment provides a method for measuring nitrate in an aqueous sample, including: introducing an aqueous sample containing an amount of nitrate to a cation exchange resin; flowing the aqueous sample over copper metal; adding a reducing reagent to the aqueous sample; adding a colorimetric indicator to the aqueous sample; and measuring the amount of nitrate in the aqueous sample by measuring a change in intensity of the absorbance. Other aspects are described and claimed.

Nitrate detection with copper oxidation

An embodiment provides a method for measuring zinc and copper in an aqueous sample, including: reducing an aqueous sample containing an amount of zinc and an amount of copper with a reducing agent; buffering the reduced aqueous sample; chelating the amount of copper in the buffered aqueous sample with a copper(I) chelating agent; measuring the amount of copper in the aqueous sample by measuring a first change in intensity of the absorbance of the copper chelated aqueous sample; chelating the amount of zinc in the buffered aqueous sample with a zinc(II) chelating agent; and measuring the amount of zinc in the aqueous sample by measuring a second change in intensity of the absorbance of the zinc chelated aqueous sample. Other aspects are described and claimed.

Zinc and copper measurement

An embodiment provides a method for measuring free chlorine in a solution, including: preparing a thiocarbamate-based indicator; introducing the thiocarbamate-based indicator to a solution, wherein the solution contains an amount of free chlorine and the introducing causes a change in fluorescence of the solution; and measuring the amount of free chlorine in the solution by measuring a change in intensity of the fluorescence. Other aspects are described and claimed.

Ultra low range free chlorine measurement

An embodiment provides A method for measuring fluoride concentration in an aqueous solution, including: preparing a metal-ligand complex, wherein the metal-ligand complex comprises chromeazurol S and aluminum; placing the metal-ligand complex in a sample containing fluoride, wherein the placing generates a color change by releasing the chromeazurol S from the metal-ligand complex; and measuring, using colorimetric techniques, a concentration of fluoride within the sample, wherein the measuring comprises measuring an absorbance wavelength of a colorimetric ligand. Other embodiments are described and claimed.

Colorimetric detection of fluoride in an aqueous sample

An embodiment provides a method for measuring a concentration of lead(0) in an aqueous sample, including: introducing an aqueous sample to a reaction vessel; adding a copper(II) acetate material to the aqueous sample in the reaction vessel; chelating unreacted copper(II) material by introduction of an organosulfur compound to the aqueous sample in the reaction vessel; adding a colorimetric indicator to the aqueous sample in the reaction vessel; and measuring a concentration of lead(II) in the aqueous sample by measuring a colorimetric change of the aqueous sample caused by a reaction of lead(II) within the aqueous sample with the colorimetric indicator. Other aspects are described and claimed.

Digestion of lead(0) and subsequent colorimetric detection of lead(II)

An embodiment provides a method for measuring fluoride concentration in an aqueous solution, including: preparing a polyethylene glycol (PEG) monomethyl ether to produce an ester; reacting the ester in the presence of ammoniated tetrahydrofuran to produce an amino polyethylene glycol; placing, in a solution comprising a benzaldehyde species with a phenol functional group and a carboxylic acid functional group, a 2,3,3-trimethylindolenine derivative to produce a hemicyanine with a phenol functional group and a carboxylic acid functional group; combining, in a polar aprotic solvent, the hemicyanine with the phenol functional group and carboxylic acid functional group with a 1,1-carbonyldiimidazole (CDI) and adding the amino-PEG to produce a hemicyanine-PEG; and creating a fluoride sensitive hemicyanine species by reacting the hemicyanine-PEG that contains a phenol functional group with a SiRspecies. Other embodiments are described and claimed.

Aqueous colorimetric fluoride detection

An embodiment provides a method for measuring aluminum concentration in an aqueous sample, including: preparing a chromeazurol S indicator solution; placing the chromeazurol S indicator solution in a sample containing aluminum, wherein the placing causes the chromeazurol S to chelate aluminum within the sample creating a colored complex; and measuring, using colorimetric techniques, a concentration of aluminum within the sample, wherein the measuring comprises measuring an absorbance at a wavelength for the colored complex. Other embodiments are described and claimed.

Colorimetric detection of aluminum in an aqueous sample

A method of measuring nitrate concentration in an aqueous sample includes mixing the aqueous sample with a water-soluble thioether chosen to reduce nitrate in the aqueous sample to nitrite in the presence of a water soluble catalyst, and a water soluble reagent system adapted to interact with nitrite to generate a color; measuring color generation, and correlating the color generation to nitrate concentration.

Growing community of inventors

Fort Collins, CO, United States of America

Angella Nicholle Greenawalt