Patent ID: 11782043

Abstract:
Disclosed is a real-time method for detecting copper and silver in water in parts per billion. Total silver is detected by adding a nitric acid solution to the sample; after the silver is digested, adding a buffer solution comprising water, sodium bicarbonate, sodium carbonate and EDTA to the sample; adding an indicator comprising Cadion 2B, EtOH, and Triton X-100 to the sample; then reading the absorbance of the sample after light with an approximate target peak of 515 nm is sent through the sample; and determining the silver concentration by comparing the absorbance of the sample to the absorbances of known silver standards. Total copper is detected by adding a nitric acid solution to the sample; after the copper is digested, adding a buffer/indicator solution to the sample, where the solution comprises water, sodium citrate dihydrate, hydroxal amine hydrochloride and bathocuproine disulfonate; after one minute, reading the absorbance of the sample after light with an approximate target peak of 480 nm is sent through the sample; and determining the copper concentration by comparing the absorbance of the sample to the absorbances of known copper standards. A monitoring device for determining the level of copper or silver in a sample implements the disclosed methods.