▎ 摘　　要

NOVELTY - Determining the concentration of a treatment compound in a water source, comprises combining a water source, a treatment compound effective for treating the water source, and a graphene quantum dot having a residue of the treatment compound covalently bonded thereto to form a tagged water source; irradiating the tagged water source with a source of light having a selected first range of wavelengths; and measuring the luminescent emission of the tagged water source at a selected second range of wavelengths, where the measuring is carried out substantially contemporaneously with the irradiating. USE - The method is useful for determining concentration of treatment compound in water source (claimed) e.g. measuring the concentration of chemical species in industrial water sources. ADVANTAGE - The method: utilizes tagged materials are tailored to fluoresce at wavelengths with minimized correspondence to the natural or background fluorescence of irradiated materials in industrial water sources, enables quantification of concentration of water source treatment compound or polymer in situ by irradiation and fluorescence measurement of the water source; and treats industrial water source comprising dosing the water source with a treatment comprising at least one fluorescent tagged compound to create a treated water source, measuring fluorescence of the treated water source, and optionally adjusting dosing of the water source based on the measured fluorescence.