Abstract: Provided is a heat dried reagent composition that is dry, methods of making it, and methods of using it. The heat dried reagent composition can be characterized by one or more of stability to the heat drying conditions; storage stability of the heat dried reagent composition; fast rehydration time; rapid assay kinetics; and assay precision. The reagent composition is useful detecting and/or assessing free chlorine in an aqueous sample, such as pool water.

Abstract: Provided is a heat dried reagent composition that is dry, methods of making it, and methods of using it. The heat dried reagent composition can be characterized by one or more of: stability to the heat drying conditions; storage stability of the heat dried reagent composition; fast rehydration time; rapid assay kinetics; and assay precision. The reagent composition is useful for detecting and/or assessing total chlorine in an aqueous sample, such as pool water.

Abstract: Provided is a heat dried reagent composition that is dry, methods of making it, and methods of using it. The heat dried reagent composition can be characterized by one or more of stability to the heat drying conditions; storage stability of the heat dried reagent composition; fast rehydration time; rapid assay kinetics; and assay precision. The reagent composition is useful detecting and/or assessing free chlorine in an aqueous sample, such as pool water.

Abstract: A rotary analytical device for use with a reagent cartridge. The cartridge may have a housing, an axis, analysis chambers spaced from and located circumferentially about the axis, and a magnetically movable element located in and movable within each analysis chamber to mix fluid in the analysis chamber. The rotary analytical device may have a housing with a cavity having an axis, an impeller extending into the cavity and rotatable about the axis to receive and rotate the cartridge, a motor to rotate the impeller, at least one magnetic element near the cavity and offset from the axis, a light source in the housing to direct a beam of light into the cavity and through the analysis chamber of the cartridge, and a light sensor to receive light from the analysis chamber.

Abstract: An analytical cartridge and a rotary analytical device with which the cartridge cooperates. The cartridge may have a housing, an axis, analysis chambers spaced from and located circumferentially about the axis, and a magnetically movable element located in and movable within each analysis chamber to mix fluid in the analysis chamber. The rotary analytical device may have a housing with a cavity having an axis, an impeller extending into the cavity and rotatable about the axis to receive and rotate the cartridge, a motor to rotate the impeller, at least one magnetic element near the cavity and offset from the axis, a light source in the housing to direct a beam of light into the cavity and through the analysis chamber of the cartridge, and a light sensor to receive light from the analysis chamber.