Abstract: A highly sensitive and convenient test method, composition and device for the facile calorimetric determination of total dissolved solids in an aqueous sample having a low specific gravity is presented. The reagent composition comprises the mixture of a complex of a positively charged polyelectrolyte and a negatively charged indicator material, and an appropriate buffer system for maintaining the test system environment at an exact pH depending upon the indicator material selected. A preferable embodiment of this test system comprises the incorporation of the test composition into or with a solid state matrix material such as bibulous paper. The test system is particularly useful in the field testing of potable and recreational waters.

Abstract: Devices and test kits are provided for glucose detection and quantification in urine. The devices and kits comprise a chromogenic indicator mixture comprising a first indicator capable of color development to indicate the presence of a low-to-medium concentration of glucose, a second indicator capable of color development to indicate the presence of a higher concentration of glucose, wherein the first indicator prevents color development of the second indicator unless the higher concentration of glucose is present in the urine, and a non-chromogenic scavenger that interferes with color development of the first indicator when glucose levels are below a threshold concentration, and a carrier impregnated with the chromogenic indicator mixture.

Abstract: A test reagent composition and device are provided for determination of cyanuric acid in water, said composition including melamine, a pH indicator that changes color due to the reaction of melamine with the cyanuric acid in the water, and a stabilizing compound capable of forming hydrogen bonds with the melamine but which does not compete with the cyanuric acid.

Abstract: Test devices and methods are provided for detection of feline lower urinary tract disease. The test devices comprise a matrix impregnated with a color indicator and a stabilizer wherein the indicator remains stable when exposed to ambient conditions and wherein a positive color response remains stable for a sufficient time for the color response to be observed. The test devices may be provided for use in combination with conventional cat box filler.

Abstract: A test device and method is described for directly determining the liquid phase water content of organic solvents and indirectly the liquid phase water content of solids. The device and method utilize a reagent composition consisting basically the dried residue of a mixture of a colorimetric indicator material, preferably a cobaltous or cuprous salt, and a polymeric water barrier material, such mixture incorporated into a matrix which is contacted with or immersed into the liquid test sample, removed therefrom and the color change of the test composition correlated with a standard color chart to give a quantitative result of the amount of water in the test sample. When the method is applied to solids, the water must first be extracted from the solid using a substantially anhydrous extracting fluid such as reagent alcohol.

Abstract: A sensitive and convenient unitized method, reagent composition and test device is presented for the determination of free halogens in aqueous test fluid samples. The reagent composition basically consists of an azine type indicator material and an effective amount of a benzidine type catalytic material, the combination of two materials preferably being impregnated into a matrix material for ease of handling and use.

Abstract: A unitized, one step test reagent composition, device and method is presented for the determination of phosphorus in various test sample fluids such as soil extracts. The invention is a modification of the Murphy and Riley methodology which utilizes a molybdate salt and a reducing agent to generate "molybdenum blue" in the presence of phosphate. In addition to the molybdate salt, the test reagent composition includes a chromogenic reducing agent which contributes to the color development and a solid buffer. The composition is preferably incorporated into a matrix such as paper for ease of handling.

Abstract: A dry reagent colorimetric test system for determining analytes in sample solutions containing interfering colored materials is presented comprising a reagent impregnated matrix containing a chromogenic material responsive to the analyte being detected and a masking dyestuff for obviating the interference caused by the colored materials thus allowing a proportional visual estimation of the response of the chromogenic material due to the amount of analyte in the sample solution.

Abstract: The present invention involves a unitized dry reagent test device and method for removing the interference caused by suspended particulate materials in the calorimetric determination of analytes in samples containing such materials. More specifically, the testing methodologies of the present invention comprise the use of a multilayer reagent impregnated matrix having known particulate removal characteristics attached to a test fluid impervious support means which has known light transmission characteristics. On-site or field testing of soil samples is an advantageous and representative application of the devices and methods of the present invention.

Abstract: A test method and device is described for determining biguanides in aqueous fluids such as swimming pool water which involve contacting the fluid with a matrix incorporating a pH sensitive indicator material which exhibits the biguanide error effect. A buffer is advantageously used to maintain the test system within a defined constant pH range to eliminate the effect of pH changes on the test system.

Abstract: A unitized multilayer dry reagent analytical chemistry test structure and device and method of fabricating such device is described. The device includes two or more contiguous layers of absorbent or porous paper or polymeric material, at least one of which is incorporated with a test reagent composition, the layers attached to each other with intermediate porous attachment layers by fusion bonding. When the device is contacted with the fluid being tested the attachment layers allow the free flow of such fluid from one layer to the next.

Abstract: A test device and method of use for determination of aqueous halide ions is described. The device has a porous matrix containing a silver dichromate reagent that gives a colorimetric response in the presence of halide ions and a cationic substance that prevents the formation of silver oxide products. The cationic substance has no colorimetric response in the presence of halide ions that would interfere with the measurement of the colorimetric change of the silver dichromate reagent.

Abstract: A colorimetric test reagent composition is presented for determining the amount of cyanuric acid in water. Cyanuric acid is added to outdoor swimming pool water to stabilize the chlorine added as a sanitizer. Basically the test composition utilizes melamine and an indicator material which responds to a change in pH of the test environment caused by the action of cynanuric acid on the reagent composition. Preferably the test composition is incorporated in a porous matrix which results in a convenient solid state test device.