Abstract: The present invention provides an inexpensive and sensitive device and method for detecting and quantifying analytes present in a medium. The device comprises a metalized film upon which is printed a specific, predetermined pattern of a analyte-specific receptors. Upon attachment of a target analyte to select areas of the plastic film upon which the receptor is printed, diffraction of transmitted and/or reflected light occurs via the physical dimensions and defined, precise placement of the analyte. A diffraction image is produced which can be easily seen with the eye or, optionally, with a sensing device.

Abstract: A chemically charged-modified filter for removing charged, micron to sub-micron sized particles from an aqueous liquid, the filter being composed of a filter sheet having a plurality of individual exposed surfaces, at least a portion of which having a surface energy of less than about 45 dynes per centimeter; amphiphilic macromolecules adsorbed onto at least some individual exposed surfaces having a surface energy of less than about 45 dynes per centimeter; and chemical charge modifiers incorporated onto at least a portion of the amphiphilic macromolecules; so that when said charge-modified substrate is in contact with the aqueous liquid containing the charged, micron to sub-micron sized particles, said particles are adsorbed onto the chemically charge-modified filter.

Abstract: A derivatized polysaccharide in which at least a portion of the active hydrogens originally present in the polysaccharide are substituted by monovalent aliphatic groups containing at least two carboxylic acid groups to an extent sufficient to provide a degree of substitution of at least about 0.1. The monovalent aliphatic groups contain from 4 to about 10 carbon atoms. The polysaccharide may be cellulose. At least a portion of the carboxylic acid groups present in the derivatized polysaccharide may be crosslinked permanently or reversibly. The monovalent aliphatic groups containing at least two carboxylic acid groups may be derived from 2,3-epoxysuccinic acid; 1,2-epoxypropane-1,2,3-tricarboxylic acid; 2-(epoxyethyl)-succinic acid; or mixtures thereof. Also provided is a method of preparing a derivatized polysaccharide.

Abstract: An adsorbent filter for removing caffeine from liquids. The filter is composed of a liquid permeable matrix of fibrous material having individual exposed surfaces; and a distribution of adsorbent clay minerals attached to individual exposed surfaces of the fibrous material by substantially non-transient bonding, so that passage of a liquid having a caffeine concentration ranging from about 20 to about 100 mg per 100 mL of liquid through the matrix for a contact time of less than about 2 minutes results in at least a 40 percent reduction in the caffeine concentration of the liquid. The matrix of fibrous material may be selected from woven fabrics, knit fabrics and nonwoven fabrics. The adsorbent clay minerals include, for example, sodium bentonite clays, calcium bentonite clays, acidified bentonite clays, and modified bentonite clays containing a flocculating agent.

Abstract: Disclosed is a process for disinfecting water which provides a visual indication after the disinfection is complete. First, the water to be disinfected is generally simultaneously intermixed with at least three items. The items are: (1) a disinfectant which is adapted to render harmless substantially all pathogens present in the water upon the disinfectant being intermixed with the water for a time period T.sub.k ; (2) a colorant; and (3) a material which can remove substantially all of the disinfectant and colorant from the water over a time period T.sub.r, where T.sub.r is greater than T.sub.k. Secondly, the water, disinfectant, colorant and the removing material are allowed to remain intermixed for a time period of T.sub.r or greater. At the end of the time period T.sub.r, substantially all pathogens in the water will be rendered harmless, substantially all of the disinfectant will be removed from the water and substantially all of the colorant will be removed from the water.