Abstract: The present invention is a concentration measuring device for obtaining a concentration of a target component in a liquid sample highly accurately, and includes: an optical measuring unit 2 that measures a spectroscopic spectrum of the liquid sample; an electrochemical measuring unit 3 that electrochemically measures a property value of the liquid sample; and a concentration calculating unit 41 that calculates the concentration of the target component by performing a multivariate analysis that uses the spectroscopic spectrum and the property value as explanatory variables.

Abstract: Compositions for floor polish. Specifically, a composition for floor polish made by the two-step process including the steps of (1) providing water-borne polyurethane resin, preferably having 2-20 acid functional groups per urethane and having an acid value of 15-200 and a molecular weight of 10,000 to 1,000,000, and (2) reacting the polyurethane resin with a calcium compound, not complexed with amines or ammonia, in an amount sufficient to form 0.05 to 0.9 chemical equivalents of calcium crosslinkages relative to the acid functional groups of the polyurethane resin. The invention also includes a floor polish made by a three-step process including the steps of (1) providing an emulsion of a water-borne polyurethane resin as described above, (2) adjusting the pH of the emulsion to a pH value within the range of 4.5 to 9 by adding a base to the emulsion, and (3) reacting the water-borne polyurethane resin with a calcium compound as described above.