Abstract: A composition, test means (and device) and method for determining peroxidatively active substances in a test sample are disclosed. The composition, test means (and device) and method are rendered resistant to the adverse affects of ascorbate which may be present in the sample by the inclusion in the composition of a metal chelate which is polycarboxyalkylamine derivative having the formula: ##STR1## where: (a) R.sub.1 is hydrogen or straight or branched chain alkyl alcohol or alkyl carboxylic acid radicals having from 2 to 3 carbon atoms; R.sub.2, R.sub.3, R.sub.x and R.sub.y, same or different, are straight or branched chain alkyl alcohol or alkyl carboxylic acid radicals having from 2 to 3 carbon atoms; where at least two of R.sub.1, R.sub.2, R.sub.3, R.sub.x or R.sub.y are alkyl carboxylic acid radicals so defined;(b) R.sub.p and R.sub.

Abstract: A composition, test device, method of making a test device and process for determination of an analyte in a liquid sample are disclosed. More particularly, there is provided a composition for the determination of an analyte in a sample which composition comprises an analyte-responsive component comprising a pyridine nucleotide susceptible of reduction in response to the presence of said analyte and at least one constituent interreactive with said analyte to cause reduction of the pyridine nucleotide, an uncoupler effective to generate an oxidizing substance from the reduced form of said pyridine nucleotide, a peroxidatively active substance, and an indicator which, when oxidized, is not susceptible to reduction by said reduced pyridine nucleotide. The pyridine nucleotide can be nicotine adenine dinucleotide (NAD) or nicotine adenine dinucleotide phosphate (NADP).

Abstract: A composition is disclosed for determining the ionic strength or specific gravity of an aqueous test sample, the composition comprising a strongly acidic or strongly basic polyelectrolyte, a buffer substance capable of providing a pH of about 5.5, and an indicator means capable of producing a detectable response to ion exchange between the polyelectrolyte and the sample. The test device comprises a carrier matrix incorporated with the test composition, and the method for its use comprises contacting an aqueous test sample with the device and observing a detectable response.

Abstract: A test means for determining the ionic strength or specific gravity of an aqueous test sample, the test means comprising a weakly acidic or weakly basic polyelectrolyte which is at least partially neutralized, and an indicator means capable of producing a detectable response to ion exchange between the polyelectrolyte and the sample. The test device comprises a carrier matrix incorporated with the test means, and the method for its use comprises contacting an aqueous test sample with the device and observing a detectable response.

Abstract: Test means, such as a composition or device, method of making a test device and process for determination of at least one oxidizing substance, such as a peroxide, are disclosed. More particularly, the contemplated test means comprises a hydrazone and 8-amino-1-napthol-5,7-disulfonic acid (Chicago acid). Further provided is a test system for the determination of a constituent in a sample, having means responsive to the presence of said constituent in said sample to produce at least one oxidizing substance and a composition for determining said at least one oxidizing substance, wherein said composition comprises a hydrazone and 8-amino-1-napthol-5,7-disulfonic acid (Chicago acid). The test system is preferably of the type which determines peroxides formed from enzymatic conversion of constituents in biological fluids. When in the form of compositions the test means can optionally be incorporated with a carrier, such as a tablet or matrix, to provide a test device.