ASCORBATE INTERFERENCE-RESISTANT COMPOSITION, DEVICE AND METHOD FOR THE DETERMINATION OF PEROXIDATIVELY ACTIVE SUBSTANCES

摘要

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: IMAGE where: (a) R1 is hydrogen or straight or branched chain alkyl alcohol or alkyl carboxylic acid radicals having from 2 to 3 carbon atoms; R2, R3, Rx and Ry, 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 R1, R2, R3, Rx or Ry are alkyl carboxylic acid radicals so defined; (b) Rp and Rq, same or different, are straight or branched chain alkylene radicals having from 1 to 3 carbon atoms or divalent 1,2-cycloaliphatic radicals having from 6 to 9 carbon atoms; (c) n is an integer having a value of from 0 to 1; m is an integer having a value of from 0 to 2; where if m is greater than 0, repeated Rp and repeated Rq radicals may be the same or different; and (d) M is Fe+3. The composition also comprises an organic hydroperoxide and an indicator capable of providing a detectable response in the presence of peroxide and the peroxidatively active substance. The test means comprises a carrier matrix incorporated with the composition, and the method comprises immersing the test means (or device) in the test sample and observing a color or other detectable response.