Patent ID: 9588123
Date: 2017-03-07
CPC Classifications: C12Q,G01N

Claim:
1. An aqueous composition for colorimetric analysis comprising a benzidine chromogenic substrate and N,N,N-trimethylglycine, wherein the benzidine chromogenic substrate is 3,3′,5,5′ tetramethylbenzidine (3,3′,5,5′ TMB) wherein the N,N,N-trimethylglycine is present in the composition in the range of 0.25 M to 1 M, wherein the composition has a pH in the range of 3 to 4, wherein the N,N,N-trimethylglycine and 3,3′,5,5′ TMB are present in the composition in a molar ratio in the range of 20:1 to 1,000:1, and wherein the N,N,N-trimethylglycine improves the solubility of the 3,3′,5,5′ TMB in the aqueous composition.