A Colorimetric Direct Method for the Determination of Serum Copper by Use of TAMSMB

Abstract

Optimum reaction conditions were evaluated for assay of serum copper by use of guanidin hydrochloride as a decomposing agent for high order structure of protein and TAMSMB as a copper chelating and color deveroping agent.These reaction condition were judged to be optimum: (a) concentration of guanidin hydrochloride should be more than2.5mol/l, pH4.2with acetate buffer 0.5mol/l, the mixture of potassium iodate4.5mmol/l and potassium iodide 0.4mmol/l as a oxidizing agent for various reductants in serum.(b) sample pretreatment with the solution of buffered guanidin hydrochioride and oxidizing agent for 5min period is absolutely effective to cause copper release from protein and combert it to oxidized form, After this treatment, the TAMSMB-copper coupling reaction are compieted within one min.Using these reaction conditions, we devised an improved direct method for measuring serum copper without a deproteinizing process.Results compare well with those by atomic absorption spectrometry.The within day and day to day reproducibility with pooled serum (copper concentration of 110μg/dl) by this method were c.v. 0.65% and 1.62%, respectively.