Spectrophotometric study on the interaction of serum albumin with arsenazo III

The interaction of arsenazo Ⅲ with serum albumin and the optimum condition for the determination of protein were investigated by spectrophotometry.In a Clark—Lubs buffer solution of pH 3.0,arsenazo Ⅲ interacts with bovine serum albumin and they form a compound with an maximum absorption wavelength of 550 nm in the presence of surfactant OP.The apparent molar absorptivity of the compound is e_(550nm)=4.36×10~5L·mol~(-1)·cm~(-1).Beer's law is obeyed over 0～80mg·L~(-1)of protein.The proteins in human serum were determined by the proposed methed with satisfactory results.