Spectrophotometric Study on the Interaction between Arsenazo M and Proteins

Arsenazo M could bind with bovine serum albumin to form a complex in Clark-Lube buffer at pH 2.3 and room temperature, which gives a maximum absorption peak at 625 nm with a red shift of 75 nm compared with that of Arsenazo M itself. The apparent molar absorptivity of the BSA-Arsenazo M complex is 3.21′105 L×mol-1×cm-1. The linear ranges for protein determination are wide (at least 0-100 mg/mL).