Patent ID: 6844196

Claim:
A method for determining concentration of antioxidant in a sample solder plating solution, comprising the steps of: (a) providing a complexing solution comprising molybdenum dichloride dioxide, a binding agent for complexing with tin and lead ions in said sample solder plating solution, and a buffering agent for stabilizing pH value of said sample solder plating solution; (b) adding the sample solder plating solution into said complexing solution, so as to form an antioxidant-molybdenum complex that is detectable by UV-Vis spectroscopy; (c) conducting UV-Vis absorption analysis at a wavelength that maximizes UV absorbance of said antioxidant-molybdenum complex; and (d) determining the antioxidant concentration in said sample solder plating solution, based on the UV-Vis absorption analysis result.