US Patent 7354732 Method of assay with sulfonic acid compound and nitro compound

A method for measuring an analyte in a sample by using a redox reaction is provided, which gives values with excellent reliability. Prior to the redox reaction, at least one of a sulfonic acid compound and a nitro compound is added to the sample to eliminate the influence of hemoglobin and any hemoglobin degradation products as reducing substances contained in the sample. Subsequently, a reducing or oxidizing substance derived from the analyte is caused to generate, and the amount thereof is measured by the redox reaction. The amount of the analyte is determined from the measurement value. The sulfonic acid compound may be sodium lauryl sulfate, and the nitro compound may be 4-nitrophenol, etc.