Abstract: A visual-spectrophotometry method for peroxide value (POV) of oil-in-water emulsions was studied in this paper. The determination conditions, precision, accuracy and influencing factors of the method were discussed in detail. The results showed that, when the concentration of Fe3+ is in the range of 0～4mg/L, the relationship between absorbance at 510nm and concentration of Fe3+ -thiocyanate complex compound accords with the Lambert & Bill’s law. The relative standard deviation is 0.60%. The rates of recovery are 98.2%～101.2%. The limited detection POV is 1.701meq/kg. The results indicated that this method can provide high precision and accuracy and low cost of reagents. This method is suitable for hydroperoxides analysis ofo il-in-watere mulsions.

Key words: emulsion, peroxide value, spectrophotometry