| In this study,a new method for determining peroxide content of fats and oils was described. The technique was based on spectrophotometric monitoring at 318 nm of ferrocene oxide generated from ferrocene oxidation with cumene hydroperoxide present in oxidized oils and fats. The optimized reaction conditions were: the concentration of ferrocene was 29 mmol/L as solution;solvent was 2-propanol; the temperature was 60?the reaction time was 30 min; the maximum absorption wavelength of the complex was 318 nm. The method was applied successfully to the determination of peroxide value in five fats and oils samples. The results showed that the linear relationship between the two method is y=8.3223x-2.398(where x is the peroxide value of ferric thiocyanate method; y is the peroxide value of ferrocene method). The ferric thiocyanate method was less sensitivity to oxygen and light. FeCl2 reagent was susceptible to oxidation, and the experimental procedure requires dark. The proposed method could be instead of ferric thiocyanate method, because it is stable, simple, cheap and could be used to the quality control of edible oil.In order to better understand the reaction product of ferrocene and cumene hydroperoxide, methanol was used as an agent, and the reaction substrate and product could be separated well by TLC. The flow rate was 0.5 mL/min and the column temperature was 35? .The mobile phase was eluted with gradient elution of n-hexane and isopropanol, and the detection was performed on the column with the temperature of 250 mm ×4.6 ?m, and a sample volume of 20 ?L. The detection wavelength was 318 nm. The peak time of ferrocene was 6.443 min, and the peak times of cumene hydroperoxide were 6.473 min and 6.694 min. However the reaction products of ferrocene and cumene hydroperoxide appeared new absorption peaks, times of which were 12.968 min and 14.121 min, and the 3D diagram showed that the new absorption peaks at 318 nm were observed for ferrocene and cumene hydroperoxide. |
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