Separation and determination of a peroxide mixture by HPLC with postcolumndetection

A simple and rapid method using HPLC with postcolumn detection has been dev eloped for the separation and determination of a peroxide mixture. A hydrog en peroxide(H2O2), methyl-hydroperoxide (MHP) and peroxosulfate mixture was chosen for the sample. LC separation was carried out on an Inertsil ODS-2 column(4.6 mm i.d. x 250 mm length) using pH-adjusted distilled water with H3PO4 as the mobile phase at a flow rate of 1 ml/min. An oxidizing reaction of I- by pet-oxide was applied to the postcolumn reaction. Thus, a 10% KI aq. solution at a flow rate of 0.5 ml/min was used as the reaction solution . Teflon tubing (0.5 mm i.d. x 10 m length) was used as a reaction coil at 90 degrees C. UV detection was performed at 348nm. The detection limits (S/ N = 3) for H2O2 and MHP were 35 ppb and 50 ppb, respectively. Under this an alytical condition, peroxides and I- reacted quantitatively. Thus, the dete rmination of various kinds of peroxides is possible by comparing the peak a reas with that of a H2O2 Standard solution, even if the standard substance of the peroxides is not available. Since the proposed system uses only easi ly available apparatus and reagents, this method is suitable for process co ntrol.