High-performance liquid chromatography of selected organic peroxides with oxidative amperometric detection

Abstract

Reversed-phase high-performance liquid chromatography with oxidative amperometric detection was optimized for the determination of several organic peroxides in drinking water under ideal conditions. The determinations were performed under isocratic conditions using acetonitrile and methanol as the organic modifiers with 0.05 M potassium phosphate buffer solution. The oxidative amperometric response of the organic peroxides was dependent on the concentration of organic modifier and the electrode potential. The optimum electrode potential (EOxAPP), for the simultaneous determination of the organic peroxides was approximately +1.150 +/- 0.05 V versus the Ag/AgCl reference electrode. The maximum analytical signal for butan-2-one peroxide and tert-butyl hydroperoxide, when using acetonitrile, was obtained with 20% v/v organic modifier. For cumene hydroperoxide, the maximum analytical signal was achieved with approximately 35% v/v acetonitrile. The retention time of cumene hydroperoxide, on an octyldecylsilane column (250 x 4 mm id), decreased sharply from > 100 to < 10 min when the organic modifier concentration was varied from 5 to 50% v/v. The retention time of butan-2-one and tert-butyl hydroperoxide, under the same conditions, varied by < 10 min. The calibration curves for the aliphatic peroxides and aromatic peroxide were linear from 2 to 200 ng and from 0.2 to 200 ng injected, respectively.

Analysis of inorganic and small organic ions with the capillary electrophoresis microchip

“…Since the redox behavior of phenolic and organic peroxide compounds is well defined, these organic species make ideal candidates for electrochemical detection. These compounds have also been monitored by amperometric flow detection in conventional liquid chromatography [38,39] and CE systems [24,40,41]. Therefore, separating and detecting these compounds on microchip devices demonstrates the potential for portable, sensing applications in the future.…”

On-line deoxygenation in reductive (and oxidative) amperometric detection: environmental applications in the liquid chromatography of organic peroxides

“…The flow rate was 1.0 ml min 21 unless stated otherwise, and the column back-pressures at this flow rate ranged from ca. 1800 to 2400 lb in 22 . The pump(s) performed at optimum efficiency when the flow rate was 1.0 ml min 21 .…”