Removal of Dissolved Oxygen Interference in the Amperometric Detection of Monochloramine Using a pH Control Method

Monochloramine amperometric determination was investigated using a pH control method to eliminate dissolved oxygen as an interferent. This method allowed local pH conditions to become more acidic, causing the production of dichloramine. This species showed an onset of electro-reduction at 450 mV, far outside of the oxygen reduction region. Monochloramine was calibrated using this method and showed good linearity (0.99) and a limit of detection of 0.03 ppm.