Rapid and selective determination of peroxyacetic acid in disinfectants using flow injection analysis

The development and application of a flow injection analysis (FIA) method f or the automated determination of peroxyacetic acids in the presence of hyd rogen peroxide is described. The selective oxidation of 2,2'-Azino-bis(3-et hylbenzothiazoline)-6-sulphate) (ABTS) to a green radical cation (ABTS*(+)) is the basis for this method. A reagent stream and a carrier stream into w hich the sample is injected are combined in a low dead volume mixing tee. A short reaction coil provides for a reaction time of 6 s after which detect ion is performed by UV/vis spectroscopically at lambda=405 nm. Major advant ages of the method are the simple experimental setup and the high selectivi ty towards hydrogen peroxide. Real samples have been investigated and the m ethod has been validated using independent techniques including microplate spectrophotometry and liquid chromatography. (C) 1999 Elsevier Science B.V. All rights reserved.