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

The development and application of a flow injection analysis (FIA) method for the automated determination of peroxyacetic acids in the presence of hydrogen peroxide is described. The selective oxidation of 2,2'-Azino-bis(3-ethylbenzothiazoline)-6-sulphate) (ABTS) to a green radical cation (ABTS*(+)) is the basis for this method. A reagent stream and a carrier stream into which 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 detection is performed by UV/vis spectroscopically at lambda=405 nm. Major advantages of the method are the simple experimental setup and the high selectivity towards hydrogen peroxide. Real samples have been investigated and the method has been validated using independent techniques including microplate spectrophotometry and liquid chromatography. (C) 1999 Elsevier Science B.V. All rights reserved.