Flow Injection Analysis with Microdialysis Probes Enable Minimally Invasive and Dynamic H2O2 Measurements

This paper describes the optimization of a published flow injection analysis system coupled with microdialysis probes (MDP-FIA) for in-situ sampling and online measurements of hydrogen peroxide (H2O2). By modifying the commonly used Na2CO3 buffer by addition of EDTA and a changed order in reagent injection, interfering transition metals such as Fe(II) and Fe(III) are complexed and removed from the system without interfering with the chemiluminescent reaction of the used acridinium ester and H2O2. The system was then used to monitor changes in H2O2 concentration upon microwaving seawater and filtered seawater in the presence and absence of agar.