The beginning of a long, but interesting journey – University of Copenhagen

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08 December 2017

The beginning of a long, but interesting journey

First steps towards a doctoral degree

A small insight into the early stages of my life as a PhD student at the Research Centre for Toxic Compounds in the Environment – or RECETOX, as it is conveniently abbreviated.

by ESR12 Marcel Schneider

I started working on my PhD project within the NaToxAq network at RECETOX at the Masaryk University in Brno, Czech Republic in early May. During these first months of my studies, I was mainly focusing on reviewing literature to identify the current state-of-the-art and further research needs. As this is an important and time consuming task, I will primarily deal with it for another few months and also every once in a while during the whole project. I also had the chance to start some preliminary experiments in the laboratory, ozonating water and subsequently determining the dissolved ozone concentration using UV absorbance readings and the indigo discoloration method. The latter utilizes the oxidizing capability of ozone, which is why I am going to use it for degrading cyanobacterial toxins. An acidic aqueous solution of indigotrisulfonate is proportionally decolorized by dissolved ozone from dark blue to colorless depending on the ozone concentration1. Right now, I am optimizing the experimental design to obtain a sufficient dissolved ozone concentration and am also working on validating the procedure, to ensure significant quality of the results.

Indigotrisulfonate stock solution on the left-hand side and discoloration of the indigo dye caused by reaction with dissolved ozone on the right-hand side.

In autumn, I met my ESR colleagues, their supervisors and other participants of the NaToxAq project for the first time during the first NaToxAq summer school in Helsingør, Denmark, where we discussed our PhD projects and had several courses on scientific topics and on complementary skills. Just a few weeks later, I went to the 6th International Symposium – Marine and Freshwater Toxins Analysis in Baiona, Spain where many interesting topics were presented and discussed.


1Bader H., Hoigné J. 1982. Determination of Ozone in Water by the Indigo Method: A submitted Standard Method. Ozone: Science & Engineering 4:169-176.