The number of chemical pollutants in our waters, for example from industry or agriculture, is continuously increasing and already amounts to thousands of substances, without taking transformation products into account. It is currently not possible to screen for all substances, so the substances that are particularly harmful to the environment should be prioritized first. Effect-directed analysis (EDA) offers a solution here: the complexity is reduced by fractionating samples and identifying problematic fractions through effect-based methods. Finally, high-resolution mass spectrometric methods can be used to potentially identify the substances that are responsible for a certain effect. The EDA concept is established, but still has potential for improvement, which is addressed in this work.

One approach for improvement is the expansion of the chemical space, for example through online enrichment and the combination of stationary phases with different selectivity. Initially, a column switching was therefore established that enabled improved limits of detection by online enrichment. In addition, online dilution was established as a tool for reducing strong solvent influences. The application was demonstrated on the analysis of polycyclic aromatic hydrocarbons in both aqueous and oranic solvents. Polar substances represent a further challenge in water analysis, not only in the field of EDA. Due to the further development of the column switching, polar and non-polar analytes with a polarity range of logP -5.1 to +13.2 could be enriched and separated.

For technical reason it was important to miniaturize the developed column switching, as the flow rates of the conventional LC were too high. By adapting the switching to the miniaturized LC, the flow rate could be reduced from 0.3 mL/min to 25 µL/min. With this flow rate, an autosampler could be converted into a fractionation unit. This setup was not used for fractionation in microtiter plates, as is usually the case, but on thin-layer chromatography plates (TLC). The advantage lies in an additional separation dimension with a freely selectable stationary phase. Applications have shown that this additional separation dimension can separate coeluting substances that are contained in a fraction.

However, biochemical assays, especially those based on TLC plates, are very labor-intensive and have a low sample throughput, which makes them particularly suitable for automation. First, however, the theoretical foundation had to be laid, as automation in the laboratory is still hardly widespread. The focus was on an introduction to the available technology and considerations for laboratory automation.

A flexible laboratory automation concept was developed on the basis of the automation principles presented above. The main focus was on simple adaptation to individual requirements, even for complex laboratory processes. Therefore, a concept was developed to flexibly automate complex workflows. Using this concept, the robot-supported automation of the workflow involving seven different stations was achieved without the need for programming knowledge. These stations proved themselves in practical use and the robot was able to carry out the workflow without errors.

The next step is to connect the optimized parts of the effect-directed analysis to the overall assay. Once this has been implemented, a significant increase in sample throughput can be expected with a simultaneous increase in information gain.