Toxic cyanobacteria blooms are prevalent throughout the world. Therefore, human exposure to toxins produced by cyanobacteria is to be expected. The current lack of reliable quantitative data from research and monitoring in different matrices is restricting the implementation of risk assessment methodologies to evaluate the health impact on human and animal populations. Uncovering the relevant exposure routes for risk assessment requires ready-to-use analytical methodologies specific for each matrix to quantify these harmful compounds. Indeed, these methodologies require adaptations depending on the targeted matrix and complexity of the analyzed toxin mixture. Furthermore, crucial analytical parameters, like limits of detection and quantification, reproducibility and measurement uncertainty, have to be safeguarded and well-defined to ensure the reliability of the method.

As microcystins are currently the most observed cyanotoxins in Europe, multiple methods were developed to quantify eight microcystins and nodularin in different environmental and food matrices using a UHPLC-MS/MS approach. Methods were developed to evaluate the toxins in environmental water and collected cyanobacteria biomass. Moreover, methods for drinking water and food matrices (specific methods for fruits and  vegetables, culinary herbs, algal-based food supplements, fish, and milk) were also developed.

After these methods were successfully developed and validated, they are now application-ready for monitoring and research. Dealing with the differences in matrix effect through adaptation of pH, dilution of extracts, the application of solid phase extraction and optimization of the UHPLC gradient was vital to successfully develop methods in the different matrices. The finalized methods are applicable for the quantification of toxin levels corresponding to relevant (suggested) guideline values, like those provided for drink and recreational water, and food supplements.