ESR3 Massimo Picardo

Project: Non-target screening of natural toxins in surface water reservoirs

Principal supervisor: Dr. Marinella Farré

Intro to project: 

Acquatic organisms are naturally present in the environment, an important group of these concerns cyanobacteria. They have the distinction, from other microorganisms, of being the oldest known microorganisms, more than 3.5 billion years old. Cyanobacteria are one of the largest and most important groups of bacteria on earth, they produce a variety of unusual metabolites wich function is still not clear, a large group of these metabolites includes toxins and other pharmaceutically active substances. Natural toxins are composed of different groups that could be classified by the chemical, physical properties, toxicity and producing bacterias. In literature, most reported toxic compounds in environmental samples are cyanotoxins of wich are reported different compounds and congeners: hepatotoxic peptides called microcystins (that concern about of 80 congeners) and nodularins. Neurotoxic alkaloids like anatoxins and saxitoxins, cytotoxic and dermatotoxic alkaloids of wich they consider aplysiatoxins and lyngbiatoxins, and more other compounds. Since cyanotoxins have been recognized dangerous and harmful for humans, many authors have conducted studies on occurrence and distributions in environmental sample, confirming the natural presence in water. In order to qualify and quantify toxins content, lots of analytical methods have been reported. The aim of this project could be divided into more steps. In a first stage, we want to build a library with all known and unknown toxins mass spectra reported in the literature, in order to allow a fast and efficient determination. Then we planned to develop and optimize an HPLC-HRMS method to permit an accurate determination of the different compounds, a previous purification and concentration step using solid phase extraction (SPE) is planned. Following steps consider the characterization of new toxin congeners, different sites sampling, photo and chemical oxidation, and concentration decreasing strategies. The plan is not yet definitive and has to be discussed more.