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Author Laquintana Alonso, Diego |
Abstract Cyanobacteria are gram negative prokaryotic microorganisms that can thrive in almost all ecosystems. They occur naturally, but there are three factors that increase the abundance of cyanobacterial blooms: eutrophication of the water, temperature, and light exposure. Cyanobacteria produce sec-ondary metabolites known as cyanotoxins which are toxic to both humans and animals, causing illness or even death. Cyanotoxins can be classified in diverse groups depending on the effect that they have in living organisms. Hepatotoxins and neurotoxins are the two main groups from which microcystins and anatoxins are the principal representatives respectively. Due to climate change and the increas-ing temperatures, cyanobacterial blooms presenting cyanotoxins are becoming more abundant worldwide. This presents a risk for both drinking and recreational water. Therefore, specific, and sen-sitive analytical methods for the identification and quantification of cyanotoxins are required. This project focuses on the development and optimization of an analytical method using liquid chroma-tography coupled to triple quadrupole mass spectrometry (LC-MS/MS), a highly selective and sensi-tive technique, for the determination and quantification of five cyanotoxins: anatoxin-a, microcystin-LR, microcystin-RR, microcystin-YR and microcystin-LA, using nodularin as an internal standard. The method is based on direct water injection, minimizing the sample preparation steps, and increasing sample throughput and analyte recovery. The optimization was carried out by evaluating several pa-rameters such as specific transitions or fragment ions, compound and source parameters, injection volumes and the use of filters. Once optimized, the method was validated. Good linearity, accuracy and precision were observed and detection limits around 1 μg/L were achieved for the five cyanotox-ins. Lastly a series of environmental samples were analysed in which cyanotoxins were below LOD, but an interference was identified, which could be differentiated from anatoxina. |
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Director Ortiz Almirall, Xavier |
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Degree IQS SE - Undergraduate Program in Chemistry |
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Date 2022-06-18
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