Implementatie en optimalisatie van de TOP analyse voor PFAS met een UHPLCMS/MS
Implementatie en optimalisatie van de TOP analyse voor PFAS met een UHPLCMS/MS
Samenvatting
Perfluoro alkyl substances (PFAS) are substances in which contain multiple fluorine atoms. The fluorine atoms are bound to, often, long carbon chains. PFAS are able to repel dirt and water, due to the large amount of fluorine atoms in the molecules. PFAS are also chemically and thermally stable. Many of these PFAS are suspected of, or familiar with, carcinogenic and/or reprotoxic effects and are known to bioaccumulate. These properties are which makes PFAS – potentially – dangerous.
In this study, PFAS are subdivided into three substance groups. These substance groups consist of perfluoro carboxylic acids (PFCA); perfluoro sulfonic acids (PFSA) and PFAS precursors. PFCA and PFSAs are substances with fully fluorinated carbon chains which contain a carboxylic acid (PFCA) or sulfonic acid (PFSA). PFAS precursors are PFAS compounds which can be oxidized to PFCA and/or PFSAs. Due to the – potentially – dangerous properties of PFAS, 31 different PFAS compounds are monitored in surface water by Rijkswaterstaat using an SPE-LC-MS/MS method. In addition to these 31 different PFAS compounds, there may be many more PFAS compounds present in the surface water. However, it is unknown which PFAS compounds and how many more of these compounds are present in surface water. To visualize the amount of hidden PFAS compounds, the Total Oxidizable Precursor (TOP) method can be used. The TOP-method oxidizes all PFAS precursors to PFCA and / or PFSAs. After oxidation of the PFAS precursors, the PFAS can be analysed with the PFAS target analysis of Rijkswaterstaat. The determination of present unknown PFAS precursors in surface- and saltwater, can be achieved by comparing PFAS concentrations of samples to which the TOP-method is and isn’t applied. When the TOPmethod is applied, it is impossible to identify the PFAS precursors from which the PFCA and/or PFSA’s were oxidized.
In this study the TOP-method was used to demonstrate the presence of unknown PFAS precursors. The TOP-method was implemented and optimized by using PFAS added blanks. Surface water samples using the TOP-method contained higher PFAS concentrations compared to samples that were analysed via the PFAS target analysis. The TOP-method has not yet been optimized for saltwater, more research is needed to achieve an optimal TOP-method for salt water.
Organisatie | Hogeschool Leiden |
Opleiding | Chemie |
Afdeling | Faculteit Techniek |
Datum | 2019-05-17 |
Type | Bachelor |
Taal | Nederlands |