Substances that will forever be present around us - PFAS
There is increasing concern about the persistence and effects of per- and polyfluorinated alkyl substances (PFAS) in the environment. WHAT IS PER AND PFAS? Per- and polyfluoroalkyl substances (PFAS) are a large group of anthropogenic chemicals (CnF2n+1COOH) used in many commercial products with various applications such as polymers, fire-resistant polyurethane foam, cookware, food packaging, and textiles.
Since these chemicals are very stable and resistant to degradation while also being toxic to humans, the presence of PFAS in our environment raises serious global concerns.
Due to their wide use, PFAS have been detected in food, water, wastewater, soil, and human blood samples.
The Ministry of Health published a new amendment to the Regulation on compliance parameters, analysis methods, and monitoring of water intended for human consumption (Official Gazette 64/2023), defining the maximum allowable concentration (MAC) of PFAS for assessing the quality of water intended for human consumption as well as the measurement uncertainty of methods for chemical analysis and water condition monitoring.
Allowable Concentration for PFAS
The total maximum allowable concentration for PFAS amounts to 0.5 µg/L and refers to the sum of all perfluoroalkyl and polyfluoroalkyl substances, while for the sum of PFAS, the MAC is 0.1 µg/L and applies to PFAS considered a concern regarding water intended for human consumption, the perfluoroalkyl part with three or more carbon atoms (i.e., – CnF2n-, n ≥ 3) or the perfluoroalkylether part with two or more carbon atoms (i.e., – CnF2nOCmF2m-, n and m ≥ 1).
In the latest scientific opinion of the European Food Safety Authority (EFSA), four PFAS - PFOS, PFOA, PFHxS, and PFNA - were assessed.
Currently available methods for detecting PFAS include gas or liquid chromatography (GC or LC) with tandem mass spectrometry (MS/MS). The methods are expensive and time-consuming but are selective and sensitive.
Methods for Detecting PFAS
Detection of PFAS is challenging because these compounds lack chromophores or electroactive groups and are therefore not optically or electrochemically active.
Therefore, methods such as UV-Vis spectroscopy or electrochemistry cannot be directly applied to measure these compounds. Low legal limits pose additional challenges in their detection and quantification.
The distribution of PFAS, toxicity, and removal and remediation techniques are still widely studied in the environment, so information about these contaminants, also known as "forever chemicals," is increasingly published in the scientific literature.
Given their ubiquity in the environment, removing them from the environment is an important research area. Environmental samples contain residual concentrations of PFAS, and their number is extremely large (about 15000). For these reasons, there is a need for an even more selective and sensitive analysis method.
Determination of 24 per- and polyfluorinated alkyl substances (PFAS) in food and environmental samples
Sample Control laboratory has a validated method for determining 24 per- and polyfluorinated alkyl substances (PFAS) in food and environmental samples using liquid chromatography with a mass detector (UPLC-MS/MS).
Figure 1. PFAS standard at a concentration of 10 µg/L
Scientific Seminar: CHALLENGES AND SOLUTIONS IN MICROPLASTICS ANALYSIS
Join us at the scientific seminar "Challenges and Solutions in Microplastics Analysis", organized by Sample Control LLC and the Department of Medical Biochemistry and Hematology of the Faculty of Pharmacy and Biochemistry, University of Zagreb.
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