|Abstract Title:||Automated Sample Preparation for Determination of Perfluoroalkyl and Polyfluoroalkyl Substances PFAS in drinking water according to USEPA 537.1 and European Regulation|
|Presenter Name:||Mrs Angelika Koepf|
|Co-authors/Co-presenters:||Mr Sebastian Wierer|
Dr Uwe Aulwurm
Mr Matthew Giardina
Dr Hans Rainer Wollseifen
Abstract Information :
Over 60 years, perfluoroalkyl and polyfluoroalkyl substances PFAS are used in everyday materials with nonstick coatings. They get into the environment during manufacturing process, use and disposal for these. Sewage plants are mostly not able to purify wastewater with PFAS, so it accumulates in sewage sludge, that is often used in agriculture. The chemicals reaches the groundwater and get absorbed again through plants. Humans mostly incorporate PFAS through food or contaminated drinking water. PFAS can be found globally in the environment, wildlife, human tissues and blood and are considered as cancerogenic and to cause other severe health problems. The topic of PFAS is as present as ever, since the latest EU Drinking Water Directive, was entered into force on January 12th 2021, with new changes in regards of PFAS as well as the USA updated their respective regulation US EPA 537.1 lately.Analytically, the determination of PFAS using LCMSMS methods is challenging and not yet harmonized as is for other POPs such as PCDDPCDF but the sample preparation holds the same challenges for laboratories independent of regional regulation. Besides the burden to spend a lot of manual work time in SPE cleanup with subsequent concentration, a key challenge is to keep the background of analytes as low as possible as PFAS are found ubiquitously. Additionally, fluorocarbon materials, commonly used in laboratory systems, are prone to a release of small amounts of PFAS that significantly increase background levels. Therefore, any fluorocarbon materials of the FREESTYLE PFAS system were consequently removed and replaced by polyethylene or polypropylene, respectively. Environmental e.g. soil, water, as well as biota e.g. animal tissure, food, PFAS samples can be cleaned on SPE with FREESTYLE fullyautomated. With the addition of a subsequent automated concentration, it is simple to overcoming this both major daily shortages. PFAS compounds of existing DIN 3840742 and the analytes of updated USEPA 537.1 were processed on a FREESTYLEPFAS XANA system. Results will be shown that all compounds are recovered and do not adhere to the system. For prove of the background free sample preparation, PFAS background levels of neat solvents, spiked and pure samples were compared. Confirmation of all Validation requirements for USEPA 537.1 will be presented. Due to the specifically designed PFAS system, which is virtually free of fluorocarbon compounds, any blank values coming from the system are minimized. This was shown by PFAS background measurements of the instrument that were equal to the values obtained with neat solvent. Furthermore, by the application of fully automated parallel sample preparation, multiple samples can be processed at the same time on the FREESTYLE XANA system. Thus, a high sample throughput at low demand of personnel resources is obtained. Adding the automated DEVA vacuum Centrifuge, that allows for unattended parallel concentration of the collected PFAS Eluate, allows analyte protecting concentration step, that is stopped reliable before dryness due to a special designed Sensor. The analytical targets of the applied method were found with good recoveries and very low standard variations resulting from the reliable and robust automation.