A direct solid sampling approach for fluorine determination via ETV/ICP-QQQ-MS

Abstract

Organic fluorine sum parameters are used to detect F-containing pollutants, e.g., per- and polyfluoroalkyl substances (PFASs), in the environment, within materials, or for monitoring technical processess, e.g., thermal decomposition of PFAS during municipal waste incineration. However, established approaches determining the extractable organic and adsorbable organic fluorine content (EOC and AOC) require laborious and error-prone sample preparation. We report a solid sampling-electrothermal vaporization (ETV) method for direct fluorine measurement based on the formation of [¹³⁸Ba¹⁹F]⁺ with an inductively coupled plasma-triple quadrupole-mass spectrometer (ICP-QQQ-MS). Method development involved the instrumental setup for Ba introduction and fluorine-specific tuning of lens and collision-reaction cell (CRC) parameters. An inorganic fluorine fraction was detected in a cyclonic dust sample from a municipal waste incineration plant as a peak above a broad background signal. The content was estimated through standard addition using a NaF solution to 2300 µg g⁻¹. With a limit of detection (LOD) of 130 µg g⁻¹, which was below the reported value for an electrothermal vaporization/inductively coupled plasma-mass spectrometry (ETV/ICP-MS) approach, acquiring [¹⁹F]⁺. The method's potential for fractionation analysis was demonstrated by analyzing polytetrafluoroethylene (PTFE) powder.