Development of an interface for the on-line coupling of HPLC and HR-cs-GFAAS for fluorine speciation analysis

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In the field of pharmaceuticals fluorination of organic molecules leads to new, promising properties (e.g. changed metabolism of drugs). Fluorinated substances are also beneficial in the area of technical applications.Growing production volumes and application fields lead to an increase of these substances within the (aquatic) environment. Due to their new properties a different distribution, speciation as well as bioavailability in the environment is most likely.Analytical techniques comprising high sensitivity, fluorine-selectivity as well as a fluorine species-unspecific detector response are missing. Thus, the main objective of this project is the development of a complementary method, which enables fluorine-speciation analysis for various applications including analysis of (aquatic) environmental samples to assess the load situation, distribution and bioavailability as well as speciation of fluorinated compounds. Further fields that would profit from such method are pharmaceutical, medical as well as material sciences.High resolution-continuum source -graphite furnace atomic absorption spectrometry (HR-cs-GFAAS) enables fluorine detection in the molecular absorption (MAS) mode. However, up to now HR-cs-GFAAS has not been coupled on-line with a separation systems (e.g. HPLC), which is mandatory for fluorine speciation analysis.Thus, the main objectives of this project are:I) Coupling-interface designA new interface comprising a micro-droplet generator for the on-line coupling of nanoHPLC with HR-cs-GFMAS will be designed, constructed and installed. In addition the adaption and optimization of the graphite furnace heating program for transient signals as well as raw data extraction and data evaluation will be tackled.II) Fluorine SpeciationThe parameters of the newly developed interface for fluorine speciation analysis will be optimized with fluorinated test substances. Furthermore, a nanoHPLC separation method for several fluorine-containing organic test substances will be developed to investigate the species-unspecific response of GFMAS in dependence of organic solvent gradients. The developed system will be validated in terms of LOD, LOQ, linearity, robustness, intra- & inter-day reproducibility.III) Real sample analysisWater sample preparation as well as sample/species enrichment strategies for fluorinated organic substances and related species with regard to expected low environmental concentrations will be developed and optimized. Water samples from waste water treatment plants as well as surface waters will be sampled and analyzed by means of nanoHPLC/HR-cs-GFMAS and complementary nanoHPLC/ESI-Q-ToF-MS to unravel molecular structures of the detected fluorine species.IV) Suitability for routine analysisSimplification of the newly developed interface is planned to obtain an applicable method for fluorine speciation which is transferable to other laboratories as well as further fields of application.