Quality Control and Evaluation Criteria for Enantiomer-Selective Separation Methods in Environmental Sciences

For the quantification of trace amounts of pollutants, complex validation protocols for method validation and quality control (QC) are required today in order to provide reliable results suitable for further statistical treatment in national and international surveys and pollutant monitoring programmes. National and international protocols today are in place to ensure the expected data quality in environmental pollutant monitoring and research. Due to these internationally accepted measures, the unequivocal identification of the respective compounds is expected to be confirmed and documented in scientific publications and official reports (Asmund and Cleemann 2000; Viswanathan and Salmon 2000; Asmund et al. 2004; Xu et al. 2013). These QC criteria need also to be documented in comprehensive accreditation protocols and are today a mandatory part of national and international pollutant monitoring programmes. Major QC parameters like instrument response, linear range, relative compound-specific recovery rates, non-linear responses, the limit of detection (LOD), method detection limit (MDL), limit of quantification (upper and lower LOQ) and contamination control (blank values), etc., are an integrated part of the quantification procedure together with the instrument-specific identification parameters (i.e. m/z, retention time windows, etc.). Usually, the methods are associated with compound-specific overall uncertainties which in turn can be used for further statistical assessments and data comparison (Schofield et al. 2001). For more in-depth information on method validation and quality control in environmental analytical chemistry, we refer to the following books (Kateman and Pijpers 1981; de Bievre and Gunzler 2005; Majcen and Taylor 2010; Matsuda 2012), a selection of comprehensive reviews (van Zoonen et al. 1998; Indrayanto 2018; Sajnog et al. 2018) and the updated web-page of EuraChem, the European network of organisations, aiming at establishing a system for the international traceability of chemical measurements and the promotion of good quality practices. (retrieved 10.05.2020: https://www.eurachem.org/index.php/publications/mnu-rdlst/130-rdl-validation=).