Overcoming the challenges of "difficult to analyse" compounds and matrices

ACS 2023 -- Analytical chemists often face hurdles in developing reliable residue methods due to a range of scientific challenges. These can typically include poor instrument response, poor stability, unfavourable chemical properties, lack of selectivity or the need to quantify at very low concentrations. Furthermore, some sample matrix types can also present problems due to the nature of the co-extracted material that may interfere with the quantitation technique. There may also be restrictions as to the approaches used in the case of adhering to previous studies, specific sponsor needs or "official" method requirements as well as reproducing methods validated in different laboratories using alternative equipment. Analytical chemists must be thoughtful and creative in overcoming these challenges in order to arrive at a robust and reliable methodology than can meet the necessary validation criteria and be used routinely for study sample analysis.