Critical review on analytical methodologies for highly polar organophosphate pesticides in environmental samples

Highly polar pesticides include compounds such as glyphosate and its metabolite AMPA, glufosinate and its metabolite MPPA, phosphonic acid, ethephon, and fosetyl-Al. Their unique physicochemical properties —such as low octanol/water coefficient (log K ow < 0), poor retention on reversed-phase columns, strong binding affinities to matrix components, and poor ionization and fragmentation efficiency in mass spectrometry— make their residue determination problematic. Consequently, the development of suitable analytical methods remains highly challenging. This review provides a comprehensive literature search of the most recent analytical methodologies for the determination of these compounds in environmental samples, along with a critical discussion of key issues related to their residue determination in different sample matrices. With a focus mainly on liquid chromatography-mass spectrometry methods, the different steps of the analytical workflow are discussed, including sample treatment, chromatographic separation and detection. At each step, the review highlights analytical challenges and pivotal aspects to offer an in-depth understanding of the analytical determination of these highly polar pesticides.