“…Lipophilic species are mostly neutral with hydrophobic properties, owing to the alkyl groups . Chromatographic approaches, like ion-pairing reversed-phase, ion-exchange, ion-exclusion, and reversed-phase chromatographies, are reported to facilitate speciation of arsenicals in marine sample extracts, owing to variabilities in their physicochemical properties. , For example, at pH 7, MMA at p K a = 2.6 and DMA at p K a = 6.1 are anions and arsenocholine (AsC), tetramethylarsonium ion (TETRA), and trimethylarsine oxide (TMAO) at p K a = 3.6 are cations, while arsenobetaine (AsB) at p K a = 2.18 is zwitterionic. , Methylated arsenicals and AsSugars have been successfully isolated on anion-exchange (AE) columns, , while cation-exchange (CE) columns provide effective isolations for AsB, AsC, DMA, TMAO, TETRA, and DMAA. , AsLipids, however, require additional separation, using RP-LC typically with a C8 or C18 column. ,, …”