Magnetic solid phase extraction as a valuable tool for elemental speciation analysis

Despite the increasing number of articles on trace elemental speciation with magnetic solid phase extraction (MSPE), there are no dedicated reviews that cover the group of elements with most related literature, and hence the need for this one. This article provides a comprehensive review of the relevant literature related to Cr, Hg, As, Se, and other metals and metalloids with a special focus on the sorbents, species determined, interactions involved between them and applications, mainly to environmental, food and biological samples. Moreover, this review covers the analysis of metallic nanoparticles (NPs) and the ions that are generated from them as a new facet of speciation. The analytical performance of the methods is addressed from a presentative and critical point of view and, finally, future trends and the related challenges are shown.