title: A review of recent trends in electrospray ionisation-mass spectrometry for the analysis of metal-organic ligand complexes.
abstract: Electrospray ionisation-mass spectrometry (ESI-MS) is used in a wide variety of fields to examine the formation, stoichiometry and speciation of complexes involving metals and organic ligands. This article reviews the literature in this area over the past 5 years, examining trends in ESI-MS use and novel applications that enhance the scope of the technique. ESI-MS can provide direct information on changes in speciation with metal:ligand ratio and pH, identify metal oxidation state directly and allow insight into competitive interactions in ternary systems. However, both the instrumental set-up and artefacts in the electrospraying process can affect the species distribution observed, and changes in solution chemistry can affect the relative ion intensity of species. Therefore, ESI-MS data is at its most powerful when corroborated by data from other experimental techniques, such as pH potentiometry. The challenges in interpreting direct ESI-MS data quantitatively are discussed in detail, with reference to differences in the ion intensities of species, signal suppression and quantifying species distributions. The use of HPLC-ESI-MS is also reviewed, highlighting challenges and applications. Overall, the need for more standard reporting of quality assurance data is discussed, to strengthen the applications of ESI-MS to metal-organic ligand complexes further.
authors.affiliation: Biogeochemistry Research Centre and Consolidated Radioisotope Facility (CORiF), School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK. Mkeith-roach@plymouth.ac.uk
authors.forename: Miranda J
authors.initials: MJ
authors.lastname: Keith-Roach
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods / Q000639:trends; D006863:Hydrogen-Ion Concentration; D008024:Ligands; D009942:Organometallic Compounds / Q000032:analysis* / Q000737:chemistry / Q000145:classification; D010084:Oxidation-Reduction; D011786:Quality Control; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods* / Q000639:trends*
chemical_list: D008024:Ligands; D009942:Organometallic Compounds