Speciation single particle

Neubauer, K. R., M. V. Johnston, and A. S. Wexler, Chromium Speciation in Aerosols by Rapid Single-Particle Mass Spectrometry, Int. J. Mass Spectrom. Ion Processes, 151, 77-87 (1995). 

Control of the particle valence/conduction band oxidation/reduction potential is not only achieved through a judicious choice of particle component material band edge redox thermodynamics of a single material are also affected by solution pH, semiconductor doping level and particle size. The relevant properties of the actinide metal are its range of available valence states and, for aqueous systems, the pH dependence of the thermodynamics of inter-valence conversion. Consequently, any study of semiconductor-particle-induced valence control has to be conducted in close consultation with the thermodynamic potential-pH speciation diagrams of both the targeted actinide metal ion system and the semiconductor material. 

A number of speciation schemes have been devised whereby a range of analytical techniques is applied to a single sample in order to provide as much information as possible about the different species. The first reasonably comprehensive scheme was developed by Batley and Florence [32]. The scheme has been applied mainly to the speciation of metals in sea water. The broad conclusion of their studies is that lead is associated largely with colloidal inorganic particles [33]. 

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