Separation and preconcentration of trace elements

In situ growth of Fe3O4nanoparticles for dispersive magnetic micro-solid phase extraction of cadmium followed by ETAAS detection

“…The resulting mechanism depends on the nature of the solid phase employed for extraction. 31 In the case of nanosized solid phases, the most probable mechanisms are surface adsorption or occlusion. In order to estimate the co-precipitation mechanism for Cd, we used two approximation laws: the Berthelot-Nernst law, eqn (1) (occlusion) and the Doerner-Hoskins law, eqn (2) (surface adsorption): log…”

“…The equation for the Berthelot- that can be retained by the interaction with Fe 3 O 4 NPs through an ion-exchange reaction along with surface hydrolysis. 31 Interference study…”

Analytical Chemistry of Element Determination (Non‐Nuclear and Nuclear)

“…The text is preceded by a strange table of contents that, for each chapter, omits titles and authors and provides incomplete pagination. Several relevant chapters are on systematic errors in trace analysis (Tölg and Tschöpel 1994); sampling and sample preparation (Woittiez and Sloof 1994); separation and preconcentration of trace elements (Terada 1994); atomic absorption spectrometry (Pelly 1994); and instrumental and radiochemical NAA (Alfassi 1994b, c). The book on environmental chemical analysis by Kebbekus and Mitra (1998), contains one chapter on spectroscopic methods with brief sections on background to spectroscopy, LAS, AAS, ICPAES and XRF.…”

“…A variety of approaches may be employed for isolation/separation and concentration and those tabulated by Ihnat et al (2001) include: no preconcentration or isolation/separation procedures applied; physico-chemical separation/preconcentration; hydride generation; cold vapor generation (Hg); solvent extraction including complexation; precipitation, coprecipitation; chromatography including extraction, ion exchange, adsorption; distillation, volatilization; electrolysis, electrodeposition. Terada (1994), in a chapter on separation and preconcentration of trace elements, presents a good, detailed treatment of separation and concentration procedures. The following section headings and subheadings indicate the wide ranging techniques available and indicate his thorough coverage: * separation and preconcentration of trace elements by coprecipitation (coprecipitation with inorganic precipitants/collectors, coprecipitation with organic precipitants/collectors * separation and preconcentration of trace elements by flotation (ion flotation; flotation after coprecipitation); * separation and preconcentration of trace elements by solvent extraction (extraction of metal chelates; extraction of ionic associates; extraction of complex metalloacids; extraction involving solvation/ coordination by organic compounds; extraction with amines); * separation and preconcentration of trace elements by ion exchange (ion-exchange resins[types: cation exchangers (strong acid, weak acid), anion exchangers (strong base, weak base), chelating resin]; preconcentration; ion chromatography); * separation and preconcentration by sorption [activated carbon; porous polymers (styrene-divinylbenzene copolymers; polyurethane foams; poly(chlorotrifluoroethylene) (PCTFE) resin); complex-forming adsorbents (reagent-immobilized silica gel or glass beads; reagent-loaded silica gel or glass beads);natural polymers (cellulose; chitin and chitosan)].…”