Preconcentration group separations

Inorganic arsenic and antimony compounds can be preconcentrated or separated by PEEK that contain pendant carboxyl groups [93]. This enrichment is useful in the course of final analysis by microwave plasma atomic spectrometry. The modified PEEK is used in a flow injection column adsorption preconcentration before the spectrometer. 

The effect of pH of the sample, eluent flow rate, and the amount of silica on sorption and elution experimental parameters were investigated by a new phase, which was synthesized from a high surface area silica gel with a 3-trimethoxysilyl-l-propanol group. In addition, both batch and column techniques were applied to identify the characteristics of this modified silica and its application to the preconcentration and separation of Co and Ni prior to determination by graphite furnace atomic absorption spectrometry (GFAAS). ""... 

A new silica gel-based chelating sorbent, with thiourea as a functional group, was used for the FI online preconcentration and separation of trace levels of silver, gold, and palladium. The selected metal ions were adsorbed onto a column packed with thiourea-modified silica gel (TuSG). The sorbent exhibited excellent stability and the sorption properties of TuSG did not change after 1000 cycles of use. The selected metals in a secondary nickel alloy, an anode slim, an electrolytic solution, and three national certified ore samples were determined satisfactorily using the proposed method. ... 

Fedotov, P.S. Maryutina, T.A. Grebneva, O.N. Kuz min, N.M. Spivakov, B.Ya. Use of countercurrent partition chromatography for the preconcentration and separation of inorganic compounds group extraction of Zr, Hf, Nb, and Ta for their subsequent determination by inductively coupled plasma atomic emission spectrometry. J. Anal. Chem. 1997,52,1034. 

Solvent extraction is also suitable for group separation and preconcentration in many analyses. The basic technique can be applied in either a liquid-liquid contact mode or using extraction chromatographic techniques. When the sample is not too complex and... 

Analysis to determine the rare-earth content of materials can have many different objectives. Successful separations require a judicious combination of appropriate group separation/preconcentration, separation of individual members of the series, and the proper detection technique. Recent reviews that are readily available in the chemical literature offer compilations of cookbook methods for conducting analyses of samples of different types. In the following sections, we will offer a brief summary of preferred methods for specific types of analyses and provide appropriate literature references for the reader to pursue for details beyond those offered herein. The emphasis of this section will he on the literature covering the period 1990-1997, which has not been discussed in previous English-language reviews of the subject. Some earlier reports describing important fundamental advances in lanthanide separations will be included. 

Yan, X.-P, Kerrich, R., and Hendry, M. J. (1999) Row injection on-line group preconcentration and separation of (ultra)trace rare earth elements in environmental and geological samples by precipitation using a knotted reactor as a filterless collector for inductively coupled plasma mass spectrometric determination. J. Anal. At. Spectrom., 14,215-21. 

Although chelating resins were widely used to preconcentrate and to separate elements and group elements in seawater [209], the first report on related HPCIC was made by Moyers and Fritz [210] in late 1977. The main principles of HPCIC were later formulated and studied by Timerbaev et al. [211] and Jones et al. [212]. 

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