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Solid-Phase Extraction on Alkyl-bonded Silica Gels in Inorganic Analysis

“…Such flow systems have the following advantages over off-line modes: high sampling frequency and throughput of analysis (one analytical separation/determination run takes 10 -200 s), low consumption of reagents and sample (0.1 -2 ml), decreased risk of sample contamination due to the use of totally closed systems, etc. [111][112][113][114][115][116][117][118][119][120][121] For example, combining a micro-scale flow-injection (FI) preconcentration system on-line with electrothermal atomic absorption spectrometry (ET AAS) resulted in a powerful integrated system that permitted fully automatic operation, avoiding time-consuming manual work and improving the accuracy and precision. [112][113][114] Different microcolumns packed with as small amounts of C18-boned silica gel as 15 µl and eluate volumes of 40 µl were used in such systems.…”

Determination of platinum by atomic absorption spectrometry with chromatographic preconcentration from aqueous solutions

“…The use of modifiers cannot fully eliminate the inhomogeneity of sample vapors in the atomizer. In addition, the separation of analytes from the matrix significantly simplifies the calibration of the atomic absorption spectrometer.Although methods for the separation of platinum and platinum-group metals have long been sought, the number of methodological solutions suitable for ETAAS is limited [2]. The majority of procedures for the extraction and adsorption preconcentration of platinum-group metals is based on the use of extractants and adsorbents bearing nitrogen-and sulfur-containing functional groups; these reagents cannot extract analytes from aqueous solutions of the composition acceptable for ETAAS [3].…”

“…In addition, most procedures for determining platinum were developed for hydrochloric acid and chloride solutions. Electrothermal atomic absorption spectrometry is no exception [2]. For this method, extraction chromatography using oxygen-containing extractants as the stationary phase offers most promise as the preconcentration method.…”

“…However, in the majority of papers on the determination of platinum-group methods by atomic absorption spectrometry, e.g., in [1][2][3], it was noted that matrix components significantly affect the analytical signal, especially when the concentration of matrix components is several orders of magnitude higher than that of the analyte. This effect must be studied and taken into account in each particular case.…”

Preconcentration of Cadmium and Zinc on a Chelating Sorbent and Their Determination by Flame Atomic Absorption Spectrometry

“…The main procedures of the spectrometric determination of heavy-metal ions do not always meet modern requirements for the detection limit and require their separation from concomitant elements. To increase the determination sensitivity, combined methods that involve preconcentration appear promising.The use of chelating polymer sorbents (PCSs) allows one to perform individual or group preconcentration of microelements from large volumes of solutions of complex composition, to decrease the detection limit, and to eliminate or significantly reduce the influence of macrocomponents, which improves the reliability and accuracy of analysis [3-6].As a rule, chemically modified, complexing sorbents based on cellulose, polystyrene, silica, porous glass, polyurethane foam, and acrylic fiber; ionexchangers chemically modified with complexing reagents highly selective for the recovered elements; aluminum oxide; and, less commonly, commercial anion and cation exchangers are used for element preconcentration [10][11][12][13][14]. However, we have found no data on the analytical application of polybutadienebased sorbents.…”