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Small is beautiful PRAKTYKA
THE TECHNIQUE OF SPE IN INDIRECT DETERMINATION OF THALLIUM SPECIATION
Thallium (I) and thallium (III) are significantly different in terms of toxicity so it is important to determine the speciation
of thallium. Chromatographic methods of speciation are now often replaced by solid phase extraction (SPE), because
of lower costs and shorter time of separation. In the SPE technique analytes are separated from the sample matrix to a
sorbent packed in polyethylene or polypropylene columns. The solid phase may also be placed between teflon disks.
In case of thallium speciation both organic (e.g. nitrocellulose) and inorganic sorbents (e.g. oxides, carbon nanotubes)
are applied. Commercially available columns are relatively cheap. The extraction is selective and high recoveries are
obtained. SPE can be coupled with a variety of detection methods. Unfortunately, during the experimental work one
can obtain lower preconcentration and separation effects than it appears from the literature data, because sorbents
often have unrepeatable stability or sorption capacity.
ANALITYKA – NUMER 2, ROK (XVI) 2015 35
