Development of DGT technique for determination of mercury in various matrix

abstract

English

Diffusive gradient in thin films technique (DGT) has become a routine tool for determination of labile metal species or other metal species. Since the introduction of DGT technique in 1995 [1], more applications possibilities of this technique appeared. Because the concentration of mercury in analysed samples is usually very low and the matrix of the analysed sample is often very complex, the preconcentration capability and capability of analyte separation from sample matrix are the major advantages of DGT technique. However, the application of DGT technique for determination of mercury requires special types of sorption gels, because the commercially available sorbents commonly used in DGT technique are not able to effectively bind mercury associated with some natural ligands such as chlorides, humic acids etc [2]. Some of applicable sorbents cannot be used because of their high cost or inconvenient particle size. In the presented work new sorption gel for DGT technique with thiol functional groups was prepared by immobilization of L-cysteine on amino-modified silica via reaction of glutaraldehyde. The prepared sorbent was characterized by FTIR-DRIFT technique and the presence of immobilized cysteine molecules was confirmed by characteristic bands in obtained spectra. In the further synthesis of new resin different concentrations of L-cystein were used resulting into different load of thiol groups on sorbents. Sorbents prepared from different Lcystein concentrations were characterized by CS elemental analysis. Finally, sorbent containing the highest concentration of thiol functional groups was incorporated into the polyacrylamide gel from which the sorption gel discs for DGT technique were cut and performance of DGT sampling units with new sorption gel was tested in the laboratory.

DGT, mercury

DIVIŠ, P.; REICHSTÄDTER, M.

2. 10. 2017

261