PREPATARION OF NEW SORPTION GEL DISCS FOR DETERMINATION OF MERCURY IN FOOD MATRIXES BY DIFFUSIVE GRADIENT IN THIN FILMS TECHNIQUE

abstrakt

angličtina

Diffusive gradient in thin films technique (DGT) has become a routine tool for speciation analysis of metals in natural waters, sediments and soils. Since its introduction in 1994, more application possibilities appeared - one of them in food chemistry e.g. lead determination in soy sauces. Since the concentration of toxic metals in food matrixes is usually very low, the application of DGT technique with appropriate gel discs is very suitable for their determination. Not only that DGT technique extracts metals from the food matrixes, it has also allowed to determinate very low concentrations of metals due to its preconcentration ability. The usage of DGT technique for determination of some metals in food matrixes requires special types of sorption gel discs, because the commercially available gel discs aren't able to effectively bind these metals from matrixes with high concentration of natural ligands, such as chlorides or organic acids. A typical example of this occurrence is the determination of mercury by DGT technique. In the presented work new sorption gel disc with thiol functional group for DGT technique was prepared by immobilization of L-cysteine on amino-modified silica via reaction with glutaraldehyde. The prepared sorbent was characterized by FTIR-DRIFT technique and also by elemental analysis techniques, incorporated into polyacrylamide hydrogel layer and its performance for determination of mercury in food matrixes by DGT technique was tested.

DGT, sorption, mercury

REICHSTÄDTER, M.; DIVIŠ, P.; POŘÍZKA, J.

19. 7. 2016