Development of DGT technique for determination of hazardous metals in food matrixes: Step I - preparation of sorption gel

abstract

English

Diffusive gradient in thin films technique (DGT) has become a routine tool for speciation analysis of metals in natural waters, soils and sediments. 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 are not 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 presence of cysteine was confirmed by many absorption bands in spectre. In synthesis of following sorbents, different concentrations of L-cysteine were used resulting into different load of thiol groups content on sorbents. These sorbents were characterized by CS elemental analysis technique and after optimalisation of L-cysteine concentration, the sorbent was incorporated into polyacrylamide hydrogel layer. In the further work the performance of prepared sorption gel for determination of mercury in food matrixes by DGT technique will be tested.

DGT, mercury, glutaraldehyde, cysteine

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

23. 3. 2017

Vysoké učení technické v Brně, Fakulta chemická, Purkyňova 464/118, 612 00 Brno

978-80-214-5488-0

Studentská odborná konference Chemie je život 2017, Sborník abstraktů

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