A Functionalised Carbon Fiber for Flexible Extraction and Determination of Hg(II) Using Au(NP)-Thiol-CF Inductively Coupled Plasma Mass Spectrometry

Abstract

This work illustrates the improvement in ultra-trace Hg(II) determination in water based on a novel flexible extraction and preconcentration technique (FEPT). This method focuses on the covalent functionalisation of carbon fibre (CF) based on (3-mercaptopropyl)trimethoxysilane. The functionalisation of CF is carried out in two steps: functionalising the surface of CF using acid treatment to obtain hydroxy and carboxyl groups on the surface, followed by a condensation reaction between the carboxyl or hydroxy groups on the carbon (CF-OH) and (3-mercaptopropyl)trimethoxysilane to form mercapto-CF (CF-SH). FTIR, EDX, SEM, XRD and UV-Vis were utilised to confirm the modification. ICP-MS is utilised to determine the Hg(II) and to assess the influence of the memory effect on the results using Au3+ solution and suspended Au nanoparticles (Au-NPs). The result shows that the Au-NPs improve Hg(II) detection and eliminate the memory effect. This study also includes appropriate parameters for contact time, eluent solution, pH, and the foreign metal and ions preconcentration factor. As a result, thiol-CF shows high Hg(II) uptake, flexibility, and stability during the analysis process, with a recovery of 98.96% ± 0.41% for 10 preconcentration factors. These features make FEPT a valuable method for extracting pollutants and overcoming the problems associated with the analysis of such samples.