Modification of carbon nanotubes with a Keplerate polyoxomolybdate as efficient sorbent for the extraction (HF-μ-SPE) of naproxen in hair samples

In continuation of our ongoing research on the development of novel catalytic methods for oxidation of organic compounds in green media [1-3], we describe the modification of CNT with polyoxomolybdates. In this work, we described a synthesis method of the polyoxomolybdate (POMo) and the modification of carbon nanotube(CNTs) through a chemical modified approach. POMo was prepared by a one-step reaction at room temperature and characterized by FT-IR, XRD, Uv-Vis and TEM [4].These uniform nano-polyoxomolybdate has an average size of 5–25 nm. In this research, the Keplerate carbon nanotubes/silica composite was used in the pores and lumen of a hollow fiber as the hollow-fiber micro-solid-phase extraction device. Based on chemical adsorption between POMo and carboxylic acid groups in CNT, which were introduced to the CNTs by adding dilute nitric acid, POMo was successfully located on the CNTs as the modifier. The hollow-fiber was used for the microextraction of the analyte from hair sample under the optimized conditions as sensitive technique to determinate naproxen. After optimizing the reaction conditions (pH, salt, volume of donor and desorption phase, extraction and desorption time), extraction of naproxen in the presence of hollow-fiber combined with fluorescence spectrophotometry was performed.