Resumo

BAEZA-MARRUFO, R. et al. Surface modification of poly(tetrafluorethylene) magnetic stirring bars with plasma of hexamethyldisiloxane and its applications in the stir bar sorptive extraction technique. Superf. vacío [online]. 2012, vol.25, n.1, pp.49-55. ISSN 1665-3521.

This paper explores the potential of plasma polymerization to modify the surface of stir bars for its use in Stir Bar Sorptive Extraction (SBSE). The modification of the poly(tetrafluoroethylene) surface of stir bars was done through plasma polymerization of hexamethyldisiloxane (30 min, 110 W and 1.4×10^-1 Torr). The coating was characterized by contact angle, Fourier Transform Infrared Spectroscopy, Energy Dispersive X-ray Analysis and Scanning Electron Microscopy. The modified stir bars were applied in SBSE to extract five organophosphorus pesticides (dichlorvos, diazinon, dichlofenthion, malathion and fensulfothion) from synthetic aqueous solutions. The extracts were analyzed by gas chromatography with mass spectrometric detection. The modified bars adsorbed four pesticides (stirring 60 min, back extraction with 1.4 mL of isooctane and 15 min of sonication).

Palavras-chave : Gas Chromatography; Stir bar sorptive extraction; Pesticides; Plasma polymerization; Hexamethyldisiloxane.