Fabrication of a hierarchical dodecyl sulfate-layered double hydroxide nanocomposite on porous aluminum wire as an efficient coating for solid-phase microextraction of phenols

We have synthesized, by a hydrothermal crystallization method, a layered double hydroxide of aluminum that is intercalated with the dodecyl sulfate anion. This nanocomposite is formed on a porous aluminum wire and can be used as a fiber coating for solid-phase microextraction. The nanocomposite has a flowerlike morphology and a high specific surface. The coating can be prepared easily, is mechanically stable, and exhibits relatively high thermal stability. It is capable of extracting phenolic compounds from water samples. Following thermal desorption, the phenols were quantified by GC-MS. The effects of extraction temperature, extraction time, sample ionic strength, stirring rate, pH, desorption temperature and desorption time were studied. Under optimal conditions, the repeatability for one fiber (for n = 5), expressed as the relative standard deviation, is between 3.9 and 7.6 %. The detection limits range from 0.2 to 4 pg mL(-1). The method is simple, fast, and inexpensive. The fibers are thermally stable and yield better recoveries than conventional methods of analysis.