Micro-solid phase extraction based on oxidized single-walled carbon nanohorns immobilized on a stir borosilicate disk: Application to the preconcentration of the endocrine disruptor benzophenone-3

A novel micro-solid-phase extraction approach is presented. It consists of a borosilicate disk with oxidized singlewalled carbon nanohorns (o-SWNHs) immobilized in its pores. The o-SWNH disk is placed in the screw of a portable drill that allows the extraction unit to be stirred inside the sample. The technique was applied to the extraction of benzophenone-3 from swimming pool water samples, followed by its determination with ultrahigh performance liquid chromatography with photodiode array detection. The variables affecting extraction were optimized, and the method was characterized in terms of linearity, limit of detection (0.16 mu g L-1) and precision (the relative standard deviation is lower than 11.9%). The enrichment factor is as high as 1379 and it involves an absolute recovery of 68.9%. Relative recoveries are close to 90%. The method is likely to represent a new approach towards microextraction of organic species using this nanomaterial. (C) 2014 Elsevier B.V. All rights reserved.