Oxidized carbon nanotubes as sorbent for miniaturized solid-phase extraction of progestins from environmental water samples prior to their determination by HPLC-UV

Abstract

A solid-phase extraction method is presented for micro-extraction of three progestins (levonorgestrel, 19-norethisterone acetate andmedroxyprogesterone acetate) from water samples. A mini-column was packed with 60 mg of oxidized multiwalled carbon nanotubesand coupled to a flow injection assembly. The extraction parameters, such as washing solution, eluent type, eluent volume, flow rateand sample volume, were optimized. Separation and determination were performed by HPLC with UV detection. The method has agood linear range (0.90?9.0 μg L−1), acceptable limits of detection (0.05?0.14 μg L−1) and low RSDs (0.8?4.6%). Attractive features ofthe method include low consumption of organic solvents and preconcentration factors of up to 100. The method was applied to analyzestream, underground and effluent water samples, and recoveries between 74 and 121% were obtained.