A Micro-Coated Wire Ion-Selective Electrode for Flow-Injection Analysis of Trazodone in Pharmaceuticals, Human Urine and Serum

A novel micro-coated wire trazodone-selective electrode placed in an FIP system is characterized and used to determine trazodone levels in various samples. The electrode is based on the immobilization of a PVC-sensing membrane, composed of a trazodone-tetraphenylborate ion-exchanger, on a platinum wire and incorporated in a novel miniaturized FIA-cell. The method provided a fast, stable and near-Nernstian response over a wide trazodone concentration range (5 × 10⁻⁶–5 × 10⁻³ M) with a mean slope of 53.9 ± 0.4 mV dec⁻¹ of concentration and a mean detection limit of 4.4 × 10⁻⁶ ± 1.8 × 10⁻⁷ M. The electrode also showed good repeatability, reproducibility and selectivity with respect to some inorganic and organic compounds, including the main trazodone metabolite. The electrode provided good analytical results in the determination of trazodone in pharmaceuticals and spiked urine and serum samples.