Determination of carphedon in human urine by solid-phase microextraction using capillary gas chromatography with nitrogen–phosphorus detection

Abstract

Carphedon is a phenyl derivative of nootropil and is effective in increasing physical endurance and cold resistance, and is used for amnesia treatment. Carphedon was extracted from human urine samples by solid-phase microextraction with a 65 µm carbowax–divinylbenzene-coated fiber. This analysis was performed by using capillary gas chromatography with nitrogen–phosphorus detection and optimized at pH 9.6, 30% NaCl, immersion time 10 min and desorption in the GC injector at 250 °C for 3 min. The regression equation for carphedon showed good linearity in the range from 0.1 to 10 µg ml^–1 for human urine samples. The limit of detection was 0.01 µg ml^–1. The developed method is more sensitive and simpler in sample preparation than liquid–liquid extraction and can be applied to doping analysis for stimulants.