Fiber-in-tube solid-phase extraction using a polyetheretherketone capillary, and effective on-line coupling with microcolumn liquid chromatography

Abstract

On-line coupling of fiber-in-tube solid-phase extraction (SPE), using polyetheretherketone (PEEK) tubing, with microscale liquid chromatography (LC) has been investigated. PEEK tubing and polymer filaments are introduced as new medium for extraction of phthalates—diethyl phthalate (DEP), dipropyl phthalate (DPP), and dibutyl phthalate (DBP). Approximately 300 pieces of polymer filament were packed into a PEEK capillary 100 mm long (0.25 mm i.d.) and the capillary was installed in the injection valve as the sample loop. Desorption and injection of the analytes were performed simultaneously withoutuse of the desorption solvent required by conventional SPE methods. The results obtained showed that effective on-line coupling of this sample-preparation method with liquid chromatography and other liquid-phase separation techniques can be accomplished for the high-throughput analysis of complex mixtures, without large consumption of organic solvents. The limits of detection for these phthalates, approximately 1.0 ng mL−1, and the extraction time, 10 min, indicate the future possibilities of this technique.