In-tube molecularly imprinted polymer solid-phase microextraction for the selective determination of propranolol

A molecularly imprinted polymer (MIP) material was synthesized for use as a n in-tube solid-phase microextraction (SPME) adsorbent. The inherent select ivity and chemical and physical robustness of the MIP material was demonstr ated as an effective stationary-phase material for in-tube SPME. An automat ed and on-line MIP SPME extraction method nas developed for propranolol det ermination in biological fluids. This simplified the sample preparation pro cess and the chromatographic separation of several P-blocker compounds. The method developed for propranolol showed improved selectivity in comparison to alternative in-tube stationary-phase materials, overcoming the limitati ons of existing SPME coating materials. Preconcentration of the sample by t he MIP adsorbent increased the sensitivity, yielding a limit of detection o f 0.32 mug/mL by UV detection. Excellent method reproducibility (RSD < 5.0% ) and column reusability(> 500 injections) were observed over a fairly wide linear dynamic range (0.5-100 mug/mL) in serum samples. To our knowledge, this is the first report on the automated application of a MIP material for in-tube SPME. The method was inexpensive, simple to set up, and simplified the choice of SPME adsorbent for in-tube extraction. The approach can pote ntially be extended to other MIPs for the determination of a wide range of chemically significant analytes.