Monitoring Propofol Serum Levels by Rapid and Sensitive Reversed-Phase High-Performance Liquid Chromatography During Prolonged Sedation in ICU Patients

Abstract

A quick and sensitive reversed-phase high-performance liquid chromatography (HPLC) method has been developed in order to determine the concentration of Propofol (2,6 diisopropylphenol) in human serum. Propofol can be isolated from serum by adding 0.5 mL precipitating solution. This consists of an acetonitrile and perchloric acid (67:33, v/v) mixture, which also contains dibutylphthalate (2 mg/100mL) as internal standard. The sample is then mixed for 1 min on a vortex-mixer. The endogenous serum substances precipitated by acetonitrile and perchloric acid are further separated by centrifugation. The supernatant is directly injected into the HPLC system. A 250- × 4.6-mm column, packed with 10-μm Spherisorb reversed-phase octadecylsilane particles (C₁₈), is used for chromatographic separation. The mobile phase consists of an acetonitrile—water mixture (67:33 ratio) with 0.4 mL acetic acid (pH 4). Propofol is monitored by a UV-visible detector at 270 nm and 0.1-0.002 absorbance units full scale (AUFS). The detection limit of Propofol (in human serum) is 0.1 mg/L for a 20-μL injection volume. The time of the assay is less than 20 min, including sample preparation.