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/100 mL) 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- x 4.6-mm column, packed with 10-microns 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-microL injection volume. The time of the assay is less than 20 min, including sample preparation.

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Sixteen rubber vulcanizers using IPPD as anti-oxidant were monitored for the presence of the parent compound in the urine during two consecutive working weeks using HPLC for analysis. At least two components in the excretion kinetics could be demonstrated: a fast one, as end-shift urinary concentrations significantly exceeded before-shift ones, and a less rapid one, as before-shift values at the end of the week significantly differed from those determined at the beginning. A skin absorption experiment was also performed. It demonstrated three components in the excretion kinetics, with apparent half-times of approximately 3, 7 and 24 h. Excretion ceased 7 d after skin exposure.