High-performance liquid chromatographic method for the determination of trace amounts of acetaminophen in plasma.

A method is described for the rapid, sensitive, and precise quantitation of acetaminophen in human plasma. The assay involved a single acetonitrile extraction and high-performance liquid chromatographic analysis using a reverse-phase column, with a mobile phase of methanol and water. The limit of quantitation of acetaminophen by this method was 8 ng/mL; only 0.1 mL of the plasma sample was required for the determination. N-Propionyl-p-aminophenol was used as the internal standard.