Electron-capture GLC determination of pseudoephedrine in serum

A GLC assay was developed for pseudoephedrine in serum using 3-methylamino-1-phenyl-1-propanol as an internal standard. After extraction from serum with benzene under alkaline conditions, pseudoephedrine was derivatized with pentafluorobenzyl bromide and quantitated by electron-capture GLC. The method has a detection limit of approximately 0.02 microgram/ml of serum using 1-ml samples.