Gas chromatographic separation of optically active anti-inflammatory 2-arylpropionic acids using (+)- or (-)-amphetamine as derivatizing reagent.

A method is described for the derivatization of several non-steroidal anti-inflammatory arylalkanoic acids (ibuprofen, ketoprofen, naproxen, fenoprofen, flurbiprofen, pirprofen, cicloprofen, tiaprofenic acid, etodolic acid) with optically active amphetamine. The usefulness of this reagent compared to alpha-methylbenzylamine is described. The enantiomers are separated as diastereoisomers using capillary gas chromatography with nitrogen-phosphorus detection. The procedure is readily applied to the quantification of the enantiomers in urine and plasma samples.