Determination of GHB in urine and serum by LC/MS using a simple one-step derivative

A sensitive and specific method for the determination of gamma-hydroxybutyric acid (GHB) in urine and serum is described. Prior to quantification by LC/MS in a Pauli-type ion trap, the molecule is converted by a fast and simple one-step procedure into its n-butyl ester derivative. Hexa-deutero GHB has been used as internal standard.