An ionspray ionization mass-spectrometric method for the determination of N1,N12-diacetylspermine (Ac2Spm) was developed using 15N-labeled Ac2Spm as the internal standard. Concentrations of Ac2Spm in the urine obtained from 17 cancer patients measured by the present method correlated well with those measured by ELISA, showing the usefulness of the two methods.
