GLC-mass fragmentographic determination of mannitol and sorbitol in plasma.

A GLC-mass fragmentographic method was developed for the simultaneous determination of mannitol and sorbitol as their n-butyldiboronate derivatives in plasma. The plasma sample was deproteinized, and the subsequent supernatant was concentrated to dryness; the resulting residue was then dissolved in pyridine containing n-butylboronic acid to allow derivation. An aliquot of this solution was injected into the gas chromatograph-mass spectrometer and analyzed by a selected-ion monitoring method using galactitol as the internal standard. Detection was limited to 20 ng/0.1 ml of plasma for both mannitol and sorbitol. A rapid, precise, and sensitive assay for the determination of mannitol and sorbitol in plasma was established.