ANALYSIS OF NEUROPEPTIDES BY PERFUSION LIQUID-CHROMATOGRAPHY ELECTROSPRAY ION-TRAP MASS-SPECTROMETRY

Perfusion high-performance liquid chromatography (HPLC) combined with electrospray ion trap mass spectrometry (ITMS) was evaluated for the d etermination of neuropepetides in plasma. Perfusion HPLC offers the ca pability of resolving neuropeptides spiked into plasma in 5 min compar ed to the 30-60 min separations performed on packed capillary C18 colu mns. Electrospray combined with the ITMS provides the ability to ioniz e these neuropeptides and mass analyze them with high sensitivity and specificity. Sub-picomole quantities of neuropeptides injected on-colu mn could be specifically detected in a plasma matrix. The electrospray -ITMS mass spectrum of each neuropeptide showed multiply charged ions which could be used to determine or confirm their molecular weights.