INTERFACING OF CE IN A PVP MATRIX TO ION-TRAP MASS-SPECTROMETRY - ANALYSIS OF ISOMERIC AND STRUCTURALLY RELATED (N-ACETYLAMINO)FLUORENE-MODIFIED OLIGONUCLEOTIDES

This work demonstrates the interfacing of capillary electrophoresis in a poly(N-vinylpyrrolidone) (PVP) solution to electrospray ionization ion trap mass spectrometry (ESI-ITMS). This methodology was used for o n-line analysis of modified and unmodified oligonucleotides. Oligonucl eotides were covalently modified using the model carcinogen 2-(N-aceto xy-N-acetylamino)fluorene. In the presence of PVP, separation was achi eved for a set of isomeric (N-acetylamino)fluorene (AAF)-modified olig onucleotides differing only in their base sequences, while open-tube c ontrol experiments showed no separation between these compounds. The r esolved analytes were identified by ESI-ITMS with negative ion detecti on. Online acquisition of MS and MS/MS data allowed unambiguous identi fication of all structural isomers. Baseline separation was also accom plished for a 10-compound mixture containing a series of five nonisome ric AAF-modified oligonucleotides and their unmodified parent oligonuc leotides.