Durable Emitters for Nanospray Mass Spectrometry

DESCRIPTION (provided by applicant): The long-term goal of this project is to develop miniaturized electrospray ionization (or nanospray) emitters that have enhanced durability and sensitivity versus those currently available. Nanospray mass spectrometry has improved detection limits, requires less sample volume, and uses lower flow rates (resulting in reduced consumption of analyte) than conventional electrospray ionization. However, commercial nanospray emitters which use thin gold films are readily destroyed by electrical discharge. An alternative to gold coatings for nanospray emitters employing conductive polyaniline has been developed at the University at Buffalo (UB). Polyaniline coatings exhibit high resistance to destruction by electrical discharge and retain the sensitivity improvements of nanospray over electrospray. The demonstrated superior durability of polyaniline-coated emitters to current commercial emitters should permit, for the first-time, routine coupling of capillary separations techniques to nanospray. The advantage of such a coupling is that it would permit highly sensitive detection and characterization of biological molecules and drugs directly from complex biological mixtures (e.g., cerebrospinal fluid, blood plasma, etc.). This powerful combination of analytical technologies will have important implications in detection of protein molecules indicative of disease states (e.g., hemoglobin, prealbumin). The immediate objective here is to demonstrate operational capillary electrophoresis and capillary liquid chromatography coupled to nanospray MS using polyaniline-coated emitters, and to produce commercially an integrated capillary column-nanospray emitter unit.