A colloidal XXXX -coated emitter for sheathless capillary electrophoresis/nanoelectrospray ionization mass spectrometry.

@entity7302 @entity15583 @entity450 @entity3440 @entity5723 @entity1090
A colloidal @entity15583 -coated emitter is introduced for sheathless capillary electrophoresis/nanoelectrospray ionization time-of-flight mass spectrometry (CE/ESI-TOFMS). The conductive coating can be produced by brushing the capillary tip to construct a fine layer of @entity5723 -based colloidal @entity15583 . The fabrication involves a single step and requires less than 2 min. Full cure properties develop in approximately 2 h at room temperature and then the tip is ready for use. The coated capillary tip is applied as a sheathless electrospray emitter. The emitter has proven to bear stable electrospray and excellent performance for 50 microm i.d. x 360 microm o.d. and 20 microm i.d. x 360 microm o.d. capillaries within the flow rate of 80-500 nL/min; continuous electrospray can last for over 200 h in positive mode. Baseline separation and structure elucidation of two clinically interesting basic drugs, @entity1090 and @entity7302 , are achieved by coupling pressure-assisted CE to ESI-TOFMS using the described sheathless electrospray emitter with a bare fused- @entity3440 capillary at pH 6.7. It is found that the signal intensity of m/z in sheathless CE/ESI-TOFMS at pH 6.7 is approximately 50 times higher than that at pH 9.0 for the two analytes, although the @entity450 ( @entity450 ) at pH 9.0 provides sufficient flow rate (approximately 150 nL/min) to maintain electrospray.
