Performance of a sheathless porous tip sprayer for capillary electrophoresis–electrospray ionization-mass spectrometry of intact proteins

摘要: Abstract The performance of a prototype porous tip sprayer for sheathless capillary electrophoresis–mass spectrometry (CE–MS) intact proteins was studied. Capillaries with were inserted in stainless steel needle filled static conductive liquid and installed conventional electrospray ionization (ESI) source. Using BGE 100 mM acetic acid (pH 3.1) positively charged coating, highly reproducible efficient separation four model (insulin, carbonic anhydrase II, ribonuclease A lysozyme) obtained. protein mass spectra good quality allowing reliable determination the some their impurities. Sheath-liquid CE–MS using same an isopropanol–water–acetic sheath showed slightly lower to similar analyte responses. However, as noise levels increased sheath-liquid CE–MS, detection limits improved by factor 6.5–20 CE–MS. response could be enhanced nanoESI source adding 5% isopropanol BGE, leading 50-fold 140-fold compared interfacing – equivalent sub-nM three out proteins. Clearly, provides high sensitivity