Multi-inlet sampling device for mass spectrometer ion source

[0055]FIG. 5 shows exemplary positive ion mode results obtained using the multi-inlet sampling device in conjunction with an atmospheric pressure nanoelectrospray ionization source (modified Agilent G1982B) and a time of flight mass analyzer (Agilent G1969 API-TOF). The top plot is a base peak chromatogram identifying a number of extracted peptide ions obtained from analysis of 50 femtomole of a bovine serum albumin (BSA) tryptic digest (Michrom Bioresources, Auburn, Calif.). The lyophilized digest was reconstituted in 95:5 (v / v) water / acetonitrile with 0.1% formic acid prior to use.

[0056] An Agilent Technologies 1100 series nanoflow LC system (Agilent, Little Falls, Del.) provided solvent delivery and separations. 50 femtomole of the bsa digest was loaded onto a Zorbax 300SB-C18 column (Agilent), 50mm×0.075 mm i.d. with 3.5 μm particle diameter and 300 Å pore size, maintained at 30° C. After equilibrating in mobile phase A (water with 0.1% (v / v), formic acid), flowing at 300 nl