Figure 1. Illustration of the EESI setup attached to the LTQ-XL mass spectrometer for direct protein analysis. The charged reagent plume
was created using ESI in channel 2, and the untreated biological samples were infused for EESI ionization through channel 1. The analyte ions produced at atmospheric pressure were then guided to the ion trap mass analyzer for further analysis. The distance a between the EESI and the ion entrance of the LTQ instrument was 10 mm; the distance b between the tips of channels 1 and 2 was 2–3 mm. The angle a formed between channels 1 and 2 was 608; the angle b formed between the channel 1 and the heated capillary of the LTQ instrument was 1508. The temperature of the ion entrance capillary was maintained at 2008.

2010-陈焕文-Angew. Chem. Int. Ed..pdf