COMBINING ELECTROSPRAY-IONIZATION AND THE FLOWING AFTERGLOW METHOD

The design and implementation of a simple electrospray ionization sour ce for a flowing afterglow/triple quadrupole device are described, Ion s can be electrosprayed directly into the room temperature flow tube t hrough a heated capillary without the need for differential pumping or ion focusing, Detected ion currents at the detector sampling orifice as high as 3 pA have been achieved, and the mass spectra indicate litt le or no re-clustering of the desolvated ions with the background solv ent vapor in the flow tube, Spatially and temporally resolved ion/mole cule reactions of electrosprayed ions can be carried out in the how re actor under thermal energy conditions, Sufficient ion densities can be achieved for tandem mass spectrometric experiments in the triple quad rupole analyzer, including energy-resolved collision-induced dissociat ion, Selected chemical applications illustrating these features are de scribed, including proton transfer reactions with aromatic polysulfona te dianions and multiply protonated polypeptides and threshold CID of a doubly charged transition metal coordination complex. (C) 1997 by Jo hn Wiley & Sons, Ltd.