A Multiple Channel Electrospray Source Used To Detect Highly Reactive Ketenes from a Flow Pyrolyzer

This work detects protonated molecular ions of highly reactive pyrolytic products--cyclopentadienylideneketene, cyclohexadienylideneketenimine, and acetylketene--using a flow pyrolyzer connected to a multiple-channel electrospray mass spectrometry. The ketene generated in the flow pyrolyzer is directly conducted into the central channel of a seven-channel electrospray ionization source by a stream of nitrogen gas. Concurrently, a methanol solution containing 0.1% trifluoroacetic acid is electrosprayed through the outside six channels. The protonated methanol ions and the charged droplets generated from the outside six electrospray channels facilitate the ionization of the neutral ketenes through ion-molecule reactions or absorption followed by protonation.