Publications by authors named "Hefeng Pan"

Collision-induced dissociation (CID) mass spectra of a few haloaniline isomers, (chloroanilines, dichloroanilines, difluoroanilines, chloro-fluoroanilines and bromo-fluoroanilines) were characterized. The mass spectral behaviour of difluoroanilines was different from those of the corresponding regioisomers of the other haloanilines. For all ortho regioisomers except difluoroanilines, CID mass spectra resulted in hydrogen halide as well as halogen radical loss.

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The atmospheric pressure solids analysis probe (ASAP), in conjunction with ion mobility time-of-flight mass spectrometry (IM-ToF-MS), has been applied to the impurity profiling study of ten 2-naphthalenamines. The impurity profiles achieved by ASAP-IM-MS were compared with those obtained by liquid chromatography-electrospray ionisation-mass spectrometry (LC-ESI-MS). All the impurities at the level of 0.

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A non-covalent-bonded dimer was detected in the positive ion electrospray ionisation (ESI) mass spectra of a synthetic impurity. In tandem mass spectrometry (MS/MS) experiments using collision-induced dissociation (CID), the ion was found to behave as a [M+H]+-type precursor ion for fragmentation until MS5. The dimer was probably formed through multi-hydrogen bonds over a proton bridge.

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