| Abstract: | Negative corona discharge atmospheric pressure chemical ionization (APCI) was used to investigate phenols with varying numbers of tert‐butyl groups using ion mobility spectrometry–mass spectrometry (IMS‐MS). The main characteristic ion observed for all the phenolic compounds was the deprotonated molecule [M–H]−. 2‐tert‐Butylphenol showed one main mobility peak in the mass‐selected mobility spectrum of the [M–H]− ion measured under nitrogen atmosphere. When air was used as a nebulizer gas an oxygen addition ion was seen in the mass spectrum and, interestingly, this new species [M–H+O]− had a shorter drift time than the lighter [M–H]− ion. Other phenolic compounds primarily produced two IMS peaks in the mass‐selected mobility spectra measured using the [M–H]− ion. It was also observed that two isomeric compounds, 2,4‐di‐tert‐butylphenol and 2,6‐di‐tert‐butylphenol, could be separated with IMS. In addition, mobilities of various characteristic ions of 2,4,6‐trinitrotoluene were measured, since this compound was previously used as a mobility standard. The possibility of using phenolic compounds as mobility standards is also discussed. Copyright © 2009 John Wiley & Sons, Ltd. |
