FA-SIFT study of the reactions of H3O+center dot(H2O)(n) (n=0, 1, 2), NO+ and O-2(center dot+) with the terpenoid aldehydes citral, citronellal and myrtenal and their alcohol analogues

作者：Amelynck C^*; Mees B; Schoon N; Bultinck P

来源：International Journal of Mass Spectrometry, 2015, 379: 52-59.

DOI：10.1016/j.ijms.2014.12.005

• FA-SIFT
• SIFT-MS
• Ion/molecule reactions
• Terpenoids
• Aldehydes
• Alcohols

Biogenic volatile organic compounds (BVOCs) significantly contribute to atmospheric chemistry, air quality and climate. On-line detection of these compounds can be performed by Selected Ion Flow Tube-Mass Spectrometry (SIFT-MS), provided the rate constants and product ion distributions of the underlying ion/molecule reactions are known. These parameters are presented for the reactions of the SIFT-MS reagent ions H3O+center dot(H2O)(n) (n = 0-2), NO+ and O-2(center dot+) with the terpenoid aldehydes citral, citronellal and myrtenal and the terpenoid alcohols citronellol and myrtenol. The experiments were performed at 295 K and 1.5 hPa in a Flowing Afterglow Selected Ion Flow Tube (FA-SIFT) instrument. All studied reactions proceed at the collision rate which is beneficial for the BVOC detection sensitivity. Non-dissociative proton transfer, and elimination of a water molecule or simultaneous ejection of a water molecule and C4H8 following protonation were observed as the major mechanisms for most H3O+ reactions. Reactions of H3O+center dot(H2O) mainly proceeded by non-dissociative proton transfer, possibly followed by ejection of a water molecule, whereas the main observed mechanism for H3O+center dot(H2O)(2) reactions was ligand switching followed by elimination of up to three water molecules. Charge transfer occurred for all NO+ reactions and was accompanied by other major mechanisms such as hydride transfer and/or elimination of a water molecule following charge transfer and/or ternary association. The O-2(center dot+) reactions generally resulted in strong fragmentation. The product ion distributions suggest that selective detection of some isomeric terpenoids might be possible. However, interference with simultaneously emitted monoterpenes could be a problem.

• 出版日期2015-3-15