Fast quantification of whisky lactone in oak wood by ion mobility spectrometer

An Ion Mobility Spectrometry (IMS) apparatus has been used to detect the beta-methyl-gamma-octalactone (Whisky Lactone - WL) standard in the air and as well WL vapours originating from the oak wood samples. The IMS was equipped with Atmospheric Pressure Chemical Ionisation (APCI) ion source based on a Corona Discharge (CD) and was operated in the positive polarity. The IMS spectrum of WL exhibits two peaks, a monomer with reduced ion mobility value K-0 = 1.39 cm(2 )V(-1) s(-1) and dimer K-0 = 1.09 cm(2) V-1 s(-1). Using Ion Mobility orthogonal acceleration Time of Flight mass spectrometer (IMS-oaTOF MS) these peaks were identified as protonated monomer M center dot H+center dot(H2O)(0,1) and dimer M-2 center dot H+ ions respectively. The limit of detection study resulted in LOD for WL of 50 PPbv. Detection of WL from oak wood samples of different Quality Level (QL) categories (categories 1 to 10), indicated strong correlation between the QL category number and the response of the IMS.