Qualitative methods for VOC detection in condensed hookah tobacco and steam stone smoke

Abstract

This work offers a preliminary investigation of the compounds in smoke from hookah tobacco and tobacco-free steam stone products. A preconcentration extraction method involving headspace solid phase microextraction (SPME) and gas chromatography mass spectrometry (GC–MS) was developed for the qualitative analysis of condensed hookah smoke (CHS). A simulated hookah apparatus was constructed to smoke hookah tobacco or steam stones with coconut, wood, or electronic charcoals used as the heat source. The vapor was collected by condensing the mainstream smoke as it passed through a 15mL vacuum cold trap vial inside an acetonitrile/dry ice cold bath at −40°C. Multiple SPME fibers (a 50/30μm DVB/CAR®/PDMS fiber, a 65μm PDMS/DVB fiber, an 85μm CAR®/PDMS fiber, a 100μm PDMS fiber, and an 85μm Polyacrylate fiber) were used to qualitatively screen compounds present in the highly complex hookah smoke condensate. An in-house reference composed of 3R4F reference cigarettes was used to estimate SPME extraction and desorption times (5min and 1min, respectively). Chromatograms indicated that the hookah tobacco condensate contained more compounds than the steam stone condensate and a preliminary attempt was made to assign peaks to their source compounds using mass spectral information. Principal component analysis (PCA) of peak signal intensities suggested that the 65μm PDMS/DVB, 85μm CAR®/PDMS, and 85μm Polyacrylate fibers extracted tobacco and steam stone volatile organic compounds (VOCs) most consistently. The complexity of hookah tobacco and steam stone smoke limits our ability to quantify the compounds at this time, however identification and quantitation will be the focus of future work.