Aldehydes and ketones (AKs) in cigarette smoke are risk to humans and environment. Due to the complexity of itself and the interference of the smoke tar matrix, the aldehydes and ketones in particle phase (AKPs) of mainstream smoke (MSS) and sidestream smoke (SSS) have not been well investigated. In this study, the AKPs of MSS and SSS were derivatized into polar products by reaction with Girard T reagent. The derivatives were isolated rapidly by column chromatography and analysed by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Fifteen species of aldehydes and ketones were detected by positive ion electrospray ionization (ESI) FT-ICR MS: O1–6, N1O1–4, N2O1–3 and N3O2–3. The total number of AKPs obtained by ESI FT-ICR MS in MSS and SSS is about 1100 and 970, respectively. After hydrolysis, the original AKPs were obtained and 63 carbonyls were identified and quantified by gas chromatography–mass spectrometry (GCMS). The nitrogen-containing and high-oxygen AKPs were further characterized by Orbitrap mass spectrometry. Structures of compounds with high relative abundance in the mass spectrum were speculated (e.g. a series of degradants of cembrenediol) by comparison with the results of GCMS.
Characterization of chemical composition in cigarette smoke is essential for establishing smoke-related exposure estimates. Currently used methods require complex sample preparation with limited capability for obtaining accurate chemical information. We have developed an in situ solid-phase microextraction (SPME) method for online processing of smoke aerosols and directly coupling the SPME probes with confined-space direct analysis in real time (cDART) ion source for high-resolution mass spectrometry (MS) analysis. In a confined space, the substances from SPME probes can be efficiently desorbed and ionized using the DART ion source, and the diffusion and evaporation of volatile species into the open air can be largely avoided. Using SPME-cDART-MS, mainstream smoke (MSS) and side-stream smoke (SSS) can be investigated and the whole analytical protocol can be accomplished in a few min. More than five hundred substances and several classes of compounds were detected and identified. The relative contents of 13 tobacco alkaloids were compared between MSS and SSS. Multivariate data analysis unveiled differences between different types of cigarette smoke and also discovered the characteristic ions. The method is reliable with good reproducibility and repeatability, and has the potential to be quantitative. This study provides a simple and high-efficiency method for smokeomics profiling of complex aerosol samples with in situ online extraction of volatile samples, and direct integration of extracted probes with a modified ambient ionization technique.