Rapid Analysis of Mouth Retention in Cigarette Smoke During Nature Smoking by On-Line Photoionization Mass Spectrometry

Measurement of the retention of cigarette smoke components in the human mouth is very important for evaluating smoking-related diseases. A newly developed rapid sampling design approach based on vacuum ultraviolet photoionization time-of-flight mass spectrometry (VUV-PI-TOF MS) was described and a cigarette smoke smoking system was applied for the online mouth retention study of gaseous mainstream cigarette smoke components during natural smoking. To determine the amounts of smoke constituents, the cigarette smoke inhaled or exhaled by subjects was directly introduced into the vacuum chamber through the heated fused silica capillaries, photoionized and analyzed with a TOF mass spectrometer without any tedious collection and pretreatment procedures. According to the 14 selected species in mainstream cigarette smoke, mouth retention of 7 adult male smokers were studied, who smoked cigarette according to 3 predefined smoking patterns: no inhalation (pattern A), normal inhalation (pattern B) and deep inhalation (pattern C). The results showed that after 2 s holding time, the 14 cigarette species mouth retention level in 7 subjects of 3 smoking patterns could be attributed to three categories: aldehyde ketone constituents performed high mouth retention; methanethiol, phenol and nitrogen heterocyclic compounds performed medium mouth retention, while the retention of unsaturated hydrocarbons was relatively low. The differences in the retention between different constituents could be interpreted in terms of each constituent’s physical properties such as volatility and solubility. Furthermore, for 5 different Virginia type cigarettes products, these selected constituents that retained in human mouths of 3 different smoking patterns were all followed the same trend. In conclusion, this new sampling design approach can offer the accurate mouth retention of selected mainstream smoke constituents for smokers during the natural smoking process by themselves, and can provide a basis analysis tool for further study of the retention of smoke constituents in the human respiratory tract.