On-line detection of radioactive and non-radioactive heavy metals in tobacco smoke using portable laser-induced breakdown spectroscopy.

Tobacco smoke is a complex mixture consisting of hundreds of toxic and carcinogenic chemicals, which may cause many diseases once inhaled. Among these toxic substances, radioactive and non-radioactive heavy metals present great health concerns to both active and passive smokers. However, conventional methodologies for characterizing heavy metals in smoke require intensive and time-consuming preparation procedures, and thus prevent their on-line applications. We report here a portable laser-induced breakdown spectroscopy (PLIBS) device for on-line detection of radioactive and non-radioactive heavy metals in tobacco smoke with ultra-high sensitivity. Two local cigarette brands were investigated, and a number of heavy metals were detected. In particular, several radioactive metals show very strong atomic emissions, and a limit of detection down to parts per trillion was obtained by single-shot PLIBS. The linear dependencies of their spectral intensities on the smoke concentrations were revealed, suggesting that the PLIBS is a promising tool for high-throughput and quantitative analysis of heavy metals in tobacco smoke. Tobacco emission dynamics were also investigated, and the results suggest the potential applications of the PLIBS in smoke risk assessment.