A feasibility study on oxidation state of arsenic in cut tobacco, mainstream cigarette smoke and cigarette ash by X-ray absorption spectroscopy

摘要

This work describes the application of synchrotron-based X-ray Absorption Near-Edge Structure spectroscopy to study the oxidation state of arsenic in cigarette mainstream smoke, cut tobacco and cigarette ash. The level of arsenic in the total particulate matter of the smoke is approximately 1 ppm for the standard research reference cigarette 2R4F and its replacement 3R4F. Smoke particulate samples collected by a conventional glass-fiber membrane (commercially known as Cambridge filter pad) and a jet-impaction method were analyzed and compared. In addition smoke particulate samples were aged either at ambient temperature or at 195 K. X-ray Absorption Near-Edge Structure spectroscopy results revealed that the cut tobacco powder and cigarette ash contained almost exclusively As~V. The smoke particulate samples however contained a mixture of As~(III) and As~V. The As~V in the smoke particulate was reduced to As~(III) upon aging. Stabilizing the smoke particulate matter at 195 K by solid CO2 slowed down this aging reaction and revealed a higher percentage of As~V. This behavior is consistent with the redox properties of the arsenic species and the smoke particulate matrix.