Phenolic compound formation from the low temperature pyrolysis of tobacco

The formation of 10 phenolic compounds (hydroquinone, resorcinol, catechol, phenol, 4-methylcatechol, 3-methylcatechol, guaiacol, o-, m-, and p-cresol) from the pyrolysis of different tobacco types at temperatures between 350 and 600 °C was investigated. Hydroquinone, catechol, guaiacol, 3-methylcatechol, and 4-methylcatechol were formed predominately at temperatures ≤350 °C from the primary decomposition of tobacco components. Cresols formed predominately between 350 and 600 °C and evolved from the residual solid (char) that forms at temperatures above 350 °C. Phenol and resorcinol were found to form over both temperature ranges, ≤350 °C and between 350 and 600 °C suggesting contributions from both the decomposition of tobacco components and the 350 °C residual solid. The trend in the yields of hydroquinone and catechol obtained from the tobacco types tested; bright (flue cured), burley, and oriental followed bright ∼ oriental > burley. All three tobacco samples gave similar yields of phenol and cresols. Water extraction of tobacco was shown to significantly reduce the yields of phenolic compounds. The addition of 5 and 21% oxygen to the pyrolysis setup led to a significant reduction in the yields of hydroquinone and catechol but the yields of phenol and cresols remained relatively unchanged. Quinic acid and quinic acid derivatives present in tobacco are identified as important precursors of hydroquinone, catechol, and phenol.