Some elements of smoke are attribute in the combustion source. Guaiacol and its derivatives are products and solutions of pyrolysis of lignin and therefore are characteristic of Wooden smoke; other markers are syringol and derivates, as well as other methoxy phenols. Retene, an item of pyrolysis of conifer trees, https://broadfar.com/oraco-global-trends-in-heat-not-burn-products/