Analysis of Scopoletin and Caffeic Acid in Tobacco by GC–MS After a Rapid Derivatization Procedure

Abstract

A method has been developed for rapid analysis of polyphenols, including scopoletin and caffeic acid, in tobacco samples. After extraction, and a rapid derivatization procedure, the polyphenols were analyzed by gas chromatography–mass spectrometry. Two extraction techniques, ultrasonic and reflux extraction, were compared. The results showed that ultrasonic extraction was better than reflux extraction, because of its similar extraction efficiency and its simplicity. A 99:1 mixture of N,O-bis(trimethylsilyl)trifluoracetamide and trimethylchlorosilane was used for derivatization. When acetone was used as solvent to accelerate the reaction the derivatization time was reduced to within 5 min. With GC–MS detection in single-ion-monitoring mode, three polyphenols (chlorogenic acid, kaempferol, and quercetin) were analyzed qualitatively and four polyphenols (pyrocatechol, scopoletin, esculetin, and caffeic acid) were analyzed quantitatively. In quantitative analysis the limit of detection (LOD; signal-to-noise ratio = 3) was between 15.2 pg and 1.2 pg, and relative standard deviations (RSD) were <6.8% (n = 5). Scopoletin and caffeic acid were analyzed quantitatively in a tobacco sample; the amounts present were 0.062 and 0.55 mg g−1, respectively.