Abstract
Ultrasound and microwave techniques were used to extract tobacco alkaloids, and response surface methodology was used to optimize extraction conditions. Ultrasonic technique factors were temperature, 30–85°C; time, 3–45 min; solvent volume, 8–80 mL. Microwave extraction factors were pressure, 15–75 psi; time, 3–40 min; power, 30–90% of the maximum magnetron power of 650 W. Soxhlet and solvent AOAC-modified extraction methods were also applied after some improvements. Nicotine, nornicotine, anabasine, and anatabine were quantified by gas chromatography. A steam distillation International Standards Organization method for total alkaloid evaluation was used as reference. The results obtained by the different methods were compared using a least squares deviation test. The ultrasonic and the proposed modified-AOAC extraction method were the more convenient with regard to practicability and precision. The relative deviations (n = 5) were as follows: For the ultrasonic method in low-level alkaloid tobaccos, 0.7% nicotine and 1.4–14% minor alkaloids; in high-level alkaloid tobaccos, 2.4% nicotine and 4.5–5.1% minor alkaloids. For the modified AOAC method in low-level alkaloid tobaccos, 0.9% nicotine and 2.4–11.6% minor alkaloids; and in high-level alkaloid tobaccos, 1.7% nicotine and 2.0–2.4% minor alkaloids.