title: Comparison of methods for extraction of tobacco alkaloids.
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 degrees 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.
authors.affiliation: Centro de Investigação de Ciências Agrárias Tropicais, DAIAT, Instituto Superior de Agronomia, Tapada da Ajuda, Lisbon, Portugal.
authors.forename: N M
authors.initials: NM
authors.lastname: Jones
authors.forename: M G
authors.initials: MG
authors.lastname: Bernardo-Gil
authors.forename: M G
authors.initials: MG
authors.lastname: Lourenço
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification*; D000704:Analysis of Variance; D002849:Chromatography, Gas; D006358:Hot Temperature; D007202:Indicators and Reagents; D008872:Microwaves; D010947:Plants, Toxic; D012997:Solvents; D014026:Nicotiana / Q000737:chemistry*; D014465:Ultrasonics
chemical_list: D000470:Alkaloids; D007202:Indicators and Reagents; D012997:Solvents