Chromatograms depicting separation of alkaloids on a 150×3mm, 3.5m particle size Zorbax ExtendC-18column and detection at 260nm.The mobile phase (flow rate 0.8mL/min) consisted of agradient of acetonitrile and15m Mammonium formate in water(pH adjustedto10.5with triethylamine);the gradient elution was 9–10%acetonitrile from 0 to 5 min and then10 to13%acetonitrile from 5 to13 min. (A) Standard solution of alkaloids and IS,(B)Extraction from Nicotiana benthamiana fresh leaves.1.Cotinine;2.Caffeine(IS);3.Nornicotine;4.Anatabine;5.Myosmine; 6. Anabasine; 7. Nicotine