Analytical Method Development and Validation of Phenothrin, Promecarb and Penconazole in Tobacco using Liquid Extraction and Gas Chromatography

A sensitive method for the determination of phenothrin, promecarb and penconazole residues in tobacco has been developed. Several solvents such as, hexane, ethyl acetate and dichloromethane were tested in order to minimize agricultural products residue. In the study, the best recovery was achieved with dichloromethane. Pesticides residues are extracted from the samples with dichloromethane. Additional clean-up steps are not required for tobacco matrices. Determination and quantification of phenothrin, promecarb and penconazole are performed by gas chromatography-flame ionization detector (GC/FID) and gas chromatography-nitrogen/phosphorus (GC/NPD). The method has been validated for tobacco matrices. Under the optimum conditions, phenothrin R 2 value 0.999, promecarb R 2 value 0.999, and penconazole R 2 value 0.999. Limits of determination were 0.008 µg mL -1 for phenothrin, 0.011 µg mL -1 for penconazole and 0.007 µg mL -1 for promecarb . The standard deviations (SDs) levels were in the range 0.01-0.20. Recoveries of phenothrin, promecarb and penconazole from tobacco were found to be higher than 85%. Under this developed method, the concentrations of phenothrin, promecarb and penconazole in the 10 tobacco samples were below the LOD values.