Authors:Syed Musharraf, Muhammad Shoaib, and Najam-ul-Haq
A sensitive, selective, precise, and robust densitometric method for the analysis of nicotine (drug component of Nicotiana tabacum) in various tobacco products (TPS), including smoked (cigarette and beedi), sniffing (sniffing niswar), dipping (niswar), and chewing (gutka) tobacco brands, was developed and validated as per the ICH guideline. TLC glass plates, precoated with silica gel 60F-254, were used for the analysis. Densitometric analysis of nicotine was carried out in the absorbance mode at 262 nm. The mobile phase consisted of petroleum ether-acetone-diethylamine (7.6:2:0.4) v/v, and gave a sharp and symmetrical nicotine peak (RF = 0.57 ± 0.005) under saturated environment. Linear regression data (LRD) for the calibration curve showed a good linearity with r = 0.997 ± 0.0013. The method was validated for precision, recovery, and robustness. The limits of detection (LOD) and quantitation (LOQ) were found to be 3.15 and 9.54 ng per spot, respectively. Statistical analysis indicated that the method is reproducible and selective for the estimation of nicotine in various TPS.
Authors:Syed Musharraf, Muhammad Shoaib, Dileep Kumar, and Muhammad Najam-ul-Haq
Permethrin is widely used in household pests and insect-controlling products. A sensitive and robust TLC-densitometric method for the separation and quantification of an important pyrethroid, permethrin in household products was developed. TLC aluminum plates, precoated with 0.2-mm thick layer of silica gel 60F254, were used for the analysis. Densitometric analysis of permethrin was carried out in the absorbance mode at λmax 227 nm for both cis and trans isomers. Mobile phase consisted of hexane-diethylether-ethylacetate (8.8:0.8:0.4, v/v) which gave sharp and symmetrical peaks of cis- and trans-permethrin at RF = 0.72 and 0.62, respectively. Linear regression data for the calibration curves in the concentration ranges of 300 to 1800 ng spot−1, showed a good linearity r = 0.996 ± 0.0015 and r = 0.993 ± 0.0029 for cis- and trans-permethrin, respectively. The limits of detection (LODs) for cis- and trans-permethrin were found to be 1.6 and 2.4 ng spot−1, respectively, and limits of quantitation (LOQs) were 4.9 and 7.4 ng spot−1, respectively. The developed method was validated for various validation parameters that proved the method was reproducible, precise, and highly accurate for the determination of permethrin isomers in household pesticide and insecticide products.