RESUMO
Objective: To analyse the two marker compounds lupeol (LP) and stigmasterol (ST) from methanolic extract of Hygrophila auriculata (H. auriculata). Methods: Separation was achieved on aluminium plates precoated with silica gel 60F254 with toluene-methanol-formic acid (7.0:2.7: 0.3 v/v/v) as mobile phase. Results: Densitometric analysis was performed at 530 nm in the reflectance mode. Compact bands for LP and ST were obtained at RF 0.52 ± 0.02 and 0.28 ± 0.05. Linearity (r2=0.998 5 and 0.993 7), limit of detection (45 and 18 ng/band) limit of quantification (135 and 54 ng/band), recovery (98.2%-99.7% and 97.2%-99.6%), and precision (<2.18 and 1.91) were satisfactory for LP and ST respectively. Linearity range for LP and ST were 100-1 000 and 50-500 ng/band and the contents estimated as (0.19±0.1)% and (0.47±0.1)% w/w respectively. Conclusion:The method demonstrated efficient analysis testing of LP and ST in samples; therefore it can be used for routine analysis.
RESUMO
A rapid, simple and sensitive chromatographic method (RP-HPTLC) has been developed for the extraction and quantitative estimation of Theobromine in different extract tea samples (Camellia sinensis). Separation was performed on Silica gel 60 f254 HPTLC plates with ethyl acetate: methanol (27:3 v/v), as mobile phase. The determination was carried out in the UV region, using densitometric absorbance at 274 nm. The maximum concentration of Theobromine in tea samples was found to be 2.313 %. The theobromine response was found to be linear over range 3-15 μg per zone. Limit of detection and quantitation were found to be 30 and 140 ng/ spot respectively. The HPTLC method was validated in terms of precision, accuracy, sensitivity and robustness. The proposed method provided precise and accurate analysis for extraction and estimation of theobromine by HPTLC-UV.