Stability-indicating high performance thin layer chromatographic determination of sulfanilamide in human urine

A simple, sensitive, selective, precise and stability-indicating high-performance thin-layer chromatographic ( HPTLC ) method was developed and applied to human urine for the densitometric determination of sulfanilamide. A mixture of chloroform-ethyl acetate-xylene (2.5: 4.0: 1.0, v/v/v) was used as a mobile phase. The system was found to give compact spots for sulfanilamide (retardation factor, R f = 0.21±0.02). The linear regression analysis data for the calibration plots showed good linear relationship with r 2 = 0.9970 ± 0.0003 and r 2 = 0.9947 ± 0.020 within the concentration range of 50–250 ng per spot and 100–1000 ng per spot with respect to peak area, respectively. The limit of detection ( LOD ) and quantification ( LOQ ) were 8 and 25 ng per spot, respectively. Sulfanilamide was subjected to acid and alkali hydrolysis, oxidation, dry heat and wet heat treatment. According to the International Conference on Harmonization ( ICH ) guidelines the method was validated for precision, recovery and robustness. The ultraviolet ( UV ) spectra of the degradation products which had different spectra from sulfanilamide were also recorded.