Pre-column dervatization of amino acids from nigella sativa L seed hydrolysates by reversed phase HPLC

A rapid and sensitive method for analysis of amino acid hydrolysates of nigella sativa L seed has been developed using O-phthaldialehyde(OPA ) as a pre-column derivatizing agent. OPA reagents in the presence of mercaptoethanol react rapidly with primary amino acids ( less than 60 sec.) to form isindole derivatives which easily separated with good selectivity on ODS column. Resolution of amino acid derivatives is carried out with a methanol gradient in 0.01 maqueous sodium acetate. pH 7.1 . The quantitation of amino acid derivatives is reproducible within an average relative deviation of + 1.4% the linearity for most amino acids were more than 0.9993 with detection limit of 0.2 ppm. 15 amino acid were detected in the analysis of the seed protein hydrolysate. The presence of glutamic acid, alanine, leucine, cystine phenylalanine, aspartic acid in large quantities. The common separated amino acids were detected by U.V at 338 nm within 21 minutes

Safety method, Spectrophotometric Determination of Sulfamethaxazole drug in bulk and Pharmaceutical Preparations

A simple, cheap, fast, accurate, Safety and sensitive spectrophotometric method for the determination of sulfamethaxazole (SFMx), in pure form and pharmaceutical dosage forms. has been described The Method is based on the diazotization of the drug by sodium nitrite in acidic medium at 5Cº followed by coupling with salbutamol sulphate (SBS) drug to form orange color the product was stabilized and measured at 452 nm Beer’s law is obeyed in the concentration range of 2.5-87.5 ?g ml-1 with molar absorptivity of 2.5x104 L mole-1 cm-1. All variables including the reagent concentration, reaction time, color stability period, and sulfamethaxazole /salbutamol ratio were studied in order to optimize the reaction conditions. No interferences were observed Results of analysis were validated statistically and by recovery studies. These methods are successfully employed for the determination of sulfamethaxazole in some pharmaceutical preparations.. The developed method is easy to use and accurate for routine studies relative to HPLC and other techniques