Studying Newly Synthesized and Developed 4-Hydroxy-3-Methoxybenzaldehyde Schiff Bases by UV Spectrophotometry and High Performance Liquid Chromatography

Abstract

Green synthesis is the design of chemical products and processes that reduces or eliminates the use and generation of hazardous substances. Schiff bases of 4-hydroxy-3- methoxybenzaldehyde (vanillin) were prepared using various aromatic amines and base catalyst in the presence of aqueous media. High performance liquid chromatography (HPLC) and ultraviolet (UV) spectrophotometry methods were developed for qualitative study of the synthesized 4-hydroxy-3- methoxybenzaldehyde Schiff bases. HPLC was carried out by reversed phase on a C18 column with a mobile phase composed of acetonitrile and 0.5% triethyl amine (pH 4.5 adjusted with orthophosphoric acid (60:40, v/v)). UV measurements were performed at λmax 286 nm for compound V1 ((E)-4-(4-hydroxy-3-methoxybenzylideneamino)benzoic acid), λmax 336 nm for compound V2 ((E)-4-(4-hydroxy-3-methoxybenzylideneamino)phenol), and λmax 320 nm for compound V3 ((2-methoxy-4-(E)-(phenylimino)methyl)phenol). Both the HPLC and UV methods showed good reproducibility and precision and were successfully applied to study 4-hydroxy-3- methoxybenzaldehyde derivatives. The standard de-viations of relative peak area and retention times for 4-hydroxy-3-methoxybenzaldehyde derivatives were within 2% indicating the suitability of the system. The proposed economical methods can be applied for rou-tine analysis of 4-hydroxy-3-methoxybenzaldehyde derivatives of any type.