Binary and ternary complexes of sulphamethoxazole

New Spectrophotometric Method for the Assay of Sulfadiazine Drug Based on Diazotization Coupling Reaction

A sensitive, simple and rapid spectrophotometric procedure for the assay of trace quantities of sulfadiazine (SDZ) drug as bulk and in diluted solution is characterized. The procedure depends on the diazotization reaction which is produced by coupling SDZ with (4-amino-2-hydroxy acetophenon) (AHA) to produce an intense colored complex spectrophotometrically determined at 410 nm. Beer’s law was applied in the range of concentration 0.5 - 15 ppm; the molar absorptivity and Sandell’s sensitivity were 2.8484 × 104 L mol-1 cm-1 and 0.008 μg cm-2 respectively. The method limit of detection (LOD) was 0.443 μg mL-1 and LOQ (the method limit of quantitation) was 0.249 μg mL-1. The procedure is not based on solvent extraction and the additives and excipients do not significantly influence the developed procedure.