Indirect spectrophotometric determination of sulfadiazine based on localized surface plasmon resonance peak of silver nanoparticles after cloud point extraction

Abstract A novel, efficient, easy to use, environmentally friendly and cost-effective methodology is developed for the indirect spectrophotometric determination of sulfadiazine in different samples. The method is based on the micelle-mediated extraction of silver sulfadiazine and converting the silver content of the resultant surfactant-rich phase to the silver nanoparticles via generation of [Ag(NH 3 ) 2 ] + followed by its chemical reduction using ascorbic acid. The changes in the amplitude of localized surface plasmon resonance peak of silver nanoparticles as a function of sulfadiazine concentration in the sample solution was monitored using fiber optic linear array spectrophotometry at 457 nm. The experimental conditions were thoroughly investigated and optimized. Under the optimized condition, the developed procedure showed dynamic linear calibration within the range of 10.0–800.0 μg L − 1 with a detection limit of 2.8 μg L − 1 for sulfadiazine. The relative standard deviation of the method for six replicate measurements at 150.0 μg L − 1 of sulfadiazine was 4.7%. The developed method was successfully applied to the determination of sulfadiazine in different samples including well water, human urine, milk and pharmaceutical formulation.