Development of new spectrophotometric method for determination of sulfamethoxazole based on diazo coupling reaction

Abstract EN

Sulfamethoxazole (SMX) was treated with sodium nitrite and hydrochloric acid for diazotization reaction followed by coupling with chromotropic acid in alkaline medium to form,an orange colored azo dye compound which exhibits maximum absorption (λmax) at 513nm and the concentration of(SMX) was determined spectrophotometrically.

The optimum reaction conditions and other analytical parameters were evaluated.

In addition to classical univariate optimization, modified simplex method (MSM) has been applied in optimization of the variables affecting the color producing reaction.

Beer’s law obeyed in the concentration range of 0.5–20μg.mL-1 with molar absorptivity of 3.1786 × 104L.mol-1.cm-1.

The limit of detection was found to be 0.043μg.mL-1 and the Sandell's sensitivity value was 7.9681μg.cm-2.

The proposed method could be successfully applied to the determination of (SMX) in synthetic sample and urine.