Use of Alizarin Red S as an Ion-Pair Reagent for the Spectrophotometric Assay of Fexofenadine in Pharmaceuticals and in Spiked Human Urine

Figure 1

Absorption spectra of the ion-pair complex of FFH-AZS (6 μg mL⁻¹ FFH) in method A and dianionic form of the dye (2 μg mL⁻¹ FFH-AZS ion-pair) in method B.

(a)

(b)