8.

Kinetic linear regression model at pH 2 (A) and pH 7 (B), pseudo-second order. For the kinetic tests, 50 mL solutions of McIlvaine buffer at pH 2 and pH 7, to which 10 mg of tartrazine and 0.1 g of previously dried BSY (24 h at 105 °C) were added. The solutions were stirred continuously at room temperature (25 °C), and aliquots of 3 mL were collected at times between 5 and 120 min. After centrifugation (5000g, 10 min), the samples were analyzed by spectrophotometry UV–vis at 425 nm.