Fig. 4From: Silica-titania xerogel for solid phase spectrophotometric determination of salicylate and its derivatives in biological liquids and pharmaceuticalsThe dependence of silica-titania xerogels absorbance on the time of contact with salicylate derivatives. λ 410 nm. 1 2 × 10−3 M sodium salicylate, pH 2.0, 2 3∙× 10−3 M salicylamide, pH 2.0, 3 2.5∙× 10−3 M methylsalicylate, pH 7.6Back to article page