Solid Phase Extraction Combined Direct Spectrophotometric Determination of Brilliant Blue in Food Using β-Cyclodextrin Polymer

A new and sensitive solid phase extraction (SPE) combined direct spectrophotometry for determination of brilliant blue (BB) in food has been developed, in which beta-cyclodextrin polymer (beta-CDP) is used as a SPE adsorbent to extract BB from aqueous solutions to form a solid supramolecular complex with a 1:3 molar ratio of BB to beta-CDP, and BB in beta-CDP was directly determined by a solid phase spectrophotometry. SPE conditions were pH 7.0, temperature 20 degrees C, ionic strength 0.1 mol/l, and shaking time 40 min. The calibration curve is linearity in the concentration range of 0.05-12.0 mu g/ml. The proposed method was applied to the determination of BB in food samples at 627 nm maximum absorption wavelength with satisfactory results.