Application of ultrasonic-assisted inclusion complex formation with α-cyclodextrin for simultaneous spectrophotometric determination of gallic acid and vanillic acids in fruit samples.

There are various methodologies to generate second-order data. Spectrophotometric method owing to its high sensitivity continues to be of wide interest to analytical chemists. Spectra recording at different interval time while the reaction is proceeded, or at different pHs, or at different concentrations of complexing agent are examples of strategies by which one can generate second-order data by the spectrophotometric method. In this work, for the first time, we employed α-CD as an inclusion complexing agent under ultrasonic irradiation for simultaneous determination of gallic acid (GA) and vanillic acid (VA). UV spectra of a mixture of two analytes were recorded as a function of α-CD concentration. A calibration set containing 9 reference samples was used to construct model using bilinear least squares/residual bilinearization (BLLS/RBL) as second-order calibration method. The predictive ability of the resulting model was validated by a test set including 5 samples. Finally, the proposed model was successfully applied to simultaneously determine the content of GA and VA in five fruit juice samples. Satisfactory results in terms of the recovery yields were obtained. In a word, UV-spectroscopy coupled with a strategy to yield a second-order data in combination to second-order calibration methods has high potential to be a simple, quick and accurate analysis procedure for the determination of various types of chemical structures in practice.