Application of an inclusion complex for determination of dithianon residues in water and fruits

A 3,3′-benzidine/β-cyclodextrin fluorescence derivative (BCDFD) was prepared and characterized by means of elemental analysis and 1H NMR. An inclusion complex was formed between BCDFD and the pesticide dithianon based on the internal cavity of β-cyclodextrin (β-CD), and the binding constant (KS ) of the inclusion complex was investigated. The inclusion complex could be applied for the determination of dithianon residues. Based on this, a sensitive method for the determination of dithianon was established. The linear dynamic range was from 0.63 to 12.5 mg L−1 with a correlation coefficient of 0.9927. The limit of detection for an aqueous solution of standard and the relative standard deviation (RSD) were 10.6 µg L−1 and 0.76%, respectively. The proposed method has been successfully applied for the determination of dithianon residues in water and fruit samples with satisfactory results, and recoveries in the range of 96.0–108% were obtained. The method is rapid, direct, economical, and sensitive for dithianon analysis.