A novel spectrofluorometric method for the determination of methiocarb using an amphiphilic p-sulfonatocalix[4]arene

The characteristics of host–guest complexation between tetrabutyl ether derivatives of p -sulfonatocalix[4]arene (SC4Bu) and methiocarb [3,5-dimethyl-4-(methylthio) phenyl methylcarbamate] were investigated by fluorescence spectrometry. Upon addition of methiocarb, the fluorescence intensity of SC4Bu was quenched regularly and a slight red shift was observed for the maximum emission peak. These results indicated that the SC4Bu-methiocarb complex was formed a 1:1 mole ratio. An association constant of 1.67   ×   10 4   L   mol −1 was calculated by applying a deduced equation. The interaction mechanism of the inclusion complex was discussed. Based on the results, a novel spectrofluorimetric method was described for the determination of methiocarb with a detection limit at 0.05   μg   mL −1 . This method is very simple and shows high sensitivity and selectivity. Moreover, the proposed method was successfully applied to the determination of methiocarb in water samples.