Electrochemical determination of maltol in beverages with glassy carbon electrode and its silica sol–gel modified electrode

The electrochemical behavior of maltol on a glassy carbon (GC) electrode was investigated. The results were applied to differential pulse voltammetric determination of maltol in beverages pretreated by ultrafiltration. Under the optimum experimental conditions, the linear range is 1×10−5 to 6×10−4 mol l−1 maltol and the relative standard deviation for 0.4 mmol l−1 maltol is 0.6% (n=9). The detection limit was 5 μmol l−1. Furthermore, silica sol–gel film on GC electrode could be used as suitable selective membrane, which integrated selective membrane on the electrode and substituted for the pretreatment of ultrafiltration. Under the above conditions, maltol was determined by semi-differential linear sweep voltammetry at a silica sol–gel modified GC electrode in the concentration range of 5×10−6 to 5×10−4 mol l−1. The detection limit was 2 μmol l−1 and the relative standard deviation for 0.1 mmol l−1 maltol was 0.7% (n=7). The proposed method is of sensitivity, simplicity, rapidness and no contamination. It had been applied to the direct determination of maltol in beverages such as grape wines, drinks and beers without any pretreatment. The results obtained with the present method were satisfactory with those obtained by spectrophotometry. It could be used as a simple and practical method for the determination of the flavor enhancer maltol in beverages.