Quercetin tethered pristine-multiwalled carbon nanotube modified glassy carbon electrode as an efficient electrochemical detector for flow injection analysis of hydrazine in cigarette tobacco samples

摘要

Hydrazine is one of the hazardous chemicals present in tobacco and known to be human carcinogen. It is highly challenging to detect hydrazine present in the tobacco selectively. Since, hydrazine molecule didn't have any chromophore, indirect methods like separation coupled derivatization technique have been reported for the detection. Herein, we report a direct and separation-less flow injection analysis (FIA) coupled electrochemical detection technique (ECD) for hydrazine in tobacco. Quercetin (Qn, a plant-derived flavonoid found in fruits, vegetables, leaves and grains) tethered pristine-multiwalled carbon nanotube modified glassy carbon electrode (GCE/pristine-MWCNT@Qn) has been developed as a selective electrochemical detector for FIA and characterized by electro-chemical and physico-chemical techniques. At an optimal condition the new FIA-ECD showed a hydrazine calibration plot in a range 5-3000 mu M with a detection limit value 136 nM/20 mu L. This electrochemical detector is found to be tolerable to several electro-active chemical entities such as ascorbic acid, uric acid, dopamine, cysteine, nitrite, benzene, ammonium chloride, nitrate, citric acid, oxalic acid (negligible interferences), aromatic amine and sulfide. The applicability of this technique is further tested by analyzing the hydrazine content in different brand of cigarettes with appreciable recovery values. (C) 2014 Elsevier Ltd. All rights reserved.