Determination of catechin in green tea using a catechol oxidase biomimetic sensor

Journal of the Brazilian Chemical Society

Osório, Renata El-Hage M. de Barros¹  Anjos, Ademir dos¹  Micke, Gustavo Amadeu¹  Vieira, Iolanda C.¹  Fernandes, Suellen C.¹  Universidade Federal de Santa Catarina, Florianópolis, Brazil¹  Neves, Ademir¹ 

关键词: catechin;    green tea;    biomimetic sensor;    square wave voltammetry;   

DOI  :  10.1590/S0103-50532008000600024

学科分类：化学（综合）

来源: SciELO

【 摘 要 】

A catechol oxidase biomimetic sensor, based on a novel copper(II) complex, was developed for the determination of catechin in green tea and the results were compared with those obtained by capillary electrophoresis. The dinuclear copper(II) complex, [Cu2(HL)(µ-CH3COO)](ClO4), containing the ligand N,N-[bis-(2-pyridylmethyl)]-N',N'-[(2-hydroxybenzyl)(2-hydroxy-3,5-di-tert-butylbenzyl)]-1,3-propanediamine-2-ol (H3L), was synthesized and characterized by IR, 1H NMR and elemental analysis. The best conditions for the optimization of the biomimetic sensor were established by square wave voltammetry. The best performance for this sensor was obtained in 75:15:10% (m/m/m) of the graphite powder:nujol:copper(II) complex, 0.05 mol L-1 phosphate buffer solution (pH 7.5) and frequency, pulse amplitude, scan increment at 30 Hz, 80 mV, 3.3 mV, respectively. The analytical curve was linear in the concentration range 4.95 × 10-6 to 3.27 × 10-5 mol L-1 (r = 0.9993) with a detection limit of 2.8 × 10-7 mol L-1. This biomimetic sensor demonstrated long-term stability (9 months; 800 determinations) and reproducibility with a relative standard deviation of 3.5%. The recovery of catechin from green tea samples ranged from 93.8 to 106.9% and the determination, compared with that obtained using capillary electrophoresis, was found to be acceptable at the 95% confidence level.

【 授权许可】

Unknown