木犀草素在直流加热单边热石墨柱电极上电化学行为及吸附溶出分析

Electrochemical behavior studies and adsorptive stripping analysis of luteolin at single-sided heated graphite cylinder electrodes with direct current heating

单边热石墨柱电极(ss-HGCE)应用于重要黄酮类化合物木犀草素的吸附溶出分析.采用直流加热,与交流加热相比,装置简单方便便宜.吸附预富集阶段对电极加热,能有效地增强木犀草素方波伏安溶出峰电流.这是因为对电极加热引起的强制热对流,这种热对流能够增强传质,促进吸附,因此增强溶出响应.结果表明,预富集步骤对电极加热到58℃,检出限可达1.0×10-8mol/L(S/N=3),比室温28℃时的1.3×10-7mol/L(S/N=3)降低了一个数量级,相应灵敏度也提高了.应用于模拟血清样品中木犀草素含量的测定,平均回收率是101.7%.

Single - sided heated graphite cylindrical electrode （ ss - HGCE） was used to perform adsorptive stripping square wave voltammetric （SWV） measurement of luteolin, one of the important flavonoids. Direct current heating power supplier was adoped to heat the electrode because of its low cost, simplicity and convenience. The SWV stripping peak current could be signigicantly enhanced with increasing the electrode temperature only during preconcentration step. This enhancement was mainly contributed to the forced thermal convection induced by heating the electrode rather than the bulk solution, which is able to improve mass transfer ang facilitate adsorption hence enhance stripping response. The detection limit of 1.0 ×10 ^-8 mol/L（S/N = 3 ） could be achieved at an electrode temperature of 58℃ during 5 min preconcentration, one magnitude lower than that at room temperature 28 ℃, the corresponding sensitivity was also improved. This method was applied to determination of luteolin in spiked serum, the average recovery was 101.7%.