羟磷灰石/SDBS丝网印刷碳电极快速测定茶叶痕量铅

doi:10.13305/j.cnki.jts.2012.06.002

摘要/Abstract

摘要： 为改善快速测定铅电化学传感器的稳定性、灵敏度和安全性,本研究利用SDBS（十二烷基苯磺酸钠）分散羟磷灰石替代惯用的有毒汞修饰丝网印刷碳电极,并滴加Nafion膜增加稳定性,构建了一种快速测定痕量铅的新型电化学传感器。采用方波溶出伏安法,支持电解质为0.1mol/L HAc-NaAc,在优化的羟磷灰石量、测试底液pH、富集时间等工作条件下,得到2~300μg/L线性范围内的铅标准曲线,检测限为0.46µg/L（S/N=3）;其重复性好,连续5次测定后的相对标准偏差为4.59%;本方法与ICP-MS法对茶叶样本的测定结果相近。研究出的快速检测铅的新型电化学传感器具有较好的稳定性、灵敏度和安全性,且测定结果准确,具有一定的应用潜力。

关键词: 羟磷灰石, 电化学传感器, 快速测定铅, 茶叶

Abstract: In order to improve the stability, sensitivity and safety of the electrochemical sensor for rapid determination of lead, the usual toxic mercury with screen-printed carbon electrode was replaced by the hydroxyapatite dispersed by SDBS, with added Nafion membrane to increase stability, so to establish a new electrochemical sensor for rapid determination of trace lead. The analysis was performed by square-wave stripping voltammetry, Sodium acetate buffer (0.1mol/L) was employed as the supporting electrolyte. Under the optimized working conditions, including amount of hydroxyapatite, pH of solution, accumulation time, a linear response range from 2μg/L to 300μg/L was obtained, the detection limit for lead determination was 0.460µg/L(S/N) =3. The sensor presented good repeatability, evaluated in terms of relative standard deviation (R.S.D.=4.59%). The result determined by this method was similar to ICP-MS method. The novel electrochemical sensor for rapid detection of lead effectively improved the sensitivity, stability and security. In addition, it had accurate results and possessed a certain application potential.

Key words: hydroxyapatite, electrochemical sensor, rapid determination of trace lead, tea

中图分类号:

杨舫, 赵广英, 窦文超. 羟磷灰石/SDBS丝网印刷碳电极快速测定茶叶痕量铅[J]. 茶叶科学, 2012, 32(6): 485-493. doi: 10.13305/j.cnki.jts.2012.06.002.

YANG Fang, ZHAO Guang-ying, DOU Wen-chao. Hydroxyapatite/SDBS Modified Screen-printed Carbon Electrodes for the Rapid Determination of Trace Lead in Tea[J]. Journal of Tea Science, 2012, 32(6): 485-493. doi: 10.13305/j.cnki.jts.2012.06.002.

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