Development of an ultrasensitive electrochemiluminescence inhibition method for the determination of tetracyclines.
Development of an ultrasensitive electrochemiluminescence inhibition method for the determination of tetracyclines.
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DOI：
10.1016/j.aca.2010.12.043
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发表时间：
2011-03
影响因子：
6.2
通讯作者：
Zhiyong Guo;Panpan Gai
中科院分区：
文献类型：
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作者：
Zhiyong Guo;Panpan Gai
建立了电化学发光（ECL）抑制法测定蜂蜜中四环素（TC）、土霉素（OTC）、金霉素（CTC）和强力霉素（DC）4种四环素类抗生素的方法。结果表明，4种四环素对Ru（bpy）32+/DBAE体系的电化学发光信号有明显的抑制作用。基于电化学发光信号的变化，建立了一种简单、灵敏的检测方法。考察了电化学发光抑制法的最佳实验条件，包括扫描方式和扫描速率、缓冲溶液的种类和pH值、Ru（bpy）32+和DBAE的浓度等。在优化的实验条件下，在4.0×10 - 11 ~ 4.0×10 - 9 gmL-1的浓度范围内，猝灭的ECL强度与浓度的对数呈良好的线性关系。检测限为2.0×10− 12 gmL −1。所提出的ECL系统获得的结果，在灵敏度方面，是远远优于以前报道的方法。此外，该方法已成功地应用于测定蜂蜜样品中的总残留量的四个TC。方法的相对标准偏差为4.9- 14.3%，加标回收率为87.5 ~ 115.0%。提出了Ru（bpy）32+/DBAE体系猝灭效应的可能机理。
An electrochemiluminescence (ECL) inhibition method is developed for quantitative determination of four tetracyclines (TCs) in honey samples, including tetracycline (TC), oxytetracycline (OTC), chlortetracycline (CTC) and doxycycline (DC). It was found that the four TCs strongly inhibited the ECL signal of the Ru(bpy)32+/DBAE system. Based on the ECL signal changes, a simple and ultrasensitive detection method for TCs was thus established. The optimum experimental conditions including the scan mode and scan rate of the applied potential, the type of the buffer solution and its pH, and the concentration of Ru(bpy)32+and DBAE for the ECL inhibition method, were investigated in detail. Under the optimized conditions, the quenched ECL intensity versus the logarithm of the concentration of TCs is in good linear relationship over a concentration range from 4.0×10−11to 4.0×10−9gmL−1. The detection limits were found to be 2.0×10−12gmL−1. The results obtained by the proposed ECL system, in terms of sensitivity, were much better than those of previously reported methods. In addition, the method was applied successfully to determine the total residuals of the four TCs in honey samples. The relative standard deviations were found in a range of 4.9–14.3%, and the recoveries were obtained from 87.5% to 115.0%. A possible mechanism for the quenching effects of Ru(bpy)32+/DBAE system was also proposed.