Determination of guanine and adenine by high-performance liquid chromatography with a self-fabricated wall-jet/thin-layer electrochemical detector at a glassy carbon electrode.
Determination of guanine and adenine by high-performance liquid chromatography with a self-fabricated wall-jet/thin-layer electrochemical detector at a glassy carbon electrode.
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DOI：
10.1016/j.talanta.2014.11.042
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发表时间：
2015-03
期刊：
影响因子：
6.1
通讯作者：
Yaping Zhou;Hongling Yan;Q. Xie;S. Yao
中科院分区：
文献类型：
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作者：
Yaping Zhou;Hongling Yan;Q. Xie;S. Yao
建立了一种同时测定鸟嘌呤（G）和腺嘌呤（A）的壁喷射/薄层安培电化学检测器（ECD）-高效液相色谱（HPLC）联用方法。在优化的条件下，分析物在玻碳电极（GCE）上检测，HPLC-ECD校准曲线显示出良好的线性（R2>0.997）。G和A的检测限分别为0.6 nM和1.4 nM（S/N=3），低于UV-vis检测器和商用电化学检测器的检测限。我们已成功地应用此HPLC-ECD测定了盐酸消化小牛胸腺双链DNA中G和A的含量。此外，我们详细比较了G和A通过循环伏安法（CV）和HPLC-ECD系统在裸GCE和电还原氧化石墨烯（ERGO）修饰的GCE上的分析。我们发现，G和A在电极表面的吸附可以改变它们的阳极CV峰，并且G和A在电极表面的有限位置上的竞争吸附可以导致它们的阳极CV峰信号的串扰效应，但是HPLC-ECD系统对这种电极吸附不敏感，并且可以给出更可靠的分析结果。
A sensitive wall-jet/thin-layer amperometric electrochemical detector (ECD) coupled to high-performance liquid chromatography (HPLC) was developed for simultaneous determination of guanine (G) and adenine (A). The analytes were detected at a glassy carbon electrode (GCE) and the HPLC−ECD calibration curves showed good linearity (R2>0.997) under optimized conditions. Limits of detection for G and A are 0.6 nM and 1.4 nM (S/N=3), respectively, which are lower than those obtained with an UV–vis detector and a commercial electrochemical detector. We have successfully applied this HPLC−ECD to assess the contents of G and A in hydrochloric acid-digested calf thymus double-stranded DNA. In addition, we compared in detail the analysis of G and A by cyclic voltammetry (CV) and by the HPLC−ECD system on both bare GCE and electroreduced graphene oxide (ERGO) modified GCE. We found that the adsorption of G and A on the electrode surfaces can vary their anodic CV peaks and the competitive adsorption of G and A on the limited sites of the electrode surfaces can cause crosstalk effects on their anodic CV peak signals, but the HPLC−ECD system is insensitive to such electrode-adsorption and can give more reliable analytical results.