title: 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.
abstract: 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 (R(2)>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.
authors.affiliation: Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education of China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, China; College of Pharmacy, Zunyi Medical University, Zunyi 563000, China.
authors.forename: Yaping
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education of China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, China.
authors.forename: Hongling
authors.initials: H
authors.lastname: Yan
authors.affiliation: Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education of China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, China. Electronic address: xieqj@hunnu.edu.cn.
authors.forename: Qingji
authors.initials: Q
authors.lastname: Xie
authors.affiliation: Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education of China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, China.
authors.forename: Shouzhuo
authors.initials: S
authors.lastname: Yao
mesh_terms: D000225:Adenine / Q000032:analysis* / Q000737:chemistry; D000327:Adsorption; D002851:Chromatography, High Pressure Liquid; D004247:DNA / Q000737:chemistry*; D055664:Electrochemical Techniques; D004566:Electrodes; D006108:Graphite / Q000737:chemistry; D006147:Guanine / Q000032:analysis* / Q000737:chemistry
chemical_list: D006147:Guanine; D006108:Graphite; D004247:DNA; C427203:calf thymus DNA; D000225:Adenine
keywords: Adenine; Electrode-adsorption effect; Guanine; High-performance liquid chromatography; Wall-jet/thin-layer amperometric electrochemical detector