Boumya W, Laghrib F, Lahrich S, Farahi A, Achak M, Bakasse M, El Mhammedi M A
Univ. Hassan 1, Laboratoire de Chimie et Modélisation Mathématique, Faculté Polydisciplinaire, Khouribga 25000, Morocco.
Univ. Chouaib Doukkali, Laboratoire des Sciences de l'Ingénieur pour l'Energie, Ecole Nationale des Sciences Appliquées, El Jadida, Morocco.
Heliyon. 2017 Oct 12;3(10):e00392. doi: 10.1016/j.heliyon.2017.e00392. eCollection 2017 Oct.
A simple, selective and sensitive electrochemical method is described for the determination of different aldehydes at glassy carbon electrode using electrochemical impedance spectroscopy (EIS). The measurements were performed after their derivatization with 2,4-dinitrophenylhydrazine (DNPH) in acidic medium. The impedance measurements were investigated in the frequency range from 100 mHz to 100 kHz at a potential of 1.0 V versus Ag/AgCl. The Nyquist plots were modeled with a Randle's equivalent circuit. The charge transfer resistance was identified as the dependent parameter on relevant concentration of aldehydes (determined as their hydrazones). Under the optimized conditions, the linearity was established over the concentration range of 1000-0.05 μmol L. The limits of detection (LODs) obtained were from 0.097 to 0.0109 μmol L. Finally, the developed method has been applied to the determination of aldehydes in drinking water, orange juice and apple vinegar samples with relative standard deviations (RSDs) < 3.1% and acceptable recovery rate (around of 80%).
描述了一种简单、选择性好且灵敏的电化学方法，用于在玻碳电极上使用电化学阻抗谱（EIS）测定不同的醛类。在酸性介质中用2,4 - 二硝基苯肼（DNPH）对醛进行衍生化后进行测量。在相对于Ag/AgCl为1.0 V的电位下，在100 mHz至100 kHz的频率范围内研究阻抗测量。用Randle等效电路对奈奎斯特图进行建模。电荷转移电阻被确定为醛类相关浓度（以腙的形式测定）的相关参数。在优化条件下，在1000 - 0.05 μmol L的浓度范围内建立了线性关系。获得的检测限（LOD）为0.097至0.0109 μmol L。最后，所开发的方法已应用于饮用水、橙汁和苹果醋样品中醛类的测定，相对标准偏差（RSD）< 3.1%，回收率可接受（约80%）。
