This work deals about the evaluation and improvement of analytical and electrochemical features of chemically modified electrode based on dihexadecyl hydrogen phosphate (DPH) and carbonaceous materials. The electrochemical features of films obtained were evaluated by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Between the modifications evaluated, the glassy carbon electrode (GCE) modified with CB and DPH (DHP-CB/GCE) showed lower resistance to charge transfer and higher electron transfer rate. Additionally, the highest current of U(VI) was obtained with DHP-CB/GCE in a very stable way, the process present quasi-reversible behavior and it is controlled by a mixture of diffusion and absorption. The best instrumental conditions for U(VI) determination were obtained applying frequency of 15 Hz, amplitude of 100 mV, and deposition potential of − 0.1 V (by square wave cathodic stripping voltammetry). Among the electrolyte compositions (acetate and citrate buffers), ionic strength (from 0.10, 0.15, to 0.20 mol L⁻¹), and pH (from 3.6 to 5.6) evaluated, the highest current of U(VI) were obtained in 0.15 mol L⁻¹ of acetate buffer, pH 5.6. The method was accurate, linear, and sensitive (detection limit of 0.088 μg L⁻¹ using 300 s of deposition).

这项工作涉及评估和改进基于磷酸二十六烷基氢（DPH）和碳质材料的化学修饰电极的分析和电化学特性。通过电化学阻抗谱（EIS）和循环伏安法（CV）评估获得的膜的电化学特性。在评估的修饰之间，用CB和DPH修饰的玻璃碳电极（GCE）（DHP-CB / GCE）显示出较低的电荷转移阻力和较高的电子转移速率。此外，用DHP-CB / GCE以非常稳定的方式获得了U（VI）的最高电流，该过程具有准可逆的行为，并且受扩散和吸收的混合作用控制。U（VI）测定的最佳仪器条件是使用15 Hz的频率，100 mV的振幅，和沉积电势为-0.1 V（通过方波阴极溶出伏安法）。在电解质组合物（乙酸盐和柠檬酸盐缓冲液）中，离子强度（0.10、0.15至0.20 mol L^-1）并评估pH（3.6至5.6），在0.15 mol L ^-1的乙酸盐缓冲液pH 5.6中获得了最高的U（VI）电流。该方法准确，线性且灵敏（使用300 s沉积时的检出限为0.088μgL ^-1）。