The interest in new emerging pollutants (NEPs) does not only focus on the main compounds but also the degradation or intermediate products. It is important to have an effective primary treatment for the removal/degradation of NEPs from hospital and clinical wastewater to protect the environment. In this study, nifedipine degradation was performed by an electro-oxidation method using titanium-based mixed metal oxide (MMO) electrode. The determination of nifedipine was carried out by differential pulse voltammetry at hanging mercury drop electrode using Britton–Robinson buffer (BRB). The nifedipine oxidation peak was observed at + 0.7 V at a scan rate of 20 mV s⁻¹ in BRB pH 8. Titanium-based electrodes with different metal oxide compositions were assessed as an anode material for nifedipine degradation as follows: TiO₂/Ti, IrO₂–TiO₂/Ti, RuO₂–TiO₂/Ti, and IrO₂–RuO₂–TiO₂/Ti. The electro-oxidation of nifedipine was monitored using cyclic voltammetric techniques, and the degradation intermediates were confirmed using LC–MS. Approximately 65–83% of nifedipine degradation was achieved using RuO₂–TiO₂/Ti and IrO₂–TiO₂/Ti electrodes. Interestingly, RuO₂–IrO₂–TiO₂ electrode showed complete (100%) electro-oxidation of nifedipine at 30 min. Two nifedipine degradation intermediates were identified, namely 5-methoxycarbonyl-2,6-dimethyl-4-phenyl-1,4-dihydropyridine-3-carboxylic acid (compound I) and 2,6-dimethyl-4-phenyl-1,4-dihydropyridine-3,5-dicarbaldehyde (compound II) during the electro-oxidation process using RuO₂–IrO₂–TiO₂ electrode. Finally, the degradation pathway of nifedipine by MMO electrode was proposed. This is the first report on the nifedipine degradation using MMO titanium electrode by the electro-oxidation process.

对新兴污染物（NEP）的关注不仅集中在主要化合物上，而且还集中在降解或中间产物上。对于医院和临床废水中的NEP去除/降解，有效的初级处理对保护环境非常重要。在这项研究中，硝苯地平的降解是通过使用钛基混合金属氧化物（MMO）电极的电氧化方法进行的。硝苯地平的测定是使用Britton-Robinson缓冲液（BRB）在悬挂的汞滴电极上通过差分脉冲伏安法进行的。在+ 0.7 V处以20 mV s ^-1的扫描速率观察到硝苯地平氧化峰在BRB pH 8中评估。具有不同金属氧化物成分的钛基电极作为硝苯地平降解的阳极材料，如下所述：TiO ₂ / Ti，IrO ₂ -TiO ₂ / Ti，RuO ₂ -TiO ₂ / Ti和IrO ₂ -RuO ₂ -TiO ₂ / Ti。使用循环伏安法监测硝苯地平的电氧化，并使用LC-MS确认降解中间体。使用RuO ₂ -TiO ₂ / Ti和IrO ₂ -TiO ₂ / Ti电极可实现约65-83％的硝苯地平降解。有趣的是，RuO ₂ –IrO ₂–TiO ₂电极在30分钟时显示硝苯地平完全（100％）的电氧化。鉴定了两个硝苯地平降解中间体，即5-甲氧基羰基-2,6-二甲基-4-苯基-1,4-二氢吡啶-3-羧酸（化合物I）和2,6-二甲基-4-苯基-1,4 -二氢吡啶-3,5-二甲醛期间使用的RuO电氧化处理（化合物II）₂ -IrO ₂ -TiO ₂电极。最后，提出了用MMO电极降解硝苯地平的途径。这是关于使用MMO钛电极通过电氧化工艺降解硝苯地平的第一份报告。