The photoelectrochemical quantification of phenolic compounds such as hydroquinone (HQ) and 4-aminophenol (4-AP) is accomplished by integrating a photoelectrochemical cell into a flow injection analysis (FIA) setup. It is a well-known fact that during the electroanalysis of phenolic compounds, the electrode surface is susceptible to poisoning. However, electrode fouling can be reduced significantly by using the FIA system with periodic washing of the electrode. Reactive oxygen species (ROS), which are generated on the surface of TiO₂ under UV light, can oxidize phenolic compounds such as 4-AP. The oxidized form of 4-AP is reduced back at the electrode surface, generating a measurable signal proportional to its concentration. The factors influencing the performance of the sensor, such as flow rate, applied potential for back reduction and pH, are investigated in detail. In the concentration range 0.0125–1.0 µM, a linear correlation between the photocurrent and the concentration of 4-AP was observed with a sensitivity of 0.6 A M⁻¹ cm⁻² and a limit of detection of 18 nM. A straightforward analytical methodology for the on-site, highly sensitive and low-cost quantification of phenolic compounds is presented, based on the use of TiO₂ in a photoelectrochemical flow cell.

通过将光电化学电池集成到流动注射分析（FIA）装置中，可以完成对苯二酚（HQ）和4-氨基苯酚（4-AP）等酚类化合物的光电化学定量分析。众所周知的事实是，在酚类化合物的电分析过程中，电极表面容易中毒。但是，通过使用带有定期清洗电极的FIA系统，可以大大减少电极结垢。在TiO ₂表面产生的活性氧（ROS）在紫外线下，可以氧化4-AP等酚类化合物。4-AP的氧化形式在电极表面被还原，产生与其浓度成正比的可测量信号。详细研究了影响传感器性能的因素，例如流速，反向还原的应用电位和pH值。在0.0125–1.0 µM的浓度范围内，观察到光电流与4-AP浓度之间存在线性关系，灵敏度为0.6 AM ^-1 cm ^-2，检出限为18 nM。基于在光电化学流通池中使用TiO ₂，提出了一种用于现场，高灵敏度和低成本定量酚类化合物的简单分析方法。