Engineered nanoparticles (ENPs) have been widely developed in various fields in recent years, resulting in an increasing occurrence of nanoparticles in the natural environment. However, the tiny substances have created unexpected confusion in environmental sample testing due to the negative nanoeffect of ENPs. In this paper, a novel technique of spectrophotometric determination of p-nitrophenol (PNP) was developed under the interfering impact of nano-Fe(OH)₃, widely distributed in the natural environment as a typical example of ENPs. Because of the strong absorption at the two characteristic peaks of PNP, namely, 317 nm and 400 nm, nano-Fe(OH)₃ interfered with the colorimetric determination of PNP. Thus, the developed testing method, with HCl acidification at 60°C and ascorbic acid (AA) masking FeCl₃, was proposed and successfully realized the accurate determination of PNP in water samples by ultraviolet spectrophotometry with 317 nm as the absorption wavelength. The final colorimetric system of 5% HCl, 10% CH₃OH, and 1% ascorbic acid was confirmed by optimized batch experiments, and the optimum condition of acidification pretreatment was heating at 60°C for 20 min. Further results demonstrated that the proposed novel method had good accuracy and reproducibility even in high-salinity natural water bodies such as groundwater and surface water. The testing technique presented in this paper provided an interesting and useful tool for problem solving of PNP surveys under ENPs’ interference and practically supported water quality assessment for a better environment.

中文翻译：

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ENP干扰分光光度法测定对硝基苯酚。

近年来，工程纳米颗粒（ENP）在各个领域得到了广泛的发展，导致在自然环境中纳米颗粒的出现越来越多。但是，由于ENP的负面纳米效应，微小物质在环境样品测试中造成了意料之外的混乱。本文在纳米Fe（OH）₃的干扰作用下，开发了一种新的分光光度法测定对硝基苯酚（PNP）的技术，该纳米Fe（OH）₃广泛分布在自然环境中，作为ENP的典型实例。由于在PNP的两个特征峰（317 nm和400 nm）处的强吸收，纳米Fe（OH）₃干扰了PNP的比色测定。因此，提出了一种开发的测试方法，该方法在60°C下用HCl酸化，并用抗坏血酸（AA）掩盖FeCl ₃，并成功实现了以317 nm为吸收波长的紫外分光光度法准确测定水中的PNP。最终比色系统为5％HCl，10％CH ₃通过优化的分批实验确定了OH和1％的抗坏血酸，酸化预处理的最佳条件是在60°C加热20分钟。进一步的结果表明，所提出的新方法即使在高盐度天然水体（例如地下水和地表水）中也具有良好的准确性和可重复性。本文介绍的测试技术为解决ENP干扰下的PNP调查问题提供了一个有趣且有用的工具，并在实践中为更好的环境提供了支持的水质评估。