School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, China; Oil and Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University, Chengdu 610500, China.
School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, China.
Talanta. 2017 May 15;167:103-110. doi: 10.1016/j.talanta.2017.02.014. Epub 2017 Feb 6.
In this work, a colorimetric methodology was developed for free chlorine determination by constructing a fiber-optic sensor (FOS) which was designed by using a small LED as light source and two silica fibers as light transmission elements. Then the FOS was integrated with the sequential injection lab-on-valve (SI-LOV) manifold to fabricate a FOS-SI-LOV system for free chlorine detection. The colorimetric determination was based on the reaction between N,N-diethyl-p-phenylenediamine (DPD) reagent and free chlorine, which would produce a chromophore showing maximum absorbance at 511 and 551nm and detected by a micro spectrometer detector. By choosing a green LED with emission wavelength at 520nm as light source, the chlorine concentration could be simply evaluated according to Beer's law. The developed FOS-SI-LOV system showed improved performances of wide linear range (10-400μgL), low detection limit (3.5μgL, 3σ), fast analysis (6.85s) and excellent repeatability (0.0083 RSD, n=8) for chlorine determination. The proposed FOS-SI-LOV system has been applied to on-line and real-time chlorine determination in different water samples with excellent selectivity. Furthermore, this FOS-SI-LOV methodology provided a colorimetric and fluorescence detection platform for other hazardous species monitoring in water environment based on Beer's law and Stern-Volmer relationship, respectively.
在这项工作中，通过构建光纤传感器（FOS）开发了一种比色法测定游离氯的方法，该传感器是使用小的 LED 作为光源和两根二氧化硅纤维作为光传输元件设计的。然后，将 FOS 与顺序注射阀上实验室（SI-LOV）流路集成，制造用于游离氯检测的 FOS-SI-LOV 系统。比色测定基于 N，N-二乙基对苯二胺（DPD）试剂与游离氯之间的反应，该反应会产生一种生色团，在 511nm 和 551nm 处具有最大吸光度，并通过微光谱仪检测器进行检测。通过选择发射波长为 520nm 的绿色 LED 作为光源，可以根据比尔定律简单地评估氯浓度。所开发的 FOS-SI-LOV 系统具有较宽的线性范围（10-400μg/L）、较低的检测限（3.5μg/L，3σ）、快速分析（6.85s）和出色的重复性（0.0083 RSD，n=8）等优点，可用于不同水样中的在线实时氯测定。此外，该 FOS-SI-LOV 方法基于比尔定律和 Stern-Volmer 关系，分别为水环境中其他有害物质的监测提供了比色法和荧光检测平台。
