Salimi Mohsen, Nouroozi Siavash
Department of Analytical Chemistry, Faculty of Chemistry, Iran University of Science and Technology, Tehran, Iran.
Department of Chemistry, Faculty of Science, University of Zanjan, Zanjan, Iran.
Spectrochim Acta A Mol Biomol Spectrosc. 2022 Dec 15;283:121713. doi: 10.1016/j.saa.2022.121713. Epub 2022 Aug 4.
Inorganic arsenic especially As(III) is considered a carcinogenic substance and its measurement is important in water samples. In this work, an inexpensive flow injection analysis system was designed for the photometric determination of As(III) at low concentrations. For this purpose, a light-emitting diode (LED) based photometer with a miniaturized detector, was fabricated and used as a determination apparatus and methyl orange was used as a detecting reagent. The fabricated photometer employed the LEDs, as a light source and the light detector. The λ of emission for emitter and detector LEDs were 525 and 625 nm, respectively. Determination of As (III) was based on its inhibition effect on the redox reaction between methyl orange and X (Cl or Br). The decolorization of the reaction products in the FIA system was monitored using the homemade flow cell detector. Analytical figures of merit including linear responses ranging from 0.03 to 3.0 mg/l of As(III) (r = 0.994), detection limits of 0.007 mg/l As(III), RSD% of 1.5% (n = 7), low reagent consumption per determination, and sampling throughput of 50 determinations per hour were achieved.
无机砷尤其是三价砷被认为是一种致癌物质，其在水样中的测定很重要。在这项工作中，设计了一种廉价的流动注射分析系统，用于光度法测定低浓度的三价砷。为此，制作了一种基于发光二极管（LED）的带有小型化检测器的光度计，并将其用作测定仪器，同时使用甲基橙作为检测试剂。制作的光度计采用LED作为光源和光检测器。发射极和检测极LED的发射波长分别为525和625纳米。三价砷的测定基于其对甲基橙与X（氯或溴）之间氧化还原反应的抑制作用。使用自制的流通池检测器监测流动注射分析系统中反应产物的脱色情况。获得了包括0.03至3.0毫克/升三价砷的线性响应（r = 0.994）、0.007毫克/升三价砷的检测限、1.5%的相对标准偏差（n = 7）、每次测定低试剂消耗量以及每小时50次测定的采样通量等分析性能指标。
