Novel Approach to Automated Flow Titration for the Determination of Fe(III)
Novel Approach to Automated Flow Titration for the Determination of Fe(III)
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DOI：
10.3390/molecules25071533
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发表时间：
2020-04-01
期刊：
影响因子：
4.6
通讯作者：
Koscielniak, Pawel
中科院分区：
文献类型：
--
作者：
Kozak, Joanna;Paluch, Justyna;Koscielniak, Pawel
提出了一种利用分光光度检测自动流动滴定测定 Fe(III) 的新方法。该方法基于随着时间的推移严格且同时控制样品流和滴定剂流的流速的可能性。它包括在每个连续形成的单段中创建不同但精确定义的滴定剂和分析物浓度梯度，并且基于使用计算的滴定剂稀释因子。使用 EDTA 作为滴定剂，通过络合滴定形式对 Fe(III) 与磺基水杨酸的络合物形式进行验证。 Fe(III) 和 Fe(II)（使用 H2O2 氧化为 Fe(III) 后）的测定具有良好的精密度（CV 低于 1.7%，n = 6）和准确度（|RE| 低于 3.3%）。该方法用于测定自流水样品中的 Fe(III) 和 Fe(II)。测定结果与使用 ICP-OES 参考方法获得的值一致。使用该程序，可以使用 2.4 mL 的样品和滴定剂在 6 分钟内对各种分析物浓度进行滴定。
A novel approach to automated flow titration with spectrophotometric detection for the determination of Fe(III) is presented. The approach is based on the possibility of strict and simultaneous control of the flow rates of sample and titrant streams over time. It consists of creating different but precisely defined concentration gradients of titrant and analyte in each successively formed monosegments, and is based on using the calculated titrant dilution factor. The procedure was verified by complexometric titration of Fe(III) in the form of a complex with sulfosalicylic acid, using EDTA as a titrant. Fe(III) and Fe(II) (after oxidation to Fe(III) with the use of H2O2) were determined with good precision (CV lower than 1.7%, n = 6) and accuracy (|RE| lower than 3.3%). The approach was applied to determine Fe(III) and Fe(II) in artesian water samples. Results of determinations were consistent with values obtained using the ICP-OES reference method. Using the procedure, it was possible to perform titration in 6 min for a wide range of analyte concentrations, using 2.4 mL of both sample and titrant.