Agarwal Abhinav, Verma Amit Kumar, Yoshida Masafumi, Naik Radhey Mohan, Prasad Surendra
Department of Chemistry, University of Lucknow Lucknow 226007 India
Department of Natural Sciences, Faculty of Knowledge Engineering, Tokyo City University Tokyo Japan.
RSC Adv. 2020 Jul 1;10(42):25100-25106. doi: 10.1039/d0ra03487h. eCollection 2020 Jun 29.
Mercury(ii) ions act as catalyst in the substitution of cyanide ion in hexacyanoruthenate(ii) by pyrazine (Pz) in an acidic medium. This property of Hg(ii) has been utilized for its determination in aqueous solutions. The progress of reaction was followed spectrophotometrically by measuring the increase in absorbance of the yellow colour product, [Ru(CN)Pz] at 370 nm ( , = 4.2 × 10 M s) under the optimized reaction conditions; 5.0 × 10 M [Ru(CN) ], 7.5 × 10 M [Pz], pH 4.00 ± 0.02, ionic strength () = 0.05 M (KCl) and temp. 45.0 ± 0.1 °C. The proposed method is based on the fixed time procedure under optimum reaction conditions. The linear regression (calibration) equations between the absorbance at fixed times ( = 15, 20 and 25 min) and [Hg(ii)] were established in the range of 1.0 to 30.0 × 10 M. The detection limit was found to be 1.5 × 10 M of Hg(ii). The effect of various foreign ions on the proposed method was also studied and discussed. The method was applied for the determination of Hg(ii) in different wastewater samples. The present method is simple, rapid and sensitive for the determination of Hg(ii) in trace amount in the environmental samples.
在酸性介质中，汞（II）离子可催化吡嗪（Pz）取代六氰合钌（II）酸根中的氰离子。汞（II）的这一特性已被用于其在水溶液中的测定。通过在优化反应条件下（5.0×10⁻⁵ M [Ru(CN)₆]⁴⁻、7.5×10⁻⁴ M [Pz]、pH 4.00±0.02、离子强度（I）= 0.05 M（KCl）、温度45.0±0.1 °C）测量黄色产物[Ru(CN)₅Pz]²⁻在370 nm处吸光度的增加（ε = 4.2×10³ M⁻¹ s⁻¹），用分光光度法跟踪反应进程。所提出的方法基于最佳反应条件下的固定时间程序。在1.0至30.0×10⁻⁷ M范围内建立了固定时间（t = 15、20和25分钟）时的吸光度与[Hg(II)]之间的线性回归（校准）方程。发现汞（II）的检测限为1.5×10⁻⁷ M。还研究和讨论了各种外来离子对所提出方法的影响。该方法用于测定不同废水样品中的汞（II）。本方法对于环境样品中痕量汞（II）的测定简单、快速且灵敏。
