基于 5-甲基-4-(2-噻唑偶氮)间苯二酚和三正辛基甲基氯化铵的镍(II)萃取显色体系。

Extraction-Chromogenic System for Nickel(II) Based on 5-methyl-4-(2-thiazolylazo)resorcinol and Aliquat 336.

出版信息

Acta Chim Slov. 2020 Mar;67(1):151-158.

Abstract

A water-isobutanol extraction-chromogenic system for NiII, based on the azo dye 5-methyl-4-(2-thiazolylazo)resorcinol (MTAR; H2L) and the ionic liquid Aliquat 336 (A336), was studied. Under the optimal conditions (cMTAR = 2.0 × 10-4 mol dm-3, cA336 = 5.6 × 10-3 mol dm-3, pH 8.5 and extraction time t = 1 min), NiII is extracted as a ternary complex which can be represented by the formula (A336+)2[Ni(L2-)2]. In the absence of A336, or in a slightly acidic medium, a binary complex, [Ni(HL-)2], with an absorption maximum at l = 548 nm and a shoulder at 590 nm is formed. The following extraction-spectrophotometric characteristics were determined at the above-mentioned optimal conditions: lmax (545 nm), molar absorptivity (5.0 × 104 dm3 mol-1 cm-1), Sandell's sensitivity (1.2 × 10-3 ∆g cm-2), Beer's law limits (0.05-3.1 mg cm-3), constant of extraction (Log K = 6.1) and fraction extracted (99.2%). The effect of foreign ions was studied; the most serious interferences were caused by CoII, CuII and CrIII.

摘要

一种基于偶氮染料 5-甲基-4-(2-噻唑基偶氮)间苯二酚 (MTAR; H2L) 和离子液体 Aliquat 336 (A336) 的镍(II)水-异丁醇萃取显色体系进行了研究。在最佳条件下 (cMTAR = 2.0 × 10-4 mol dm-3, cA336 = 5.6 × 10-3 mol dm-3, pH 8.5 和萃取时间 t = 1 min)，镍(II)被萃取为一种可表示为 (A336+)2[Ni(L2-)2]的三元配合物。在没有 A336 的情况下，或在略酸性介质中，形成一种二元配合物 [Ni(HL-)2]，其最大吸收波长为 l = 548nm 且在 590nm 处有肩峰。在上述最佳条件下，测定了以下萃取分光光度特性：lmax (545nm)、摩尔吸光系数 (5.0 × 104 dm3 mol-1 cm-1)、桑德尔灵敏度 (1.2 × 10-3 ∆g cm-2)、比尔定律范围 (0.05-3.1 mg cm-3)、萃取常数 (Log K = 6.1) 和萃取分数 (99.2%)。研究了外来离子的影响；最严重的干扰来自 CoII、CuII 和 CrIII。