A simple spectrophotometric determination of trace level mercury using 1,5-diphenylthiocarbazone solubilized in micelle
A simple spectrophotometric determination of trace level mercury using 1,5-diphenylthiocarbazone solubilized in micelle
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DOI：
10.2116/analsci.21.507
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发表时间：
2005-05-01
影响因子：
1.6
通讯作者：
Branger, MI
中科院分区：
文献类型：
--
作者：
Khan, H;Ahmed, MJ;Branger, MI
在微酸性（0.07 - 0.17 M H2SO 4）水溶液中，使用1，5-二苯硫代卡巴松（双硫腙）作为新型胶束分光光度试剂（λ（max）= 490 nm），提出了一种非常简单、超灵敏且具有相当选择性的非萃取分光光度法，用于快速测定超痕量汞（II）。胶束体系的存在避免了以前的溶剂萃取步骤，降低了成本，毒性，同时提高了灵敏度，选择性和摩尔吸光系数。反应是瞬时的，吸光度保持稳定超过24小时。测得汞的平均摩尔吸光系数和Sandell灵敏度分别为5.02 × 10（4）L mol（-1）cm（-1）和10 ng cm（-2）。线性校准图，得到0.05 - 10毫克L-1的汞;螯合物的化学计量组成为1：2（汞：双硫腙）。该方法的特点是由1 μ g L-1的汞的检测限。超过60种阳离子、阴离子和络合剂（如EDTA、酒石酸盐、草酸盐、柠檬酸盐、磷酸盐、硫脲、叠氮化物、SCN-）的大量过量不会干扰测定。该方法已成功应用于许多环境水样（饮用水和污染水）、生物样品（人血和尿、牛奶和鱼）和土壤;含有汞（一）和汞（二）以及复杂合成混合物的溶液。该方法具有较高的精密度和准确度（对于0.1 mg L-1，s = +/- 0.01）。
A very simple, ultra-sensitive and fairly selective non-extractive spectrophotmetric method is presented for the rapid determination of mercury(II) at ultra-trace level using 1,5-diphenylthiocarbazone (dithizone) as a new micellar spectrophotometric reagent (lambda(max) = 490 nm) in a slightly acidic (0.07 - 0.17 M H2SO4) aqueous solution. The presence of a micellar system avoids the previous steps of solvent extraction and reduces the cost, toxicity while enhancing the sensitivity, selectivity and the molar absorptivity. The reaction is instantaneous and the absorbance remains stable for over 24 h. The average molar absorption coefficient and Sandell's sensitivity were found to be 5.02 x 10(4) L mol(-1) cm(-1) and 10 ng cm(-2) of Hg, respectively. Linear calibration graphs were obtained for 0.05 - 10 mg L-1 of Hg; the stoichiometric composition of the chelate is 1:2 (Hg:dithizone). The method is characterized by a detection limit of 1 mu g L-1 of Hg. Large excesses of over 60 cations, anions and complexing agents (e.g. EDTA, tartrate, oxalate, citrate, phosphate, thiourea, azide, SCN-) do not interfere in the determination. The method was successfully applied to a number of environmental water samples (potable and polluted), biological samples (human blood and urine; milk and fish) and soils; solutions contained both mercury(I) and mercury(II) as well as complex synthetic mixtures. The method has high precision and accuracy (s = +/- 0.01 for 0.1 mg L-1).