Spectrophotometric Determination of the Trace Amount of Thallium in Water and Urine Samples by Novel Oxidative Coupling Reaction

Abstract

A novel, simple, rapid, sensitive and selective method has been proposed for the trace determination of thallium by spectrophotometric detection. This method is based on the oxidation of MBTH (3-methyl-2-benzothiazolinone hydrazone hydrochloride) by thallium(III) to form diazonium cation, which couples with IPH (Imipramine hydrochloride) in phosphoric acid medium at room temperature giving a blue colored species having a maximum absorption at 635 nm. The reagents and manifold variables influences on the sensitivity were investigated and the optimum reaction conditions have been established. The calibration curve was found to be linear over the range 0.1-5 μg mL-1with the molar absorptivity and Sandell’s sensitivity of 2.9x104L mol-1cm-1, 0.0071 μg cm-2respectively. The tolerance limit of the method towards various ions usually associated with thallium has been detected. The relative standard deviation for five replicate determination of 2μg mL-1thallium was 0.47%. The method has been successfully applied for the determination of thallium(ІΙΙ) and thallium(I) in synthetic, standard reference materials, water and urine samples with satisfactory results. The performance of the proposed method was evaluated in terms of student’st-test and variance ratioF-test, to find out the significance of proposed method over the reported methods.

Light- and H2O2-Mediated Redox Transformation of Thallium in Acidic Solutions Containing Iron: Kinetics and Mechanistic Insights

“…The kinetics experiments of Tl redox transformation were examined by quantifying residual or generated Tl(III) concentrations with the 3-methyl-2-benzothiazolinonehydrazone hydrochloride (MBTH) method modified from a previous study. 58 The Tl(III) concentrations were determined using a HACH DR5300 UV−vis spectrophotom-eter. Briefly, 1 mL of the reaction solution was sampled and immediately mixed with the solution containing 1 mL of 5 M orthophosphoric acid, 1 mL 0.2% (w/v) imipramine hydrochloride (IPH) and 1 mL of 0.5 M NaF, followed by 1 mL of 0.01% (w/v) MBTH.…”

Thallium Use, Toxicity, and Detoxification Therapy: An Overview

“…The measurement is usually carried out for spectrophotometric determination. The method is focused on the oxidation of 3-methyl-2-benzothiazolinone hydrazone hydrochloride by Tl 3+ to diazonium cation, in the presence of imipramine hydrochloride in phosphoric acid medium to obtain a blue-colored solution with a maximum absorption length of 635 nm [39]. A possible mechanism of Tl toxicity is its ability to affect glutathione (GSH) activity.…”

Presence of thallium in the environment: sources of contaminations, distribution and monitoring methods

“…The measurement is usually based on the addition of a chelating agent or a reagent, which allows for spectrophotometric determination. For example, Nagaraja et al (2009) described a method which is focused on the oxidation of 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) by thallium (III) to diazonium cation, which is then treated with imipramine hydrochloride (IPH) in a phosphoric acid medium at room temperature in order to yield a blue-colored product with a maximum absorption at 635 nm.…”