Determination of Ultra Trace Amounts of Uranium (VI) by Adsorptive Stripping Voltammetry Using L-3-(3, 4-dihydroxy phenyl) Alanine as a Selective Complexing Agent

Abstract

The spectrophotometric behavior of uranium (VI) with L-3-(3, 4-dihydroxy phenyl) alanine (LDOPA) reagent revealed that the uranium can form a ML 2 complex with LDOPA in solution. Thus a highly sensitive adsorptive stripping voltammetric protocol for measuring of trace uranium, in which the preconcentration was achieved by adsorption of the uranium-LDOPA complex at hanging mercury drop electrode (HMDE), is described. Optimal conditions were found to be a 0.02 M ammonium buffer (pH 9.5) containing 2.0 Â 10 À5 M (LDOPA), an accumulation potential of À0.1 V (versus Ag=AgCl) and an accumulation time of 120 sec.The peak current and concentration of uranium accorded with linear relationship in the range of 0.5-300 ng ml À1 . The relative standard deviation (at 10 ng ml À1 ) is 3.6% and the detection limit is 0.27 ng ml À1 . The interference of some common ions was studied. Applicability to different real samples is illustrated. The attractive behavior of this reagent holds great promise for routine environmental and industrial monitoring of uranium.

Rapid Determination of Uranium in Water Samples by Adsorptive Cathodic Stripping Voltammetry Using a Tin-Bismuth Alloy Electrode

“…High uranium concentration in environment is considered to be a serious health threat to human beings, because it can cause birth defects, immune system damage and cancer to the kidney, brain, liver, heart, and other systems [2,3]. The WHO and USEPA have regulated the maximum concentration level of uranium in both drinking and environmental waters [4]. Hence, it is of great necessity to monitor the trace amount of uranium in water systems, which is of particularly public concern, especially after the Fukushima Daiichi nuclear accident in 2011 [5].…”

“…In addition, the predominant species of uranium in aqueous solution is uranyl ion, which can readily form complexes with different ligands. Various complexing agents have been exploited, such as L-DOPA [4], 8-hydroxyquinoline [16], chloranilic acid [17], arsenazo-III [18], Mordant red 19 [19], aluminon [20], dipicolinic acid [21], pyromellitic acid [22], Chromazzorul-S [23], and cupferron [24,25].…”

Adsorptive Cathodic Stripping Voltammetric Determination of Uranium(VI) in Presence of N‐Phenylanthranilic Acid

“…Adsorptive stripping analysis is one of the most widely used methods for the determination of uranium at trace and ultra‐trace levels 26–30. Although ACSV method also includes a preconcentration (accumulation) step for interfacial adsorption of an uranium complex on the electrode prior to voltammetric measurement, but this is generally carried out over a short period of time (a few min).…”

“…Moreover, the preconcentration step in adsorptive stripping analysis is performed in situ, which is not generally possible with the other analytical techniques. A number of complexing agents have been suggested for determination of uranium by ACSV including cupferron ( N ‐nitrosophenylhydroxylamine) 22–28, L ‐3‐(3,4‐dihydroxyphenyl)alanine 29,30, catechol 31, mordant blue 9 32, aluminon 33, dipicolinic acid (2,6‐pyridinedicarboxylic acid) 34, chloranilic acid (2,5‐dichloro‐3,6‐dihydroxy‐l,4‐benzoquinone) 35–38, propyl gallate 28,39, diethylenetriaminepentaacetic acid (DTPA) 39, xylidyl blue‐1 40, potassium hydrogen phatalate 41, Schiff base N,N’‐ethylenebis(salicylidenimine) in aqueous 4‐(2‐hydroxyethyl)‐1‐piperazineethanesulfonic acid medium 42, benzene‐1,2,4,5‐tetracarboxylic acid (pyromellitic acid) 43, mordant red‐19 44, and oxine 28,45. Many of these procedures suffer from interferences by several coexisting metal ions 25–35.…”

Simultaneous quantification of Bi(III) and U(VI) in environmental water samples with a complicated matrix containing organic compounds

“…These include inductively coupled plasma–optical emission spectrometry (Sun and Wu 2011; Chandrasekaran et al 2011); inductively coupled plasma–mass spectrometry (Takata et al 2011; Krishna and Arunachalam 2004); atomic absorption spectrometry (Zhang and Adeloju 2008; Kumar et al 2001); and numerous stripping procedures such as potentiometric stripping analysis (Gadhari et al 2010; Wang et al 1984), anodic stripping voltammetry (Huang 2004; Pournaghi-Azar et al 2010) and, most of all, adsorptive stripping voltammetry (AdSV) (Hajian and Shams 2003; Gholivand and Romiani 2006a, b; Khaloo et al 2007; Shams 2001; Babaei et al 2006; Novotný et al 2003; Lin et al 2005; Kefala et al 2006; Piech et al 2007; Korolczuk et al 2007; Kadi and El-Shahawi 2009; Abbasi et al 2008). Such a keen demand for adsorptive stripping procedures lies in the capabilities they offer, such as low cost and portable instrumentation, a low detection limit and the possibility of the simultaneous determination of a few elements.…”