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Separation and Determination of Medium Lanthanides: A New Experiment with Use of Ion-Exchange Separation and Fast Fourier Transform Continuous Cyclic Voltammetry

2009; Elsevier BV; Volume: 4; Issue: 12 Linguagem: Inglês

10.1016/s1452-3981(23)15252-7

1452-3981

Mohammad Reza Pourjavid, Parviz Norouzi, Mohammad Reza Ganjali, Ali Nemati Kharat, Hassan Ali Zamani, Majid Javaheri,

Electrochemical sensors and biosensors

Separation of medium lanthanides (Sm3+, Eu3+, Gd3+, Tb3+ and Dy3+) on Nucleosil 100-5-SA (an ion-exchange column) in the presence of α-hydroxyisobutyric acid (HIBA) as an elution agent was investigated. Determinations were performed by Fast Fourier Transform Continuous Cyclic Voltammetry (FFT-CCV) in a flowing solution. It should be stressed that this technique is: simple, precise, accurate, time saving and economical. The influence of HIBA concentration and pH of the eluent was studied. The best performance obtained was at; pH 4.0, scan rate 30 V s-1, accumulation potential -300 mV, and accumulation time 0.3 s. The proposed method displays a linear dynamic range between 0.26-23 mg L-1 and a detection limit of 0.08 mg L-1. Precision, inter-day precision and accuracy of the assay have been presented too. A comparative evaluation of medium lanthanide distribution in sophisticated monazite and xenotime mineral solutions using both FFT-CCV and Inductively Coupled Plasma Atomic Emission Spectrometric (ICP-AES) techniques were carried out. In detail, the advantages this method illustrates in comparison with other reported methods are the following; no necessity for oxygen removal from test solution, a suitable detection limit and fast determination of any such compound in a wide variety of chromatographic methods. Potential waveform consisted of steps for cleaning, accumulation and potential ramp of the analyte, and it was continuously applied on an Au disk microelectrode (12.5 mm in radius).