Utilization of a triacetylcellulose membrane to immobilize 5-(2′,4′-dimethylphenylazo)-6-hydroxypyrimidine-2,4-dione for erbium determination in real samples

Zakia Al-Mallah, Alaa S. Amin

Index: 10.1016/j.jiec.2018.02.027

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Abstract

A membrane optode formed by physical inclusion of a chromophore 2-amino-6-(1,3-thiazol-2yldiazenyl)phenol (ATDP) into a plasticized cellulose triacetate (CTA) matrix was investigated for preconcentration, extraction and colorimetric determination of Er(III) from aqueous samples. The optode was examined for erbium uptake in borate buffer medium (∼ 125 ng mL−1) at pH 8.5–9.0. The inclusion of an anion-exchanger tri-isooctylamine (TiOA) was found to be necessary for the formation of Er(III)– ATDP complex in the optode matrix, resulting into distinct colour change of the optode from red to violet color after erbium sorption. The composition of the optode was prepared by varying the amounts of different plasticizers and TiOA to obtain minimum response time towards Er(III) in borate buffer medium. The effects of different experimental parameters involved in the detection and quantification of Er(III) using optode were optimized. The optode analytical performance was performed in terms of interference of cations and anions, reusability, equilibration time, detection limit, etc. and compared with the conventional colorimetric method for Er(III) using different chromophores. The optode developed in the present study was tested in real samples with good results comparing to the GF-AAS method.