Speciation of inorganic selenium by solid phase extraction using nanozirconium oxide/boron oxide composite material


Abstract: The speciation and preconcentration of selenium were carried out by solid phase extraction using nanozirconium oxide/boron oxide (ZrO$_{2}$/B$_{2}$O$_{3})$. Electrothermal atomic absorption spectrometry (ETAAS) was used for detection. This preconcentration and/or speciation method depends on the retention of Se(IV) ions selectively as its ammonium pyrrolidine dithiocarbamate (APDC) complex on the sorbent. The effects of pH, flow rate, and volume of sample solution and eluent type were investigated for determining the optimum preconcentration and speciation conditions. The effects of other ions that may interfere with the determination and speciation of selenium were also investigated. Moreover, the analytical performance criteria of the method such as detection limit, quantification limit, linear working range, precision, and accuracy were also determined under the optimum experimental parameters. The analytical limit of detection for Se(IV) was 1.21 $\mu $g L$^{-1}$. The accuracy of the method was checked by applying it to certified reference material (NIST 1643e) and spiked water samples. It was shown that the determination could be performed with a relative error of about 10%. The precision of the method was also at an acceptable level for analytical purposes for trace analysis (relative standard deviation deviation <5%).

Keywords: Speciation, preconcentration, selenium, solid phase extraction, nanometal oxide, electrothermal atomic absorption spectrometry

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