2026-05-31T20:03:58Zhttps://riuma.uma.es/rest/oai/request

oai:riuma.uma.es:10630/206682026-02-03T11:57:08Zcom_10630_2254col_10630_37959

Development of an on-line MSPE-ICP-OES method for the preconcentration and speciation of Cr(III)/Cr(VI) in aqueous samples Morales-Benítez, Irene García-Mesa, Juan Carlos Montoro-Leal, Pablo López-Guerrero, María del Mar Vereda-Alonso, Elisa Isabel Extracción (Química) Reactores químicos SHOTGUN PRESENTATION In this work, a new double-reactor method for the analysis and speciation of trace amounts of Cr(III)/Cr(VI) ions in environmental samples has been developed combining on-line magnetic solid phase extraction (MSPE) with inductively coupled plasma optical emission spectrometry (ICP OES). For the preconcentration and speciation of Cr, a new magnetic graphene oxide (MGO) functionalized with p-sulfanilic acid has been syhthesized. This material presents good capacity of adsorption towards Cr(III) and Cr(VI) species. The FI manifold used for on-line preconcentration and elution is shown in Fig.1. The eight-port valve (V) was changed from position A-B, and vice versa allowing the load of sample of the two reactors (R1 and R2) followed of the elution of Cr(VI) with NH3 3.2 % in R1 and total Cr with HNO3 2.3 % in R2 to ICP-OES. Subtracting the signal of Cr (VI) to the signal of Cr(III)+Cr(VI), both ions can be determined. Moreover, several flow and chemical variables were optimized by two multivariate central composite designs (CCD). The optimized method offers good sensitivity and precision. The accuracy of the proposed method was verified using certified reference materials. The obtained results were in good agreement with the certified values and high recoveries were achieved for the spiked samples. Thus, the new adsorbent has demonstrated to be useful for the preconcentration and speciation of Cr(III)/Cr(VI). 2021-01-08T08:49:58Z 2021-01-08T08:49:58Z 2020 2021-01-08 conference output https://hdl.handle.net/10630/20668 eng 4 th International Caparica Christmas Conference on Sample Treatment 2020 Caparica (Portugal) Del 30/11/2020 al 03/12/2020 open access