Estratégias de microextração em fases sólida e líquida para determinação de cobre e cromo em água empregando técnicas eletroanalíticas e espectrométricas

Abstract

A rapid and essential example for the analysis of chromate ions in water samples is combined analysis with flow injection, with an in-line preconcentration as a minicolumn. The chromate ions in the samples were retained in the double-lamellar hydroxide filled (LDH) minicolon and then eluted with 0.1 mol L-1 Na2CO3 at a flow rate of 0.5 mL min-1 directly into the F AAS. The adsorbent was characterized by medium infrared spectroscopy (MIR), scanning electron microscopy (SEM) and BET (Brunauer, Emmett, Teller). The preconcentration was promoted through the interaction between the ion chromate and the HDL material in its double layers. Some variables that influence the extraction of metallic ions were studied. Under optimized conditions, the method presented enrichment factors of 44.53, the relative standard deviation (RSD) was 4.7%, the detection limit of 1.42 μg L-1 and linearity of 5.0-200, 0 μg L-1. The verification of accuracy was performed through the analysis of a certified reference material for water (APS-1071 NIST).