Otimização multivariada e aplicação do sorvente SiO2-Nb2O5 para determinação em linha de Ni(II) em matriz aquosa

Abstract

In this study a new method for Ni(II) determination in aqueous samples using solid phase extraction coupled to a flow injection system and flame atomic absorption spectrometry was developed. The sorbent used for Ni(II) preconcentration and extraction was silica gel chemically modified with niobium(V) oxide. Flow and chemical variables of the system were optimized through a multivariate procedure. The factors selected were buffer type, eluent concentration, and sample and eluent flow rates. The detection limit was 0.8 μg L-1 and the precision was 1.5%. Results for recovery tests using different environmental samples were between 100.2 and 103.8%.