Amberlite XAD-2 functionalized with Nitroso R salt: synthesis and application in an online system for preconcentration of cobalt

The synthesis and characterization of the resin Amberlite XAD-2 functionalized with Nitroso R salt and its application in an online system for preconcentration of cobalt and determination by flame atomic absorption spectrometry (FAAS) is proposed. Cobalt(II) ions are sorbed in a minicolumn packed with the synthesized solid phase. Thereafter, these ions are eluted by acid solution to the nebulizer of a flame atomic absorption spectrometer. Sample throughput is 51 h(-1) or 18 h(-1), depending on preconcentration time, 60 s or 180 s, respectively. Cobalt was determined at pH 6.5-8.0, using a sample flow rate of 9.5 ml min(-1). Elution was performed with 30 mul of 1.0 mol l(-1) hydrochloric acid. The enrichment factors obtained were 79 and 223, with 3sigma detection limits of 1.25 and 0.39 mug l(-1), for respective preconcentration periods of 60 and 180 s. The accuracy of the procedure was evaluated by analysis of biological certified material. The method was successfully applied for cobalt determination in natural water samples. (C) 2003 Elsevier B.V. All rights reserved.