On-line Preconcentration System for Cobalt Determination in Bee Honey using Flow Injection-Flame-AAS

S. CERUTTI, R. FERNÁNDEZ ORSI, M. KAPLAN, J.A. GÁSQUEZ, R.A. OLSINA, L.D. MARTINEZ

INSTRUMENTATION SCIENCE AND TECHNOLOGY

Taylor and Francis

Lugar: USA; Año: 2004 vol. 32 p. 401 - 412

1073-9149

A methodology for the on-line preconcentration and determination of cobalt by flameatomic absorption spectrometry (FAAS) coupled with flow injection (FI) in bee honeysamples is proposed. For the retention of cobalt, 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol(5-Br-PADAP) complexing reagent, and Amberlite XAD-7 resin wereused, at pH 9.5. The Co-(5-Br-PADAP) complexes were completely removed fromthe column with ethanol. An enrichment factor (EF) of 50-fold for a sample volumeof 50mL was obtained. The detection limit (DL) for the preconcentration of 50mLof aqueous solution was 0.18 ugL-1. The precision for 10 replicate determinationsat the 10 ug L-1 cobalt levels was 3.6% relative standard deviation (RSD), calculatedwith peak heights obtained. The calibration graph using the preconcentration systemfor cobalt was linear with a correlation coefficient of 0.9997 at levels near the DL, up to at least 300 ug L-1. The method was successfully applied to determination oftotal cobalt in honey samples.