Copper determination by flow injection on-line sorbent preconcentration coupled with flame atomic absorption spectrometry using 1,10 phenanthroline

Abstract

1,10 Phenanthroline (phen) has been tested as a complexing agent, which is more stable and selective than sodium-diethyldithiocarbamate (DDTC) and ammonium-pyrrolidinedithiocarbamate (APDC), for on-line preconcentration of copper on RP-C₁₈ material in a microcolumn with a flow injection–flame atomic absorption spectrometer (Fl–FAAS) system. The on-line formed copper-phen complexes can be adsorbed on the C₁₈ sorbent material. Various parameters affecting the copper-phen complex formation and its subsequent adsorption on the microcolumn as well as its elution into the nebulizer of the atomic absorption spectrometer (AAS) were optimized. A 2.5 × 10⁻³ mol/L phen in 2% ethanol was mixed on-line with aqueous sample solution acidified with 0.1% (v/v) nitric acid and flowed through the microcolumn for 30 seconds. The adsorbed copper-phen complexes in the microcolumn were eluted with ethanol for 10 seconds into the nebulizer of AAS. A good precision (RSD = 3.0%; n = 14), high enrichment factor (32) and sample throughput (80 samples h⁻¹) with detection limit 0.3 μg/L were obtained. The method was applied to the standard reference materials such as sea water, mussels (biological), and GSS-1 (geological), for copper determination, and the results were in good agreement with the certified values. © 2000 John Wiley & Sons, Inc. Lab Robotics and Automation 12:97–103, 2000