The Efficiency of a Microcolumn of Rice Bran for On‐line Trace Enrichment in FI‐AAS,a Highly Selective System for On‐line Preconcentration and Determination of Copper

A flow injection flame atomic absorption spectrometry system incorporating a microcolumn of rice bran was designed, and its capability for on‐line trace enrichment of copper, cadmium and lead was studied. Analytes were deposited on the microcolumn by processing a standard or solution of analytes on the column. Injection of 250 μL of nitric acid (1 mol/L) then served to elute the retained species to FAAS. The procedure was successfully applied for determination of copper in tap water, well water and multivitamin tablets. The accuracy was assessed through recovery experiments and independent analysis by furnace‐AAS. A sample volume of 20 mL of copper resulted in a preconcentration factor of 96; precision value at the 20 μg/L was 4.1%.