On-line solid phase extraction coupled to flame atomic absorption spectrometry for the determination of trace copper and zinc in environmental and biological samples

Abstract

In this work, bamboo charcoal (BC) was used as a sorbent for on-line solid phase extraction (SPE) coupling with flame atomic absorption spectrometry (AAS) for trace copper and zinc determination in environmental and biological samples. Under the optimum pH of 5.5 (for Zn) and 7.0 (for Cu), trace copper and zinc were effectively adsorbed on the microcolumn and the retained cations were efficiently eluted with HCl or HNO3 with an appropriate concentration and flow rate for on-line AAS determination. With a sample loading time of 60 s at a sample flow rate of 7.6 mL min−1, the enhancement factors of 39 (for Cu) and 30 (for Zn) and detection limits (3σ) of 0.60 µg L−1 (for Cu) and 0.36 µg L−1 (for Zn), respectively, were achieved. The sample throughput was 45 h−1. At the level of 20 µg L−1of Cu(II) and Zn(II), the precision (RSD, n = 11) were found to be 0.26% and 1.6%, respectively. The proposed method has been successfully applied to the determination of copper and zinc in environmental and biological samples.