Preconcentration of Pb with Aminosilanized Fe3O4 Nanopowders in Environmental Water Followed by Electrothermal Atomic Absorption Spectrometric Determination

A new preconcentration method to determine lead in environmental waters using the aminosilanized magnetite Fe3O4 powder sorbent has been developed. The preconcentration method was combined with electrothermal atomization atomic absorption spectrometry (ETAAS) and a graphite atomizer. Trace amount of sorbent (3 mg) could be applied into the preconcentration of Pb. According the preconcentration, the detection limits were 14 and 19 pg·mL−1 with bare and aminosilanized Fe3O4, respectively. The effect of interferent elements such as Al, Ca, Co, Fe, K, Mg, Na, Ni, and Zn (1000 ng·mL−1 versus Pb 1 ng·mL−1) on the preconcentration of Pb using bare magnetite was evaluated, and some elements (Al, Ni, and Zn) were found to interfere with the Pb preconcentration. The aminosilanized Fe3O4 sorbent was found to be effective in eliminating the severe interferences. The enrichment factors were 34 for the preconcentration with aminosilanized Fe3O4. The recovery of spiked Pb in the case of the sorbent with aminosilanized Fe3O4 was in the range of 75 to 110%. From the analytical data, the preconcentration technique was found to be useful for the determination of trace lead in environmental waters.