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

Tomoharu Kusutaki,Hideyuki Katsumata,Mai Furukawa,Ikki Tateishi,Satoshi Kaneco

doi:10.3390/chemengineering3030074

Abstract

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.

Highlights

In recent years, the contamination of aquatic systems with toxic heavy metals has become a serious problem
The enrichment factor is defined as the Pb concentration in the final solution after the preconcentration divided by the initial Pb concentration in the solution before the preconcentration
Because the lead species of PbOH+ appear from pH 6, the electrostatic repulsion becomes more weak upon increasing the pH from 3 to 5

Summary

Introduction

The contamination of aquatic systems with toxic heavy metals has become a serious problem. The analysis and effective recovery of Pb(II) metal in water has been a crucial subject related to the quality of human life [2]. Several analytical techniques, such as electrochemical methods [3], atomic absorption spectrometry [4,5,6], inductively coupled plasma-atomic emission spectroscopy (ICP-AES) [7], and inductively coupled plasma mass spectrometry (ICP-MS) [8], have been explored for the determination of lead. To extract the target analyte metals from the sample matrix, and to determine an increase in the metal concentration, preconcentration and separation procedures such as solvent extraction [8], coprecipitation [9], cloud point extraction (CPE) [10], solid-phase extraction (SPE) [11,12,13], and magnetic solid-phase extraction (MSPE) have been performed [14,15]

Methods

Results

Conclusion