On-line Green Solid Phase Extraction of Trace Rare Earth Elements and Uranium in Environmental Samples and ICP OES Detection

Naeemeh Zari,Seyyed H Ahmadi,Jalal Hassan,Kourosh Tabar-Heydar

doi:10.5935/0103-5053.20160074

Abstract

An on-line solid phase extraction (SPE) method using mini column packed with natural sorbent based on cotton roll dyed by quinalizarin was developed for simultaneously pre-concentration of rare earth elements and uranium at trace levels in environmental samples followed by inductively coupled plasma optical emission spectrometry (ICP OES) determination. Various parameters such as sample and eluent flow rate, sample volume and matrix ions on the method efficiency have been investigated. Under the optimized conditions, the limits of detection (LODs, 3σ) for rare earth elements were in the range of 0.002-0.300 µg L-1 and 0.420 µg L-1 for uranium. The relative standard deviation (n = 5) were lower than 6% except for samarium and uranium. The method was successfully applied for determination of trace rare earth elements and uranium in lake, well, tap water and carbonate mineral samples. The accuracy of the proposed method was validated by add-found method and direct analysis by ICP OES. This method has some advantages such as simplicity, rapidity, green chemistry and high sensitivity.

Highlights

Nowadays ground water globally has gained more paramount attention
Thirty milligrams of quinalizarin was dissolved in dimethyl sulfoxide (DMSO) and the cotton roll was dyed in prepared solution on heater at temperature of 100 oC for at least 4 h
The radio frequency of inductively coupled plasma optical emission spectrometry (ICP OES), nebulizer gas flow rate, sample uptake rate and viewing height were selected as independent variables

Summary

Introduction

Nowadays ground water globally has gained more paramount attention. For the protection and safe use of ground water, it is important to know the origin of water and how it is influenced by the environment. Thirty milligrams of quinalizarin was dissolved in dimethyl sulfoxide (DMSO) and the cotton roll was dyed in prepared solution on heater at temperature of 100 oC for at least 4 h. It was washed by cold distilled water and dried in an oven. 25 mL of aqueous sample solution (100 μg L−1) of REEs and U (adjusted to desired pH) was loaded on prepared mini column at flow rate of 2 mL min−1 with peristaltic pump and rotary valve in load position. The injection valve was switched back to loading position and tubing lines were washed by distilled water to eliminate remaining acid

Findings

Result and Discussion

Conclusions