A green preconcentration method for determination of cobalt and lead in fresh surface and waste water samples prior to flame atomic absorption spectrometry.

Naeemullah Naeemullah,Tasneem Gul Kazi,Hassan Imran Afridi,Faheem Shah,Kapil Dev Brahman,Sadaf Sadia Arian,Sumaira Khan

doi:10.1155/2012/713862

Abstract

Cloud point extraction (CPE) has been used for the preconcentration and simultaneous determination of cobalt (Co) and lead (Pb) in fresh and wastewater samples. The extraction of analytes from aqueous samples was performed in the presence of 8-hydroxyquinoline (oxine) as a chelating agent and Triton X-114 as a nonionic surfactant. Experiments were conducted to assess the effect of different chemical variables such as pH, amounts of reagents (oxine and Triton X-114), temperature, incubation time, and sample volume. After phase separation, based on the cloud point, the surfactant-rich phase was diluted with acidic ethanol prior to its analysis by the flame atomic absorption spectrometry (FAAS). The enhancement factors 70 and 50 with detection limits of 0.26 μg L−1 and 0.44 μg L−1 were obtained for Co and Pb, respectively. In order to validate the developed method, a certified reference material (SRM 1643e) was analyzed and the determined values obtained were in a good agreement with the certified values. The proposed method was applied successfully to the determination of Co and Pb in a fresh surface and waste water sample.

Highlights

Release of large quantities of metals into the environment is responsible for a number of environmental problems [1]
Triton X-114 was chosen for the formation of the surfactant-rich phase due to its excellent physicochemical characteristics, low cloud point temperature, high density of the surfactant-rich phase, which facilitates phase separation by centrifugation, and commercial availability and relatively low price and low toxicity
This method is a promising alternative for the determination of Co and Pb linked with flame atomic absorption spectrometry (FAAS)

Summary

Introduction

Release of large quantities of metals into the environment (especially in natural water) is responsible for a number of environmental problems [1]. Highly sensitive and selective methods have needed to be developed to determine the trace level of Pb in water samples. CPE is one of the most reliable and sophisticated separation methods for the enrichment of trace metals from different types of samples. While other methods such as LLE are usually time consuming and labor intensive and require relatively large volumes of solvents, which are responsible for public health problems and a major cause of environmental pollution [17,18,19,20,21,22]. The proposed method was applied for the determination of trace amount of both metals in fresh surface and waste water samples

Experimental

Findings

Result and Discussion

Conclusion