Separation and Preconcentration of Trace Amounts of Lead from Water Samples Using Solvent-Assisted Dispersive Solid Phase Extraction

Abstract

This paper describes a new approach for the preconcentration of lead (Pb 2+ ) by solventassisted dispersive solid phase extraction (SADSPE) prior to analyzing by flame atomic absorption spectrometry (FAAS). In this method, the dispersion of the sorbent was achieved by injecting a solution of the sorbent into the aqueous sample. Thereby, a cloudy solution formed. The cloudy state resulted from the dispersion of the fine particles of the sorbent in the bulk aqueous sample. Pb ions reacted with 1-(2-pyridylazo)-2-naphthole (PAN) as chelating agent to form a hydrophobic complex. After extraction, phase separation was performed by centrifugation and as a result, the enriched analyte in this demented phase could be determined by FAAS. Some parameters that influenced solvent-assisted dispersive solid phase extraction and subsequent determination were evaluated in detail. Under optimized conditions (pH 9, PAN concentration: 1.0 × 10 -3 mol L -1 , sorbent: 0.1% m/v 1,4-dichlorobenzene, disperser solvent: 0.5 mL ethanol), a preconcentration factor of 50 could be obtained, and the limit of detection (LOD) for lead was 1.3 μg L -1 . Relative standard deviation for ten replicate determinations of the standard solution containing 20 μg L -1 lead was 5.0%. The proposed method was successfully applied for the determination of lead in water samples with satisfactory results. ]]>

Optimization of Emulsion Liquid Membrane for Lead Separation from Aqueous Solutions

“…Therefore, a limit of 0.01 ppm for Pb in the surface water was recognized by WHO and USEPA [1]. There are several methods for treating Pb discharges such as smelting [2], adsorption [3], ion exchange [4], and liquid-liquid extraction [5]. Recently, liquid membranes [LM] have great attention to extract lead ions from wastewater streams [6][7][8][9].…”

Application of solvent-assisted dispersive solid phase extraction combined with flame atomic absorption spectroscopy for the determination of trace amounts of Cadmium

“…Recently, a novel extraction technique as a high performance and powerful preconcentration method termed as SA-DSPE was demonstrated by Jamali et al (2013). Solvent-assisted dispersive solid phase extraction has been used for the pre-concentration and separation of trace amounts of metals from complex matrices (29)(30)(31)(32)(33)(34). SA-DSPE can be considered as a new, fast, simple and reliable procedure for separation and detection of heavy metals (30).…”