Application of solvent-assisted dispersive solid phase extraction combined with flame atomic absorption spectrophotometer for the preconcentration and determination of trace amounts of lead in drinking water samples of Bandar Abbas City

There has long been concern about the issue of contamination by heavy metal because of their toxicity for plant, animal and human beings and their lack of biodegradability. Lead has toxic effects on human health. Thus, determination of this element is often required in environmental samples. In this research, solvent-assisted dispersive solid phase extraction (SA-DSPE) combined with flame atomic absorption spectrometry, was used for determination of trace amounts of lead in drinking water samples.
In this approach, the dispersion of the sorbent was achieved by injecting a mixture of solution of the sorbent and disperser solvent 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 aqueous sample. The cloudy solution was centrifuged and the enriched lead in the sediment phase dissolved in ethanol and determined by flame atomic absorption spectrophotometer. Some effective parameters for SA-DSPE, such as: pH, concentration of chelating agent, type and amount of sorbent, type and volume of dispersive solvent and salt effect were investigated and optimized. Under the optimized conditions, the detection limit for lead ions was 12.6 µg/L. Calibration curve was made in the range of 20-400 µg/L, obtaining good linearity (R2 = 0.9981). Finally, SA-DSPE was successfully applied for trace determination of lead in drinking water samples. SA-DSPE is environment friendly and strong against high contents of salt. The other benefits of the method are its simplicity, ease of operation, good precision, short extraction time, low cost, and a good enrichment factor.