Dispersive liquid -liquid microextraction of trace amounts of Pb2+ by using 8-hydroxyquinoline

The excessive people number increase and the industrial activity pattern these days especially from the second half of the fallowing century has resulted environmental pollution especially with heavy metals. Between heavy metals some metals such as lead and cadmium are geobiotic which means they are not needed for body`s metabolism and even in small quantities can be harmful to body. These toxic substances penetrate through grain and other crops with water and agriculture soil [1-2].In this research, dispersive liquid-liquid micro-extraction (DLLME) method coupled to atomic absorption spectrometry (AAS) is used to measure trace amounts of Lead. This method is simple, eco-friendly with low use of organic solvents and also economic. Lead complex as formed with 8-hydroxyquinoline in aqueous solution. Methanol and carbon tetrachloride as a dispersive and extraction solvent were rapidly injected into aqueous solution. Lead concentration was measured by AAS. In this study optimized parameters such as pH, type and volume of extraction and dispersive solvent, ligand concentration, extraction time, speed and time of centrifuge. In calibration curve condition, this method was linear in concentration range 0.15- 3.0 ng mL-1. Enrichment factor 96 and limit of detection 0.04 ng mL-1 was obtained. The relative standard deviation was 2.32 ng mL-1. Different samples of rice in different areas were analyzed with presented method