Pre-concentration and Determination of Low-traces of Copper Ions in Different Mediums Using Dispersive Liquid-liquid Micro-extraction (DLLME)

In the paper, in order to pre-concentrate and measure the low values of cu ions, the new, simple, quick and very sensitive method of dispersed liquid-liquid micro extraction (dllme) coupled with flame atomic absorption spectrometry (aa) has been utilized. the dllme technique coupled with aa )aa-dllme) was run inside one narrow tube which constitute aqueous samples. in this method, a mixture of toluene and methanol 90:10 (v/v) was injected into the aqueous sample as extractor and disperser agent and then cu and diethyldithiocarbamate (ddtc) complex was concentrated inside the toluene and was collected on the sample solution. in order to optimize the factors affecting on the process, different parameters affected on the cu extraction such as kind and volume of extractor, volume of dispersing solvent, ph of sample solution, ligand concentration, time for bubble formation and salt effect were studied. under optimal condition, limit of detection (lod), relative standard deviation (rsd) and limit of linearity (lol) for calibration curve were measured and were obtained as: 1.2 μg.l^-1, 3.64% and 0.01-1 mg.l^-1, respectively. this method was successfully applied to determine cu in environmental waters, milk powder, liquid milk and orange juice.