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

Document Type: Research Paper


1 Young Researchers and Elite Club, East Tehran Branch, Islamic Azad University, Tehran, Iran

2 Department of chemistry, Arak branch, Islamic Azad University, Arak, Iran

3 Young Researchers and Elite Club, Arak Branch, Islamic Azad University, Arak, Iran


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