Abstract
A novel dispersive liquid-liquid microextraction (DLLME) procedure was developed using 3hydroxy-4-methy1-2(31-1)-thiazole- thione for the separation and preconcentration of Cu(II) prior to quantification by flame atomic absorption spectrometry (FAAS). Ethanol (0.5 mL) was used as the dispersion solvent, and a mixture of ethanol, carbon tetrachloride, and 3-hydroxy4methy1-2(3H)thiazolethione was rapidly injected with a syringe into a sample containing Cu(ll). Fine droplets formed, and then the mixture was centrifuged. The lower organic phase was isolated and dissolved in concentrated nitric acid to a total volume of 250 pL. A 25-4 aliquot of this solution was introduced into a FAAS using a microinjection system. The influence of parameters such as pH, volume, and type of the extraction solvent, the volume and type of the dispersion solvent, and the amount of 3hydroxy-4-methy1-2(3H)-thiazole- thione was examined. The relative standard deviation (%RSD), limit of detection (LOD), limit of quantification (LOQ), preconcentration factor (PF), and enhancement factor (EF) were 5.34%, 2.54iig/L, 8.48 pg/L, 60, and 42, respectively.
The proposed method was evaluated by analyzing certified reference materials and was applied successfully to the analysis of water samples. The presented method can be of particular use to laboratories that do not have access to instrumentation such as graphite furnace, ICP-OES, and ICP-MS.