Surfactant-Assisted Emulsification and Surfactant-Based Dispersive Liquid-Liquid Microextraction Method for Determination of Cu(II) in Food and Water Samples by Flame Atomic Absorption Spectrometry

Background: Copper (Cu) is an essential metal for humans at certain concentrations. However, it can be toxic at higher concentrations. Therefore, determination of Cu content of foodstuff is important. Objective: The aim of the study was to develop a simple, economical, and environmentally friendly surfactant-mediated extraction method for the determination of Cu using surfactants and flame atomic absorption spectrometry (FAAS). Methods: A nonionic surfactant-assisted emulsification and surfactant-based dispersive liquid-liquid microextraction method was developed for the separation, preconcentration, and determination of Cu by FAAS. Triton X-15 nonionic surfactant, which is insoluble in water, was used as an extractive agent. Triton X-114 (TX-114) nonionic water-soluble surfactant was used as a disperser solvent. Dithizone was used as a complexing agent for complexation of Cu(II) at pH 4. Results: The detection and quantitation limits of the method were determined as 1.61 and 3.82 mu g/L, respectively. The preconcentration factor was obtained as 50. Relative SD based on 10 replicates was obtained as 3.7%. Accuracy of the developed method was proved using certified standard reference materials. Cu(II) content of edible mushroom samples was determined between 12 and 19 mu g/g. Recoveries were obtained between 96 and 101%. Conclusions: The developed surfactant-assisted emulsification and surfactant-based dispersive liquid-liquid microextraction method has represented the wide linear ranges, low detection limit, and high preconcentration factor for Cu ions. Highlights: TX-114 surfactant was used as both sticking agent and disperser solvent. The method does not require expert personnel and high operational costs. The method is environmentally friendly because mainly surfactants and low-toxicity organic solvents are used in the recommended procedure.