Simultaneous Determination of Iron and Cobalt using Spectrophotometry after Catanionic Mixed Micellar Cloud Point Extraction Procedure

Abstract

A new preconcentration method which utilises a mixture of cationic and anionic surfactants for separation and spectrophotometric determination of iron and cobalt simultaneously has been developed. The metal ions, iron and cobalt were complexed with thiocyante. The hydrophobic complexes of iron and cobalt were then extracted into catanionic mixed micelles of cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulphate (SDS). Different parameters like concentration of HCl, concentration of thiocyanate, concentrations of the surfactants (CTAB and SDS), equilibration temperature and time were studied to get maximum efficiency. The linear ranges of Fe3+ and Co2+ were found to be 0.139 – 0.838 μg mL–1 and 5.89 – 35.4 μg mL–1, respectively the detection limits obtained were 1.54 ng mL–1 and 6.18 ng mL–1. The developed procedure has been employed for the retrieval of Fe3+ and Co2+ in water samples successfully (tap water and sea water). 98 – 107% recoveries were obtained.

Cobalt separation from water and food samples based on penicillamine ionic liquid and dispersive liquid-liquid microextraction before determination by AT-FAAS

“…For this purpose, the procedures must be developed for the separation and preconcentration of cobalt from samples. There are many methodologies for extraction cobalt from difficulty matrixes including, the magnetic solid phase extraction (MSPE) [19], dispersive micro-solid phase extraction (D-μ-SPE) [20], the liquid-liquid extraction (LLE), the dispersive liquid-liquid microextraction (DLLME) [21], the electrochemistry methods (ECM) [22], the cloud point extraction (CPE) [23] and the precipitation [24]. Recently, the ultra-assisted dispersive liquidliquid microextraction (USA-DLLME) [25] has been used as one of the most practical methods for the separation of metal ions.…”

Use of a Hydrophobic Azo Dye for the Centrifuge-Less Cloud Point Extraction–Spectrophotometric Determination of Cobalt

“…The reported heating temperatures for CPE systems based on the same surfactant, TX-114, are commonly between 40 °C and 65 °C [ 23 , 31 , 32 , 35 , 36 , 38 , 39 , 59 , 60 , 61 ]. The results of our experiments at 50 °C are represented in Figure 6 .…”

“…The reagent is commercially available and does not need to be synthesized. It is not necessary to add electrolyte to increase the extraction efficiency [ 36 , 37 , 40 , 41 ] or organic solvent to provide synergistic extraction [ 33 ] or to reduce the viscosity of the SRP [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ].…”

“…It can be easily combined with various sample preparation techniques to improve analytical characteristics and extend the scope of application. The list of such techniques comprises liquid–liquid extraction [ 27 ], dispersive liquid–liquid microextraction [ 28 ], continuous sample drop flow-based microextraction [ 29 ], deep eutectic solvent microextraction [ 30 ], and cloud point extraction (CPE) [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 ].…”