استخلاص سائل – سائل لأيونات السيريوم ) III ( الغادولينيوم ) III ) والثوليوم ) III ( باستخدام كواشف ا زو جديدة وتطبيقاتها التحليلية

Liquid-Liquid Extraction of Cerium (III), Gadolinium (III) and Thulium (III) Ions Using New Azo Reagent and Analytical Applicatio

abstract

In this study, a new azo derivatives 3-(4-(dimethylamino) phenyl)diazenyl) -2-hydroxy-5-sulfobenzoicacid(DPDBA) and 3-(2-hydroxy-4-methylphenyl)diazenyl) pentane-2,4-dione (HMPDP) have been prepared from react of diazonium salt pairs of the (N1, N1-dimethylbenzene-1,4-diamine dihydrochloride) with 2-hydroxy-5-sulfobenzoic acid dihydrate and from react of diazonium salt pairs of the 2-amino-5-methylphenol with pentane-2,4-dione , respectively .
The reagent (DPDBA) has a structure formula (C15H15N3O6S) , (green-yellow) color powder, molecular weight (365.360g/mol ), The reagent melts (183-185°C) , the reagent has maximum wavelength (λmax=406nm).While the reagent (HMPDP) has a structure formula (C12H14N2O3) , a reddish orange color powder, the reagent molecular weight (234.260g/mol). The reagent melts at (193-194°C) , the reagent has maximum wavelength (λmax=440nm).
The reagents (DPDBA) and (HMPDP) diagnosed by spectroscopic methods such as UV-Vis., FT-IR, 1HNMR , 13CNMR and Mass spectrometry.
The process of extracting liquid-liquid for Cerium (III), Gadolinium (III) and Thulium (III)ions, separately, with new azo reagents and investigate the feasibility of sequentially separating the extracted ions.
A study was conducted to demonstrate the impact of different variables on the distribution ratio (D) and the extraction percentage (%E).
The optimum pH for the extraction of Cerium (III), Gadolinium (III) and Thulium (III)ions with (DPDBA) was (6,2,1) and it was (3,7,6) with (HMPDP) reagent, separately and respectively. The best time for equilibrium was (30,20,40) minutes for Cerium (III), Gadolinium (III) and Thulium (III)ions with (DPDBA) ,While these period were (15,30,20) minutes for Cerium (III), Gadolinium (III) and Thulium
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(III)ions with (HMPDP),respectively, The results demonstrated that the most effective extraction solvents were chloroform and toluene.
The effect of the interfering compound on extraction processes was determining by using cations and anions. The findings showed that the presence of varied cations and anions concentrations caused changes in (D) and (%E) values.
Additionally, the impact of oxidizing and reducing agents was investigated. According to the study findings the use of oxidizing and reducing agents had little effect on the (D) and (%E) percentages.
The (D) and (%E) values fall as a result of the enrichment extraction process, The findings show that a desirable (aqueous/organic) phase ratio was (1:1) in this investigation. This is demonstrated by the significant increase in separation efficiency and distribution ratio of Cerium (III), Gadolinium (III) and Thulium (III)ions when phase ratio (aq./org.) changed from (30:5) to (5:5) for ions under study.
The results also showed that (D) and (E %) values augmented with the increase of the concentration of Cerium (III), Gadolinium (III) and Thulium (III) ions by using the optimum concentration from reagents (DPDBA) and (HMPDP) ,
The impact of temperature, on the values of (D) for Cerium (III), Gadolinium (III) and Thulium (III)ions was determined by using the reagents (DPDBA) and (HMPDP), The result showed the lowering for (%E) by raising the temperature.
The reactions between the ions under the study and reagents were exothermic, according to calculations of the thermodynamic functions (ΔS, ΔG, ΔH), (ΔH= – 41.193, – 51.226, – 19.224) kJ/mol with (DPDBA) and (ΔH= – 48.6930, -55.218, – 35.729) kJ/mol, respectively.
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The effect on the values of D and (%E) was determined by using ammonium chloride as “salting out’. The study showed that (D) and (E %) values for these ions was slightly effect.
The batch extraction technique used to enhance the extraction efficiency but the results showed that this technique not effected.
The study of the stoichiometry of the extracted complexes by using two methods mole ratio and Job’s (continues change). The results showed that the ratio of Cerium (III), Gadolinium (III) and Thulium (III) ions, with reagents was (1:3).
The study was applied geologically on two samples of the granite rock, where the two samples contain the cerium ion in different concentrations, after preparing the samples and applying the extraction process with the prepared organic reagents and fixing the study conditions, close results were obtained from the proven real results.
Finally, the possibility of sequential separation of the mixture of Cerium (III), Gadolinium (III) and Thulium (III) lanthanum ions from each other was studied using the two prepared reagents and by controlling the separation conditions, which are the acidity function and the reaction time, Where the results showed the possibility of separation in varying proportions and the scheme was proposed for this study.