Publications Scientifiques

Permanent URI for this communityhttps://dspace.univ-boumerdes.dz/handle/123456789/10

Browse

Subject: search.filters.subject.Complexation

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Liquid-liquid extraction and simultaneously spectrophotometric determination of Co (II) and W (VI) using crown ether (DB-18-C6) in aqueous media and in high speed steel
    (Taylor and Francis Online, 2020) Saoud, Abdesselam; Hammadou née Mesdour, Souad; Arzu, Nabieva; Boudjema, Hamada; Abdeltif, Amrane; Nabiev, Mohamed
    An analytical reagent ether crown DB-18-C-6 was extensively used forthe simultaneous and individual extraction and spectrophotometricdetermination of the tungsten and cobalt at microgram levels. Theligand reacts with two metals, and the ion-association systems wereextractable into chloroform giving a yellowish [(DB-18-C-6∙NH4)+2[WO(SCN)5]2]and[(DB-18-C-6∙NH4)+2[Co(SCN)4]2-]complexes.Theabsorption peaks of these complexes were found overlapping atλmax of 415 nm and 621.6 nm, respectively. Under optimum condi-tions, the [WO(SCN)4]2-] complexation and extraction are possible onlyin concentrated medium (2.5 M of HCl). While, the [Co(SCN)4]2-]wasextractable at a pH range of 4–10. The linear ranges were 29.45–-147.25μgmL−1for Co(II) and 1.8–183 μg/mL for W(VI) with molarabsorptivity,ε=1.7×104andε=1.6×104dm3mol−1cm−1,respec-tively. The accuracy and reproducibility of the proposed method forvarious amounts of cobalt and tungstenintheirbinarymixtureweretested, and the effects of diverse ions on their extraction were alsoinvestigated. The developed method was successfully applied for thesimultaneous determination of Co(II) and W(VI) in high-speed steel(HS2-9-1-8) containing 2% W, 9% Mo, 1% V, and 8% Co.
  • No Thumbnail Available
    Item
    Liquid–liquid extraction and quantitative determination of tungsten (VI) using macrocyclic reagent (DB-18-C-6) as a thiocyanate complex [WO (SCN)5]2
    (Taylor & Francis, 2014) Nabiev, M.; Hamada, B.; Nabieva, A. M.; Amrane, A.; Nasrallah, N.; Saoud, A.
    In recent years, the extraction using crown ethers has reached a resounding success in different scientific and technical fields. In this work, the authors report the results of the main steps of extraction and determination (proportioning) of the tungsten ion (VI) using a chloroformed solution of crown ether. The dibenzo–18–C-6(2,3,11,12-dibenzo-1,4,7,10,13,16-hexaoxacyclooctadeca- 2,11-diene according to the IUPAC systematic nomenclature). The identification and quantification of W(VI) using the absorption spectrum, the influence of the necessary reagents, the needed acidity level for complete extraction and complexation of W (VI) using a crown ether, and the influence of multivalent metal ions were examined, considering that the sensitivity, selectivity, and detection limits have been determined. This system obeys Beer’s law in the range of 0.18–18.3 lgcm 3of tungsten with a molar absorption of 1.6 104 mol 1 cm 1 at 415nm and the detection, quantification limits were, respectively, equal to 0.7–1.8 lgcm 3. The developed method was applied for the extraction of W(VI) in the high speed steel (HSS): HS2–9-1–8 containing 2% W, 9% Mo, 1% V, and 8% C