scholarly journals Extraction-Spectrophotometric Studies on the Complex Formation of Iron(III) with 4-(2-Thiazolylazo)Resorcinol and Tetrazolium Salts

2014 ◽  
Vol 10 (3) ◽  
pp. 2491-2501 ◽  
Author(s):  
Kiril Blazhev Gavazov ◽  
Teodora S. Stefanova ◽  
Galya K. Toncheva
Keyword(s):  
Equilibrium Constants ◽  
Liquid Extraction ◽  
Association Constants ◽  
Molar Ratio ◽  
Tetrazolium Salt ◽  
Optimum Conditions ◽  
Tetrazolium Chloride ◽  
Iron Extraction ◽  
Liquid Liquid Extraction ◽  
Linear Relationships

Four liquid-liquid extraction-chromogenic systems containing Fe(III), 4-(2-thiazolylazo)resorcinol (TAR), tetrazolium salt (TZS), water and chloroform were studied. 2,3,5-Triphenyl-2H-tetrazolium chloride (TTC), 3-(4,5-dimethyl-2-thiazol)-2,5-diphenyl-2H-tetrazolium bromide (MTT), 3-(2-naphtyl)-2,5-diphenyl-2H-tetrazolium chloride (TV), and 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyl-2H-tetrazolium chloride (INT) were the examined TZSs. Optimization experiments for iron extraction were performed and the following parameters were found for each system: pH(opt), CTAR(opt), CTZS(opt), shaking time (opt), and l(opt). Under the optimum conditions, the molar ratio of the reacting Fe(III), TAR and TZS is 1:2:2 and the general formula of the extracted species is (TZ+)2[FeII(TAR2–)2]. Some equilibrium constants (constants of association, constants of distribution, and constants of extraction) and analytical characteristics (molar absorptivities, Sandell’s sensitivities, Beer’s law limits, etc.) were calculated. Linear relationships involving the molecular mass of TZ+ were discussed.

scholarly journals Ternary ion-association complexes between the indium(III) - 4-(2-pyridylazo)resorcinol anionic chelate and some tetrazolium cations

2011 ◽  
Vol 9 (6) ◽  
pp. 1143-1149 ◽  
Author(s):  
Galya Toncheva ◽  
Kiril Gavazov ◽  
Vanya Lekova ◽  
Kirila Stojnova ◽  
Atanas Dimitrov
Keyword(s):  
Complex Formation ◽  
Ternary Complex ◽  
Ion Association ◽  
Liquid Extraction ◽  
Extraction Time ◽  
Tetrazolium Salt ◽  
Optimum Conditions ◽  
Tetrazolium Chloride ◽  
Tetrazolium Bromide ◽  
Liquid Liquid Extraction

AbstractComplex formation and liquid-liquid extraction were studied in systems containing indium(III), 4-(2-pyridylazo)resorcinol (PAR), tetrazolium salt (TZS), water and chloroform. Two different TZS were used: 2,3,5-triphenyl-2H-tetrazolium chloride (TTC) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT). The optimum conditions for extraction of In(III) as a ternary complex, (TT+)[In(PAR)2] or (MTT+)[In(PAR)2], were found: pH, extraction time, concentration of PAR and concentration of TZS. The constants of extraction (Kex), constants of association (β), constants of distribution (KD) and recovery factors (R%) were determined. The apparent molar absorptivities in chloroform were calculated to be ɛ′520=6.6×104 L mol−1 cm−1 and ɛ′515=7.1×104 L mol−1 cm−1 for the systems with TTC (I) and MTT (II), respectively. Beer’s law was obeyed for In(III) concentrations up to 3.4 µg mL−1 in both the cases. The limits of detection (LOD=0.07 µg mL−1I and LOD=0.12 µg mL−1II), limits of quantification (LOQ=0.24 µg mL−1I and LOQ=0.41 µg mL−1II) and Sandell’s sensitivities (SS) were estimated as well.

scholarly journals Liquid-liquid extraction of ion-association complexes of cobalt(II)-4-(2-pyridylazo)resorcinol with ditetrazolium salts

2015 ◽  
Vol 80 (2) ◽  
pp. 179-186 ◽  
Author(s):  
Vidka Divarova ◽  
Kirila Stojnova ◽  
Petya Racheva ◽  
Vanya Lekova ◽  
Atanas Dimitrov
Keyword(s):  
Equilibrium Constants ◽  
Ion Association ◽  
Liquid Extraction ◽  
Tetrazolium Chloride ◽  
Molar Ratios ◽  
Liquid Liquid Extraction ◽  
Blue Tetrazolium ◽  
Blue Tetrazolium Chloride ◽  
Extraction Equilibria ◽  
Ditetrazolium Salts

The formation and liquid-liquid extraction of ion-association complexes between Co(II)-4-(2-Pyridylazo)resorcinol (PAR) anionic chelates and cations of three ditetrazolium chlorides were studied: Blue Tetrazolium chloride (BTC), Neotetrazolium chloride (NTC) and Nitro Blue Tetrazolium chloride (NBT). The optimum conditions for the formation and solvent extraction of the ion-association comlpex chelates were determined. It has been found that in the systems of Co(II)-PAR-DTS, the reactants are reacted in molar ratios 1:2:1 and the general formula of complexes was suggested. The extraction equilibria were investigated and quantitatively characterized by the equilibrium constants and the recovery factors. The analytical characteristics of the complexes were calculated.

scholarly journals Complex Formation in a Liquid-Liquid Extraction System Containing Cobalt(II), 4-(2-Pyridylazo)resorcinol, and Nitron

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Petya Vassileva Racheva ◽  
Kiril Blazhev Gavazov ◽  
Vanya Dimitrova Lekova ◽  
Atanas Nikolov Dimitrov
Keyword(s):  
Complex Formation ◽  
Limit Of Detection ◽  
Equilibrium Constants ◽  
Ion Association ◽  
Molar Absorptivity ◽  
Liquid Extraction ◽  
Optimum Conditions ◽  
Limit Of Quantification ◽  
Liquid Liquid Extraction ◽  
Experimental Parameters

Complex formation and liquid-liquid extraction were studied in a system containing cobalt(II), 4-(2-pyridylazo)resorcinol (PAR), 1,4-diphenyl-3-(phenylamino)-1H-1,2,4-triazole (Nitron, Nt), water, and chloroform. The effect of some experimental parameters (pH, shaking time, concentration of PAR, and concentration of Nt) was systematically investigated, and the optimum conditions for cobalt extraction as an ion-association complex, (NtH+)[Co3+(PAR)2], were found. The following key equilibrium constants were calculated: constant of association (Log β=4.77±0.06), constant of distribution (LogKD=1.34±0.01), and constant of extraction (LogKex=6.11±0.07). Beer’s law was obeyed for Co concentrations up to 1.7 μg mL−1 with a molar absorptivity of 6.0×104 L mol−1 cm−1 at λmax=520 nm. Some additional characteristics, such as limit of detection, limit of quantification, and Sandell’s sensitivity, were estimated as well.

scholarly journals LIQUID-LIQUID EXTRACTION-SPECTROPHOTOMETRIC DETERMINATION OF MOLYBDENUM USING o-HYDROXYTHIOPHENOLS

2017 ◽  
Vol 10 (8) ◽  
pp. 3003-3011
Author(s):  
Ali Z. Zalov ◽  
Kiril Blazhev Gavazov
Keyword(s):  
Spectrophotometric Determination ◽  
Spectral Characteristics ◽  
Liquid Extraction ◽  
Molar Ratio ◽  
Fundamental Properties ◽  
Liquid Liquid Extraction ◽  
Linear Relationships ◽  
Relative Standard ◽  
Mo Content

27 liquid-liquid extraction-chromogenic systems containing Mo(VI), o-hydroxythiophenol derivative {HTPDs: 2-hydroxy-5-chlorothiophenol (HCTP), 2-hydroxy-5-bromothiophenol (HBTP) or 2-hydroxy-5-iodothiophenol (HITP)} and aromatic amine (AA) were studied. Aniline (An), N-methylaniline (mAn), N,N-dimethylaniline (dAn), o-toluidine (o-Tol), m-toluidine (m-Tol), p-toluidine (p-Tol), 3,4-xylidine (o-Xyl), 2,4-xylidine (m-Xyl), and 2,5-xylidine (p-Xyl) were the examined AAs. Optimization experiments for molybdenum extraction-spectrophotometric determination were performed and the following parameters were found for each of the systems: organic solvent (opt), pH (opt), CHTPD (opt), CAA (opt), shaking time (opt), l (max) and e (max). Under the optimum conditions, the molar ratio of the reacting Mo(V), HTPD and AA was 1:2:2 and the degrees of Mo extraction were R³98.4%. Linear relationships involving the spectral characteristics of the extracted complexes (lmax or emax) and some fundamental properties of the halogen substituent in the HTPD were discussed. The effect of foreign ions was examined and two sensitive, selective and precise procedures for extraction-spectrophotometric determination of molybdenum were proposed. The relative standard deviations for Mo content of (3-5)´10–4 mass % were 4% (HCTP-An procedure) and 3% (HBTP-An procedure).

scholarly journals Phenylmethoxybis(tetrazolium) ion-association complexes with an anionic indium(III) — 4-(2-pyridylazo)resorcinol chelate

2013 ◽  
Vol 11 (2) ◽  
pp. 280-289 ◽  
Author(s):  
Teodora Stefanova ◽  
Kiril Gavazov
Keyword(s):  
Limit Of Detection ◽  
Ion Association ◽  
Molar Absorptivity ◽  
Tetrazolium Salt ◽  
Limit Of Quantification ◽  
Tetrazolium Chloride ◽  
Liquid Liquid Extraction ◽  
Blue Tetrazolium ◽  
Blue Tetrazolium Chloride ◽  
Molar Absorptivity Coefficient

AbstractComplex formation and liquid-liquid extraction were studied in systems containing indium(III), 4-(2-pyridylazo)resorcinol (PAR), phenylmethoxybis(tetrazolium) salt (MBT), water and chloroform. The following MBTs, which differ only by the number of -NO2 groups in their cationic parts, were used: 3,3′-(3,3′-dimetoxy-4,4′-biphenylene)bis(2,5-diphenyl-2H-tetrazolium chloride) (Blue Tetrazolium chloride, BT), 3,3′-(3,3′-dimetoxy-4,4′-biphenylene)bis[2-(4-nitrophenyl)-5-phenyl-2H-tetrazolium chloride] (Nitro Blue Tetrazolium chloride, NBT) and 3,3′-(3,3′-dimetoxy-4,4′-biphenylene)bis[2,5-di(4-nitrophenyl)-2H-tetrazolium chloride] (Tetranitro Blue Tetrazolium chloride, TNBT). The composition of the formed ternary complexes was determined, In:PAR:MBT=1:2:2, and the optimum conditions for their extraction found: pH, shaking time, concentration of the reagents and the sequence of their addition. Some key constants were estimated: constants of extraction (Kex), constants of association (β) and constants of distribution (KD). BT appears to be the best MBT for extraction of the In(III)-PAR species, [In3+(OH)3(PAR)2]4−, (Log Kex=10.9, Log β=9.8, Log KD=1.12, R%=92.7%). Several additional characteristics concerning its application as extraction-spectrophotometric reagent were calculated: limit of detection (LOD = 0.12 µg cm−3), limit of quantification (LOD = 0.40 µg cm−3) and Sandell’s sensitivity (SS =1.58 ng cm−2); Beer’s law is obeyed for In(III) concentrations up to 3.2 µg mL−1 with a molar absorptivity coefficient of 7.3×104 L mol−1 cm−1 at λmax=515 nm.

scholarly journals Powerful Concentration of Rhodium in Plating Wastewater Using Homogeneous Liquid–Liquid Extraction (HoLLE) and Study for Scale-up

2017 ◽  
Vol 7 (4) ◽  
pp. 44 ◽  
Author(s):  
Takeshi Kato ◽  
Shotaro Saito ◽  
Shigekatsu Oshite ◽  
Shukuro Igarashi
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Aqueous Phase ◽  
Scale Up ◽  
Volume Ratio ◽  
Liquid Extraction ◽  
Optimum Conditions ◽  
Homogeneous Liquid ◽  
Liquid Liquid Extraction ◽  
Plating Wastewater

A powerful technique for the concentration of rhodium (Rh) in plating wastewater was developed. The technique entails complexing Rh with 1-(2-pyridylazo)-2-naphthol (PAN) followed by homogeneous liquid–liquid extraction (HoLLE) with Zonyl FSA. The optimum HoLLE conditions were determined as follows: [ethanol]T = 30.0 vol.%, pH = 4.00, and Rh:PAN = 1:5. Under these optimum conditions, 88.1% of Rh was extracted into the sedimented liquid phase. After phase separation, the volume ratio [aqueous phase (Va) /sedimented liquid phase (Vs)] of Va and Vs was 1000 (50 mL → 0.050 mL). We then applied the new method to wastewater generated by the plating industry. The phase separation was satisfactorily achieved when the volume was scaled up to 1000 mL of the actual wastewater; 84.7% of Rh was extracted into the sedimented liquid phase. After phase separation, Va/Vs was 588 (1000 mL - 1.70 mL).

Thermodynamic parameters for the complexation of Tc(IV) with bromide under aqueous conditions

2020 ◽  
Vol 108 (5) ◽  
pp. 409-414
Author(s):  
Cecilia Eiroa-Lledo ◽  
Donald E. Wall ◽  
Nathalie A. Wall
Keyword(s):  
Working Conditions ◽  
Equilibrium Constants ◽  
Liquid Extraction ◽  
Complexation Reaction ◽  
Hydrolysis Constant ◽  
Carboxylate Ligands ◽  
Liquid Liquid Extraction ◽  
Varied Temperature ◽  
Aqueous Conditions ◽  
Aqueous Complexes

AbstractTechnetium-99 is a long-lived fission product present in nuclear wastes, found mainly as Tc(VII) and Tc(IV) in the environment. The quantification of the equilibrium constants for the formation of Tc(IV) aqueous complexes has been limited to carboxylate ligands and interactions with the halides is mostly unknown. This work reports equilibrium constants of the formation of the TcO(OH)+ complexes with Br−, in a 3 M NaClO4 solution of pcH 2 and varied temperature, using a liquid-liquid extraction system. Neutron activation confirmed the suitability of the extraction technique for this work. Under the working conditions, Br− forms a weak exothermic TcO(OH)Br complex, with a Gibbs free energy (ΔGr) of 3 ± 3 kJ · mol−1 at a temperature of 273.15 K. The values for ΔHr (−32 ± 3 kJ · mol−1) and ΔSr (106 ± 9 J · mol−1 · K−1) of the complexation reaction were quantified using a van’t Hoff analysis. This work also showed that bromide addition does not displace the hydroxide from TcO(OH)+, as the equilibrium constant of bromide addition is much weaker than the first hydrolysis constant of the metal.

scholarly journals The solvent extraction and spectrophotometric determination of vanadium (V) with 4-(2-thiazolylazo)resorcinol and tetrazolium salts

2007 ◽  
Vol 5 (1) ◽  
pp. 257-270 ◽  
Author(s):  
Kiril Gavazov ◽  
Vanya Lekova ◽  
Atanas Dimitrov ◽  
Georgi Patronov
Keyword(s):  
Association Constants ◽  
Tetrazolium Salt ◽  
Fast Method ◽  
Tetrazolium Chloride ◽  
Blue Tetrazolium Chloride ◽  
Tetrazolium Violet ◽  
Ion Associate ◽  
The Relationship ◽  
Optimum Extraction

AbstractThe formation and extraction of ion-associate complexes between the vanadium(V)-4-(2-thiazolylazo)resorcinol (TAR) anionic chelate and the cations of some mono-and ditetrazolium salts {3-(4,5-dimethyl-2-thiazol)-2,5-diphenyl-2H-tetrazolium bromide (Thiazolyl blue, MTT), 3-(2-naphtyl)-2,5-diphenyl-2H-tetrazolium chloride (Tetrazolium violet), 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyl-2H-tetrazolium chloride (Iodonitrotetrazolium chloride), 3,3′-[3,3′-dimetoxy(1,1′-biphenyl)-4,4′-diyl]-bis[2,5-diphenyl-2H-tetrazolium] chloride (Tetrazolium blue chloride) and 3,3′-(3,3′-dimetoxy-4,4′-biphenylene)bis[2-(4-nitrophenyl)-5-phenyl-2H-tetrazolium chloride] (Nitro blue tetrazolium chloride)} have been studied. The optimum extraction conditions have been found. The composition of the V-TAR-monotetrazolium and V-TAR-ditetrazolium complexes extracted into chloroform has been determined to be 1:2:3 and 2:4:3 respectively. The extraction, distribution and association constants, and the recovery factors have been calculated. The relationship between the molecular weight of tetrazolium cations, and the association constants of their complexes has been discussed. The special behavior of the tetrazolium cations, containing-NO2 groups has been noticed. The effects of foreign ions and reagents on the extraction of vanadium with TAR and the best tetrazolium salt-MTT have been studied. A sensitive, selective, simple and fast method for the determination of vanadium has been developed.

Measuring the Phthalates of Xiangjiang River Using Liquid-Liquid Extraction Gas Chromatography

2011 ◽  
Vol 301-303 ◽  
pp. 752-755 ◽  
Author(s):  
Xiao Juan Zhu ◽  
Yin Yan Qiu
Keyword(s):  
Gas Chromatography ◽  
Water Environment ◽  
Liquid Extraction ◽  
Dioctyl Phthalate ◽  
Optimum Conditions ◽  
Xiangjiang River ◽  
Chromatography Method ◽  
Extraction Solvent ◽  
Liquid Liquid Extraction ◽  
Ethylhexyl Phthalate

Objective: To observe the phthalates pollution situation in water environment and design the liquid-liquid extraction gas chromatography method to measure phthalates in Xiangjiang River water. Methods: The water samples were collected from six monitor points of the Xiangjiang River’s Changsha period. After liquid-liquid extraction, gas chromatography was used to measure and analyze the phthalates pollution in this period of the river. Results: Dioctyl phthalate resin (DOP) and dibutyl phthalate (2- ethylhexyl) phthalate (DEHP) were detectable in all samples from six monitor points, the concentrations of DEHP were from 0.62-15.23μg/L, DOP were from 0.04-0.21μg/L. Conclusion: The optimum conditions for the extraction of phthalates are: 0.025ml dichloromethane as extraction solvent, centrifuge speed at 4000r/min, extraction time 20 minutes, and this method is appropriate for monitoring the phthalates pollution in water environment.

Hydrophobic Deep Eutectic as a New Solvent for Liquid-Liquid Extraction and Its Potential Application in Ligandless Extraction of Cu (II)

2020 ◽  
Vol 7 (1) ◽  
pp. 32-39
Author(s):  
Nur Hidayah Sazali ◽  
Tham Wei Jie ◽  
Nurul Yani Rahim
Keyword(s):  
Contact Time ◽  
Capric Acid ◽  
Cost Effective ◽  
Liquid Extraction ◽  
Environmentally Benign ◽  
Optimum Conditions ◽  
Initial Concentration ◽  
Liquid Liquid Extraction ◽  
Ft Ir ◽  
The Cost

Background: The cost-effective and environmentally benign solvent of hydrophobic deep eutectic (DES) was prepared for the removal of Cu (II) from aqueous solution. Hydrophobic DES has been gaining increasing attention from researchers for the replacement of hazardous solvent consumption in liquid-liquid extraction (LLE). Objectives: To synthesize the hydrophobic DES and optimize the parameters for ligandless LLE using DES, and LLE with DES-LIG, respectively. Materials and Methods: The fatty acid-based DES was prepared using a mixture of capric acid (C10) and lauric acid (C12) as a potential solvent for the extraction of Cu (II). The DES was characterized via FT-IR, NMR, and TGA. The removal percentage of Cu (II) was compared between ligandless LLE and other conventional LLE techniques. DES was used as the solvent in the ligandless LLE, while 1,10-phenanathroline ligand with DES (DES-LIG) was used in the conventional LLE techniques. The optimized parameters such as pH, initial concentration, and contact time for Cu (II) removal were studied and analyzed using atomic absorption spectroscopy (AAS). Results and Discussion: The ligandless LLE with DES demonstrated the highest removal percentage of Cu (II) at optimum conditions of pH 8, initial concentration of 80 μg mL-1, and contact time of 45 minutes. Conclusion: The removal of Cu (II) was more effective in ligandless LLE using DES.

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