scholarly journals Extraction-spectrophotometric investigations on two ternary ion-association complexes of gallium(III)

2012 ◽  
Vol 10 (4) ◽  
pp. 1262-1270 ◽  
Author(s):  
Kirila Stojnova ◽  
Kiril Gavazov ◽  
Galya Toncheva ◽  
Vanya Lekova ◽  
Atanas Dimitrov

AbstractComplex formation and liquid-liquid extraction were studied in systems containing Ga(III), azoderivative of resorcinol {4-(2-pyridylazo)resorcinol (PAR) or 4-(2-thiazolylazo)resorcinol (TAR)}, 2,3,5-triphenyltetrazolium chloride (TTC), water and chloroform. The optimum conditions w.r.t. pH, extraction time, concentration of ADR and concentration of TTC for the extraction of Ga(III) as an ion-associate complex were found.. The composition of the extracted complexes, (TT+)[Ga(PAR)2] (I), (TT+)[Ga(TAR)2] (II) or (TT+)2[Ga(OH)(TAR)2] (III), and the constants of association (β) between 2,3,5-triphenyltetrazolium cation (TT+) with corresponding anionic chelates were established by several methods. The constants of distribution (KD) and extraction (Kex) of the principal species I and III were determined as well. The apparent molar absorptivities of the chloroform extract at the optimum extraction-spectrophotometric conditions were ɛ′510=9.5×104 L mol−1 cm−1 (I) and ɛ′530=4.6×104 L mol−1 cm−1 (III). The validity of Beer’s law was checked and analytical characteristics that were calculated are reported herein.

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Petya Vassileva Racheva ◽  
Kiril Blazhev Gavazov ◽  
Vanya Dimitrova Lekova ◽  
Atanas Nikolov Dimitrov

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.


2011 ◽  
Vol 9 (6) ◽  
pp. 1143-1149 ◽  
Author(s):  
Galya Toncheva ◽  
Kiril Gavazov ◽  
Vanya Lekova ◽  
Kirila Stojnova ◽  
Atanas Dimitrov

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.


2017 ◽  
Vol 7 (4) ◽  
pp. 44 ◽  
Author(s):  
Takeshi Kato ◽  
Shotaro Saito ◽  
Shigekatsu Oshite ◽  
Shukuro Igarashi

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).


2015 ◽  
Vol 80 (2) ◽  
pp. 179-186 ◽  
Author(s):  
Vidka Divarova ◽  
Kirila Stojnova ◽  
Petya Racheva ◽  
Vanya Lekova ◽  
Atanas Dimitrov

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.


2011 ◽  
Vol 301-303 ◽  
pp. 752-755 ◽  
Author(s):  
Xiao Juan Zhu ◽  
Yin Yan Qiu

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.


Author(s):  
H. Köszegi-Szalai ◽  
T.L. Paál ◽  
L. Barcza

The complex-formation equilibria of mercury(II) with acetylcysteine and captopril have been studied by pH-metric and liquid-liquid extraction methods applying dithizone as a competitive ligand during the latter measurements. The stability constants of three differently protonated Hg(II)/ligand 1:2 complexes of extreme stability have been determined by the combination of extraction and pH-metric data.The formation of the less stabil Hg(II)-ligand 1:3 complexes with the coordination of three sulfhydrilate groups has been followed and the values of βThe differences in the Hg(II) complex formation and protonation equilibria between the two ligands and the possible binding sites in the complexes have been discussed.


2020 ◽  
Vol 7 (1) ◽  
pp. 32-39
Author(s):  
Nur Hidayah Sazali ◽  
Tham Wei Jie ◽  
Nurul Yani Rahim

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.


2016 ◽  
Vol 99 (3) ◽  
pp. 806-812 ◽  
Author(s):  
Joanna Sonia Dobrowska ◽  
Sezin Erarpat ◽  
Dotse Selali Chormey ◽  
Krystyna Pyrzyńska ◽  
Sezgin Bakirdere

Abstract Determination of nicotine at trace levels in different matrixes is crucial because of nicotine's strongly addictive property. In this study, a simple and fast analytical method was developed using liquid–liquid extraction with GC-MS. Chloroform was used as an extraction solvent. Different parameters for extraction, such as pH of the solution, types and volumes of extraction and supporter solvents for dispersion, extraction period, and salt type and its amount, were optimized. To improve the precision, naphthalene was used as an internal standard. The calibration plot of nicotine was linear from 0.010 to 2.0 mg/L with a correlation coefficient 0.9996. The LOD and LOQ for nicotine after extraction were 2.6 and 8.8 ng/mL, respectively. Under the optimum conditions, tap water, wastewater, and saliva samples were analyzed for their nicotine content. The spiking experiments yielded satisfactory recoveries of 97.6 ± 3.5, 96.8 ± 1.1, and 85.1 ± 1.3% for tap water, wastewater, and saliva samples, respectively.


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