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 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 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
Keyword(s):  
Complex Formation ◽  
Ion Association ◽  
Chloroform Extract ◽  
Liquid Extraction ◽  
Optimum Conditions ◽  
Triphenyltetrazolium Chloride ◽  
Liquid Liquid Extraction ◽  
Ion Associate ◽  
Optimum Extraction ◽  
Principal Species

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.

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 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 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 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).

Determination of Parabens from Water Samples Using Cloud Point Extraction, Vortex Extraction and Liquid–Liquid Extraction Method Coupled with High Performance Liquid Chromatography

2020 ◽  
Vol 17 (2) ◽  
pp. 765-772
Author(s):  
Noorashikin Md Saleh ◽  
N. M. Hafiz ◽  
Nik Nur Atiqah NikWee
Keyword(s):  
Cloud Point ◽  
Water Samples ◽  
Extraction Method ◽  
Optimum Parameter ◽  
Cloud Point Extraction ◽  
Liquid Extraction ◽  
Extraction Time ◽  
Solvent Ratio ◽  
Liquid Liquid Extraction ◽  
Method Of Extraction

A straightforward and efficient way for extraction of parabens that is methylparaben, ethylparaben, propylparaben and benzylparaben in environmental water samples was developed through optimizing parameters for each method of extraction. In this study, methods involved were cloud point extraction, vortex extraction, and liquid–liquid extraction. The parameters affecting the method of extraction were such as salt concentration, surfactant concentration, type of solvent, temperature, ratio of solvent to water and extraction time. The optimum parameter for cloud point extraction method were 1.0 M of salt, 1.0% v/v of surfactant, ratio of surfactant to water is 1:1, extraction time is 1 minute at 30 °C while vortex extraction method, optimum parameter is 1.0 M salt, using acetonitrile as a solvent, ratio 1 solvent: 4 water, and extracted at 1 minute. For the liquid–liquid extraction method, the optimum parameter was at 1.0 M salt, acetonitrile as a solvent, ratio of solvent to water is 1:1 and extraction time at 1 minute. The correlation coefficient for the calibration of paraben at concentration 0.2 ppm–1.0 ppm was in the range from 0.9703 to 0.9942. The limit of detection of studied paraben were 0.1627, 0.0837, 0.1156 and 0.1918 ppm, respectively. Percentage recovery for cloud point extraction, vortex extraction and liquid–liquid extraction were between 41%–147.9%, 26.5%–134.7%, and 31.4%–142.4% respectively. Each sample is repeated with triplication which the value of the relative standard deviation is less than 17.9%. Thus, the most suitable, efficient and effective method in extraction of paraben from water samples is cloud point extraction. The cloud point extraction shows the potential to be explore on the future extraction of others organic pollutants from water samples.

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.

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