scholarly journals SYNTHESIS AND STORAGE OF SINGLE PHENYLTIN COMPOUNDS SYNTHESIZED FROM ISOTOPICALLY ENRICHED TIN METAL

2009 ◽  
Vol 12 (17) ◽  
pp. 42-54
Author(s):  
Van Nguyen Dong ◽  
Wolfgang Frech ◽  
Solomon Tesfalidet

A method combining liquid liquid extraction and chromatographic fractionation has been developed for the preparation of pure monophenyltin (MPT), diphenyltin (DPhT), and triphenyltin (TPhT), synthesized from isotope enriched Sn-metal using phenylation of SnI4 in diethylether (DEE) followed by quenching with HBr and water. After two successive extractions of the aqueous HBr phase with DEE, more than 99% of the DPT and TPhT were recovered in the combined DEE phase and 94% of the MPT remained in the aqueous phase. The MPT in the aqueous phase was extracted into dichloromethane. The organic phases were vaporised and the PhTs were re-dissolved in MeOH/water/acetic acid/sodium acetate (59/30/6/8, v/v/v/w), which was also used as storing solution. Aliquots of the two solutions containing either DPhT and TPhT or MPhT were injected into a silica based C18 column for isolating and purifying single species. The yield of the purification of MPhT, DPT, and TPht was better than 99%. At -20 °C, all the fractionated phenyltin species were stable in the storing solution for at least 197 days. When these standards were stored at 4 °C or 22°C, 4% to 6% of DPhT and TPhT degraded during 27 days. The degradation of DPT and TPht increased with the ionic strength and acidity of the storage solution.

1966 ◽  
Vol 44 (24) ◽  
pp. 3057-3062 ◽  
Author(s):  
P. G. Manning

The partitioning of radiotracer 152/151Eu between aqueous sodium oxalate (Na2L) solutions and toluene solutions of thenoyltrifluoroacetone (HTTA) has been studied as a function of the oxalate concentration. The pH of the aqueous phase was controlled by means of sodium acetate – acetic acid mixtures and the ionic strength (I) by NaCl or NaClO4.At low ionic strengths (~0.05) and [L] ~10−4 M EuL+ formed, but at I = 0.95 and [L] ~10−3 M EuL2− also formed. Stability constants for the 1:1 and 1:2 (metal:ligand) complexes are reported.The magnitudes of the stepwise stability constant ratios are discussed.


1994 ◽  
Vol 77 (6) ◽  
pp. 1627-1630 ◽  
Author(s):  
Ana M Martín ◽  
Mercedes Sánchez ◽  
Pedro Espinosa ◽  
Gracia Bagur

Abstract A method was developed for the determination of tin based on the extraction of its 5,5-methylenedisalicylohydroxamic acid complex with 1.09M isobutyl methyl ketone in tributyl phosphate. After the samples were treated with nitric and hydrochloric acid, the aqueous phase was made to 0.05M in perchloric acid. When the ratio of aqueous phase to organic phase was 4:1 (v/v), the detection limit and the relative standard deviation (n = 7,50 μg tin) were 0.20 μg/mL and 0.9%, respectively. The proposed method was applied to the analysis of tin in canned fruits and vegetables. The results were in good agreement with those obtained by the phenylfluorone method.


2010 ◽  
Vol 9 (3) ◽  
pp. 452-456 ◽  
Author(s):  
Iip Izul Falah

Carbaryl (1-naphthyl-N-methylcarbamate) and carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranol-N-methylcarbamate) are very important N-methylcarbamate pesticides due to their high insecticide and nematocide effects, and widely used in vegetables plantations. The increasing use of carbamate pesticides poses a risk to human and environment. Thus, it is necessary to quantify their residue amount in food and vegetables to prevent harmful effect on animals, human and environment. This work was aimed to study of carbaryl and carbofuran analysis from fortified cabbage (Brassica oleracea) by liquid-liquid extraction, clean-up using SPE, followed by HPLC detection. Result of the work showed that detection of carbaryl using spectrophotometer detector at wavelength of 220 nm was better than at 230 and 280 nm, respectively. When the carbamates were extracted from cabbage using methanol, followed by liquid-liquid extraction using dichloromethane, cleaned-up with SPE-C18 and eluted by acetonitrile, the recovery was 96.8%. The detection by HPLC involved 4.6 x 25 mm, 5 µm C18 column, spectrophotometer detector at wavelength of 220 nm, and isocratic mobile phase at ratio of 35:65 of acetonitrile:aquabidest gave a good separation between co-extracted compounds and the carbamates.   Keywords: HPLC, carbaryl, carbofuran, extraction, clean-up


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).


Chirality ◽  
2013 ◽  
Vol 26 (2) ◽  
pp. 79-87 ◽  
Author(s):  
Panliang Zhang ◽  
Chang Liu ◽  
Kewen Tang ◽  
Jiajia Liu ◽  
Congshan Zhou ◽  
...  

2021 ◽  
Vol 11 (16) ◽  
pp. 7435
Author(s):  
Hyun Jin Jung ◽  
Kyeong Keun Oh

Low-acid hydrothermal (LAH) fractionation conditions were optimized for the effective degradation of hemicellulose from pine wood (Pinus densiflora). The hemicellulosic sugar yield was maximized at 82.5% when the pine wood was fractionated at 190 °C, with 0.5 wt.% of sulfuric acid, and for 10 min. Consecutively, acidified heat treatment with zinc chloride and solvent extraction with ethyl acetate were carried out for the recovery of bio-based platform chemicals, such as furfural and acetic acid, from liquid hydrolysate through liquid–liquid extraction (LLE). Overall, 61.5% of xylose was decomposed into furfural, and the yield of acetic acid was 62.3% and furfural 66.1%. After LAH fractionation, 64.8% of the solid remained and was pelletized. The pellets showed excellent fuel characteristics, i.e., significant ash rejection (74.5%) and high calorific values (4770 kcal/kg), and the precursors of NOx and SOx also decreased by up to 60.0% and 71.4%, respectively.


Author(s):  
Moussa Toure ◽  
Guilhem Arrachart ◽  
Jean Duhamet ◽  
Stephane Pellet-Rostaing

A study has been carried out on Ta and Nb recovery by liquid-liquid extraction process using 4-methylacetophenone (4-MAcPh) as organic phase. The 4-MAcPh was compared to methylisobutylketone (MIBK) with respect to extraction efficiencies (kD values) at different concentrations of H2SO4 in the aqueous phase. The results showed a similar extraction of Nb for both solvents. However, for Ta extraction efficiency is increased by a factor of 1.3 for 4-MAcPh. In addition, the MIBK solubilized completely after 6 mol L-1 of H2SO4 against only a loss of 0.14 to 4% for 4-MAcPh between 6 and 9 mol L-1 of H2SO4. The potential of 4-MAcPh has also been studied to selectively recover Ta from a model capacitor waste solution. The results showed a selectivity for Ta in the presence of impurities such as Fe, Ni, Mn. The 4-MAcPh also presents the advantage of having physicochemical properties adapted to its use in liquid-liquid extraction technologies such as mixer-settlers.


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