scholarly journals Liquid-liquid extraction and recovery of gallium(III) from acid media with 2-octylaminopyridine in chloroform: Analysis of bauxite ore

2010 ◽  
Vol 75 (8) ◽  
pp. 1099-1113 ◽  
Author(s):  
Sandip Mahamuni ◽  
Prakash Wadgaonkar ◽  
Mansing Anuse
Keyword(s):  
Hydrochloric Acid ◽  
Equilibrium Constants ◽  
Standard Addition ◽  
Liquid Extraction ◽  
Acid Media ◽  
Weak Organic Acid ◽  
Liquid Liquid Extraction ◽  
Extraction Reaction ◽  
Bauxite Ore

The liquid-liquid extraction of gallium(III) from hydrochloric acid solution using 2-octylaminopyridine (2-OAP) in chloroform was investigated. The extraction of gallium(III) from 6.0-9.0 mol dm-3 hydrochloric acid was found to be quantitative using 0.033 mol dm-3 2-OAP in chloroform. The effect of the reagent concentration and other parameters on the extraction of gallium(III) was also studied. The stoichiometry of the extracted species of gallium(III) was determined based on the slope analysis method. The extraction reaction proceeded via the anion exchange mechanism from hydrochloric acid and the extracted species was [RR?NH2+GaCl4-]org. The extraction of gallium(III) was performed in the presence of various ions to ascertain the tolerance limit to individual ions. The temperature dependence of the extraction equilibrium constants was examined to estimate the apparent thermodynamic functions (?H, ?S and ?G) for the extraction reaction. Gallium(III) was successfully separated from commonly associated metal ions, such as Zn(II), Pb(II), Cd(II), Hg(II), Bi(III), Al(III), Se(IV), Sb(III), Sn(IV), In(III), Tl(I) and Tl(III). However, gallium(III) was separated from Fe(III) from weak organic acid media. The procedure was also extended to the determination of gallium(III) in bauxite ore by the standard addition method.

scholarly journals New Spectrofluorimetric Method for Determining Serotonin: Application to Human Urine

2015 ◽  
Vol 7 (2) ◽  
pp. 85
Author(s):  
Abdourahmane Khonté ◽  
Diène Thiaré ◽  
Cheikh Diop ◽  
Lamine Cissé ◽  
François Delattre ◽  
...  
Keyword(s):  
Solid Phase ◽  
Standard Addition ◽  
Liquid Extraction ◽  
Good Reproducibility ◽  
Factors Affecting ◽  
Liquid Liquid Extraction ◽  
Spectrofluorimetric Method ◽  
Physicochemical Factors ◽  
Chemical Pretreatments

In this present paper, we investigate the development of simple, rapid, accurate, reproducible and sensitive methods for the determination of serotonin (5-HT) in urine. For this purpose stationary fluorescence was used as method. With regard to the analysis of serotonin, the liquid-liquid extraction (LLE) solid phase extraction (SPE) and standard addition procedures were used. Several physicochemical factors affecting the sensitivity of the fluorescence intensity of serotonin were optimized, including the system of solvent (organic, micellar), the pH and the salts. The study of the analytical performances of the method led to very low limits of detection (LOD) varying between 0.1 and 3 ng/mL and to limits of quantification (LOQ) ranging between 0.4 and 10 ng/mL. This confirms the sensitivity of the method. Thus the low values of standard deviations (DRS) (between 0.3 and 6.6%) testify the good reproducibility of the measurements with satisfactory covering rate (89 to 111%). Accordingly, our results show that the spectrofluorimetric method is simple, fast and sensitive and can be applied to the routine analysis and does not require expensive equipment nor tiresome chemical pretreatments.

scholarly journals Development and validation of a method for isolating stavudine from biological fluids

2021 ◽  
Vol 24 (1) ◽  
pp. 62-68
Author(s):  
Daria A. Borodina ◽  
Yulia A. Gonchikova ◽  
Elena A. Illarionova ◽  
Anastasia E. Mitina
Keyword(s):  
Sodium Chloride ◽  
Hydrochloric Acid ◽  
Acid Solution ◽  
Blood Plasma ◽  
Ammonium Sulfate ◽  
Biological Fluids ◽  
Liquid Extraction ◽  
Uv Spectrophotometry ◽  
Liquid Liquid Extraction

Objective - study of isolating Stavudine from biological fluids (urine, blood plasma). Materials and methods. Objects of research: substance and tablets of 30 mg Stavudine. Reagents: purified water, chloroform, ethyl acetate, dichloromethane, ether, heptane, toluene, acetone, 95% ethyl alcohol, 0.1 M hydrochloric acid solution, 10% ammonium hydroxide solution, 5%solutions of sodium sulfate, 20%sodium sulfate saturated, sodium chloride, sodium chloride saturated, 20%ammonium sulfate, ammonium sulfate saturated. Universal ionomer IT-1101. Stavudine was isolated by liquid-liquid extraction. To detect and quantify Stavudine, thin - layer sorbent chromatography (TLC) and UV spectrophotometry were used. Statistical data processing was performed using the software package for Windows XP (Microsoft Excel), and using the Student's t-test. Results. When using thin-layer chromatography to identify Stavudine, it was found that the Rf value of the spots of Stavudine extracts from biological material corresponded to the Rf value range of 0.67-0.69. The Rf spot value of the standard Stavudine witness sample corresponded to (0.68±0.01). The stability study showed that the Stavudine solution is stable in a hydrochloric acid solution of 0.1 M, in which the absorption spectrum of Stavudine is characterized by absorption maxima at wavelengths of 209±1 and 267±1 nm. The wavelength of 267±1 nm was chosen as the analytical wavelength for the quantitative determination of Stavudine. In the course of the study, various factors affecting the degree of extraction of Stavudine from aqueous solutions were studied. The extractant is ethyl acetate, pH 3, the electrolyte is a saturated solution of ammonium sulfate. The extraction time is 7 minutes, twice. Conclusion. Methods of identification and quantitative determination of Stavudine in extracts from urine and blood plasma by TLC and UV spectrophotometry have been developed. Methods of isolation of Stavudine from urine and blood plasma using the liquid-liquid extraction method have been developed (93.33±2.02%; 89.77±2.02% respectively).

scholarly journals Selective liquid-liquid extraction of antimony(III) from hydrochloric acid media by N-n-octylaniline in xylene

2004 ◽  
Vol 69 (4) ◽  
pp. 283-298 ◽  
Author(s):  
B.M. Sargar ◽  
M.M. Rajmane ◽  
M.A. Anuse
Keyword(s):  
Hydrochloric Acid ◽  
Metal Ion ◽  
Liquid Extraction ◽  
Reagent Concentration ◽  
Acid Media ◽  
Liquid Liquid Extraction ◽  
Semiconductor Thin Films ◽  
Extraction Separation ◽  
Acid Reagent ◽  
Hydrochloric Acid Media

N-n-Octylaniline in xylene was used for the extraction separation of antimony( III) from hydrochloric acid media. Antimony(III) was extracted quantitatively with 10 mL4%N-n-octylaniline in xylene. It was stripped from the organic phase with 0.5 M ammonia and estimated photometrically by the iodide method. The effect of metal ion, acid, reagent concentration and various foreign ions was investigated. The method affords binary and ternary separation of antimony(III) from tellurium(IV), selenium( IV), lead(II) bismuth(III), tin(IV), germanium(IV), copper(II), gold(III), iron(III) and zinc(II). The method is applicable for the analysis of synthetic mixtures alloys and semiconductor thin films. It is fast, accurate and precise.

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