Highest Percentage Extraction Research Articles

Effect of pH, Anions and Acids on the Extraction of Zinc (II) from Aqueous media using Acetylacetone Solutions of Sulphamethoxazole

The challenge of heavy metal contaminations have been remediated to a certain level by the application of several methods of their extractions from aqueous media. Solvent extraction of zinc (II) ions from buffered aqueous solutions into acetylacetone solution of sulphamethoxazole as a function of pH and concentration of anionic substances and certain mineral acids were investigated in this work. The aqueous medium was prepared by dissolving 1.0995g of ZnSO4.7H2O in 250 ml volumetric flask to form 1000mg/L solution. 50mg/L working concentration was prepared from the 1000mg/L by dilution method. The organic phase is 0.5 M Sulfamethoxazole solution prepared by dissolving 12.664g of the salt in 100 ml acetylacetone. 2 ml each of aqueous and organic phases were taken with micro pipette and transferred into a set of 20 ml extraction bottle and the mixture was agitated mechanically for about 30 minutes. The mixture was allowed to settle and separate into two layers. 1 ml of the aqueous phase was taken, diluted and analysed for Zn (II) ions using atomic absorption spectrophotometer at a wavelength of 213.9. The results obtained on studying the effect of pH showed that Zn (II) ion was quantitatively extracted between pH of 7.0 to pH 8.0. The highest percentage extraction 85.37% was observed at pH 8.0 in acetylacetone solution of sulphamethoxazole. Increase in pH above 8.0 resulted in a steady decrease in the extraction of Zn (II). Studies on the effect of anions showed significant extractions which changes as the anions concentrations increased. All studies on mineral acids also showed significant extractions and increase in the concentrations of the acids affected the percentage extraction. Generally Zinc (II) ions can be extracted quantitatively in mild acids and anions concentrations when buffered from slightly acidic pH ranges of 6.0 to slightly alkaline pH values of 8.5.

Electrodialysis for the tertiary treatment of municipal wastewater: Efficiency of ion removal and ageing of ion exchange membranes

Electrodialysis was applied as a tertiary treatment for effluents from a Brazilian sewage treatment plant, and the results are discussed in terms of membrane ageing and process efficiency. Current-voltage analysis and electrodialysis (ED) treatment were performed in a bench cell. The treatment was discontinuously carried out for 930 h within one year. During the experiments, samples were collected for evaluation, and the pH, conductivity and ion concentration were monitored. Thermogravimetric analyses of the membrane were also performed. A reduction in electrical conductivity and the high ion percentage extraction demonstrated the efficiency of the ED treatment, confirming the possibility of using ED as a tertiary treatment for sewage. ED showed 100% effectiveness in terms of meeting the quality standards established by Brazilian legislation on the discharge of effluents. Additionally, important corrosive (Cl−) and encrusting ions (Ca2+ and Mg2+) that limit certain industrial uses of water were satisfactorily removed, giving the treated effluent a suitable quality for industrial purposes. The treatment did not suffer harmful fouling effects in terms of ion extraction in the membrane ageing study, indicating the possibility of long-term treatment without requiring cleaning for the membranes; however, this needs to be validated by scaling up the process.

A Comparison Study on Microwave-Assisted Extraction of Catalpol from <i>Rehmannia glutinosa Libosch</i> with Conventional Methods

Catalpol, an iridoid glycoside, has been verified to be of neuroprotection and may be a potential agent for the treatment of neurodegenerative disease. The extraction technology of catalpol has been tested in this paper. We used different extraction methods including extraction at room temperature (ERT), heat reflux extraction, Soxhlet extraction, ultrasonic extraction and microwave-assisted extraction (MAE) to evaluat the percentage extraction of catapol fromRehmannia glutinosa Libosch.The extracts were analyzed by high performance liquid chromatography (HPLC). Methanol (100%, v/v) extracted high percentage extraction of catapol compared to ethanol (60%, v/v) which achieved the highest percentage extraction of catapol in different concentration of ethanol. The results showed that the percentage extraction of catalpol fromRehmannia glutinosa Liboschby MAE was more efficient in short time followed by ultrasonic extraction, Soxhlet extraction, heat reflux extraction and ERT methods. MAE has need of 4 min, whereas ultrasonic extraction, Soxhlet extraction, heat reflux extraction and ERT techniques require 70, 140, 180 min and 60 h respectively, to leach higher percentage extraction of catalpol. The time taken by MAE was nearly 18 times less than the ultrasonic extraction, 35 times less than Soxhlet extraction, 45 times less than heat reflux extraction and 900 times less than ERT for the highest percentage extraction of catalpol. The present results showed that the high extraction efficiency and considerable saving of time by MAE were more competent than the conventional extraction techniques.

Silica coated magnetic particles using microwave synthesis for removal of dyes from natural water samples: Synthesis, characterization, equilibrium, isotherm and kinetics studies

Monitoring pollutants in water samples is a challenge to analysts. So, the removal of Napthol blue black (NBB) and Erichrome blue black R (EBBR) from aqueous solutions was investigated using magnetic chelated silica particles. Magnetic solids are widely used in detection and analytical systems because of the performance advantages they offer compared to similar solids that lack magnetic properties. In this context, a fast, simple and clean method for modification of magnetic particles (Fe3O4) with silica gel was developed using microwave technique to introduce silica gel coated magnetic particles (SG-MPs) sorbent. The magnetic sorbent was characterized by the FT-IR, X-ray diffraction (XRD), and scan electron microscope (SEM) analyses. The effects of pH, time, weight of sorbent and initial concentration of dye were evaluated. It was interesting to find from results that SG-MPs exhibits high percentage extraction of the studied dyes (100% for NBB and 98.75% for EBBR) from aqueous solutions. The Freundlich isotherm with r2=0.973 and 0.962 and Langmuir isotherms with r2=0.993 and 0.988 for NBB and EBBR, respectively were used to describe adsorption equilibrium. Also, adsorption kinetic experiments have been carried out and the data have been well fitted by a pseudo-second-order equation r2=1.0 for NBB and 0.999 for EBBR. The prepared sorbent with rapid adsorption rate and separation convenience was applied for removal of NBB and EBBR pollutants from natural water samples with good precision (RSD%=0.05–0.3%).

Extraction of penicillin G from aqueous solutions: Analysis of reaction equilibrium and mass transfer

Analysis of the reaction equilibrium and mass transfer in the extraction of penicillin G (Pen G) into an organic phase is an important research area to develop a cost-effective process for its separation from an aqueous fermentation media. In order to evaluate this, equilibrium experiments were first carried out to select the organic phase (composed of the carrier and solvent) that gives good values for the distribution of penicillin G between the aqueous and organic phases. An organic phase of Amberlite LA-2 in any of the solvents (Shellsol TK/butyl acetate/tributyl phosphate) gave high distribution coefficient and the stoichiometry of the reaction has been shown to follow a simple ratio of 2:2. The performance of the organic phases was evaluated in a membrane contactor and very high percentage extraction was achieved. The extraction was performed by contacting a “feed” solution containing penicillin G (flowing in the fiber side) with an “organic phase” of Amberlite LA-2 in one of the solvents (flowing on the shell side) of the contactor. The antibiotic solutes formed complex with the Amberlite LA-2 molecules which were transported across the fiber wall to the shell side and extracted in the organic phase. The extraction in once-through mode was low and the feed/organic solutions need to be recycled to increase the percentage extraction. In the recycle mode operated at flow rates of 3.6–4.4 mL/s, an extraction of 90–98% was achieved. A simple mathematical model and its semi-analytical solution presented here can be used to determine the overall mass transfer coefficient using the experimental values of the distribution coefficient, operating parameters and the dimensions of the membrane module.

Chemical Extraction of Arsenic from Contaminated Soil

A series of batch extraction experiments were conducted using a fortified soil with different extracting solutions such as inorganic acids (hydrochloric acid (HCl), sulfuric acid (H2SO4), phosphoric acid (H3PO4), perchloric acid (HClO4), or nitric acid (HNO3)), organic acids (acetic acid (C2H4O2), citric acid (C6H8O7)) and alkaline agent (NaOH). Various concentrations were used to investigate the removal efficiency and to optimise the concentration of each extractant. In the present investigation a Kuroboku soil contaminated with arsenite (As(III)) was used as a model soil. Arsenic was extracted most efficiently by 5% H3PO4 with a maximum of more than 99% from the model soil. Sulfuric acid also showed high percentage extraction efficiency. On the other hand, C2H4O2 and oxidizing acids such as HNO3 and HClO4 showed low efficiency of As extraction compared with C6H8O7. Although, NaOH also showed higher extraction efficiencies compared with organic and oxidizing acids but mainly arsenate (As(V)) was found to be the major component. A significant fraction of the As(III) was oxidized to As(V) during mineral acid and alkaline extraction and extraction efficiency also varied with the concentration of the acid and alkali solution.

病態変動に伴う薬物の血漿中濃度変動パターンを推定する簡易ソフトの開発

We developed easy-to-use software based on Microsoft Excel in order to predict qualitative changes in drug concentration in plasma-time profiles due to changes in patients' clinical conditions and obtain information for determining optimal dosage regimens.We selected 443 therapeutic agents that are widely used in patients and examined 7 pharmacokinetic parameters in healthy volunteers for each of the drugs selected : bioavailability (F ), percentage of drug dose excreted unchanged into the urine (Ae ), fraction of drug not bound to serum protein (fp ), total clearance (CLtot ), volume of distribution (Vd ), biological half life (t1/2 ) and time of occurrence of highest plasma drug concentration following administration (tmax ). The drugs were then categorized according to elimination route (renal excretion or hepatic metabolism), high or low percentage extraction by the kidneys/liver, extent of protein binding (protein-binding sensitive or not) and large or small volume of distribution, and the drugs were tabulated by the software using these pharmacokinetic parameters.Next, typical time courses of the plasma concentration of each category of drugs and their unbound fractions were created by the software for 4 types of administration : bolus intravenous injection, constant intravenous infusion, and single and repeated oral administration. The software was also used to infer typical time courses for plasma concentrations due to 4 assumed changes in clinical conditions (1. increase in fp , 2. decrease in intrinsic renal or hepatic clearance, CLint,x , 3. decrease in renal or hepatic blood flow, Qx , 4. increase in fp with a decrease in Qx ) based on the general name of brand name for the drugs that were input.The software we developed indicated that the elimination pharmacokinetics of about 80% of the selected drugs depended on renal excretion or hepatic metabolism and it was effective in creating plasma concentration-time profiles due to changes in clinical conditions. It should therefore be a useful tool for pharmacists in hospitals and community pharmacies.

Comparison of techniques for the extraction of the anti-cancer drug camptothecin from Nothapodytes foetida

Extraction methods using stirring extraction, Soxhlet extraction, ultrasonic extraction and microwave-assisted extraction (MAE) were evaluated for the percentage extraction of camptothecin (CPT) and 9-methoxycamptothecin (9-Me-CPT) from Nothapodytes foetida. The extracts were analyzed by high performance liquid chromatography (HPLC). Methanol (90%, v/v) extracted high percentage extraction of CPT and 9-Me-CPT compared to ethanol (90%, v/v). The results shows that the percentage extraction of CPT and 9-Me-CPT from N. foetida by MAE was more efficient in short time followed by Soxhlet extraction, ultrasonic and stirring extraction methods. Maximum percentage extraction of CPT (2.67%, w/w) was obtained by MAE technique. MAE has need of 3 min, whereas ultrasonic extraction, Soxhlet extraction and stirring extraction techniques require 30, 120 and 30 min, respectively to leach higher percentage extraction of CPT and 9-Me-CPT. The times taken by the microwave extraction process was 40 times less than the Soxhlet extraction for percentage extraction of alkaloids. The present results show that the extraction efficiency and considerable saving of time by MAE was more competent than the other extraction techniques.

Acid washing and stabilization of an artificial arsenic-contaminated soil

An acid-washing process was studied on a laboratory scale to extract the bulk of arsenic(V) from a highly contaminated Kuroboku soil (Andosol) so as to minimize the risk of arsenic to human health and the environment. The sorption and desorption behavior of arsenic in the soil suggested the possibility of arsenic leaching under acidic conditions. Artificially contaminated Kuroboku soil (2830 mg As/kg soil) was washed with different concentrations of hydrogen fluoride, phosphoric acid, sulfuric acid, hydrogen chloride, nitric acid, perchloric acid, hydrogen bromide, acetic acid, hydrogen peroxide, 3:1 hydrogen chloride–nitric acid, or 2:1 nitric acid–perchloric acid. Phosphoric acid proved to be most promising as an extractant, attaining 99.9% arsenic extraction at 9.4% acid concentration in 6 h. Sulfuric acid also attained high percentage extraction. The arsenic extraction by these acids reached equilibrium within 2 h. Elovich-type equation best described most of the kinetic data for dissolution of soil components as well as for extraction of arsenic. Dissolution of the soil components could be minimized by ceasing acid washing in 2 h. The acid-washed soil was further stabilized by the addition of lanthanum, cerium, and iron(III) salts or their oxides or hydroxides which form insoluble complex with arsenic. Both salts and oxides of lanthanum and cerium were effective in immobilizing arsenic in the soil attaining less than 0.01 mg/l As in the leaching test.

Rate of extraction of ground pyrethrum flowers in contact with dilute miscellae

AbstractA very fine state of subdivision is necessary to obtain a high percentage extraction of pyrethrum flowers, but very fine powders present difficulties in orthodox apparatus, and a method of extracting material finer than 200 mesh is outlined. This method is assumed to give complete extraction and is utilized to assay the residues of pyrethrum flowers normally ground for industrial and for analytical purposes, which have been extracted in stages over a period of time, and an empirical equation is deduced enabling percentage extraction at any time to be calculated from constants determined for such powders.