WorldWideScience

Sample records for hydrochloric acid separating

  1. Separation of metal ions by anion exchange in mixtures of hydrochloric acid and hydrofluoric acid

    Energy Technology Data Exchange (ETDEWEB)

    Faris, J.P.

    1978-12-01

    Distribution coefficients were determined for the adsorption of more than 40 elements on anion-exchange resins from mixtures of HCl (0.1 to 12M) and HF (0.1-8M). Two resins, Dowex 1 x 10, 200 to 400 mesh and Dowex 1 x 4, 100 to 200 mesh, were used. Distribution coefficients were also determined for the adsorption of many elements on both resins from 0.1 to 12M HCl and 0.1 to 12M HF. Anion exchange in the presence of HF was found useful for separating impurities from various materials for their subsequent determination, and specific procedures used in our spectrochemical laboratory for this purpose are outlined. The results of a literature search on the use of anion exchange in hydrofluoric acid and fluoride-containing media are presented in an extensive bibliography. 404 references, 9 tables.

  2. Hydrochloric acid recycling from chlorinated hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Sowieja, D. [Sulzer Escher Wyss GmbH, Ravensburg (Germany); Schaub, M. [Sulzer Chemtech Ltd., Winterthur (Switzerland)

    1993-12-31

    Chlorinated hydrocarbons present a major ecological hazard since most of them are only poorly biodegradable. Incineration is an economical process for their destruction, however the usually recovered sodium or calcium chlorides do not present a value and their disposal may even be very costly. Recovery of hydrochloric acid may therefore present an economical solution, mainly were large quantities of highly chlorinated compounds can be processed (author) 6 refs., 4 figs., 1 tab.

  3. Hydrochloric acid for treating metabolic alkalosis.

    Science.gov (United States)

    Korkmaz, A; Yildirim, E; Aras, N; Ercan, F

    1989-09-01

    Six patients with severe metabolic alkalosis were treated with intravenous hydrochloric acid (HCl) infusion. HCl was given through a central venous catheter, at a concentration of 0.1 mEq per ml. At least two of the following criteria were considered for initiation of the therapy: An arterial pH of greater than 7.45, a base excess (BE) of greater than +7 mmol/L, a PaCO2 of greater than 50 mmHg. The HCl amount was calculated using the BE formula, however, two thirds was infused for avoiding excessive acid loading. Patients were monitored by the blood gases, serum electrolytes, hemoglobin, hematocrit, bilirubin determinations and blood smear findings. While a significant decrease was noticed in pH and BE values, moderate changes were detected in PaCO2 due to different ventilatory status of the cases. All laboratory test results remained within normal limits and no complication was encountered. The advantage of the therapy is that less volume is needed for the correction of alkalosis, particularly in the cases requiring fluid restriction. HCl therapy, moreover, is a safe and time-saving method because of having rapid response to the treatment in the critically ill surgical patients.

  4. HYDROXYLAMMONIUM [ON 111 AQUEOUS HYDROCHLORIC ACID

    African Journals Online (AJOL)

    octacyanomolybdateiv) anion by hydroxylammonium ion has been studied in aqueous hydrochloric ... of substrates have been investigated in aqueous solution (1-7). The results of ... (4) and nitrogen was identified as described previously (8).

  5. An unusual presentation of hydrochloric acid ingestion: a mystery unraveled.

    Science.gov (United States)

    Ganapathy, Vinod Prabhu; Das, Rashmi Ranjan; Chinnakkannan, Selvakumar; Panda, Shasanka Shekhar

    2015-03-01

    Unintentional acid ingestion is less commonly encountered than alkali ingestion. The injury develops for hours to days after ingestion and often results in progressively increasing difficulty in airway management. However, gastric perforation is rare. A 3-year-old boy presented to us with an orotonsillopharyngeal membrane and severe upper airway obstruction. Subsequently, he was diagnosed with a case of gastric perforation due to unintentional hydrochloric acid ingestion. He was treated with partial gastrectomy and feeding jejunostomy, and the recovery was good. Unintentional hydrochloric acid ingestion is rare in children. The manifestations masquerade many other clinical conditions, and the diagnosis is difficult in cases in which history of ingestion is not available. Treatment is symptomatic, and emergency surgery is indicated in case of gastrointestinal perforation.

  6. Kinetic study of free fatty acid esterification reaction catalyzed by recoverable and reusable hydrochloric acid.

    Science.gov (United States)

    Su, Chia-Hung

    2013-02-01

    The catalytic performance and recoverability of several homogeneous acid catalysts (hydrochloric, sulfuric, and nitric acids) for the esterification of enzyme-hydrolyzed free fatty acid (FFA) and methanol were studied. Although all tested catalysts drove the reaction to a high yield, hydrochloric acid was the only catalyst that could be considerably recovered and reused. The kinetics of the esterification reaction catalyzed by hydrochloric acid was investigated under varying catalyst loading (0.1-1M), reaction temperature (303-343K), and methanol/FFA molar ratio (1:1-20:1). In addition, a pseudo-homogeneous kinetic model incorporating the above factors was developed. A good agreement (r(2)=0.98) between the experimental and calculated data was obtained, thus proving the reliability of the model. Furthermore, the reusability of hydrochloric acid in FFA esterification can be predicted by the developed model. The recoverable hydrochloric acid achieved high yields of FFA esterification within five times of reuse.

  7. Accidental intoxication with hydrochloric acid and hydrofluoric acid mixture

    Directory of Open Access Journals (Sweden)

    Anna Smędra-Kaźmirska

    2014-08-01

    Full Text Available The paper describes a fatal case of accidental ingestion of a mixture of hydrochloric acid and hydrofluoric acid. The man was admitted to hospital, where appropriate treatment, adequate to his condition, was instituted. Numerous ventricular fibrillation episodes, for which the patient was defibrillated repeatedly, were observed during the period of hospitalization. The patient was in a critical condition, with progressive symptoms of hypovolemic shock and multiorgan failure. On the next day after admission, signs of electromechanical dissociation progressing to asystole were noted. The instituted resuscitation procedure proved ineffective and the patient died. Autopsy revealed brownish discoloration of the esophageal, gastric, and small intestinal mucous membranes. Numerous ulcerations without signs of perforation were found both in the esophagus and in the stomach. The mucous membrane of the small intestine demonstrated focal rubefactions, whereas no focal lesions of the large intestinal mucosa were seen. Microscopic investigation of the biopsy specimens collected from the stomach, duodenum and small intestine revealed mucous membrane necrosis foci, reaching the deeper layers of the wall of these organs. The mucous membrane of the large intestine was congested. Bioptates obtained from the lungs indicated the presence of hemorrhagic infarcts and focal extravasations. Poisoning with the aforementioned acids with consequent necrosis of the esophageal, gastric, duodenal and small intestinal walls with hemorrhages to the gastrointestinal tract, as well as extravasations and hemorrhagic infarcts in the lungs was considered to be the cause of death.

  8. Accidental intoxication with hydrochloric acid and hydrofluoric acid mixture.

    Science.gov (United States)

    Smędra-Kaźmirska, A; Kędzierski, M; Barzdo, M; Jurczyk, Ap; Szram, S; Berent, J

    2014-01-01

    The paper describes a fatal case of accidental ingestion of a mixture of hydrochloric acid and hydrofluoric acid. The man was admitted to hospital, where appropriate treatment, adequate to his condition, was instituted. Numerous ventricular fibrillation episodes, for which the patient was defibrillated repeatedly, were observed during the period of hospitalization. The patient was in a critical condition, with progressive symptoms of hypovolemic shock and multiorgan failure. On the next day after admission, signs of electromechanical dissociation progressing to asystole were noted. The instituted resuscitation procedure proved ineffective and the patient died. Autopsy revealed brownish discoloration of the esophageal, gastric, and small intestinal mucous membranes. Numerous ulcerations without signs of perforation were found both in the esophagus and in the stomach. The mucous membrane of the small intestine demonstrated focal rubefactions, whereas no focal lesions of the large intestinal mucosa were seen. Microscopic investigation of the biopsy specimens collected from the stomach, duodenum and small intestine revealed mucous membrane necrosis foci, reaching the deeper layers of the wall of these organs. The mucous membrane of the large intestine was congested. Bioptates obtained from the lungs indicated the presence of hemorrhagic infarcts and focal extravasations. Poisoning with the aforementioned acids with consequent necrosis of the esophageal, gastric, duodenal and small intestinal walls with hemorrhages to the gastrointestinal tract, as well as extravasations and hemorrhagic infarcts in the lungs was considered to be the cause of death.

  9. Integrated Computational and Experimental Protocol for Understanding Rh(III) Speciation in Hydrochloric and Nitric Acid Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Samuels, Alex C.; Boele, Cherilynn A.; Bennett, Kevin T.; Clark, Sue B.; Wall, Nathalie; Clark, Aurora E.

    2014-12-01

    A combined experimental and theoretical approach has investigated the complex speciation of Rh(III) in hydrochloric and nitric acid media, as a function of acid concentration. This has relevance to the separation and isolation of Rh(III) from dissolved spent nuclear fuel, which is an emergent and attractive alternative source of platinum group metals, relative to traditional mining efforts.

  10. Thermodynamics and kinetics of lutetium extraction with HEH(EHP) in hydrochloric acid medium

    Institute of Scientific and Technical Information of China (English)

    DONG Jinshi; XU Yang; WANG Liangshi; HUANG Xiaowei; LONG Zhiqi; WU Shengxi

    2016-01-01

    Solvent extraction has been the most widely used technique for rare earths separation. In this study, thermodynamics and kinetics of lutetium extraction with HEH (EHP) in hydrochloric acid medium were investigated. The extraction mechanism and the relevant parameters were determined by experiment research which can guide the practical extraction process. The data indicated that chloride ion had no effect on lutetium extraction, the rate constant increased when stirring speed was enhanced. Effects of temperature, HEH (EHP) concentration, acidity, and chloride concentration were also studied. Thickness of the diffusion film was also calculated to be 4.66×10–3 cm at 150 r/min.

  11. Determination of uranium isotopes in environmental samples by anion exchange in sulfuric and hydrochloric acid media.

    Science.gov (United States)

    Popov, L

    2016-09-01

    Method for determination of uranium isotopes in various environmental samples is presented. The major advantages of the method are the low cost of the analysis, high radiochemical yields and good decontamination factors from the matrix elements, natural and man-made radionuclides. The separation and purification of uranium is attained by adsorption with strong base anion exchange resin in sulfuric and hydrochloric acid media. Uranium is electrodeposited on a stainless steel disk and measured by alpha spectrometry. The analytical method has been applied for the determination of concentrations of uranium isotopes in mineral, spring and tap waters from Bulgaria. The analytical quality was checked by analyzing reference materials.

  12. Laboratory investigation of three distinct emissions monitors for hydrochloric acid.

    Science.gov (United States)

    Dene, Charles E; Pisano, John T; Durbin, Thomas D; Bumiller, Kurt; Crabbe, Keith; Muzio, Lawrence J

    2016-12-01

    The measurement of hydrochloric acid (HCl) on a continuous basis in coal-fired plants is expected to become more important if HCl standards become implemented as part of the Federal Mercury and Air Toxics Standards (MATS) standards that are under consideration. For this study, the operational performance of three methods/instruments, including tunable diode laser absorption spectroscopy (TDLAS), cavity ring down spectroscopy (CRDS), and Fourier transform infrared (FTIR) spectroscopy, were evaluated over a range of real-world operating environments. Evaluations were done over an HCl concentration range of 0-25 ppmv and temperatures of 25, 100, and 185 °C. The average differences with respect to temperature were 3.0% for the TDL for values over 2.0 ppmv and 6.9% of all concentrations, 3.3% for the CRDS, and 4.5% for the FTIR. Interference tests for H2O, SO2, and CO, CO2, and NO for a range of concentrations typical of flue gases from coal-fired power plants did not show any strong interferences. The possible exception was an interference from H2O with the FTIR. The instrument average precision over the entire range was 4.4% for the TDL with better precision seen for concentrations levels of 2.0 ppmv and above, 2.5% for the CRDS, and 3.5% for the FTIR. The minimum detection limits were all on the order of 0.25 ppmv, or less, utilizing the TDL values with a 5-m path. Zero drift was found to be 1.48% for the TDL, 0.88% for the CRDS, and 1.28% for the FTIR. This study provides an evaluation of the operational performance of three methods/instruments, including TDL absorption spectroscopy (TDLAS), cavity ring down spectroscopy (CRDS), and FTIR spectroscopy, for the measurement of hydrochloric acid (HCl) over a range of real-world operating environments. The results showed good instrument accuracy as a function of temperature and no strong interferences for flue gases typical to coal-fired power plants. The results show that these instruments would be viable for the

  13. Recovery of Co(Ⅱ) and Ni(Ⅱ) from hydrochloric acid solution of alloy scrap

    Institute of Scientific and Technical Information of China (English)

    SHEN Yong-feng; XUE Wen-ying; NIU Wen-yong

    2008-01-01

    A hydrometallurgical process was developed for recovery of nickel and cobalt from the hydrochloric acid leaching solution of alloy scraps. The process consists of five major unit operations: 1) leaching with 6 mol/L hydrochloric acid under the L/S ratio of 10:1 at 95 ℃ for 3 h; 2) copper replacement by iron scraps under pH value of 2.0 at 80 ℃, and stirring for 1 h; 3) removal of iron and chromium by chemical precipitation: iron removal under pH value of 2.0 at 90 ℃ by dropwise addition of sodium chlorate and 18% sodium carbonate solution, then chromium removal under pH value of 4.0 at 70 ℃ by addition of nickel carbonate solution, stirred by air flow for 2 h; 4) selective separation of cobalt from nickel by extraction using 30% trialkyl amine+50% kerosene (volume fraction) and tri-n-butylphosphate (TBP) as a phase modifier with the O/A ratio of 2:1, and stripping of cobalt with 0.01 mol/L HC1; 5) crystallization of nickel chloride and electrodeposition of cobalt. It is found that the nickel recovery of 95% and the cobalt recovery of approximately 60% with purity over 99.9% are obtained by this process.

  14. Extraction of trace thorium from hydrochloric acid media by 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone

    Institute of Scientific and Technical Information of China (English)

    YANG Wei-Fan; YUAN Shuang-Gui; XU Yan-Bing; XIAO Yong-Hou; XIONG Bing

    2003-01-01

    The paper describes the solvent extraction of trace thorium from hydrochloric acid media by1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) using a radioactive tracer technique. The percent extraction ofthorium was studied as a function of acidity, PMBP concentration and equilibrium time. The back-extraction behaviorof thorium from the organic phase was also tested. Separation of thorium was performed from fission products pro-duced in 14 MeV neutron bombardment of natural uranium by employing the PMBP extraction procedure. Thegamma-ray spectra of the separated thorium fractions show that thorium can be separated from most of fission prod-ucts and a large amount of uranium.

  15. Comparison between phosphoric acid and hydrochloric acid in microabrasion technique for the treatment of dental fluorosis

    OpenAIRE

    Mahshid Mohammadi Bassir; Golnaz Bagheri

    2013-01-01

    Purpose: To compare the effectiveness of phosphoric acid (H 3 PO 4 )-pumice compound with conventional hydrochloric acid (HCl)-pumice compound in treating different severities of dental fluorosis with the microabrasion technique. Materials and Methods: Sixty-seven anterior teeth from seven patients with different severities of dental fluorosis were treated. In each patient, half of the teeth were treated with HCl-pumice compound and the other half with H 3 PO 4 -pumice compound (split-mou...

  16. Camphor Sulfonic Acid-hydrochloric Acid Codoped Polyaniline/polyvinyl Alcohol Composite: Synthesis and Characterization

    OpenAIRE

    Jorge Enrique Osorio-Fuente; Carlos Gómez-Yáñez; María de los Ángeles Hernández-Pérez; Fidel Pérez-Moreno

    2014-01-01

    A complementary dopant system formed by hydrochloric and camphor sulfonic (CSA) acids was used in the in-situ synthesis of a polyaniline (PANi)/polyvinyl alcohol (PVA) composite. The conductivity measurements showed that the use of CSA either as single dopant or codopant caused a decrement up to 2 orders of magnitude on the overall conductivity as well as an improvement on thermal stability. The PANi/PVA composites were characterized by spectroscopic and thermal analysis. Conducting emeraldin...

  17. Hydrochloric acid recovery from rare earth chloride solutions by vacuum membrane distillation

    Institute of Scientific and Technical Information of China (English)

    TANG Jianjun; ZHOU Kanggen

    2006-01-01

    The possibility of the recovery of hydrochloric acid from rare earth (RE) chloride solutions was first experimentally studied by batch vacuum membrane distillation (VMD). The recovery by continuous VMD was also studied to devise methods that enabled the operation of VMD setup in a stable condition as well as to increase the membrane-operating life The results indicated that HCl separation with RE by VMD was possible, and the recovery ratio of 80% could be achieved by batch VMD. In continuous VMD, when the temperature of circular solutions, circular rate, and downstream pressure was62-63℃, 5.4 cm/s, and 9.33 kPa, respectively, the HCl concentration in circular solutions and the processing capacity per membrane area were obtained. The mathematical results were in accordance with the experimental ones.

  18. Selenium dioxide catalysed oxidation of acetic acid hydrazide by bromate in aqueous hydrochloric acid medium

    Indian Academy of Sciences (India)

    R S Yalgudre; G S Gokavi

    2012-07-01

    Selenium dioxide catalysed acetic acid hydrazide oxidation by bromate was studied in hydrochloric acid medium. The order in oxidant concentration, substrate and catalyst were found to be unity. Increasing hydrogen ion concentration increases the rate of the reaction due to protonation equilibria of the oxidant. The mechanism of the reaction involves prior complex formation between the catalyst and substrate, hydrazide, followed by its oxidation by diprotonated bromate in a slow step. Acetic acid was found to be the oxidation product. Other kinetic data like effect of solvent polarity and ionic strength on the reaction support the proposed mechanism.

  19. Superficial performance and pore structure of palygorskite treated by hydrochloric acid

    Institute of Scientific and Technical Information of China (English)

    LIU Yi-xin; DAI Wei-wei; Wang Ting; TAO Yong

    2006-01-01

    In order to amend the superficial performance of palygorskite and improve its application, the natural palygorskite(NP) was treated in the dipping and ionic exchanging experiments using 6 mol/L hydrochloric acid treatment. The performance and pore structure of the treated palygorskite(TP) were investigated by means of microscope analyses, FT-IR, XRF, BET-SSA and full hole distribution analytical techniques. The results show that the hydrochloric acid treatment can make the gracile and aggregating compact crystal bundles inside palygorskite clay broken and dispersed, the roughness of microcrystalline surface increases, which not only can dissolve or remove dolomite but vary the superficial performance of palygorskite to some degree. The specific surface area and pore volume increase a lot, while the mean pore size decreases. The pore structure of TP changes remarkably compared with that of NP after 6 mol/L hydrochloric acid treatment, and the relevant physicochemical performance can be improved.

  20. Extraction of Alumina from high-silica bauxite by hydrochloric acid leaching using preliminary roasting method

    Science.gov (United States)

    Valeev, D. V.; Mansurova, E. R.; Bychinskii, V. A.; Chudnenko, K. V.

    2016-02-01

    A process of dissolution Severoonezhsk deposit boehmite-kaolinite bauxite by hydrochloric acid, as well as the processes that occur during open-air calcination, were investigated. A dehydration process has been studied, and the basic phase transformation temperatures were identified. Temperature and time of calcination influence on bauxite dehydration speed were determined. It is shown that the preliminary calcination increases the extraction ratio of alumina into solution up to 89%. Thermodynamic modelling of physical and chemical processes of bauxite decomposition by hydrochloric acid and the basic forms of aluminium speciation in solution were obtained.

  1. Extraction Mechanism of La3+ from Hydrochloric Acid Solution Using Cyanex 302

    Institute of Scientific and Technical Information of China (English)

    乌东北; 牛春吉; 李德谦

    2004-01-01

    The solvent extraction of La3+ from hydrochloric acid solutions was investigated using bis(2, 4, 4-trimethylpentyl) monothiophosphinic acid(Cyanex 302, HL) as an extractant. The effect of equilibrium of aqueous acidity on extraction of La3+ using Cyanex 302 in different diluents was discussed. The effects of extractant concentration and chloride ion on the extraction reaction were also studied. Stoichiometry of the extraction reactions and the nature of metal complexes formed were determined using slope analysis technique and IR measurement.

  2. Acidification of formula with citric acid is equally effective and better tolerated than acidification with hydrochloric acid.

    Science.gov (United States)

    Mehall, John R; Saltzman, Daniel A; Jackson, Richard J; Smith, Samuel D

    2002-08-01

    To determine whether acidification of formula with citric acid is equally protective against bacterial translocation and gut colonization but better tolerated than acidification with hydrochloric acid in neonatal rabbits. Paired animal model with control. Animal laboratory. Premature neonatal New Zealand rabbit pups. A standard neonatal rabbit model in two versions, a bacterial challenge and a no bacterial challenge model, was used to assess bacterial translocation and gut colonization. Two hundred forty-six rabbit pups were delivered by cesarean section 1 day premature and randomly placed into two groups sorted by type of formula acidification (hydrochloric acid or citric acid). Pups were gavage fed pH 3 kitten formula every 12 hrs. Ranitidine hydrochloride at 20 mg x kg(-1) x day(-1) was added to all formula. Bacterial challenge animals were given 1 x 10(6) colony-forming units/mL of Enterobacter cloacae with the third feeding. Animals in the no bacterial challenge group received no bacterial challenge. Animals were killed on day of life 3, and the liver, spleen, mesenteric lymph nodes, and cecum were sequentially harvested and cultured. Organs were qualitatively judged for growth, whereas cecal cultures were quantified as colony-forming units/gram. Stomach biopsies were performed to look for mucosal damage. Long-term tolerance was assessed in 48 pups fed formula acidified to pH 3 with either hydrochloric acid or citric acid and 20 animals fed pH 7 formula without ranitidine. Weight gain and mortality rate were followed for 14 days. Gut colonization and bacterial translocation to liver, spleen, and mesenteric lymph nodes were equivalent between citric acid and hydrochloric acid in both bacterial challenge and no bacterial challenge models. Long term, citric acid animals exceeded hydrochloric acid animals in daily weight gain and survival (p formula with citric acid is equally protective against bacteria but better tolerated than acidification with hydrochloric

  3. Influence of Formazan Derivatives on Corrosion Inhibition of Mild Steel in Hydrochloric Acid Medium

    OpenAIRE

    Venkatesan, P.; Anand, B.; P. Matheswaran

    2009-01-01

    Formazan of benzaldehyde (FB) and formazan of p-dimethyl amino benzaldehyde (FD) were synthesized. These compounds were studied as corrosion inhibitor for mild steel in 1.11 N hydrochloric acid by weight loss method. The result showed that the corrosion inhibition efficiency of these compounds was found to vary with the temperature and acid concentration. Also, it was found that the corrosion inhibition behaviour of FD is greater than that of FB. The kinetic treatment of the results gave firs...

  4. Inhibitory effect of some carbazides on corrosion of aluminium in hydrochloric acid and sodium hydroxide solutions

    Energy Technology Data Exchange (ETDEWEB)

    Fouda, A.S. [El-Mansoura Univ. (Egypt). Dept. of Chemistry; Madkour, L.H. [Tanta Univ. (Egypt). Dept. of Chemistry; Elshafei, A.A. [El-Mansoura Univ. (Egypt). Dept. of Chemistry; Elasklany, A.H. [El-Mansoura Univ. (Egypt). Dept. of Chemistry

    1995-06-01

    The dissolution of aluminium in hydrochloric acid and sodium hydroxide solutions in the presence of semicarbazide, thiosemicarbazide and sym.diphenylcarbazide as corrosion inhibitors has been studied using thermometric, weight-loss and polarization methods. The three methods gave consistent results. The higher inhibition efficiency of these compounds in acidic than in alkaline madia may be due to the less negative potential of aluminium in hydrochloric acid solution, favouring adsorption of the additive. The adsorption of these compounds were found to obey Frumkin adsorption isotherm. Cathodic polarization measurements showed that these compounds are cathodic inhibitors and their adsorption in the double layer does not change the mechanism of the hydrogen evolution reaction. The results are analysed in terms of both molecular and cationic adsorption. (orig.)

  5. Rare earth elements recycling from waste phosphor by dual hydrochloric acid dissolution.

    Science.gov (United States)

    Liu, Hu; Zhang, Shengen; Pan, Dean; Tian, Jianjun; Yang, Min; Wu, Maolin; Volinsky, Alex A

    2014-05-15

    This paper is a comparative study of recycling rare earth elements from waste phosphor, which focuses on the leaching rate and the technical principle. The traditional and dual dissolution by hydrochloric acid (DHA) methods were compared. The method of dual dissolution by hydrochloric acid has been developed. The Red rare earth phosphor (Y0.95Eu0.05)2O3 in waste phosphor is dissolved during the first step of acid leaching, while the Green phosphor (Ce0.67Tb0.33MgAl11O19) and the Blue phosphor (Ba0.9Eu0.1MgAl10O17) mixed with caustic soda are obtained by alkali sintering. The excess caustic soda and NaAlO2 are removed by washing. The insoluble matter is leached by the hydrochloric acid, followed by solvent extraction and precipitation (the DHA method). In comparison, the total leaching rate of the rare earth elements was 94.6% by DHA, which is much higher than 42.08% achieved by the traditional method. The leaching rate of Y, Eu, Ce and Tb reached 94.6%, 99.05%, 71.45%, and 76.22%, respectively. DHA can decrease the consumption of chemicals and energy. The suggested DHA method is feasible for industrial applications.

  6. Selective liquid-liquid extraction of antimony(III from hydrochloric acid media by N-n-octylaniline in xylene

    Directory of Open Access Journals (Sweden)

    M. A. ANUSE

    2004-04-01

    Full Text Available 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 mL 4 % 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.

  7. Experimental and quantum chemical studies on corrosion inhibition performance of fluconazole in hydrochloric acid solution

    Indian Academy of Sciences (India)

    P Malekmohammadi Nouri; M M Attar

    2015-04-01

    The corrosion inhibition effect of fluconazole (FLU) was investigated on steel in 1 M hydrochloric acid solution. Weight loss measurements and atomic force microscope analysis were utilized to investigate the corrosion inhibition properties and film formation behaviour of FLU. Quantum chemical approach was also used to calculate some electronic properties of the molecule in neutral and protonated form in order to find any correlation between the inhibition effect and molecular structure of FLU molecule. The results showed that FLU can act as a good corrosion inhibitor for steel in hydrochloric acid solution at different temperatures and it can inhibit steel corrosion up to 95%. The adsorption followed the Langmuir isotherm and the thermodynamic parameters were also determined and discussed. Quantum chemical studies showed that in adsorption process of FLU molecules, nitrogen and oxygen atoms and benzene ring act as active centres.

  8. Pretreatment of corn stover for sugar production using dilute hydrochloric acid followed by lime.

    Science.gov (United States)

    Zu, Shuai; Li, Wen-zhi; Zhang, Mingjian; Li, Zihong; Wang, Ziyu; Jameel, Hasan; Chang, Hou-min

    2014-01-01

    In this study, a two stage process was evaluated to increase the sugar recovery. Firstly, corn stover was treated with diluted hydrochloric acid to maximize the xylose yield, and then the residue was treated with lime to alter the lignin structure and swell the cellulose surface. The optimal condition was 120 °C and 40 min for diluted hydrochloric acid pretreatment followed by lime pretreatment at 60 °C for 12h with lime loading at 0.1 g/g of substrate. The glucose and xylose yield was 78.0% and 97.0%, respectively, with cellulase dosage at 5 FPU/g of substrate. The total glucose yield increased to 85.9% when the cellulase loading was increased to 10 FPU/g of substrate. This two stage process was effective due to the swelling of the internal surface, an increase in the porosity and a decrease in the degree of polymerization.

  9. A Concentrated Hydrochloric Acid-based Method for Complete Recovery of DNA from Bone.

    Science.gov (United States)

    Huynen, Leon; Lambert, David M

    2015-11-01

    The successful extraction of DNA from historical or ancient animal bone is important for the analysis of discriminating genetic markers. Methods used currently rely on the digestion of bone with EDTA and proteinase K, followed by purification with phenol/chloroform and silica bed binding. We have developed a simple concentrated hydrochloric acid-based method that precludes the use of phenol/chloroform purification and can lead to a several-fold increase in DNA yield when compared to other commonly used methods. Concentrated hydrochloric acid was shown to dissolve most of the undigested bone and allowed the efficient recovery of DNA fragments <100 bases in length. This method should prove useful for the recovery of DNAs from highly degraded animal bone, such as that found in historical or ancient samples.

  10. ANTICORROSION POTENTIAL OF HYDRALAZINE FOR CORROSION OF MILD STEEL IN 1M HYDROCHLORIC ACID SOLUTION

    Directory of Open Access Journals (Sweden)

    B. M. Prasanna

    2015-05-01

    Full Text Available Anticorrosion potential of mild steel by Hydralazine as corrosion inhibitor for mild steel in 1M hydrochloric acid was investigated by chemical and electrochemical measurements at 303-333 K temperature. The maximum inhibition efficiency of inhibitor by Weight loss method is around 90%, Tafel polarization method is around 85%; electrochemical impedance spectroscopy measurement around 90% at 1250 ppm of Hydralazine in. The result shows that the inhibition efficiency increases with I 1M hydrochloric acid. Hydralazine acts as a mixed type inhibitor which inhibits the corrosion of mild steel due to the adsorption on metal surface. This adsorption system obeys the Langmuir adsorption isotherm.Activation parameters explains the effect of temperature with inhibition efficiency of inhibitor molecule.SEM images of inhibited mild steel strips shows a formation of passive protective film over the surface.

  11. Acid hydrolysis of corn stover using hydrochloric acid: Kinetic modeling and statistical optimization

    Directory of Open Access Journals (Sweden)

    Sun Yong

    2014-01-01

    Full Text Available The hydrolysis of corn stover using hydrochloric acid was studied. The kinetic parameters of the mathematical models for predicting the yields of xylose, glucose, furfural and acetic acid were obtained, and the corresponding xylose generation activation energy of 100 kJ/mol was determined. The characterization of corn stover using with different techniques during hydrolysis indicated an effective removal of xylan and the slightly alteration on the structures of cellulose and lignin. A 23five levels Central Composite Design (CCD was used to develop a statistical model for the optimization of process variables including acid concentration, pretreatment temperature and time. The optimum conditions determined by this model were found to be 108ºC for 80 minutes with acid concentration of 5.8%. Under these conditions, the maximised results are the following: xylose 19.93 g/L, glucose 1.2 g/L, furfural 1.5 g/L, acetic acid 1.3 g/L. The validation of the model indicates a good agreement between the experimental results and the predicted values.

  12. Inhibition of Mild Steel Corrosion in Hydrochloric Acid Solution by Ciprofloxacin Drug

    OpenAIRE

    2013-01-01

    The inhibition of mild steel corrosion in hydrochloric acid solution by ciprofloxacin drug as an eco-friendly and commercially available inhibitor was studied at room temperature by weight loss technique. It was found that the test drug has a promising inhibitory action against corrosion of mild steel in the medium investigated. The inhibition efficiency was found to increase with a corresponding increase in the concentration of the inhibitor. It was also found that the adsorption as well as ...

  13. Corrosion Inhibition Synergism between Lanthanum(Ⅲ) Ion and 8-Hydroxyquinoline for Zinc in Hydrochloric Acid

    Institute of Scientific and Technical Information of China (English)

    木冠南; 唐丽斌; 李学铭

    2002-01-01

    The effects of La3+ ion and chelate reagent 8-hydroxyquinoline on the corrosion rate of zinc in hydrochloric acid were investigated by using weight loss method and electrochemical method. It is found that in a specific concentration range of La3+ ion and 8-hydroxyquinoline, the obvious corrosion inhibition synergism is obtained. The mechanism of corrosion inhibition synergism was discussed on basis of adsorption theory.

  14. Kinetics of Sawdust Hydrolysis with Dilute Hydrochloric Acid and Ferrous Chloride

    Institute of Scientific and Technical Information of China (English)

    袁传敏; 颜涌捷; 任铮伟; 李庭琛; 曹建勤

    2004-01-01

    With dilute hydrochloric acid as catalyst and promoted by ferrous chloride, hydrolysis of waste sawdust to produce monosaccharides was conducted by using an one-step method in a batch-wise operation reactor. Based on the model of first order consecutive irreversible reactions, the kinetics equation incorporating the term of catalyst concentration was obtained that is suitable for describing the hydrolysis of sawdust. Activation energies were calculated for hydrolysis of sawdust and decomposition of monosaccharides.

  15. Effect of dentifrices against hydrochloric acid-induced erosion.

    Science.gov (United States)

    Messias, Danielle Cristine; Maeda, Fernando Akio; Turssi, Cecilia Pedroso; Serra, Mônica Campos

    2011-01-01

    This in vitro investigation assessed whether different dentifrices would be capable of controlling the enamel erosion progression caused by HCl. Sixty bovine enamel slabs were covered with acid-resistant varnish, except for a 2.5-mm2 circular area on the labial surface. According to a complete block design, the experimental units were immersed in HCl solution (pH 1.2; 0.1M). After storage in artificial saliva for 1 h, specimens (n = 15) were exposed to different dentifrices: Sensodyne Cool Gel (1100 ppm F), Sensodyne ProNamel (1450 ppm F), and PrevDent 5000 (5000 ppm F). The control group was immersed in deionised water. Following five cycles of erosive challenge, the slabs were prepared for porosity evaluation using solutions of copper sulfate and rubeanic acid. ANOVA demonstrated no difference in the enamel porosity as a function of the dentifrice employed (P = 0.5494). The damage caused by a simulated intrinsic erosive challenge seems unable to be controlled by fluoridated dentifrices, even when this ion is found in elevated concentrations.

  16. Corrosion inhibition of iron in hydrochloric acid by polyacrylamide

    Directory of Open Access Journals (Sweden)

    DRAGICA CHAMOVSKA

    2007-07-01

    Full Text Available The corrosion protection and/or adsorption of polyacrylamide (PAA of number average molecular weight, , between 15,000 – 1,350,000 g mol-1 on mild steel and iron (99.99 % Fe in 3 M HCl at room temperature was studied using spectrophotometry (the phenanthroline method, the weight loss method and EIS (Electrochemical Impedance Spectroscopy. It was found that the corrosion protect­tion efficiency of the PAA – adsorbed layers strongly depends on both the molar concentration of PAA in the solution and its molecular weight, reaching limiting values between 85 and 96 %. Simultaneously, it was also concluded that a relatively high surface coverage could be obtained with very low PAA concentrations (0.5 – 2 ppm, indicating the good adsorption characteristics of PAA on mild steel and iron in hydrochloride acid. The experimentally obtained results follow a Lan­gmuir adsorption isotherm. According to the best fitting parameters, the adsorption coef­f­i­cient B ranged between 2×107 and 4×108 mol-1 and depended strongly on the mole­cular weight of the PAA: B = k (for a ≈ 0.67 and k = 2.95×104 or the size of the polymer coil. As was found by EIS, the thickness of the adsorbed PAA layer was approx. 1.1 nm (for er = 15 and corresponded only to the polymer segments attached to the metal surface. On the other hand, as was found by ellipsometry, the limiting layer of the adsorbed PAA molecules was highly voluminous and relatively thick (100 – 200 nm, containing entangled polymer coils.

  17. Investigating the Acid Failure of Aluminium Alloy in 2 M Hydrochloric Acid Using Vernonia amygdalina

    Directory of Open Access Journals (Sweden)

    Olugbenga A. Omotosho

    2012-04-01

    Full Text Available The acid failure of aluminium alloy in 2 M hydrochloric acid solution in the presence of Vernonia amygdalina extract was investigated using gasometric technique. Aluminium alloy coupons of dimension 4 cm by 1 cm were immersed in test solutions of free acid and also those containing extract volumes of 2, 3, 4 and 5 cm3 at ambient temperature for 30 minutes. The volumes of hydrogen gas evolved as a result of the rate of reaction were recorded and analyzed. Analysis revealed that maximum inhibitor efficiency which corresponds to the lowest corrosion rate was obtained at optimum inhibitor volumes of 5 cm3, with reduction in the corrosion rate observed to follow in order of increasing extract volumes. Adsorption study revealed that Temkin isotherm best described the metal surface interaction with the extract phytochemicals, with 12 minutes becoming the best exposure time for the phytochemicals to adsorb to the metal surface at all volumes. Statistical modelling of the corrosion rate yielded an important relationship suitable for estimating corrosion rate values once volumes of the extract is known. Microstructural studies, showed an indirect relationship between crack growth rates and extract volumes, while consistency of the irregular intermetallic phases increases with increasing extract volumes.

  18. [Butanol extraction combined with dilute hydrochloric acid dissolution-atomic fluorescence spectrometric method for indirect determination of molybdenum in Chinese herbal medicine].

    Science.gov (United States)

    Lu, Jian-Ping; Geng, Guo-Xing; Tang, Yan-Kui; Lu, Zhi-Yong

    2012-12-01

    A method for indirectly determining the molybdenum in Chinese herbal medicine by butanol extraction and dilute hydrochloric acid dissolution was established for atomic fluorescence spectrometry. The molybdoarsenate heteropoly acid, formed in the presence of As(V) and ammonium molybdate in 0.3 mol x L(-1) sulphuric acid medium, was separated and enriched in the organic solvent, then the evaporation of organic reagent was implemented and the left residue was dissolved in dilute hydrochloric acid in which the arsenic content was determined on behalf of molybdenum. In the optimum experimental conditions, molybdenum content in 0-15 microg x L(-1) range depicts a good linear relationship, the detection limit and relative standard deviation of 0.44 microg x L(-1) and 1.1% were obtained, respectively. Spiked Chinese herbal medicine samples were determined with the proposed method, and recoveries of 95.6%-101.3% were achieved.

  19. Influence of Formazan Derivatives on Corrosion Inhibition of Mild Steel in Hydrochloric Acid Medium

    Directory of Open Access Journals (Sweden)

    P. Venkatesan

    2009-01-01

    Full Text Available Formazan of benzaldehyde (FB and formazan of p-dimethyl amino benzaldehyde (FD were synthesized. These compounds were studied as corrosion inhibitor for mild steel in 1.11 N hydrochloric acid by weight loss method. The result showed that the corrosion inhibition efficiency of these compounds was found to vary with the temperature and acid concentration. Also, it was found that the corrosion inhibition behaviour of FD is greater than that of FB. The kinetic treatment of the results gave first order kinetics. The relative corrosion inhibition efficiency of these compounds has been explained on the basis of structure dependent - electron donor properties of the inhibitors.

  20. Formation of linear polyenes in poly(vinyl alcohol) films catalyzed by phosphotungstic acid, aluminum chloride, and hydrochloric acid

    Science.gov (United States)

    Tretinnikov, O. N.; Sushko, N. I.; Malyi, A. B.

    2016-07-01

    Formation of linear polyenes-(CH=CH)n-via acid-catalyzed thermal dehydration of polyvinyl alcohol in 9- to 40-µm-thick films of this polymer containing hydrochloric acid, aluminum chloride, and phosphotungstic acid as dehydration catalysts was studied by electronic absorption spectroscopy. The concentration of long-chain ( n ≥ 8) polyenes in films containing phosphotungstic acid is found to monotonically increase with the duration of thermal treatment of films, although the kinetics of this process is independent of film thickness. In films containing hydrochloric acid and aluminum chloride, the formation rate of polyenes with n ≥ 8 rapidly drops as film thickness decreases and the annealing time increases. As a result, at a film thickness of less than 10-12 µm, long-chain polyenes are not formed at all in these films no matter how long thermal duration is. The reason for this behavior is that hydrochloric acid catalyzing polymer dehydration in these films evaporates from the films during thermal treatment, the evaporation rate inversely depending on film thickness.

  1. Effect of beverages on bovine dental enamel subjected to erosive challenge with hydrochloric acid.

    Science.gov (United States)

    Amoras, Dinah Ribeiro; Corona, Silmara Aparecida Milori; Rodrigues, Antonio Luiz; Serra, Mônica Campos

    2012-01-01

    This study evaluated by an in vitro model the effect of beverages on dental enamel previously subjected to erosive challenge with hydrochloric acid. The factor under study was the type of beverage, in five levels: Sprite® Zero Low-calorie Soda Lime (positive control), Parmalat® ultra high temperature (UHT) milk, Ades® Original soymilk, Leão® Ice Tea Zero ready-to-drink low-calorie peach-flavored black teaand Prata® natural mineral water (negative control). Seventy-five bovine enamel specimens were distributed among the five types of beverages (n=15), according to a randomized complete block design. For the formation of erosive wear lesions, the specimens were immersed in 10 mL aqueous solution of hydrochloric acid 0.01 M for 2 min. Subsequently, the specimens were immersed in 20 mL of the beverages for 1 min, twice daily for 2 days at room temperature. In between, the specimens were kept in 20 mL of artificial saliva at 37ºC. The response variable was the quantitative enamel microhardness. ANOVA and Tukey's test showed highly significant differences (penamel exposed to hydrochloric acid and beverages. The soft drink caused a significantly higher decrease in microhardness compared with the other beverages. The black tea caused a significantly higher reduction in microhardness than the mineral water, UHT milk and soymilk, but lower than the soft drink. Among the analyzed beverages, the soft drink and the black tea caused the most deleterious effects on dental enamel microhardness.

  2. Inhibition of Mild Steel Corrosion in Hydrochloric Acid Solution by Ciprofloxacin Drug

    Directory of Open Access Journals (Sweden)

    Inemesit A. Akpan

    2013-01-01

    Full Text Available The inhibition of mild steel corrosion in hydrochloric acid solution by ciprofloxacin drug as an eco-friendly and commercially available inhibitor was studied at room temperature by weight loss technique. It was found that the test drug has a promising inhibitory action against corrosion of mild steel in the medium investigated. The inhibition efficiency was found to increase with a corresponding increase in the concentration of the inhibitor. It was also found that the adsorption as well as the inhibition process followed a first-order kinetics and obeyed Langmuir’s adsorption isotherm.

  3. Effect of molecular structure of aniline-formaldehyde copolymers on corrosion inhibition of mild steel in hydrochloric acid solution.

    Science.gov (United States)

    Zhang, Yan; Nie, Mengyan; Wang, Xiutong; Zhu, Yukun; Shi, Fuhua; Yu, Jianqiang; Hou, Baorong

    2015-05-30

    Aniline-formaldehyde copolymers with different molecular structures have been prepared and investigated for the purpose of corrosion control of mild steel in hydrochloric acid. The copolymers were synthesized by a condensation polymerization process with different ratios of aniline to formaldehyde in acidic precursor solutions. The corrosion inhibition efficiency of as-synthesized copolymers for Q235 mild steel was investigated in 1.0 mol L(-1) hydrochloric acid solution by weight loss measurement, potentiodynamic polarization, and electrochemical impedance spectroscopy, respectively. All the results demonstrate that as-prepared aniline-formaldehyde copolymers are efficient mixed-type corrosion inhibitors for mild steels in hydrochloric acid. The corrosion inhibition mechanism is discussed in terms of the role of molecular structure on adsorption of the copolymers onto the steel surface in acid solution.

  4. Determination of aluminum in aluminum electrolyte by EDTA back titration with ethanol-cuprous chloride-ammonium chloride-hydrochloric acid complex solvent separation%乙醇-氯化亚铜-氯化铵-盐酸复合溶剂分离-EDTA返滴定法测定铝电解质中单质铝

    Institute of Scientific and Technical Information of China (English)

    蒲秋梅; 任凤莲; 曹福悦

    2011-01-01

    新型低温铝电解质体系物相组成复杂,单质铝的分离测定尤为困难.本文采用高选择性复合溶剂乙醇-氯化亚铜-氯化铵-盐酸(ECAH)直接分离后测定铝电解质中单质铝,成功解决了单质铝与其它铝的化合物分离困难的问题,有效降低了铝电解质溶样时铝的氟化物的微溶效应带来的误差,为铝电解质中单质铝的物相分析提供了可靠的研究方案.采用经典ED-TA络合返滴定法测得铝电解质样品中单质铝含量,加标回收率在97%~103%之间,RSD(n=6)为1.1%和1.5%.测定结果和Al-CAS-OP-CPC四元络合光度法测定结果进行比对,结果一致.%It was particularly difficult to separate and determine aluminum in new low-temperature aluminum electrolyte system because of its complicated components. In this paper, aluminum in aluminum electrolyte was directly separated and determined using high-selectivity ethanol -cuprous chlorideammomum chloride-hydrochloric acid (ECAH) as complex solvent. This method successfully settled the problem of difficult separation of aluminum from aluminum compounds, effectively reduced the determination error introduced by slight soluble effect of fluoride of aluminum during the dissolution of aluminum electrolyte, and provided a reliable research method for the phase analysis of aluminum in aluminum electrolyte. Aluminum in aluminum electrolyte samples was determined by classic EDTA complexing back titration method. The standard addition recoveries were 97%-103 %, and the relative standard deviations (RSD, n=6) were 1. 1 % and 1. 5 %, respectively. The determination results were in good agreement with those obtained by Al-CAS-OP-CPC quaternary complex photometry.

  5. Kinetic Aspects of Leaching Zinc from Waste Galvanizing Zinc by Using Hydrochloric Acid Solutions

    Science.gov (United States)

    Sminčáková, Emília; Trpčevská, Jarmila; Pirošková, Jana

    2017-10-01

    In this work, the results of acid leaching of flux skimmings coming from two plants are presented. Sample A contained two phases, Zn(OH)Cl and NH4Cl. In sample B, the presence of three phases, Zn5(OH)8Cl2·H2O, (NH4)2(ZnCl4) and ZnCl2(NH3)2, was proved. The aqueous solution of hydrochloric acid and distilled water was used as the leaching medium. The effects of the leaching time, temperature and concentration of the leaching medium on the zinc extraction were investigated. The apparent activation energy, E a = 4.61 kJ mol-1, and apparent reaction order n = 0.18 for sample A, and the values E a = 6.28 kJ mol-1 and n = 0.33 for sample B were experimentally determined. Zinc leaching in acid medium is a diffusion-controlled process.

  6. Kinetic Aspects of Leaching Zinc from Waste Galvanizing Zinc by Using Hydrochloric Acid Solutions

    Science.gov (United States)

    Sminčáková, Emília; Trpčevská, Jarmila; Pirošková, Jana

    2016-10-01

    In this work, the results of acid leaching of flux skimmings coming from two plants are presented. Sample A contained two phases, Zn(OH)Cl and NH4Cl. In sample B, the presence of three phases, Zn5(OH)8Cl2·H2O, (NH4)2(ZnCl4) and ZnCl2(NH3)2, was proved. The aqueous solution of hydrochloric acid and distilled water was used as the leaching medium. The effects of the leaching time, temperature and concentration of the leaching medium on the zinc extraction were investigated. The apparent activation energy, E a = 4.61 kJ mol-1, and apparent reaction order n = 0.18 for sample A, and the values E a = 6.28 kJ mol-1 and n = 0.33 for sample B were experimentally determined. Zinc leaching in acid medium is a diffusion-controlled process.

  7. Direct Spectroscopic Determination of Europium(Ⅱ) Concentration During Europium(Ⅲ) Electro-Reduction in Hydrochloric Acid Medium

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    UV-Vis spectroscopy was used to directly determine the concentration of Eu(Ⅱ) during electroreduction of Eu(Ⅲ) in hydrochloric acid medium. Electroreduction was carried out in a flow type electrolyzer with glassy carbon cathode at the constant potential of -800 mV vs. Ag/AgCl. The effects of oxygen and concentration of hydrochloric acid on the system were investigated. For 0.01 mol·L-1 hydrochloric acid, calibration curves for Eu(Ⅱ) absorption bands at 248 and 320 nm were constructed. Molar absorption coefficients were estimated to be 2016 and 648 L·mol-1·cm-1, respectively. The absorbance strongly decreased with decrease in pH of the solution, whereas concentration of chloride had only a negligible effect.

  8. The Comparison of Hydrochloric Acid and Phosphoric Acid Treatments in the Preparation of Montmorillonite Catalysts for RNA Synthesis

    Science.gov (United States)

    Aldersley, Michael Frank; Joshi, Prakash C.; Huang, Yixing

    2017-02-01

    The treatment of clay minerals with a preliminary acid wash and titration to pH 7 has proven to generate catalysts for the most interesting of oligomerization reactions in which activated RNA-nucleotides generate oligomers up to 40-mers. Significantly, not all clay minerals become catalytic following this treatment and none are catalytic in the absence of such treatment. The washing procedure has been modified and explored further using phosphoric acid and the outcomes are compared to those obtained when clay samples are prepared following a hydrochloric acid wash.

  9. EDTA and hydrochloric acid effects on mercury accumulation by Lupinus albus.

    Science.gov (United States)

    Rodríguez, Luis; Alonso-Azcárate, Jacinto; Villaseñor, José; Rodríguez-Castellanos, Laura

    2016-12-01

    The efficiency of white lupine (Lupinus albus) to uptake and accumulate mercury from a soil polluted by mining activities was assessed in a pot experiment with chemically assisted phytoextraction. The mobilizing agents tested were ethylenediaminetetracetic acid (EDTA) and hydrochloric acid (HCl). Two doses of each amendment were used (0.5 and 1.0 g of amendment per kg of soil), and unamended pots were used as a control. Addition of HCl to the soil did not negatively affect plant biomass, while the use of EDTA led to a significant decrease in plant growth when compared to that found for non-treated pots, with plants visually showing symptoms of toxicity. The addition of hydrochloric acid increased root, shoot and total plant Hg uptake of white lupine by 3.7 times, 3.1 times and 3.5 times, respectively, in relation to non-amended plants. The greatest efficiency was obtained for the highest HCl dose. EDTA led to higher concentrations of total plant Hg than that found with the control, but, due to the aforementioned decrease in plant biomass, the Hg phytoextraction yield was not significantly increased. These results were attributed to the capability of both amendments to form stable Hg complexes. The concentration of Hg in the water of the soil pores after the phytoextraction experiment was very low for all treatments, showing that risks derived from metal leaching could be partially avoided by using doses and chemicals suitable to the concentration of metal in the soil and plant performance.

  10. Anomalous spin polarization in the photoreduction of chromone-2-carboxylic acid with alcohol induced by hydrochloric acid

    Science.gov (United States)

    Ohara, Keishi; Mukai, Kazuo

    2000-02-01

    The addition effect of hydrochloric acid (HCl) on the photoreduction of chromone-2-carboxylic acid (CRCA) is studied by time-resolved EPR. The EPR lines of CRCA ketyl radical show an enhanced absorption in the presence of HCl, while without HCl these show an emissive character. On the other hand, the lines of the CRCA alkyl type radical show an emissive character whether HCl is included or not. The simultaneous reactions of the closely-lying two excited triplet states (T 1 and T 2) of CRCA may induce the above anomalous CIDEP behavior.

  11. Comparison of sulfuric and hydrochloric acids as catalysts in hydrolysis of Kappaphycus alvarezii (cottonii).

    Science.gov (United States)

    Meinita, Maria Dyah Nur; Hong, Yong-Ki; Jeong, Gwi-Taek

    2012-01-01

    In this study, hydrolysis of marine algal biomass Kappaphhycus alvarezii using two different acid catalysts was examined with the goal of identifying optimal reaction conditions for the formation of sugars and by-products. K. alvarezii were hydrolyzed by autoclave using sulfuric acid or hydrochloric acid as catalyst with different acid concentrations (0.1-1.0 M), substrate concentrations (1.0-13.5%), hydrolysis time (10-90 min) and hydrolysis temperatures (100-130 (°)C). A difference in galactose, glucose, reducing sugar and total sugar content was observed under the different hydrolysis conditions. Different by-product compounds such as 5-hydroxymethylfurfural and levulinic acid were also observed under the different reaction conditions. The optimal conditions for hydrolysis were achieved at a sulfuric acid concentration, temperature and reaction time of 0.2 M, 130 °C and 15 min, respectively. These results may provide useful information for the development of more efficient systems for biofuel production from marine biomass.

  12. Detection of anhydrous hydrochloric acid, HCl, in IRC+10216 with the Herschel SPIRE and PACS spectrometers

    CERN Document Server

    Cernicharo, J; Barlow, M J; Agundez, M; Royer, P; Vandenbussche, B; Wesson, R; Polehampton, E T; De Beck, E; Blommaert, J A D L; Daniel, F; De Meester, W; Exter, K M; Feuchtgruber, H; Gear, W K; Goicoechea, J R; Gomez, H L; Groenewegen, M A T; Hargrave, P C; Huygen, R; Imhof, P; Ivison, R J; Jean, C; Kerschbaum, F; Leeks, S J; Lim, T L; Matsuura, M; Olofsson, G; Posch, T; Regibo, S; Savini, G; Sibthorpe, B; Swinyard, B M; Vandenbussche, B; Waelkens, C

    2010-01-01

    We report on the detection of anhydrous hydrochloric acid (hydrogen chlorine, HCl) in the carbon-rich star IRC+10216 using the spectroscopic facilities onboard the Herschel satellite. Lines from J=1-0 up to J=7-6 have been detected. From the observed intensities, we conclude that HCl is produced in the innermost layers of the circumstellar envelope with an abundance relative to H2 of 5x10^-8 and extends until the molecules reach its photodissociation zone. Upper limits to the column densities of AlH, MgH, CaH, CuH, KH, NaH, FeH, and other diatomic hydrides have also been obtained.

  13. Molecular Structure of Phenylthiourea as a Corrosion Inhibitor for Mild Steel in Hydrochloric Acid

    Institute of Scientific and Technical Information of China (English)

    Anees A, Khadom

    2011-01-01

    The application of statistical analysis and quantum chemical models on the corrosion inhibition of mild steel in hydrochloric acid in presence of phenylthiourea (PTU) as corrosion inhibitor have been investigated. Two mathematical models were used, second order polynomial model and Arrhenius type equation model. STATISTICA software based on Levenberg-Marquardt estimation method was used to evaluate the coefficients of two Models. It follows that the two models were suitable to represent the corrosion rate data at different conditions. The correlation coefficient of second order polynomial model was 0.973, while for the Arrhenius type model was 0.919. The structure of inhibitor was optimized by ArgusLab 4.0.1 package. The quantum chemical parameters (EHoMO, ELUMO, AE, and dipole moment μ) were estimated by PM3-SCF method.

  14. Use of hydrochloric acid for determinining solid-phase arsenic partitioning in sulfidic sediments.

    Science.gov (United States)

    Wilkin, Richard T; Ford, Robert G

    2002-11-15

    We examined the use of room-temperature hydrochloric acid (1-6 M) and salt solutions of magnesium chloride, sodium carbonate, and sodium sulfide for the removal of arsenic from synthetic iron monosulfides and contaminated sediments containing acid-volatile sulfides (AVS). Results indicate that acid-soluble arsenic reacts with H2S released from AVS phases and precipitates at low pH as disordered orpiment or alacranite. Arsenic sulfide precipitation is consistent with geochemical modeling in that conditions during acid extraction are predicted to be oversaturated with respect to orpiment, realgar, or both. Binding of arsenic with sulfide at low pH is sufficiently strong that 6 M HCl will not keep spiked arsenic in the dissolved fraction. Over a wide range of AVS concentrations and molar [As]/[AVS] ratios, acid extraction of arsenic from sulfide-bearing sediments will give biased results that overestimate the stability or underestimate the bioavailability of sediment-bound arsenic. Alkaline solutions of sodium sulfide and sodium carbonate are efficient in removing arsenic from arsenic sulfides and mixed iron-arsenic sulfides because of the high solubility of arsenic at alkaline pH, the formation of stable arsenic complexes with sulfide or carbonate, or both.

  15. Cellulose acetate layer effect toward aluminium corrosion rate in hydrochloric acid media

    Science.gov (United States)

    Andarany, K. S.; Sagir, A.; Ahmad, A.; Deni, S. K.; Gunawan, W.

    2017-09-01

    Corrosion occurs due to the oxidation and reduction reactions between the material and its environment. The oxidation reaction defined as reactions that produce electrons and reduction is between two elements that bind the electrons. Corrosion cannot be inevitable in life both within the industry and household. Corrosion cannot eliminate but can be control. According to the voltaic table, Aluminum is a metal that easily corroded. This study attempts to characterize the type of corrosion by using a strong acid media (HCl). Experiment using a strong acid (HCl), at a low concentration that occurs is pitting corrosion, whereas at high concentrations that occurs is corrosion erosion. One of prevention method is by using a coating method. An efforts are made to slow the rate of corrosion is by coating the metal with “cellulose acetate” (CA). cellulose acetate consisted of cellulose powder dissolved in 99% acetic acid, and then applied to the aluminum metal. Soaking experiments using hydrochloric acid, cellulose acetate is able to slow down the corrosion rate of 47 479%.

  16. Extraction of gold from hydrochloric acid solutions by Alamine 336 and Alkylaniline

    Directory of Open Access Journals (Sweden)

    Natalya Dolgova

    2013-09-01

    Full Text Available The extraction of gold with 336 Alamin and Alkylaniline from hydrochloric acid solutions was studied. Shown that Alamin extracts gold quantitatively in the field of acidity of the aqueuous phase pH=3,0 – СHCl=3,5 M when used as diluents of kerosene and higher carboxylic acids in admixture with paraffin. The time of quantitative extraction of gold: with Alamin – 3 minutes, with Alkylaniline – 5 minutes, regardless of the choice of diluent. The composition of the extracted complex and scheme of  gold extraction process with Alamin was proposed. Extraction of gold with 5%- Alamin-HCA-paraffin can be used for development of a combined extraction -  X-ray fluorescence technique for determination of gold because the resulting solids extracts meet the requirements imposed on emitters samples in X-ray fluorescence analysis. Calibration characteritstic is linear in the range of gold content in the samples emitters 0,006-0,17 wt%.

  17. Enhanced Blood Compatibility of Metallocene Polyethylene Subjected to Hydrochloric Acid Treatment for Cardiovascular Implants

    Directory of Open Access Journals (Sweden)

    Saravana Kumar Jaganathan

    2014-01-01

    Full Text Available Blood compatibility of metallocene polyethylene (mPE was investigated after modifying the surface using hydrochloric acid. Contact angle of the mPE exposed to HCl poses a decrease in its value which indicates increasing wettability and better blood compatibility. Surface of mPE analyzed by using FTIR revealed no significant changes in its functional groups after treatment. Furthermore, scanning electron microscope images supported the increasing wettability through the modifications like pit formations and etching on the acid rendered surface. To evaluate the effect of acid treatment on the coagulation cascade, prothrombin time (PT and activated partial thromboplastin time (APTT were measured. Both PT and APTT were delayed significantly (P<0.05 after 60 min exposure implying improved blood compatibility of the surfaces. Hemolysis assay of the treated surface showed a remarkable decrease in the percentage of lysis of red blood cells when compared with untreated surface. Moreover, platelet adhesion assay demonstrated that HCl exposed surfaces deter the attachment of platelets and thereby reduce the chances of activation of blood coagulation cascade. These results confirmed the enhanced blood compatibility of mPE after HCl exposure which can be utilized for cardiovascular implants like artificial vascular prostheses, implants, and various blood contacting devices.

  18. Quantitative Leaching of a Spent Cell Phone Printed Circuit Board by Hydrochloric acid

    Directory of Open Access Journals (Sweden)

    Alafara A. Baba

    2014-07-01

    Full Text Available This paper presents a kinetic data on the hydrometallurgical recovery of some metal ions from a printed circuit board (PCB of a spent cell phone by hydrochloric acid leaching. The effects of acid concentration, temperature and particle diameter on the dissolution efficiency at various leaching time intervals were examined. The results of the leaching investigations showed that the powdered cell phone dissolution increases with increasing acid concentration, system temperature with decreasing particle diameter at 360 rpm. With 2M HCl solution, about 88.49% of the sample was dissolved within 120 minutes using 0.075-0.112 mm particle diameter at 800 C. The results of the study indicated that the dissolution reaction could be represented by a shrinking core model with surface chemical reaction. A value of 0.61, 60.67 kJ/mol and 12.9s-1 were calculated as reaction order, activation energy and frequency factor, respectively for the dissolution process.

  19. Surface chemical compositions and dispersity of starch nanocrystals formed by sulfuric and hydrochloric acid hydrolysis.

    Science.gov (United States)

    Wei, Benxi; Xu, Xueming; Jin, Zhengyu; Tian, Yaoqi

    2014-01-01

    Surface chemical compositions of starch nanocrystals (SNC) prepared using sulfuric acid (H2SO4) and hydrochloric acid (HCl) hydrolysis were analyzed by X-ray photoelectron spectroscopy (XPS) and FT-IR. The results showed that carboxyl groups and sulfate esters were presented in SNC after hydrolysis with H2SO4, while no sulfate esters were detected in SNC during HCl-hydrolysis. TEM results showed that, compared to H2SO4-hydrolyzed sample, a wider size distribution of SNC prepared by HCl-hydrolysis were observed. Zeta-potentials were -23.1 and -5.02 mV for H2SO4- and HCl-hydrolyzed SNC suspensions at pH 6.5, respectively. Nevertheless, the zeta-potential values decreased to -32.3 and -10.2 mV as the dispersion pH was adjusted to 10.6. After placed 48 h at pH 10.6, zeta-potential increased to -24.1 mV for H2SO4-hydrolyzed SNC, while no change was detected for HCl-hydrolyzed one. The higher zeta-potential and relative small particle distribution of SNC caused more stable suspensions compared to HCl-hydrolyzed sample.

  20. Surface chemical compositions and dispersity of starch nanocrystals formed by sulfuric and hydrochloric acid hydrolysis.

    Directory of Open Access Journals (Sweden)

    Benxi Wei

    Full Text Available Surface chemical compositions of starch nanocrystals (SNC prepared using sulfuric acid (H2SO4 and hydrochloric acid (HCl hydrolysis were analyzed by X-ray photoelectron spectroscopy (XPS and FT-IR. The results showed that carboxyl groups and sulfate esters were presented in SNC after hydrolysis with H2SO4, while no sulfate esters were detected in SNC during HCl-hydrolysis. TEM results showed that, compared to H2SO4-hydrolyzed sample, a wider size distribution of SNC prepared by HCl-hydrolysis were observed. Zeta-potentials were -23.1 and -5.02 mV for H2SO4- and HCl-hydrolyzed SNC suspensions at pH 6.5, respectively. Nevertheless, the zeta-potential values decreased to -32.3 and -10.2 mV as the dispersion pH was adjusted to 10.6. After placed 48 h at pH 10.6, zeta-potential increased to -24.1 mV for H2SO4-hydrolyzed SNC, while no change was detected for HCl-hydrolyzed one. The higher zeta-potential and relative small particle distribution of SNC caused more stable suspensions compared to HCl-hydrolyzed sample.

  1. Impact of α-amylase combined with hydrochloric acid hydrolysis on structure and digestion of waxy rice starch.

    Science.gov (United States)

    Li, Hongyan; Zhu, Yanqiao; Jiao, Aiquan; Zhao, Jianwei; Chen, Xiaoming; Wei, Benxi; Hu, Xiuting; Wu, Chunsen; Jin, Zhengyu; Tian, Yaoqi

    2013-04-01

    The structure and in vitro digestibility of native waxy rice starch by the combined hydrolysis of α-amylase and hydrochloric acid were investigated in this study. The combined hydrolysis technique generated higher hydrolysis rate and extent than the enzymatic hydrolysis. The granular appearance and chromatograph profile demonstrated that α-amylase and hydrochloric acid exhibited different patterns of hydrolysis. The rise in the ratio of absorbance 1047/1022cm(-1), the melting temperature range (Tc-To), and the melting enthalpy (ΔH) were observed during the combined hydrolysis. These results suggest that α-amylase simultaneously cleaves the amorphous and crystalline regions, whereas the amorphous regions of starch granules are preferentially hydrolyzed during the acid hydrolysis. Furthermore, the combined hydrolysis increased rapidly digestible starch (RDS) while decreased slowly digestible starch (SDS) and resistant starch (RS), indicating that the hydrolysis mode affected the digestion property of native waxy rice starch.

  2. Effect of foods and drinks on primary tooth enamel after erosive challenge with hydrochloric acid.

    Science.gov (United States)

    Mesquita-Guimarães, Késsia Suênia Fidelis de; Scatena, Camila; Borsatto, Maria Cristina; Rodrigues-Júnior, Antonio Luiz; Serra, Mônica Campos

    2015-01-01

    The aim of this study was to evaluate the effect of industrialised foods and drinks on primary tooth enamel previously eroded with hydrochloric acid (HCl). The crowns of one hundred two specimens were subjected to an erosive challenge with HCl and randomly divided into six groups (n = 17): Chocolate Milk (Toddynho® - Pepsico) - negative control; Petit Suisse Yogurt (Danoninho® - Danone); Strawberry Yogurt (Vigor); Apple puree (Nestlé); Fermented Milk (Yakult® - Yakult); and Home Squeezed Style Orange Juice (del Valle) - positive control. The 28-day immersion cycles for the test products were performed twice daily and were interspersed with exposure of the test substrate to artificial saliva. Measurements of enamel surface microhardness (SMH) were performed initially, after immersion in HCl and at 7, 14, 21 and 28 days of experimentation. A two-way ANOVA, according to a split-plot design, followed by the sum of squares decomposition and Tukey's test, revealed a significant effect for the interaction between Foods and Drinks and Length of Exposure (p < 0.00001). Orange juice resulted in greater mineral loss of enamel after 28 days. None of the test products was associated with recovery of tooth enamel microhardness.

  3. Two pyrazine derivatives as inhibitors of the cold rolled steel corrosion in hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Deng Shuduan, E-mail: dengshuduan@163.co [Faculty of Wood Science and Decoration Technology, Southwest Forestry University, Kunming 650224 (China); Li Xianghong; Fu Hui [Department of Fundamental Courses, Southwest Forestry University, Kunming 650224 (China)

    2011-02-15

    Research highlights: Two pyrazine derivatives of 2-aminopyrazine (AP) and 2-amino-5-bromopyrazine (ABP) are good inhibitors for the corrosion of steel in 1.0 M HCl solution. The inhibition efficiency follows the order: ABP > AP. The substitution Br of ABP is the additional centre of adsorption and increases the electron density of pyrazine ring, which can facilitate its adsorption on the metal surface. For either ABP or AP, the adsorption obeys Langmuir adsorption isotherm. Both ABP and AP act as mixed-type inhibitors. - Abstract: The inhibition effect of two pyrazine derivatives of 2-aminopyrazine (AP) and 2-amino-5-bromopyrazine (ABP) on the corrosion of cold rolled steel (CRS) in 1.0 M hydrochloric acid (HCl) was studied by weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS) methods. The results show that both AP and ABP are good inhibitors, and inhibition efficiency follows the order: ABP > AP. The adsorption of each inhibitor on CRS surface obeys Langmuir adsorption isotherm. Potentiodynamic polarization curves show that two pyrazine derivatives act as mixed-type inhibitors. EIS spectra exhibit one capacitive loop and confirm the inhibitive ability.

  4. Effect of foods and drinks on primary tooth enamel after erosive challenge with hydrochloric acid

    Directory of Open Access Journals (Sweden)

    Késsia Suênia Fidelis de MESQUITA-GUIMARÃES

    2015-01-01

    Full Text Available The aim of this study was to evaluate the effect of industrialised foods and drinks on primary tooth enamel previously eroded with hydrochloric acid (HCl. The crowns of one hundred two specimens were subjected to an erosive challenge with HCl and randomly divided into six groups (n = 17: Chocolate Milk (Toddynho® - Pepsico - negative control; Petit Suisse Yogurt (Danoninho® - Danone; Strawberry Yogurt (Vigor; Apple puree (Nestlé; Fermented Milk (Yakult® - Yakult; and Home Squeezed Style Orange Juice (del Valle - positive control. The 28-day immersion cycles for the test products were performed twice daily and were interspersed with exposure of the test substrate to artificial saliva. Measurements of enamel surface microhardness (SMH were performed initially, after immersion in HCl and at 7, 14, 21 and 28 days of experimentation. A two-way ANOVA, according to a split-plot design, followed by the sum of squares decomposition and Tukey’s test, revealed a significant effect for the interaction between Foods and Drinks and Length of Exposure (p < 0.00001. Orange juice resulted in greater mineral loss of enamel after 28 days. None of the test products was associated with recovery of tooth enamel microhardness.

  5. Heavy metal removal from sewage sludge ash by thermochemical treatment with gaseous hydrochloric acid.

    Science.gov (United States)

    Vogel, Christian; Adam, Christian

    2011-09-01

    Sewage sludge ash (SSA) is a suitable raw material for fertilizers due to its high phosphorus (P) content. However, heavy metals must be removed before agricultural application and P should be transferred into a bioavailable form. The utilization of gaseous hydrochloric acid for thermochemical heavy metal removal from SSA at approximately 1000 °C was investigated and compared to the utilization of alkaline earth metal chlorides. The heavy metal removal efficiency increased as expected with higher gas concentration, longer retention time and higher temperature. Equivalent heavy metal removal efficiency were achieved with these different Cl-donors under comparable conditions (150 g Cl/kg SSA, 1000 °C). In contrast, the bioavailability of the P-bearing compounds present in the SSA after thermal treatment with gaseous HCl was not as good as the bioavailability of the P-bearing compounds formed by the utilization of magnesium chloride. This disadvantage was overcome by mixing MgCO(3) as an Mg-donor to the SSA before thermochemical treatment with the gaseous Cl-donor. A test series under systematic variation of the operational parameters showed that copper removal is more depending on the retention time than the removal of zinc. Zn-removal was declined by a decreasing ratio of the partial pressures of ZnCl(2) and water.

  6. Direct anodic hydrochloric acid and cathodic caustic production during water electrolysis

    Science.gov (United States)

    Lin, Hui-Wen; Cejudo-Marín, Rocío; Jeremiasse, Adriaan W.; Rabaey, Korneel; Yuan, Zhiguo; Pikaar, Ilje

    2016-02-01

    Hydrochloric acid (HCl) and caustic (NaOH) are among the most widely used chemicals by the water industry. Direct anodic electrochemical HCl production by water electrolysis has not been successful as current commercially available electrodes are prone to chlorine formation. This study presents an innovative technology simultaneously generating HCl and NaOH from NaCl using a Mn0.84Mo0.16O2.23 oxygen evolution electrode during water electrolysis. The results showed that protons could be anodically generated at a high Coulombic efficiency (i.e. ≥ 95%) with chlorine formation accounting for 3 ~ 5% of the charge supplied. HCl was anodically produced at moderate strengths at a CE of 65 ± 4% together with a CE of 89 ± 1% for cathodic caustic production. The reduction in CE for HCl generation was caused by proton cross-over from the anode to the middle compartment. Overall, this study showed the potential of simultaneous HCl and NaOH generation from NaCl and represents a major step forward for the water industry towards on-site production of HCl and NaOH. In this study, artificial brine was used as a source of sodium and chloride ions. In theory, artificial brine could be replaced by saline waste streams such as Reverse Osmosis Concentrate (ROC), turning ROC into a valuable resource.

  7. Removing hydrochloric acid exhaust products from high performance solid rocket propellant using aluminum-lithium alloy.

    Science.gov (United States)

    Terry, Brandon C; Sippel, Travis R; Pfeil, Mark A; Gunduz, I Emre; Son, Steven F

    2016-11-05

    Hydrochloric acid (HCl) pollution from perchlorate based propellants is well known for both launch site contamination, as well as the possible ozone layer depletion effects. Past efforts in developing environmentally cleaner solid propellants by scavenging the chlorine ion have focused on replacing a portion of the chorine-containing oxidant (i.e., ammonium perchlorate) with an alkali metal nitrate. The alkali metal (e.g., Li or Na) in the nitrate reacts with the chlorine ion to form an alkali metal chloride (i.e., a salt instead of HCl). While this technique can potentially reduce HCl formation, it also results in reduced ideal specific impulse (ISP). Here, we show using thermochemical calculations that using aluminum-lithium (Al-Li) alloy can reduce HCl formation by more than 95% (with lithium contents ≥15 mass%) and increase the ideal ISP by ∼7s compared to neat aluminum (using 80/20 mass% Al-Li alloy). Two solid propellants were formulated using 80/20 Al-Li alloy or neat aluminum as fuel additives. The halide scavenging effect of Al-Li propellants was verified using wet bomb combustion experiments (75.5±4.8% reduction in pH, ∝ [HCl], when compared to neat aluminum). Additionally, no measurable HCl evolution was detected using differential scanning calorimetry coupled with thermogravimetric analysis, mass spectrometry, and Fourier transform infrared absorption. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Inhibition of the corrosion of mild steel in hydrochloric acid by isatin and isatin glycine

    Directory of Open Access Journals (Sweden)

    B.I. Ita

    2006-12-01

    Full Text Available The inhibition of corrosion of mild steel in hydrochloric acid by isatin glycine (ING and isatin (IN at 30-60 oC and concentrations of 0.0001 M to 0.0005 M was studied via weight loss method. At the highest inhibitor concentration studied ING exhibited inhibition efficiency of 87% while IN exhibited 84% at 60 oC. A chemical adsorption mechanism was proposed on the basis of the temperature effect and obtained average activation energy values of 143.9 kJ/mol for ING and 118.5 kJ/mol for IN. The two inhibitors were confirmed to obey the Langmuir adsorption isotherm equation at the concentrations studied. Also a first-order type of mechanism was proposed from the kinetic treatment of the result. The difference in the inhibitory properties of the inhibitors was explained in terms of the difference in their molecular structures and solubility rather than difference in molecular weights alone.

  9. Adsorption of Methylene Blue from Aqueous Solution onto Hydrochloric Acid-modified Rectorite

    Institute of Scientific and Technical Information of China (English)

    ZHANG Gaoke; LIU Guanfeng; GUO Yadan

    2011-01-01

    H+-rectorite clay,which was prepared by modifying the raw rectorite with 10% hydrochloric acid at 60 ℃C for 24 h,was used as an absorbent for removal of methyl blue (MB) from aqueous solutions.The morphology and the structure and crystallinity of the pristine rectorite and the H+-rectorite were characterized by scanning electron microscopy (SEM) technique and X-ray diffraction (XRD) technique,respectively.The results showed that the H+-rectorite exhibited high adsorption ability than the raw rectorite,and it was found that the removal percentage of MB increased with increasing in adsorbents dose,whereas the adsorption amount q,(mg/g) decreased.The equilibrium was attained within 30 min in adsorption process,and the maximum adsorption capacity of H+-rectorite for methylene blue reached as high as 37 mg/g.Besides,the effect of temperature on the adsorption of MB with H+-rectorite was investigated and the equilibrium data were well fitted to Freundlich equations.The H+-rectorite absorbent saturated with MB can be regenerated by calcinating at 400 ℃ for 2 h and the regenerated absorbent still showed higher percentage removal of MB.

  10. Eclipta Alba as Corrosion Pickling Inhibitor on Mild Steel in Hydrochloric Acid

    Institute of Scientific and Technical Information of China (English)

    M. Shyamala; A. Arulanantham

    2009-01-01

    Due to ease of application, cost effectiveness and environmentally safe, in this study, the corrosion inhibition effect of aqueous extract of Eclipta alba in 1 N hydrochloric acid has been investigated by weight loss, potentiodynamic polarization and impedance methods and the extracts of Eclipta alba were found to be effective corrosion pickling inhibitor. The effect of immersion time and temperature revealed that the extracts of Eclipta alba with an optimum concentration of 8.0% v/v showed maximum inhibition efficiency of 99.6% at 3 h immersion time and 30℃. Arrhenius plots for mild steel immersed in 1 N HCI solution in the absence and presence of optimum concentration (8.0% in v/v) of Eclipta alba extract showed the effect of temperature. Polarization studies indicate that this plant extract acts as a mixed type inhibitor. The adsorption of Eclipta alba follows Langmuir adsorption isotherm. The inhibition action may be due to the presence of the Wedelactone and also the alkaloid Ecliptine present in the leaves of Eclipta alba.

  11. Establishment of hydrochloric acid/lipopolysaccharide-induced pelvic inflammatory disease model.

    Science.gov (United States)

    Oh, Yeonsu; Lee, Jaehun; Kim, Hyeon-Cheol; Hahn, Tae-Wook; Yoon, Byung-Il; Han, Jeong-Hee; Kwon, Yong-Soo; Park, Joung Jun; Koo, Deog-Bon; Rhee, Ki-Jong; Jung, Bae Dong

    2016-09-30

    Pelvic inflammatory disease (PID), which is one of the most problematic complications experienced by women with sexually transmitted diseases, frequently causes secondary infections after reproductive abnormalities in veterinary animals. Although the uterus is self-protective, it becomes fragile during periods or pregnancy. To investigate PID, bacteria or lipopolysaccharide (LPS) extracted from gram negative bacteria has been used to induce the disease in several animal models. However, when LPS is applied to the peritoneum, it often causes systemic sepsis leading to death and the PID was not consistently demonstrated. Hydrochloric acid (HCl) has been used to induce inflammation in the lungs and stomach but not tested for reproductive organs. In this study, we developed a PID model in mice by HCl and LPS sequential intracervical (i.c.) administration. The proinflammatory cytokines, interleukin (IL)-1β, IL-6 and tumor necrosis factor-α, were detected in the mouse uterus by western blot analysis and cytokine enzyme-linked immunosorbent assay after HCl (25 mg/kg) administration i.c. followed by four LPS (50 mg/kg) treatments. Moreover, mice exhibited increased infiltration of neutrophils in the endometrium and epithelial layer. These results suggest that ic co-administration of HCl and LPS induces PID in mice. This new model may provide a consistent and reproducible PID model for future research.

  12. Studies on the inhibition of mild steel corrosion in hydrochloric acid solution by atenolol drug

    Directory of Open Access Journals (Sweden)

    G. Karthik

    2016-06-01

    Full Text Available The inhibition performance of atenolol on mild steel in 1 M hydrochloric acid solution was studied by weight loss and electrochemical methods. The results show the inhibition efficiency was found to increase with increasing the concentration of the inhibitor from 50 to 300 ppm. The maximum inhibition efficiency 93.8% was observed in the presence of 300 ppm inhibitor (in case of potentiodynamic polarization. The inhibition action of atenolol was explained in terms of adsorption on the mild steel surface. The adsorption process follows Langmuir isotherm via physical adsorption. Electrochemical Impedance spectroscopic technique (EIS exhibits one capacitive loop indicating that, the corrosion reaction is controlled by charge transfer process. Polarization measurements showed that the inhibitor is of a mixed type. The results obtained from the different methods are in good agreement. The surface morphologies of mild steel were examined by Fourier-transform infrared (FT-IR spectroscopy, scanning electron microscope (SEM. Further, the computational calculations are performed to find a relation between their electronic and structural properties.

  13. Dissolution Process of Palladium in Hydrochloric Acid: A Route via Alkali Metal Palladates

    Science.gov (United States)

    Kasuya, Ryo; Miki, Takeshi; Morikawa, Hisashi; Tai, Yutaka

    2015-12-01

    To improve the safety of the Pd recovery processes that use toxic oxidizers, dissolution of Pd in hydrochloric acid with alkali metal palladates was investigated. Alkali metal palladates were prepared by calcining a mixture of Pd black and alkali metal (Li, Na, and K) carbonates in air. Almost the entire amount of Pd was converted into Li2PdO2 after calcination at 1073 K (800 °C) using Li2CO3. In contrast, PdO was obtained by calcination at 1073 K (800 °C) using Na and K carbonates. Our results indicated that Li2CO3 is the most active reagent among the examined alkali metal carbonates for the formation of palladates. In addition, dissolution of the resulting Li2PdO2 in HCl solutions was evaluated under various conditions. In particular, Li2PdO2 rapidly dissolved in diluted (0.1 M) HCl at ambient temperature. Solubility of Pd of Li2PdO2 was found to be 99 pct or larger after dissolution treatment at 353 K (80 °C) for 5 minutes; in contrast, PdO hardly dissolved in 0.1 M HCl. The dissolution mechanism of Li2PdO2 in HCl was also elucidated by analysis of crystal structures and particulate properties. Since our process is completely free from toxic oxidizers, the dissolution process via alkali metal palladates is much safer than currently employed methods.

  14. The inhibitive effect of bipyrazolic derivatives on the corrosion of steel in hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Tebbji, K. [Laboratoire de Chimie des Eaux et Corrosion, Faculte des Sciences, B.P. 717, Oujda (Morocco); Hammouti, B. [Laboratoire de Chimie des Eaux et Corrosion, Faculte des Sciences, B.P. 717, Oujda (Morocco); Oudda, H. [Laboratoire des Procedes de Separation, Faculte des Sciences, Kenitra (Morocco); Ramdani, A. [Laboratoire de Chimie Organique-Physique, Faculte des Sciences, B.P. 717, Oujda (Morocco); Benkadour, M. [Laboratoire de Chimie des Eaux et Corrosion, Faculte des Sciences, B.P. 717, Oujda (Morocco)

    2005-12-15

    The effect of two pyrazole-type organic compounds, namely ethyl 5,5'-dimethyl-1'H-1,3'-bipyrazole-3 carboxylate (P1) and 3,5,5'-trimethyl-1'H-1,3'-bipyrazole (P2) on the corrosion behaviour of steel in 1 M hydrochloric acid (HCl) solution is investigated at 308 K by weight loss measurements, potentiodynamic polarisation and impedance spectroscopy (EIS) methods. The inhibition efficiencies obtained from cathodic Tafel plots, gravimetric and EIS methods are in good agreement. Results obtained show that the compound P2 is the best inhibitor and its efficiency reaches 84% at 10{sup -3} M. Potentiodynamic polarisation studies show that pyrazolic derivatives are cathodic-type inhibitors and these compounds act on the cathodic reaction without changing the mechanism of the hydrogen evolution reaction. The inhibition efficiency of P2 is temperature-dependent in the range from 308 to 353 K and the associated activation energy has been determined. P2 adsorbs on the steel surface according to Langmuir adsorption model. The calculation of the total partial charge of inhibitor atoms is computed.

  15. The thermal, rheological and structural properties of cassava starch granules modified with hydrochloric acid at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Beninca, Cleoci; Colman, Tiago Andre Denck [State University of Ponta Grossa - UEPG, Av. Carlos Cavalcanti, 4748, ZIP 84030-900, Ponta Grossa, PR (Brazil); Lacerda, Luiz Gustavo; Filho, Marco Aurelio Silva Carvalho [Positivo University, Curitiba, PR (Brazil); Bannach, Gilbert [Paulista State University - UNESP, Bauru, SP (Brazil); Schnitzler, Egon, E-mail: egons@uepg.br [State University of Ponta Grossa - UEPG, Av. Carlos Cavalcanti, 4748, ZIP 84030-900, Ponta Grossa, PR (Brazil)

    2013-01-20

    Highlights: Black-Right-Pointing-Pointer Untreated cassava starch was modified with standard hydrochloric acid at 20 and 50 Degree-Sign C by 8 h. Black-Right-Pointing-Pointer DSC curves allowed to verify increase in the gelatinization enthalpy in agreement with high temperature. Black-Right-Pointing-Pointer Pasting properties of the studied starches were inversely proportional to the acid treatment and increased temperature. Black-Right-Pointing-Pointer The morphology of granules as well as average size and average roughness were calculated by NC-AFM. - Abstract: Starch is arguably one of the most actively investigated biopolymer in the world. In this study, the native (untreated) cassava starch granules (Manihot esculenta, Crantz) were hydrolyzed by standard hydrochloric acid solution at different temperatures (30 Degree-Sign C and 50 Degree-Sign C) and the hydrolytic transformations were investigated by the following techniques: simultaneous thermogravimetry-differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC), as well as non-contact atomic force microscopy (NC-AFM), X-ray diffraction (XRD) powder patterns, and rapid viscoamylographic analysis (RVA). After the treatment with hydrochloric acid at different temperatures, the thermal stability, a gradual loss of pasting properties (viscosity), alterations in the gelatinization enthalpy ({Delta}H{sub gel}), were observed. The use of NC-AFM and XRD allowed the observation of the surface morphology and topography of the starch granules and changes in crystallinity of the granules, respectively.

  16. The Effect of Temperature and Acid Concentration on Corrosion of Low Carbon Steel in Hydrochloric Acid Media

    Directory of Open Access Journals (Sweden)

    Anees A. Khadom

    2009-01-01

    Full Text Available Problem statement: The effect of different temperatures and acid concentrations on the corrosion of low carbon steel in hydrochloric acid were addressed in this study. Approach: The effect of temperature was explained by application of Arrhenius equation and transition state theory, while the acid concentration effect was explained using reaction kinetic equations. The combined effect of temperature and acid concentration then modeled using a nonlinear regression method. Results: A detail of thermodynamic parameters of activation (E, ΔH* and ΔS* and kinetic studies for the corrosion reaction were obtained. Nonlinear corrosion rates as a function of temperature and acid concentration equation were estimated with a good prediction corrosion rates values. Conclusion: The values of activation energy E and enthalpy of activation ΔH* decrease with increase in acid concentration indicating the increasing in reaction rate. Entropy of activation ΔS* tend to lower values with increasing in acid concentration which indicated that the activated complex was more orderly relative to the initial state. The corrosion reaction was approximately firs order reaction. The observed corrosion rate values from the experimental data were in a good agreement with that predicated by the mathematical equation.

  17. Hydrochloric acid infusion for treatment of metabolic alkalosis associated with respiratory acidosis.

    Science.gov (United States)

    Brimioulle, S; Berre, J; Dufaye, P; Vincent, J L; Degaute, J P; Kahn, R J

    1989-03-01

    Hypercapnia due to respiratory failure can be more severe when accompanied by coexistent metabolic alkalosis. We therefore tested the hypothesis that hydrochloric acid (HCl) infusion could improve PaCO2 in 15 critically ill patients admitted with mixed respiratory acidosis and metabolic alkalosis, and a pH of between 7.35 and 7.45. HCl was infused at a constant rate of 25 mmol/h until the bicarbonate concentration decreased less than 26 mmol/L, or until the pH decreased less than 7.35 (initial pH greater than 7.40) or 7.30 (initial pH less than 7.40). Administration of 170 +/- 53 mmol of HCl decreased the bicarbonate concentration from 34 +/- 3 to 25 +/- 2 mmol/L (p less than .001), the pH from 7.41 +/- 0.03 to 7.33 +/- 0.02 (p less than .001), and the PaCO2 from 54 +/- 8 to 48 +/- 8 torr (p less than .001). Postinfusion PaCO2 could be predicted accurately from the initial status of the patients (r = .95, p less than .001) except in one patient with fixed hypercapnia. PaCO2 increased from 77 +/- 19 to 94 +/- 24 torr (p less than .001) and PaO2/PAO2 increased from 59 +/- 17 to 66 +/- 17% (p less than .001). The effects of HCl were still present 12 h after the end of the infusion. No complications related to the acid infusion were noted. These results indicate that, even in the absence of alkalemia, active correction of metabolic alkalosis by HCl infusion can improve CO2 and oxygen exchange in critically ill patients with mixed respiratory acidosis and metabolic alkalosis.

  18. Removing hydrochloric acid exhaust products from high performance solid rocket propellant using aluminum-lithium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Terry, Brandon C., E-mail: terry13@purdue.edu [School of Aeronautics and Astronautics, Purdue University, Zucrow Laboratories, 500 Allison Rd, West Lafayette, IN 47907 (United States); Sippel, Travis R. [Department of Mechanical Engineering, Iowa State University, 2025 Black Engineering, Ames, IA 50011 (United States); Pfeil, Mark A. [School of Aeronautics and Astronautics, Purdue University, Zucrow Laboratories, 500 Allison Rd, West Lafayette, IN 47907 (United States); Gunduz, I.Emre; Son, Steven F. [School of Mechanical Engineering, Purdue University, Zucrow Laboratories, 500 Allison Rd, West Lafayette, IN 47907 (United States)

    2016-11-05

    Highlights: • Al-Li alloy propellant has increased ideal specific impulse over neat aluminum. • Al-Li alloy propellant has a near complete reduction in HCl acid formation. • Reduction in HCl was verified with wet bomb experiments and DSC/TGA-MS/FTIR. - Abstract: Hydrochloric acid (HCl) pollution from perchlorate based propellants is well known for both launch site contamination, as well as the possible ozone layer depletion effects. Past efforts in developing environmentally cleaner solid propellants by scavenging the chlorine ion have focused on replacing a portion of the chorine-containing oxidant (i.e., ammonium perchlorate) with an alkali metal nitrate. The alkali metal (e.g., Li or Na) in the nitrate reacts with the chlorine ion to form an alkali metal chloride (i.e., a salt instead of HCl). While this technique can potentially reduce HCl formation, it also results in reduced ideal specific impulse (I{sub SP}). Here, we show using thermochemical calculations that using aluminum-lithium (Al-Li) alloy can reduce HCl formation by more than 95% (with lithium contents ≥15 mass%) and increase the ideal I{sub SP} by ∼7 s compared to neat aluminum (using 80/20 mass% Al-Li alloy). Two solid propellants were formulated using 80/20 Al-Li alloy or neat aluminum as fuel additives. The halide scavenging effect of Al-Li propellants was verified using wet bomb combustion experiments (75.5 ± 4.8% reduction in pH, ∝ [HCl], when compared to neat aluminum). Additionally, no measurable HCl evolution was detected using differential scanning calorimetry coupled with thermogravimetric analysis, mass spectrometry, and Fourier transform infrared absorption.

  19. Content Determination of Hydrochloric Acid Ephedrine and Hydrochloric Acid Pseudoephedrine inTongxuanlifei Granules%通宣理肺颗粒中麻黄碱含量测定方法研究

    Institute of Scientific and Technical Information of China (English)

    肖斯婷; 付欣彤; 常增荣

    2011-01-01

    目的 采用高效液相色谱法测定建立通宣理肺颗粒中盐酸麻黄碱与盐酸伪麻黄碱含量,建立其质量标准.方法 采用Phenomenex Synerg 4u Polar-RP 80A(250mm× 4.6mm,4 μm)色谱柱,流动相:甲醇:0.092%磷酸溶液(含0.04%三乙胺和0.02%二正丁胺)=1:99;检测波长:210 nm.结果 该法测定通宣理肺颗粒中盐酸麻黄碱3个浓度回收率分另为102.44%、100.93%、97.73%,RSD分别为1.30%、0.38%、1.77%(n=3);盐酸伪麻黄碱回收率分别为99.98%、96.01%、100.91%,RSD分别为1.65%、0.65%、1.91%(n=3).本品按标示量计算,含麻黄以盐酸麻黄碱与盐酸伪麻黄碱的总量计0.6 ~3 mg/袋.结论 本方法操作简便,结果可靠,准确,能有效地控制通宣理肺颗粒的质量.%Objective To establish the quality standard for Tongxuanlifei Granules (Hydrochloric acid ephedrine & Hydrochloric acid pseudoephedrine). Methods The contents of Hydrochloric acid ephedrine and Hydrochloric acid pseudoephedrine were determined on the Phenomenex Synerg 4u Polar-RP 80A (250 mm× 4.6 mm, 4 μm) column, with MeOH :0.092% Phosphoric acid solution (with 0.04% Triethylamine and 0.02% Two butyl amine)=l : 99 elution as mobile phase and detective wavelength at 210 nm. Results The average recovery of Hydrochloric acid ephedrine of there concentration was 102.44%, 100.93%, 97.73%, and RSD was 1.30%, 0.38%, 1.77% (n=3). The average recovery of Hydrochloric acid pseudoephedrine was 99.98%, 96.01%, 100.91%, and RSD was 1.65%, 0.65%, 1.91% (n=3). The detection quantity should be within 0.6 - 3 mg labeled weight. Conclusion The method is simple, reliable, accurate and can be applied to the quality control of Tongxuanlifei Granules.

  20. Characterization of Polyamide 66 membranes prepared by phase inversion using formic acid and hydrochloric acid such as solvents

    Directory of Open Access Journals (Sweden)

    Patrícia Poletto

    2011-12-01

    Full Text Available The membranes properties prepared from water/formic acid (FA/ polyamide 66 (PA66 and water/hydrochloric acid (HCl/polyamide 66 (PA 66 systems has been studied. The different solvents interact distinctly with the polymer, affecting the membrane morphology. The asymmetric structure of the membranes showed a dense top layer and a porous sublayer. The membranes M-HCl prepared from HCl/PA 66 system showed a larger dense layer (around 23 μm in compared to those prepared from FA/PA 66 system (M-FA (around 10 μm. The membrane morphology was a determinant factor in results of water absorption, porosity and pure water flux. The lower thickness of dense layer in M-FA membranes resulted in a higher water absorption and, consequently, porosity, approximately 50%, compared with M-HCl membranes, approximately 15%. The same trend was observed to permeate flux, the lower thickness of dense layer higher pure water flux.

  1. Thermal decomposition of ethylenediaminetetraacetic acid in the presence of 1,2-phenylenediamine and hydrochloric acid

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jingwen [Yancheng Institute of Technology, Yancheng (China); Gao, Jinhao [Nanjing Univ., Nanjing (China). Coordination Chemistry Institute. State Key Lab. of Coordination Chemistry; Wang, Xiaoyong [Nanjing Univ., Nanjing (China). School of Life Science. State Key Lab. of Pharmaceutical Biotechnology]. E-mail: boxwxy@nju.edu.cn

    2006-09-15

    Based on the reaction products of ethylenediaminetetraacetic acid (EDTA) with 1,2- phenylenediamine (o-PDA), a novel thermal decomposition pathway of EDTA is proposed. The strong acidic medium and the presence of o-PDA facilitate the decomposition of EDTA as evidenced by the relatively lower reaction temperature. In addition to the steps described in literatures, rearrangement process is involved in the decomposition reaction. The rearranged intermediates condense with o-PDA, forming an unexpected biologically active compound 2,2,4- trimethyl-3H-5-hydro-1,5-benzodiazepine, thus provides the possibility to explore an alternative decomposition mechanism for this widely used chelator. (author)

  2. The effects of pharmaceutically active compound doxycycline on the corrosion of mild steel in hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Shukla, Sudhish Kumar [Department of Applied Chemistry, Institute of Technology, Banaras Hindu University, Varanasi 221 005, Uttar Pradesh (India); Quraishi, M.A. [Department of Applied Chemistry, Institute of Technology, Banaras Hindu University, Varanasi 221 005, Uttar Pradesh (India)], E-mail: maquraishi.apc@itbhu.ac.in

    2010-02-15

    Corrosion inhibition of mild steel in hydrochloric acid solution by doxycycline has been studied by weight loss measurements, polarization resistance, Tafel polarization and electrochemical impedance spectroscopy. The inhibitor showed more than 95% inhibition efficiency at optimum concentration 9.02 x 10{sup -4} M. Potentiodynamic polarization suggests that it is a mixed type of inhibitor. Electrochemical impedance spectroscopy was used to investigate the mechanism of corrosion inhibition. Thermodynamic parameters were calculated to investigate mechanism of inhibition. The compound follows Langmuir adsorption isotherm. AFM studies of mild steel surface with and without inhibitor were performed and calculated roughness also supported the inhibition data.

  3. Leaching lithium from the anode electrode materials of spent lithium-ion batteries by hydrochloric acid (HCl).

    Science.gov (United States)

    Guo, Yang; Li, Feng; Zhu, Haochen; Li, Guangming; Huang, Juwen; He, Wenzhi

    2016-05-01

    Spent lithium-ion batteries (LIBs) are considered as an important secondary resource for its high contents of valuable components, such as lithium and cobalt. Currently, studies mainly focus on the recycling of cathode electrodes. There are few studies concentrating on the recovery of anode electrodes. In this work, based on the analysis result of high amount of lithium contained in the anode electrode, the acid leaching process was applied to recycle lithium from anode electrodes of spent LIBs. Hydrochloric acid was introduced as leaching reagent, and hydrogen peroxide as reducing agent. Within the range of experiment performed, hydrogen peroxide was found to have little effect on lithium leaching process. The highest leaching recovery of 99.4wt% Li was obtained at leaching temperature of 80°C, 3M hydrochloric acid and S/L ratio of 1:50g/ml for 90min. The graphite configuration with a better crystal structure obtained after the leaching process can also be recycled.

  4. Corrosion and Inhibition Effects of Mild Steel in Hydrochloric Acid Solutions Containing Organophosphonic Acid

    Directory of Open Access Journals (Sweden)

    Manish Gupta

    2013-01-01

    Full Text Available A study has been made on the mechanism of corrosion of mild steel and the effect of nitrilo trimethylene phosphonic (NTMP acid as a corrosion inhibitor in acidic medium, that is, 10% HC1 using the weight loss method and electrochemical techniques, that is, potentiodynamic and galvanostatic polarization measurements. Although corrosion is a long-time process, but it takes place at a faster rate in the beginning which goes on decreasing with due course of time. The above-mentioned methods of corrosion rate determination furnish an average value for a long-time interval. Looking at the versatility and minimum detection limit of the voltammetric method, the authors have developed a new voltammetric method for the determination of corrosion rate at short-time intervals. The results of corrosion of mild steel in 10% HC1 solution with and without NTMP inhibitor at short-time intervals have been reported. The corrosion inhibition efficiency of NTMP is 93% after 24 h.

  5. Analysis on a cracking accident of hydrochloric acid storage tank caused by vacuum%稀盐酸储槽抽裂事故的分析

    Institute of Scientific and Technical Information of China (English)

    王欣荣

    2012-01-01

    分析了盐酸脱吸工序中稀盐酸储槽抽裂事故产生的原因;通过稀盐酸储槽的压力式液位计DCS历史曲线记录来间接分析稀盐酸储槽内压力变化情况,剖析负压的形成过程。结果表明:脱吸塔产生较大的负压是因为系统急停、温度下降后在略低于盐酸溶液恒沸点时发生冷凝相变而引起的。%Reasons for a cracking accident of hydrochloric acid storage tank caused by vacuum in hydrochloric acid desorption process were analyzed. Pressure changes inside dilute hydrochloric acid storage tank were indirectly analyzed according to DCS historical graph record of the pressure type level meter for the hydrochloric acid storage tank, and the negative pressure formation process was also discussed. The results showed that the formation of large negative pressure in desorption col- umn was caused by phase transition of condensation occurred whlie the temperature of system was a little less than the constant boiling point of hydrochloric acid solution, which was caused by emer- gency shutdown of system and temperature falling.

  6. Growth and membrane fluidity of food-borne pathogen Listeria monocytogenes in the presence of weak acid preservatives and hydrochloric acid

    Directory of Open Access Journals (Sweden)

    Ioannis eDiakogiannis

    2013-06-01

    Full Text Available This study addresses a major issue in microbial food safety, the elucidation of correlations between acid stress and changes in membrane fluidity of the pathogen Listeria monocytogenes. In order to assess the possible role that membrane fluidity changes play in L. monocytogenes tolerance to antimicrobial acids (acetic, lactic, hydrochloric acid at low pH or benzoic acid at neutral pH, the growth of the bacterium and the gel-to-liquid crystalline transition temperature point (Tm of cellular lipids of each adapted culture was measured and compared with unexposed cells. The Tm of extracted lipids was measured by Differential Scanning Calorimetry (DSC. A trend of increasing Tm values but not of equal extent was observed upon acid tolerance for all samples and this increase is not directly proportional to each acid antibacterial action. The smallest increase in Tm value was observed in the presence of lactic acid, which presented the highest antibacterial action. In the presence of acids with high antibacterial action such as acetic, hydrochloric acid or low antibacterial action such as benzoic acid, increased Tm values were measured. The Tm changes of lipids were also correlated with our previous data about fatty acid changes to acid adaptation. The results imply that the fatty acid changes are not the sole adaptation mechanism for decreased membrane fluidity (increased Tm. Therefore, this study indicates the importance of conducting an in-depth structural study on how acids commonly used in food systems affect the composition of individual cellular membrane lipid molecules.

  7. Corrosion inhibition of C38 steel in 1 M hydrochloric acid medium by alkaloids extract from Oxandra asbeckii plant

    Energy Technology Data Exchange (ETDEWEB)

    Lebrini, M. [Laboratoire Materiaux et Molecules en Milieu Amazonien, CNRS 8172-UMR ECOFOG, Campus Trou Biran, Cayenne 97337, French Guiana (France); Robert, F.; Lecante, A. [Laboratoire Materiaux et Molecules en Milieu Amazonien, UAG-UMR ECOFOG, Campus Trou Biran, Cayenne 97337, French Guiana (France); Roos, C., E-mail: christophe.roos@guyane.univ-ag.f [Laboratoire Materiaux et Molecules en Milieu Amazonien, UAG-UMR ECOFOG, Campus Trou Biran, Cayenne 97337, French Guiana (France)

    2011-02-15

    Research highlights: The inhibition effect of alkaloid extract of Oxandra asbeckii plant on the corrosion of C38 steel in 1 M hydrochloric acid solution has been investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Oxandra asbeckii extract examined acted as an efficient corrosion inhibitor in 1 M HCl. Polarization studies showed that Oxandra asbeckii extract was a mixed-type inhibitor and its inhibition efficiency increased with the inhibitor concentration. - Abstract: The inhibition effect of alkaloids extract from Oxandra asbeckii plant (OAPE) on the corrosion of C38 steel in 1 M hydrochloric acid solution has been investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The corrosion inhibition efficiency increases on increasing plant extracts concentration. Cathodic and anodic polarization curves show that OAPE is a mixed-type inhibitor. The effect of temperature on the corrosion behavior of C38 steel in 1 M HCl with and without addition of plant extract was studied in the temperature range 25-55 {sup o}C. The thermodynamic functions of dissolution and adsorption processes were calculated from experimental polarization data and the interpretation of the results are given. The adsorption of this plant extract on the C38 steel surface obeys the Langmuir adsorption isotherm. Surface analysis (Raman) was also carried out to establish the corrosion inhibitive property of this plant extract in HCl solution.

  8. Hydrochloric acid alters the effect of L-glutamic acid on cell viability in human neuroblastoma cell cultures.

    Science.gov (United States)

    Croce, Nicoletta; Bernardini, Sergio; Di Cecca, Stefano; Caltagirone, Carlo; Angelucci, Francesco

    2013-07-15

    l-Glutamic acid (l-glutamate) is used to induce excitotoxicity and test neuroprotective compounds in cell cultures. However, because l-glutamate powder is nearly insoluble in water, many manufacturers recommend reconstituting l-glutamate in hydrochloric acid (HCl) prior to successive dilutions. Nevertheless, HCl, even at low concentrations, may alter the pH of the cell culture medium and interfere with cell activity. Thus, the aim of this study was to evaluate whether the reconstitution of l-glutamate powder in HCl alters its capacity to induce neurotoxicity in different human neuroblastoma cell lines. SH-SY5Y, IMR-32 and SK-N-BE(2) cells were exposed to various concentrations of l-glutamate, which was either reconstituted in HCl (1M) or post re-equilibrated to the pH of the culture medium (7.5). After 24 and 48h of incubation, changes in the cell viability of treated versus untreated cells were evaluated. The effect of an identical amount of HCl present in the l-glutamate dilutions on neuroblastoma cell survival was also investigated. Our data showed that the neurotoxicity of glutamate reconstituted in HCl was comparable to that of HCl alone. Moreover, the pH variations induced by glutamate or HCl in the culture medium were similar. When the pH of the glutamate stock solution was re-equilibrated, l-glutamate induced variation in cell viability to a lower extent and after a longer incubation time. This study demonstrated that HCl used to reconstitute l-glutamate powder might alter the effect of glutamate itself in neuroblastoma cell cultures. Thus, this information might be useful to scientists who use l-glutamate to induce excitotoxicity or to test neuroprotective agents.

  9. A Study of N,N-Diethylammonium O,O′-Di(p-methoxyphenyldithiophosphate as New Corrosion Inhibitor for Carbon Steel in Hydrochloric Acid Solution

    Directory of Open Access Journals (Sweden)

    Chuan Lai

    2016-01-01

    Full Text Available N,N-Diethylammonium O,O′-di(p-methoxyphenyldithiophosphate (EAPP as a new corrosion inhibitor was synthesized in the present work. The corrosion inhibition of EAPP in hydrochloric acid for carbon steel was evaluated by potentiodynamic polarization measurements, electrochemical impedance spectroscopy, weight loss measurements, and scanning electron microscopy. The results indicate that the EAPP is mixed type inhibitor, and the adsorption of EAPP on carbon steel surface obeys Langmuir isotherm. In addition, the inhibition efficiency increases with increasing the concentration of inhibitor and decreases with increasing the hydrochloric acid concentration, temperature, and storage time.

  10. Hydrodechlorination of Silicon Tetrachloride to Trichlorosilane Over Ordered Mesoporous Carbon Catalysts: Effect of Pretreatment of Oxygen and Hydrochloric Acid.

    Science.gov (United States)

    Kwak, Do-Hwan; Akhtar, M Shaheer; Kim, Ji Man; Yang, O Bong

    2016-02-01

    This paper reports on the catalytic reaction for the conversion of silicon tetrachloride (STC) to trichlorosilane (TCS) over pretreated ordered mesoporous carbon (OMC) catalysts by oxygen (denoted as OMC-O2) and hydrochloric acid (denoted as OMC-HCl) at 300 degrees C under N2 atmosphere. The OMC-O2 shows significantly improved the surface area (1341.2 m2/g) and pore volume (1.65 cm3/g), which results in the highest conversion rate of 7.3% as compared to bare OMC (4.3%) and OMC-HCI (5.7%). It is found that the conversion rate of STC to TCS is proportional to the number of Si-O bond over OMC catalysts, which suggests that Si-O-C bond formation is crucial to the reaction as active sites. The O2 pretreatment seems to promote the generation of oxygenated species for the formation of Si-O-C.

  11. Electrochemical study on inhibitory effect of Aspirin on mild steel in 1 M hydrochloric acid

    Directory of Open Access Journals (Sweden)

    B.M. Prasanna

    2017-02-01

    Full Text Available Aspirin was investigated as a good corrosion inhibitor for mild steel in 1 M hydrochloric acid at a temperature region from 303 to 333 K. The computed inhibition efficiency increases by increasing the inhibitor concentration and decreases by increasing the temperature. The investigation was done by weight loss, electrochemical measurements such as Tafel polarization and electrochemical impedance spectroscopy. Inhibition effect is attributed to the adsorption of inhibitor on the surface of the mild steel. The Tafel method reveals that the Aspirin acts as a mixed type inhibitor. Activation parameters suggest that the adsorption process is exothermic in nature. SEM photographs of mild steel in the absence and presence of inhibitor visualize the adsorption layer on the surface of the mild steel.

  12. Growth and membrane fluidity of food-borne pathogen Listeria monocytogenes in the presence of weak acid preservatives and hydrochloric acid.

    Science.gov (United States)

    Diakogiannis, Ioannis; Berberi, Anita; Siapi, Eleni; Arkoudi-Vafea, Angeliki; Giannopoulou, Lydia; Mastronicolis, Sofia K

    2013-01-01

    This study addresses a major issue in microbial food safety, the elucidation of correlations between acid stress and changes in membrane fluidity of the pathogen Listeria monocytogenes. In order to assess the possible role that membrane fluidity changes play in L. monocytogenes tolerance to antimicrobial acids (acetic, lactic, hydrochloric acid at low pH or benzoic acid at neutral pH), the growth of the bacterium and the gel-to-liquid crystalline transition temperature point (T m) of cellular lipids of each adapted culture was measured and compared with unexposed cells. The T m of extracted lipids was measured by differential scanning calorimetry. A trend of increasing T m values but not of equal extent was observed upon acid tolerance for all samples and this increase is not directly proportional to each acid antibacterial action. The smallest increase in T m value was observed in the presence of lactic acid, which presented the highest antibacterial action. In the presence of acids with high antibacterial action such as acetic, hydrochloric acid or low antibacterial action such as benzoic acid, increased T m values were measured. The T m changes of lipids were also correlated with our previous data about fatty acid changes to acid adaptation. The results imply that the fatty acid changes are not the sole adaptation mechanism for decreased membrane fluidity (increased T m). Therefore, this study indicates the importance of conducting an in-depth structural study on how acids commonly used in food systems affect the composition of individual cellular membrane lipid molecules.

  13. Thallium extraction from hydrochloric acid media into a deep eutectic solvent using bis(2-ethylhexyl) phosphate

    Science.gov (United States)

    Tran, Kate; Volia, Merinda; Tereshatov, Evgeny; Folden, Charles, III

    2016-09-01

    The chemical properties of superheavy elements are relatively unknown due to their short half-lives and difficulty of production. In preparation for a future experiment to study the chemical properties of element 113, separation techniques have been used to study the behavior of its homologs, In and Tl. Previous work studied the liquid-liquid extraction of radioactive 201Tl (t1 / 2 = 3 . 04 d) from various concentrations of HCl into a mixture of menthol and lauric acid that formed a so-called deep eutectic solvent (DES). This work focuses on the effects of adding an extraction agent, bis(2-ethylhexyl) phosphate (HDEHP), to the DES on the efficiency of thallium extraction. The extraction of Tl(I) was generally poor, both with and without HDEHP added. In contrast, 111In (t1 / 2 = 2 . 80 d) showed significant extraction using HDEHP added to the same DES. This difference in behavior could potentially be exploited in a future experiment on the chemistry of element 113. National Science Foundation.

  14. A New Solid Sorbent System for Rapid Monitoring of Dehydrogenated Nicotine by Using Furfural-hydrochloric Acid

    Institute of Scientific and Technical Information of China (English)

    B. AMBADE; E. K. JANGHEL; M. K. RAI; G. L. MUNDHARA

    2006-01-01

    A new solid sorbent system is developed for the monitoring of dehydrogenated nicotine in the environment. The reagent system for the indicator tube consists of furfural-hydrochloric acid and phosphoric acid impregnated over a cellulose fibre (cotton) and a humectant calcium chloride. The reagent system has also been used for the preparation of reagent paper. After exposing the indicator tubes and test paper to dehydrogenated nicotine, for a constant time, the red-violet colour developed could be compared with those obtained from standards. Alternatively the coloured compound was extracted in water and the absorbance measured at 540 nm. The lower limit of detection is 0.03 μg/m3 of nicotine for the reagent papers and indicator tubes. The lower limit of determination by spectrophotometric procedure is 0.001 μg/m3 of air.The preparation of indicator tubes, test papers and their applications for the detection and determination of nicotine in environmental tobacco smoke (ETS), mainstream smoke (MS), side stream smoke (SS) and biological samples is described in this paper.

  15. The influence of long term use of inhibitors in hydrochloric acid pickling baths on hydrogen induced stress corrosion cracking

    Energy Technology Data Exchange (ETDEWEB)

    Feser, R.; Friedrich, A.; Scheide, F. [Fachhochschule Suedwestfalen, University of Applied Science, Frauenstuhlweg 31, D-58644 Iserlohn (Germany)

    2002-09-01

    The influence of commercially available inhibitors on the absorption of hydrogen by steel (St 52, StE 460, StE 690, 42CrMo4) in 15% hydrochloric acid was studied. The pickling bath aged continuously due to the chemical reaction with oxidized steel sheets. The H{sup +}- and inhibitor concentration decreased with time. The influence of this ageing process on hydrogen-induced stress corrosion cracking was tested by in-situ tensile tests in the bath solution. With increasing ageing of the bath, the reduction in fracture area was reduced and approached the values measured for non-inhibited acid baths. Furthermore hydrogen permeation was investigated. Permeation current densities rose with increasing ageing of the pickling solution. (Abstract Copyright[2002], Wiley Periodicals, Inc.) [German] Der Einfluss von kommerziell erhaeltlichen Inhibitoren auf die Wasserstoffabsorption von Stahl (St 52, StE 460, StE 690, 42CrMo4) wurde in Salzsaeure untersucht. Die Beizbaeder wurden kontinuierlich durch die chemische Reaktion mit oxidierten Stahlblechen gealtert. Die H{sup +}- und Inhibitorkonzentration nahm mit der Zeit ab. Der Einfluss dieses Alterungsprozesses auf die wasserstoffinduzierte Spannungsrisskorrosion wurde durch in-situ Zugversuche mit Badloesung untersucht. Mit zunehmender Alterung des Bades nahm die Brucheinschnuerung ab und erreichte Werte wie sie auch in der nicht inhibierten Saeure erreicht werden. Weiterhin wurde die Wasserstoff-Permeation untersucht. Die Permeationsstromdichte steigt mit zunehmender Alterung der Beizloesung. (Abstract Copyright[2002], Wiley Periodicals, Inc.)

  16. Interaction between amylose and 1-butanol during 1-butanol-hydrochloric acid hydrolysis of normal rice starch.

    Science.gov (United States)

    Hu, Xiuting; Wei, Benxi; Zhang, Bao; Li, Hongyan; Xu, Xueming; Jin, Zhengyu; Tian, Yaoqi

    2013-10-01

    The aim of this study was to examine the interaction between amylose and 1-butanol during the 1-butanol-hydrochloric acid (1-butanol-HCl) hydrolysis of normal rice starch. The interaction model between amylose and 1-butanol was proposed using gas chromatography-mass spectrometry (GC-MS), (13)C cross polarization and magic angle spinning NMR analysis ((13)C CP/MAS NMR), differential scanning calorimetry (DSC), and thermalgravimetric analysis (TGA). GC-MS data showed that another form of 1-butanol existed in 1-butanol-HCl-hydrolyzed normal rice starch, except in the form of free molecules absorbed on the starch granules. The signal of 1-butanol-HCl-hydrolyzed starch at 100.1 ppm appeared in the (13)C CP/MAS NMR spectrum, indicating that the amylose-1-butanol complex was formed. DSC and TGA data also demonstrated the formation of the complex, which significantly affected the thermal properties of normal rice starch. These findings revealed that less dextrin with low molecular weight formed might be attributed to resistance of this complex to acid during 1-butanol-HCl hydrolysis.

  17. Preliminary study on concrete corrosion of hydrochloric acid%盐酸对混凝土的腐蚀研究

    Institute of Scientific and Technical Information of China (English)

    焦瑞敏

    2011-01-01

    In this paper,ordinary Portland cement concrete and modified concrete were corroded by hydrochloric acid which pH=1.After 60 days of corrosion,the cube compressive strength of every sample is reduced in different degree,from which we can know that amount of fly ash and fume can increase the resistance ability to acid corrosion to some degree but the styrene-butadiene latices reduced this ability of concrete.%对普通硅酸盐水泥混凝土以及改性混凝土进行pH=1的盐酸腐蚀,在腐蚀60d后,各种混凝土的立方体抗压强度均有不同程度的降低。适量的粉煤灰和硅灰可以一定程度地提高混凝土的抗酸性腐蚀性能,而丁苯胶乳的加入却会降低混凝土的这种抗酸性腐蚀性能。

  18. Electrochemical and quantum chemical studies of new thiadiazole derivatives adsorption on mild steel in normal hydrochloric acid medium

    Energy Technology Data Exchange (ETDEWEB)

    Lebrini, M. [Laboratoire de Cristallochimie et Physicochimie du Solide, CNRS UMR 8012, ENSCL, B.P. 108, F-59652 Villeneuve d' Ascq Cedex (France); Lagrenee, M. [Laboratoire de Cristallochimie et Physicochimie du Solide, CNRS UMR 8012, ENSCL, B.P. 108, F-59652 Villeneuve d' Ascq Cedex (France); Vezin, H. [Laboratoire de Chimie Organique et Macromoleculaire, CNRS UMR 8009, USTL Bat C3, F-59655 Villeneuve d' Ascq Cedex (France); Gengembre, L. [Laboratoire de Catalyse Heterogene et Homogene, CNRS UMR 8010, Bat C3, USTL, F-59655 Villeneuve d' Ascq Cedex (France); Bentiss, F. [Laboratoire de Cristallochimie et Physicochimie du Solide, CNRS UMR 8012, ENSCL, B.P. 108, F-59652 Villeneuve d' Ascq Cedex (France)]. E-mail: f.bentiss@pop.ensc-lille.fr

    2005-02-01

    In this work, a new class of thiadiazole derivatives, namely 3,5-bis(2-thienyl)-1,3,4-thiadiazole (2-TTH) and 3,5-bis(3-thienyl)-1,3,4-thiadiazole (3-TTH), have been studied as possible corrosion inhibitors for mild steel in molar hydrochloric acid (1 M HCl). Weight loss measurements, polarisation curves and AC impedance methods have been used. These studies have shown that the thiadiazole derivatives were very good inhibitors for mild steel in 1 M HCl. Comparison of results showed that 3-TTH was the best inhibitor. The potential of zero charge (PZC) of mild steel was studied by AC impedance method, and the mechanism of adsorption has been predicted. X-ray photoelectron spectroscopy surface analysis with thiadiazole derivatives shows that it chemisorbed at the mild steel/HCl interface. The adsorption of these inhibitors followed Langmuir's adsorption isotherm. The electronic properties of 2-TTH and 3-TTH, obtained using the AM1 semi-empirical quantum chemical approach, were correlated with their experimental efficiencies using the linear resistance model (LR). These inhibitors are considered as non-cytotoxic substances.

  19. Enhanced corrosion resistance of mild steel in hydrochloric acid solution by new thiadiazole derivatives: Electrochemical, theoretical and XPS studies

    Energy Technology Data Exchange (ETDEWEB)

    Bentiss, Fouad; Lebrini, Mounim; Lagrenee, Michel [Laboratoire de Cristallochimie et Physicochimie du Solide, CNRS UMR 8012, ENSCL, BP. 108, F-59652 Villeneuve d' Ascq Cedex (France); Herve, Vezin [Laboratoire de Chimie Organique et Macromoleculaire, CNRS UMR 8009, USTL Bat C3, F-59655 Villeneuve d' Ascq Cedex (France)

    2004-07-01

    In this work, a new class of thiadiazole derivatives, namely 3,5-bis(2-thienyl)-1,3,4-thiadiazole (2-TTH) and 3,5-bis(3-thienyl)-1,3,4-thiadiazole (3-TTH), have been studied as possible corrosion inhibitors for mild steel in molar hydrochloric acid (1M HCl). Polarisation curves and AC impedance methods have been used. These studies have shown that the thiadiazole derivatives were very good inhibitors for mild steel in 1M HCl. Comparison of results showed that 3-TTH was the best inhibitor. The potential of zero charge (PZC) of mild steel was studied by ac impedance method, and the mechanism of adsorption has been predicted. X-ray photoelectron spectroscopy surface analysis with thiadiazole derivatives shows that it chemisorbed at the mild steel/HCl interface. The adsorption of these inhibitors followed Langmuir's adsorption isotherm. The electronic properties of 2-TTH and 3-TTH, obtained using the AM1 semi-empirical quantum chemical approach, were correlated with their experimental efficiencies using the linear resistance model (LR). (authors)

  20. Electrochemical and theoretical investigation on the corrosion inhibition of mild steel by thiosalicylaldehyde derivatives in hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Behpour, M. [Department of Chemistry, Faculty of Science, University of Kashan, Kashan (Iran, Islamic Republic of)], E-mail: m.behpour@kashanu.ac.ir; Ghoreishi, S.M.; Soltani, N.; Salavati-Niasari, M.; Hamadanian, M.; Gandomi, A. [Department of Chemistry, Faculty of Science, University of Kashan, Kashan (Iran, Islamic Republic of)

    2008-08-15

    Inhibitory effect of three Schiff bases 2-{l_brace}[(2-sulfanylphenyl)imino]methyl{r_brace}]phenol (A), 2-{l_brace}[(2)-1-(4-methylphenyl)methylidene]amino{r_brace}-1-benznethiol (B), and 2-[(2-sulfanylphen-yl)ethanimidoyl)]phenol (C) on corrosion of mild steel in 15% HCl solution has been studied using weight loss measurements, polarization and electrochemical impedance spectroscopy (EIS) methods. The results of the investigation show that the compounds A and B with mean efficiency of 99% at 200 mg/L additive concentration have fairly good inhibiting properties for mild steel corrosion in hydrochloric acid, and they are as mixed inhibitor. All measurements show that inhibition efficiencies increase with increase in inhibitor concentration. This reveals that inhibitive actions of inhibitors were mainly due to adsorption on mild steel surface. Adsorption of these inhibitors follows the Langmuir adsorption isotherm. Thermodynamic adsorption parameters (K{sub ads}, {delta}G{sub ads}) of studied Schiff bases were calculated using the Langmuir adsorption isotherm. Activation parameters of the corrosion process such as activation energies, E{sub a}, activation enthalpies, {delta}H{sup *}, and activation entropies, {delta}S{sup *}, were calculated by the obtained corrosion currents at different temperatures. Obvious correlation was found between the corrosion inhibition efficiency and the calculated parameters. The obtained theoretical results have been adapted with the experimental data.

  1. Inhibition of Aluminium Corrosion in Hydrochloric Acid Using Nizoral and the Effect of Iodide Ion Addition

    Directory of Open Access Journals (Sweden)

    I. B. Obot

    2010-01-01

    Full Text Available The effect of nizoral (NZR on the corrosion inhibition of aluminium alloy AA 1060 in 2 M HCl solution was investigated using the mylius thermometric technique. Results of the study revealed that nizoral acts as corrosion inhibitor for aluminium in the acidic medium. In general, at constant acid concentration, the inhibition efficiency increases with increase in the inhibitor concentration. The addition of KI to the inhibitor enhanced the inhibition efficiency to a considerable extent. The adsorption of nizoral onto the aluminium surface was found to obey the Fruendlich adsorption isotherm. The value of the free energy for the adsorption process shows that the process is spontaneous.

  2. N-methyl-2-(2-nitrobenzylidene) hydrazine carbothioamide-A new corrosion inhibitor for mild steel in 1 mol·L-1 hydrochloric acid

    Institute of Scientific and Technical Information of China (English)

    K Krishnaveni; K Sampath; J Ravichandran; C Jayabalakrishnan

    2015-01-01

    The corrosion inhibition of mild steel in 1 mol·L−1 hydrochloric acid by N-methyl-2-(2-nitrobenzylidene) hydrazine carbothioamide (MNBHC) was studied using weight loss and electrochemical studies. Results obtained indicate that the inhibitor is effective in hydrochloric acid medium and the efficiency decreases with increase in temperature. Added halide additives improve the efficiency of the inhibitor. The AC impedance studies reveal that the process of inhibition is through charge transfer. Polarization studies indicate the mixed nature of the in-hibitor. From the thermodynamic, spectral and surface analyses the nature of adsorption has been found out. The adsorption of the inhibitor on mild steel follows the Langmuir isotherm.

  3. Extraction of Gold(III) from Hydrochloric Acid Solutions with a PVC-based Polymer Inclusion Membrane (PIM) Containing Cyphos® IL 104

    OpenAIRE

    2015-01-01

    Abstract: Poly(vinyl chloride) (PVC) based polymer inclusion membranes (PIMs), with different concentrations of Cyphos® IL 104 as the membrane extractant/carrier, were studied for their ability to extract Au(III) from hydrochloric acid solutions. Some of the PIMs also contained one of the following plasticizers or modifiers: 2-nitrophenyloctyl ether, dioctylphthalate, 1-dodecanol, 1-tetradecanol, or tri(2-ethylhexyl) phosphate. The best performance, in terms of extraction rate and amount of A...

  4. Effect of ethylenediamine tetraacetic acid disodium on the corrosion of cold rolled steel in the presence of benzotriazole in hydrochloric acid

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Qing [Department of Chemistry, Yunnan University, Kunming 650091 (China)]. E-mail: quqing58@yahoo.com.cn; Jiang, Shuan [Department of Chemistry, Yunnan University, Kunming 650091 (China); Bai, Wei [Department of Chemistry, Yunnan Nationalities University, Kunming 650092 (China); Li, Lei [Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming 650091 (China)

    2007-08-01

    The inhibition behavior of cold rolled steel in 0.1 M hydrochloric acid (HCl) by ethylenediamine tetraacetic acid disodium (EDTA) in the absence and presence of benzotriazole (BTA) was investigated with Tafel polarization curve and electrochemical impedance spectroscopy (EIS). The polarization curve results show that the single EDTA acts as an anodic type inhibitor while the combination of EDTA and BTA acts as mixed type inhibitor and mainly inhibits anodic reaction. All impedance spectra in EIS tests exhibit one capacitive loop which indicates that the corrosion reaction is controlled by charge transfer process. Inhibition efficiencies obtained from Tafel polarization, charge transfer resistance (R {sub t}) are consistent. The corrosion of cold rolled steel in 0.1 M HCl is obviously reduced by EDTA in combination with lower concentrations of BTA. Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM) were used to characterize the corrosion surface of cold rolled steel. Probable mechanisms are present to explain the experimental results.

  5. Effect of triamcinolone acetonide ammonia bromine joint hydrochloric acid on patients with secretory otitis media and on body's inflammatory factor and cellular immunologic parameters

    Institute of Scientific and Technical Information of China (English)

    Quan-Fu Hu; Shao-Ji Ouyang; Rong-Wei Yao; Xue-Jiang Xu; Jin-Hua He; Li-Li Zhang

    2016-01-01

    Objective:To explore the clinical effect of triamcinolone acetonide ammonia bromine joint hydrochloric acid on patients with secretory otitis media and the influences on the body's inflammatory factors and cellular immunologic parameters.Methods:A total of 40 cases of single ear secretory otitis media patients of the same period in our hospital were randomly selected as experimental group, using triamcinolone acetonide ammonia bromine joint hydrochloric acid treatment; And 40 cases of single ear secretory otitis media patients of the same period were randomly selected as control group, using dexamethasone treatment. To observe the clinical efficacy of two groups of patients and detect the inflammatory factors and cellular immune index level of the two groups of patients before and after treatment.Results:The total effective rate(90%) of treatment group is significantly higher than that (80%) of control group (P0.05). After treatment, the serum and ear effusion inflammatory cytokines levels of the two groups were significantly lower than that before treatment (P0.05); The CD4+/CD8+ levels of experimental group were significantly higher than the control group (P0.05). Conclusions: The triamcinolone acetonide ammonia bromine joint hydrochloric acid treatment is more conducive to improve the immune function of the secretory otitis media patients and treatment effect, which has important clinical significance on the treatment of secretory otitis media patients.

  6. Kinetic study of the prehydrolysis of bagasse pith with hydrochloric acid in an agitated system

    Energy Technology Data Exchange (ETDEWEB)

    Villan Guerra, J.; Iglesias, R.G.; Lopez Planes, R.

    1981-01-01

    The hydrolysis of bagasse pith at 90-100 degrees with 0.25 N HCl gave sugar in 22% yield after 120 min. With 0.5 N HCl, the yield was 28% after 240 min. The specific constants of pentosan decomposition and of sugar formation were calculated, and the kinetic parameters (frequency factor, activation energy, and order of acid concentration) were determined. The pentosan decomposition constants were higher and the activation energies lower than literature values for hydrolysis with H/sub 2/SO/sub 4/.

  7. 硫铁矿烧渣双酸酸解工艺研究%Study on decomposition process of pyrite cinder with hydrochloric acid and sulfuric acid

    Institute of Scientific and Technical Information of China (English)

    左大学; 王仁宗

    2012-01-01

    The decomposition process of pyrite cinder with hydrochloric acid and sulfuric acid , and its influence factors are studied. Through orthogonal test, the optimum process conditions are confirmed including: the consumption factor of hydrochloric acid with w(HC1) of 37% is 0.12; the consumption factor of sulfuric acid with w(H2SO4) of 65%-70% is 0.95, the reaction temperature is of 125 ℃, the reaction time is of 4h. The decomposition rate of pyrite cinder can reach to above 95%, and the product ferric sulfate solution can be used to produce polymeric ferric sulfate and iron oxide pigments.%研究了硫铁矿烧渣双酸酸解工艺及影响酸解的因素。通过正交实验,找到最适宜的工艺条件:w(HCl)37%,盐酸用量系数为0.12,硫酸用量系数为0.95,硫酸W(H2SO4)为65%~70%,反应温度为125℃,反应时间为4h,酸解率可达95%以上,制得的硫酸铁盐溶液可用作生产聚合硫酸铁及氧化铁系颜料的原料。

  8. Seed Extract of Psidium guajava as Ecofriendly Corrosion Inhibitor for Carbon Steel in Hydrochloric Acid Medium

    Institute of Scientific and Technical Information of China (English)

    K.P.Vinod Kumar; M. Sankara Narayana Pillai; G. Rexin Thusnavis

    2011-01-01

    The anticorrosion characteristics of the seeds of Psidium guajava (P. Guajava) fruits on carbon steel in acid medium were examined with weight loss data and subsequently thermodynamic factors such as heat of adsorption of the inhibitor on the metal surface (Q), change in entropy (△S), change in free energy of the reaction (△G), corrosion rate (CR) and energy of activation for corrosion reaction of carbon steel (E) were also evaluated. Adsorption isotherm was plotted to study the adsorption of the inhibitor on the metal surface with increasing concentration of the inhibitor. The functional groups responsible for inhibition were investigated using Fourier transform infrared (FT-IR) spectra. Electrochemical parameters were evaluated through the potentiodynamic Tafel polarization and impedance spectral studies. Scanning electron microscopy (SEM) micrographs were recorded to investigate the change in surface morphology. The complete study reveals the efficiency of seed extract of P. Guajava as a safe, ecofriendly and alternate corrosion inhibitor for carbon steel in acid medium.

  9. Punica granatum leave extract as green corrosion inhibitor for mild steel in Hydrochloric acid

    Directory of Open Access Journals (Sweden)

    Abboud Y.

    2013-09-01

    Full Text Available Leave of Punica granatum extract (LPGE as green inhibitor for the corrosion of mild steel in 1M HCl solution was studied using weight-loss and potentiodynamic polarization measurements. The results obtained revealed that LPGE has fairly good inhibiting properties for mild steel corrosion in 1M HCl solution, with efficiency of around 94 % at a concentration of 1 g/l. The inhibition was of a mixed anodic–cathodic nature. The film which is formed over the metal surface was analysed by FT-IR spectroscopy. Further examination using X-ray diffraction confirms the role of LPGE as an effective corrosion inhibitor for mild steel in acid media.

  10. Simultaneous Recovery of Hydrogen and Chlorine from Industrial Waste Dilute Hydrochloric Acid

    Directory of Open Access Journals (Sweden)

    N. Paidimarri

    2016-01-01

    Full Text Available Recovery of chlorine from byproduct HCl has inevitable commercial importance in industries lately because of insufficient purity or too low concentration to recycle it. Instead it is being neutralized in industries before disposing to meet stringent environmental conditions. Although recovery through catalytic oxidation processes is studied since the 19th century, their high operating conditions combined with sluggish reaction kinetics and low single pass conversions make electrolysis a better alternative. The present motive of this work is to develop a novel electrolysis process which in contrast to traditional processes effectively recovers both hydrogen and chlorine from dilute HCl. For this, an electrolytic cell with an Anionic Exchange Membrane has been designed which only allows the passage of chlorine anions from catholyte to anolyte separating the gasses in a single step. The catholyte can be as low as 3.59 wt% because of fixed anolyte concentration of 1.99 wt% which minimizes oxygen formation. Preliminary results show that the simultaneous recovery of hydrogen and chlorine is possible with high conversion up to 98%. The maximum current density value for 4.96 cm2 membrane surface area (70% active surface area is 2.54 kAm−2, which is comparable with reported commercial processes. This study is expected to be useful for process intensification of the same in a continuous process environment.

  11. Formation of Hydrogen-Ion in Isomolar Solution of Hydrochloric and Hydrobromic Acids and Their Salts

    Directory of Open Access Journals (Sweden)

    M.A. Kovaleva

    2016-09-01

    Full Text Available Despite the presence of a large amount of factual material on thermodynamic parameters of complexation of agents in different solvents, including mixed ones, obtained knowledge is specific in nature. In order to identify more general patterns, studies are relevant that would allow to interpret the obtained data taking into account the interaction between chemical forms in solutions. This paper presents a general approach to studying weak ionic interactions in solutions that allows to simultaneously determine the constants of these interactions and the parameters characterizing the influence of changes in the ionic environment on these constants by the example of chlorides and bromides of alkali metals. The obtained constants for hydrosulfate-ion formation and the imperfection parameters can be a reference material for more accurate calculation of the concentration of hydrogen ions in sulfuric acid solutions. The developed approach and patterns identified in the work can be used to study the balanced states for formation of low and medium stable complexes.

  12. Effect of commercial fluoride dentifrices against hydrochloric acid in an erosion-abrasion model.

    Science.gov (United States)

    Passos, Vanara Florêncio; de Vasconcellos, Andréa Araújo; Pequeno, José Heriberto Pinheiro; Rodrigues, Lidiany Karla Azevedo; Santiago, Sérgio Lima

    2015-01-01

    This study assessed the effect of three commercial dentifrices with different fluoride-containing compounds in controlling the progression of dentin loss using an in vitro erosion-abrasion model. Dentin specimens were randomized into four groups (n = 10): control (no F), Elmex (1,400 ppm AmF), Meridol (1,400 ppm AmF/SnF2), and Crest Pro-Health (1,100 ppm SnF2). The dentin specimens were submitted to cycles of demineralization (HCl 0.01 M for 60 s), remineralization (artificial saliva for 60 min), and immersion in 1:3 w/w of dentifrice/artificial saliva, followed by toothbrushing (150 brushing strokes). The cycle was repeated three times daily for 5 days. Surface loss was quantified by stylus profilometry. Data were submitted to one-way ANOVA and Tukey's tests (p fluoride can strengthen dental tissue against erosive acid damage. However, the beneficial effect of different fluorides present in commercial dentifrices is questionable. Thus, a determination of an effective fluoride dentifrice may be beneficial in the reduction of the erosive process in patients with gastric disorders.

  13. 盐酸浸出赤泥回收铝的研究%Study on Aluminum Recovery from Red Mud with Hydrochloric Acid

    Institute of Scientific and Technical Information of China (English)

    王克勤; 王皓; 李生虎

    2012-01-01

    The hydrochloric acid leaching process of aluminum from Bayer red mud was studied. The effects of temperature, time, ratio of liquid to solid (L/S) and concentration of hydrochloric acid on aluminum leaching rate were investigated. The industrial experiment of aluminum recovery from red mud was conducted. The results show that factors affecting the rate of aluminum extraction in sequence are temperature, L/S, hydrochloric acid concentration and leaching time. The leaching rate and recovery rate of aluminum from red mud is 88. 13% and 80. 26% respectively after two-step leached at 80℃, evaporation, de-titanium, de-calcium, neutralization and dissolving with sodium hydroxide solution.%研究了盐酸浸出拜耳法赤泥中铝的过程.考察浸出温度、浸出时间、液固比和酸度对铝浸出率的影响,并进行了赤泥回收铝的工业化试验.结果表明,影响铝浸出率的主次因素依次是浸出温度、液固比、盐酸浓度和浸出时间.赤泥在80℃下进行两段浸出,再经蒸发、除钛、除钙、中和及氢氧化钠溶液溶出,铝浸出率为88.13%,回收率为80.26%.

  14. Inhibition Behaviour of Some Isonicotinic Acid Hydrazides on the Corrosion of Mild Steel in Hydrochloric Acid Solution

    Directory of Open Access Journals (Sweden)

    M. P. Chakravarthy

    2013-01-01

    Full Text Available New corrosion inhibitors, namely, isonicotinic acid (1H-indol-3-yl-methylenehydrazide (INIMH and isonicotinic acid (1H-pyrrol-2-yl-methylenehydrazide (INPMH, have been synthesized, and their inhibitive characteristics for the corrosion of mild steel in 0.5 M HCl were investigated by mass loss and electrochemical techniques. The structures of the synthesized compounds were confirmed using spectral studies. Potentiodynamic polarization studies revealed that the investigated inhibitors are of mixed type. Various thermodynamic parameters were evaluated. Langmuir adsorption isotherm was found to be the best description for both inhibitors. FTIR spectra, energy dispersive X-ray spectroscopy (EDX, and scanning electron microscopy (SEM were performed to characterize the passive film on the metal surface.

  15. A two-stage pretreatment process using dilute hydrochloric acid followed by Fenton oxidation to improve sugar recovery from corn stover.

    Science.gov (United States)

    Li, Wenzhi; Liu, Qiyu; Ma, Qiaozhi; Zhang, Tingwei; Ma, Longlong; Jameel, Hasan; Chang, Hou-Min

    2016-11-01

    A two-stage pretreatment process is proposed in this research in order to improve sugar recovery from corn stover. In the proposed process, corn stover is hydrolyzed by dilute hydrochloric acid to recover xylose, which is followed by a Fenton reagent oxidation to remove lignin. 0.7wt% dilute hydrochloric acid is applied in the first stage pretreatment at 120°C for 40min, resulting in 81.0% xylose removal. Fenton reagent oxidation (1g/L FeSO4·7H2O and 30g/L H2O2) is performed at room temperature (about 20°C) for 12 has a second stage which resulted in 32.9% lignin removal. The glucose yield in the subsequent enzymatic hydrolysis was 71.3% with a very low cellulase dosage (3FPU/g). This two-stage pretreatment is effective due to the hydrolysis of hemicelluloses in the first stage and the removal of lignin in the second stage, resulting in a very high sugar recovery with a low enzyme loading. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Studies on quality improvement in wheat gluten's physical and chemical properties by hydrochloric acid treatment%盐酸处理对谷朊粉理化性质改良的研究

    Institute of Scientific and Technical Information of China (English)

    张德欣

    2012-01-01

    利用盐酸处理改善谷朊粉的溶解度、乳化性、起泡性等理化性质,研究盐酸与谷朊粉的相对浓度、反应温度、反应时间、盐酸浓度对谷朊粉理化性质的影响.结果表明,盐酸处理改良谷朊粉理化性质的最佳条件:谷朊粉质量百分比为8%,盐酸:谷朊粉为3.5:100(质量比),反应温度65℃.试验证明,盐酸处理对谷朊粉的溶解度、乳化性及其稳定性、起泡性及其稳定性都有显著作用.%Using hydrochloric acid treatment improves the gluten's physical and chemical properties of solubility-, emulsiftcation, foaming ability ami etc. The effects of several physical and chemical properties were researched, of hydrochloric acid and gluten relative concentration, reaction temperature, reaction time, hydrochloric acid coticentratioa on gluten. Test results showed that the rn-odified gluten hydrochloric acid treatiment for the optimum conditions of the physical and chemical properties were;mass contest of gluten %%, Hydrochloric acid to gluten 3. 5 · 100 (mass), reaction temperature 65℃, The.experiments proved! that Hydrochloric acid treatment on the gluten's solubility, emulsification and its stability, foaming ability are significantly.

  17. Extraction of Sm(IIIand Nd(III with N,N,N’,N’-tetrabutyl-3-oxy-diglycolamidefrom hydrochloric acid

    Directory of Open Access Journals (Sweden)

    Yang J.H.

    2013-01-01

    Full Text Available The extraction behavior of Sm(III and Nd(III with N,N,N’,N’-tetrabutyl-3-oxa-diglycolamide (TBDGA in 70% kerosene-30% n-octanol from hydrochloride acid wasstudied. The effect of hydrochloric acid concentration, extractant concentration,and temperature on the distribution of rare earth elementswas investigated. The extraction mechanism was established and the stoichiometry of the main extracted species was confirm to be SmCl3•2TBDGA and NdCl3•2TBDGA for Sm(III and Nd(III, respectively. The extraction distribution ratio decreases with an increase in temperature, which demonstrates that the extraction reaction is exothermic. The IR spectra of the loaded organic phase and free extractant were recorded and discussed.

  18. Ethanol-based organosolv treatment with trace hydrochloric acid improves the enzymatic digestibility of Japanese cypress (Chamaecyparis obtusa) by exposing nanofibers on the surface.

    Science.gov (United States)

    Hideno, Akihiro; Kawashima, Ayato; Endo, Takashi; Honda, Katsuhisa; Morita, Masatoshi

    2013-03-01

    The effects of adding trace acids in ethanol based organosolv treatment were investigated to increase the enzymatic digestibility of Japanese cypress. A high glucose yield (60%) in the enzymatic hydrolysis was obtained by treating the sample at 170 °C for 45 min in 50% ethanol liquor containing 0.4% hydrochloric acid. Moreover, the enzymatic digestibility of the treated sample was improved to ∼70% by changing the enzyme from acremonium cellulase to Accellerase1500. Field emission scanning electron microscopy revealed the presence of lignin droplets and partial cellulose nanofibers on the surface of the treated sample. Simultaneous saccharification and fermentation of the treated samples using thermotolerant yeast (Kluyveromyces marxianus NBRC1777) was tested. A high ethanol concentration (22.1 g/L) was achieved using the EtOH50/W50/HCl0.4-treated sample compared with samples from other treatments.

  19. Pharmacokinetics and tissue residues of hydrochloric acid albendazole sulfoxide and its metabolites in crucian carp (Carassius auratus) after oral administration.

    Science.gov (United States)

    Li, Zaijian; Chen, Cuilan; Ai, Diyun; Wang, Chunmei; Li, Jing; Qi, Yuanhua; Yi, Weixue; Shen, Hongchun; Cao, Jiyue

    2012-03-01

    The pharmacokinetics and residues elimination of hydrochloric acid albendazole sulfoxide (ABZSO) and its metabolites were studied in healthy crucian carp (Carassius auratus, 250 ± 30 g) kept at water temperatures of 10 °C and 25 °C. The concentrations of ABZSO and its metabolites concentration in plasma and tissues were determined using high-performance liquid chromatography (HPLC) using an ultraviolet detector. The results revealed that the plasma concentration of ABZSO in plasma was significantly higher than that of albendazole sulfone (ABZSO(2)), whereas albendazole-2-aminosulfone (ABZ-SO(2)NH(2)) was not detected. The plasma concentrations of ABZSO and its main metabolite ABZSO(2) concentration-time data were fitted using a single-compartment model at 10 °C and 25 °C. The absorption half-life (t₁/₂ka) of ABZSO was 3.86 h at 10 °C and 1.29 h at 25 °C, whereas the elimination half-life (t₁/₂ke) was 16.34 h at 10 °C and 6.72 h at 25 °C; the maximum plasma concentration (C(max)) and the time-point of maximum plasma concentration (T(p)) were calculated as 3.20 μg mL(-1) and 10.58 h at 10 °C, 4.39 μg mL(-1) and 3.80 h at 25 °C. The distribution volume (V(d)/F) of ABZSO was estimated to be 1.99 L kg(-1) at 10 °C and 1.53 L kg(-1) at 25 °C; the total body clearance (CL(b)) of ABZSO were computed as 0.08 and 0.19 L/(h kg) at 10 and 25 °C, respectively; the areas under the concentration-time curve (AUC) was 118.22 μg mL(-1)h at 10 °C and 63.12 μg mL(-1)h at 25 °C. The [Formula: see text] of ABZSO(2) was found to be 6.39 °C at 10 °C and 3.73 h at 25 °C, whereas the [Formula: see text] was 12.86 h at 10 °C and 6.56 h at 25 °C; the C(max) and T(p) of ABZSO(2) was calculated as 0.78 μg mL(-1) and 12.82 h at 10 °C, 1.03 μg mL(-1) and 7.04 h at 25 °C, respectively; the V(d)/F of ABZSO(2) were estimated to be 6.43 L kg(-1) at 10 °C and 4.61 Lkg(-1) at 25 °C; the CL(b) of ABZSO(2) were computed as 0.34 and 0.49 L/(h kg) at 10 °C and 25

  20. Electrochemical measurements for the corrosion inhibition of mild steel in 1 M hydrochloric acid by using an aromatic hydrazide derivative

    Directory of Open Access Journals (Sweden)

    P. Preethi Kumari

    2017-07-01

    Full Text Available The influence of an aromatic hydrazide derivative, 2-(3,4,5-trimethoxybenzylidene hydrazinecarbothioamide (TMBHC as corrosion inhibitor on mild steel in 1 M hydrochloric acid was studied by Tafel polarization and electrochemical impedance spectroscopy (EIS technique. The results showed that the inhibition efficiency (% IE of TMBHC increased with increasing inhibitor concentrations and also with increase in temperatures. TMBHC acted as a mixed type of inhibitor and its adsorption on mild steel surface was found to follow Langmuir’s adsorption isotherm. The evaluation of thermodynamic and activation parameters indicated that the adsorption of TMBHC takes place through chemisorption. The formation of protective film was further confirmed by scanning electron microscopy (SEM.

  1. Study on the inhibition of mild steel corrosion by 1,3-bis-(morpholin-4-yl-phenyl-methyl-thiourea in hydrochloric acid medium

    Directory of Open Access Journals (Sweden)

    Devaraj Karthik

    2014-12-01

    Full Text Available 1,3-Bis-(morpholin-4-yl-phenyl-methyl-thiourea (MBT was synthesized and their influence on the inhibition of corrosion on mild steel in various hydrochloric acid concentrations has been investigated by weight loss, potentiodynamic polarization, electrochemical impedance (EI, Tafel polarization, scanning electron microscope (SEM and FT-IR methods. The result of weight loss study shows that the corrosion inhibition efficiency (IE is directly proportional to the concentration of the inhibitor and inversely proportional to the temperature. Electrochemical study proved that the inhibitor acts as a mixed type inhibitor. SEM shows the formation of a protective film of the inhibitor on the mild steel. The IR data also provide evidence for the anticorrosion effect of the inhibitor.

  2. Experimental and theoretical study for corrosion inhibition of mild steel in normal hydrochloric acid solution by some new macrocyclic polyether compounds

    Energy Technology Data Exchange (ETDEWEB)

    Lebrini, M. [Unite de Catalyse et de Chimie du Solide, CNRS UMR 8181, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Lagrenee, M. [Unite de Catalyse et de Chimie du Solide, CNRS UMR 8181, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Vezin, H. [Laboratoire de Chimie Organique et Macromoleculaire, CNRS UMR 8009, USTL Bat C4, F-59655 Villeneuve d' Ascq Cedex (France); Traisnel, M. [Laboratoire des Procedes d' Elaboration des Revetements Fonctionnels, PERF UMR 8008, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Bentiss, F. [Laboratoire de Chimie de Coordination et d' Analytique, Faculte des Sciences, Universite Chouaib Doukkali, BP 20, M-24000 El Jadida (Morocco)]. E-mail: f.bentiss@pop.ensc-lille.fr

    2007-05-15

    New macrocyclic polyether compounds containing a 1,3,4-thiadiazole moiety have been prepared to study the corrosion inhibitive effect of mild steel in normal hydrochloric acid solutions. The salient features obtained from weight loss and electrochemical impedance spectroscopy (EIS) have been discussed. The results of these investigations have shown enhancement in inhibition efficiencies with the extent of the polyethylene glycol unit that forms a cavity. Data obtained from EIS show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPE) has been used. Display Omitted Adsorption of n-MCTH was found to follow the Langmuir's adsorption isotherm. The thermodynamic functions of adsorption process were calculated from experimental ac impedance data and the interpretation of the results are given. Molecular modelling has been conducted in an attempt to correlate the corrosion inhibition properties with the calculated quantum chemical parameters.

  3. Thermodynamic characterization of metal dissolution and inhibitor adsorption processes in mild steel/2,5-bis(n-thienyl)-1,3,4-thiadiazoles/hydrochloric acid system

    Energy Technology Data Exchange (ETDEWEB)

    Bentiss, F. [Laboratoire de Cristallochimie et Physicochimie du Solide, CNRS UMR 8012 ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Laboratoire de Chimie de Coordination et d' Analytique, Universite Chouaib Doukkali, Faculte des Sciences, B.P. 20, El Jadida (Morocco); Lebrini, M. [Laboratoire de Cristallochimie et Physicochimie du Solide, CNRS UMR 8012 ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Lagrenee, M. [Laboratoire de Cristallochimie et Physicochimie du Solide, CNRS UMR 8012 ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France)]. E-mail: michel.lagrenee@ensc-lille.fr

    2005-12-15

    The corrosion inhibition of mild steel in 1 M hydrochloric acid solution by some 2,5-bis(n-thienyl)-1,3,4-thiadiazoles (n-TTH) has been studied in relation to the concentration of the inhibitors as well as the temperature using chemical (weight loss) and electrochemical (ac impedance and dc polarisation) techniques. All the methods employed are in reasonable agreement. The protection efficiency increases with increasing inhibitors concentration and with increasing temperature. The thermodynamic functions of dissolution and adsorption processes were calculated from experimental polarisation data and the interpretation of the results are given. Adsorption of n-TTH was found to follow the Langmuir's adsorption isotherm and the ability of the molecule to chemisorb on the steel surface was dependent on the position of the sulphur atom on the thienyl substituent.

  4. Effect of optimized structure and electronic properties of some benzimidazole derivatives on corrosion inhibition of mild steel in hydrochloric acid medium: Electrochemical and theoretical studies

    Indian Academy of Sciences (India)

    Alokdut Dutta; Sujit Sankar Panja; M M Nandi; Dipankar Sukul

    2015-05-01

    The corrosion inhibitive action of a few benzimidazole derivatives namely 2-(benzamido) ethylbenzimidazole (BAEBI), 2-(-benzenesulphonamido) ethylbenzimidazole (BSAEBI), 2-(benzamido) methylbenzimidazole (BAMBI) and 2-(-benzenesulphonamido) methylbenzimidazole (BSAMBI), towards mild steel in hydrochloric acid has been studied using potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) methods. The results show that these compounds get adsorbed on the mild steel surface following Temkin adsorption isotherm, and act as mixed-type inhibitors. The inhibition efficiencies are found to follow the order, BAEBI > BSAEBI > BAMBI > BSAMBI. This observation is explained in terms of chain length, relative effects of amido and sulphonamido groups, possible structural factors, spatial orientations, energy gap between the frontier molecular orbitals, different intrinsic molecular parameters, like, global hardness and softness, and number of electrons transferred.

  5. Extraction of Gold(III) from Hydrochloric Acid Solutions with a PVC-based Polymer Inclusion Membrane (PIM) Containing Cyphos(®) IL 104.

    Science.gov (United States)

    Bonggotgetsakul, Ya Ya Nutchapurida; Cattrall, Robert W; Kolev, Spas D

    2015-12-08

    Poly(vinyl chloride) (PVC) based polymer inclusion membranes (PIMs), with different concentrations of Cyphos® IL 104 as the membrane extractant/carrier, were studied for their ability to extract Au(III) from hydrochloric acid solutions. Some of the PIMs also contained one of the following plasticizers or modifiers: 2-nitrophenyloctyl ether, dioctylphthalate, 1-dodecanol, 1-tetradecanol, or tri(2-ethylhexyl) phosphate. The best performance, in terms of extraction rate and amount of Au(III) extracted, was exhibited by a PIM consisting of 25 wt% Cyphos(®) IL 104, 5 wt% 1-dodecanol, and 70 wt% PVC. An almost complete back-extraction of the Au(III) extracted from this membrane was achieved by using a 0.10 mol L(-1) Na₂SO₃ receiver solution at pH 8. The stoichiometry of the extracted Au(III)/Cyphos® IL 104 adduct was determined as [P]⁺ [AuCl₄](-) H⁺ [PO₂](-) where [P]⁺ and [PO₂](-) represent trihexyl(tetradecyl) phosphonium and bis(2,4,4-trimethylpentyl) phosphinate ions, respectively. Back-extraction of Au(III) is suggested to occur by reduction of Au(III) to Au(I), with the formation of the species [Au(SO₃)₂](3-) in the aqueous receiver solution. Loss of 1-dodecanol from the newly developed PIM to the aqueous solutions in contact with it was observed, which indicated that this membrane was suitable for single use in the efficient recovery of Au(III) from hydrochloric acid solutions of electronic scrap or recycled jewelry.

  6. Inhibition Performance of Furfural on Carbon Steel in Hydrochloric Acid%糠醛对碳钢在盐酸中的缓蚀性能研究

    Institute of Scientific and Technical Information of China (English)

    杨昌炎; 杨光宏; 刘东; 丁一刚; 吴元欣; 戢峻; 李姝

    2011-01-01

    As a corrosion inhibitor, the corrosion inhibition of furfural obtained from straws by microwave pyrolysis was investigated in hydrochloric acid solution. The weight loss and electrochemistry polarization evaluation, and the absorbance of furfural on carbon steel was preliminary discussed. The results showed that furfural, as a complex inhibitor, gives nice inhibition efficiency on carbon steel in hydrochloric acid medium. The inhibition efficiency of furfural was up to 91. 3 % when the mass fraction of furfural reaches 0.7 % at room temperature. It can also reduce the activation energy of corrosion reaction. This results in a decrease of corrosion rate. The inhibition performance of furfural is affected by temperature, and its absorbance behaviors can be expressed by the equation of Langmuir model.%以秸秆催化热解制得的糠醛作为盐酸酸洗缓蚀剂,其缓蚀效率采用失重法和电化学极化法进行了评价,初步探讨其吸附性能.结果表明:糠醛属于混合型缓蚀剂,在盐酸介质中缓蚀作用良好,室温下糠醛添加量为0.7%时,其缓蚀效率可达91.3%,能使碳钢的腐蚀反应活化能降低,腐蚀速率明显下降,同时其缓蚀效率受温度的影响较大,其吸附符合Langmuir吸附规律.

  7. 植物细胞有丝分裂实验中盐酸浓度对实验效果影响的研究%Effective research on different concentrations of hydrochloric acid in plant cell mitosis experiment

    Institute of Scientific and Technical Information of China (English)

    归改霞

    2015-01-01

    目的:探讨有丝分裂实验中盐酸浓度对实验效果的影响。方法:通过使用不同浓度的盐酸做为解离液进行实验,从中选取最适合的盐酸浓度,从而达到最理想的实验效果。结果:通过实验比较,解离液中盐酸的浓度为25%比较合适。结论:植物细胞有丝分裂实验,在选材、培养、取材均为最优条件下,解离液中盐酸的浓度是实验成功的关键。当盐酸的浓度为25%时,实验成功率最高,能达到最佳效果。%Objective: To investigate effects of different concentrations of hydrochloric acid in plant cell mitosis experiment. Methods: In order to achieve the best experimental results, the most suitable concentration of hydrochloric acid was selected in experiments. Results: Based on experimental comparison, concentration of hydrochloric acid of 25% in dissociation solution is suitable. Conclusion: When other conditions are the best, concentration of hydrochloric acid is the key in plant cell mitosis experiment. When concentration of hydrochloric acid was 25%, there was highest efficiency and the best result.

  8. Extraction chromatographic separation of uranium (VI) with amberlite LA-1 from malonic acid

    Energy Technology Data Exchange (ETDEWEB)

    Narayanan, P.; Khopkar, S.M.

    1985-12-01

    Uranium(VI) was extracted between pH 2.5 to 6.0 from 0.01 mol dm/sup -3/ malonic acid on a column of silica gel with Aberlite LA-1 as the extractant. It was stripped from the column with 1-2 mol dm/sup -3/ of hydrochloric, sulfuric, and nitric acids. Uranium(VI) was separated from alkali, alkaline earths, manganese, iron, cobalt, nickel, zinc, yttrium, lanthanum, cerium in binary mixtures by exploiting the difference in the pH of formation of malonato complexes. Uranium was separated from zirconium, hafnium, thorium, scandium, and titanium by taking its advantage of stability of chloro or sulfato complexes. The method was tested for the standard reference rock samples. 15 references, 4 figures, 1 table.

  9. Electrochemical Study on Corrosion Inhibition of Copper in Hydrochloric Acid Medium and the Rotating Ring-Disc Voltammetry for Studying the Dissolution

    Directory of Open Access Journals (Sweden)

    A. K. Satpati

    2011-01-01

    Full Text Available Dissolution characteristics of copper in hydrochloric acid medium and the effect of 4-amino 1,2,4-triazole (ATA on the corrosion process have been studied using conventional electrochemical techniques and rotating ring-disc electrodes (RRDEs. Corrosion potential (corr and corrosion current density (corr were obtained by Tafel extrapolation methods. Charge transfer resistance (ct and double-layer capacitance (dl were obtained from the electrochemical impedance spectroscopy (EIS. ATA was shown to be an effective inhibitor for the copper-corrosion inhibition in acid medium. The corrosion rate was retarded in presence of inhibitors mainly because of the adsorption of the inhibitor on the electrode surface. Adsorption of the inhibitor on the metal surface was found to follow the Langmuir adsorption isotherm. Standard free energy change of the adsorption process (Δ0ad was calculated to be −54.3 kJ mol−1; such a large negative value of Δ0ad suggests the prescence of a chemisorption process.

  10. Inhibition performance of thiourea on carbon steel in hydrochloric acid%氢氟酸中硫脲对碳钢缓蚀性能的研究

    Institute of Scientific and Technical Information of China (English)

    韩成利

    2013-01-01

    The adsorption and corrosion inhibition of thiourea on carbon steel in hydrochloric acid has been investigated by weight-loss method.The experimental data have been treated with adsorption theory and sekine method.The result showed that thiourea has efficiently inhibited the corrosion of iron in hydrofluoric acid solution, the adsorption rule of thiourea on the surface of iron obeyed Langmuir isotherm.%采用失质量法研究了硫脲在氢氟酸中对碳钢的吸附及缓蚀作用,并应用吸附理论Sekine方法对实验数据进行处理。结果表明,硫脲对氢氟酸体系中碳钢的腐蚀有良好的抑制作用,硫脲在碳钢片表面产生了吸附,且低浓度下吸附基本符合Langmuir等温式。

  11. Corrosion inhibition of 6061 Al-15 vol. pct. SiC(p) composite and its base alloy in a mixture of sulphuric acid and hydrochloric acid by 4-(N,N-dimethyl amino) benzaldehyde thiosemicarbazone

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Geetha Mable [Department of Chemistry, National Institute of Technology Karnataka, Surathkal, Srinivasnagar 575 025, Mangalore, Karnataka (India); Nayak, Jagannath [Department of Metallurgical and Materials Engineering, National Institute of Technology Karnataka, Surathkal, Srinivasnagar 575 025, Karnataka (India); Shetty, A. Nityananda, E-mail: nityashreya@gmail.com [Department of Chemistry, National Institute of Technology Karnataka, Surathkal, Srinivasnagar 575 025, Mangalore, Karnataka (India)

    2011-02-15

    Research highlights: {yields} Corrosion inhibition of Al-SiC composite. {yields} DMABT as corrosion inhibitor. {yields} Inhibition through physisorption of DMABT. - Abstract: The corrosion inhibition characteristics of 4-(N,N-dimethylamino) benzaldehyde thiosemicarbazone (DMABT) on the corrosion behavior of 6061 Al-15 vol. pct. SiC(p) composite and its base alloy were studied at different temperatures in acid mixture medium containing varying concentrations of hydrochloric acid and sulphuric acid using Tafel extrapolation technique and ac impedance spectroscopy (EIS). The effect of inhibitor concentration, temperature and concentration of the acid mixture media on the inhibitor action was investigated. It was found that inhibition efficiencies increase with the increase in inhibitor concentration, but decrease with the increase in temperature and with the increase in concentration of the acid media. Thermodynamic parameters for dissolution process were determined. The adsorption of DMABT on both the composite and base alloy was found to be through physisorption obeying Freundlich adsorption isotherm.

  12. Hydrothermal synthesis of highly crystalline RuS{sub 2} nanoparticles as cathodic catalysts in the methanol fuel cell and hydrochloric acid electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yanjuan [Key Laboratory of Marine Chemistry Theory and Technology, Minisry of Education Ocean University of China, Qingdao, 266100 (China); College of Material Science and Engineering, Key Laboratory of Automobile Materials of Ministry of Education, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Li, Nan, E-mail: lin@jlu.edu.cn [College of Material Science and Engineering, Key Laboratory of Automobile Materials of Ministry of Education, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Yanagisawa, Kazumichi [Research Laboratory of Hydrothermal Chemistry, Kochi University, Kochi 780-8520 (Japan); Li, Xiaotian [College of Material Science and Engineering, Key Laboratory of Automobile Materials of Ministry of Education, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Yan, Xiao [Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012 (China)

    2015-05-15

    Highlights: • Highly crystalline RuS{sub 2} nanoparticles have been first synthesized by a “one-step” hydrothermal method. • The product presents a pure cubic phase of stoichiometric ratio RuS{sub 2} with average particle size of 14.8 nm. • RuS{sub 2} nanoparticles were used as cathodic catalysts in methanol fuel cell and hydrochloric acid electrolysis. • The catalyst outperforms commercial Pt/C in methanol tolerance and stability towards Cl{sup −}. - Abstract: Highly crystalline ruthenium sulfide (RuS{sub 2}) nanoparticles have been first synthesized by a “one-step” hydrothermal method at 400 °C, using ruthenium chloride and thiourea as reactants. The products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy/energy disperse spectroscopy (SEM/EDS), thermo gravimetric-differential thermal analyze (TG-DTA), transmission electron microscopy equipped with selected area electron diffraction (TEM/SAED). Fourier transform infrared spectra (IR), and X-ray photoelectron spectroscopy (XPS). XRD result illustrates that the highly crystalline product presents a pure cubic phase of stoichiometric ratio RuS{sub 2} and the average particle size is 14.8 nm. SEM and TEM images display the products have irregular shape of 6–25 nm. XPS analyst indicates that the sulfur exists in the form of S{sub 2}{sup 2−}. Cyclic voltammetry (CV), rotating disk electrode (RDE), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) measurements are conducted to evaluate the electrocatalytic activity and stability of the highly crystalline RuS{sub 2} nanoparticles in oxygen reduction reaction (ORR) for methanol fuel cell and hydrochloric acid electrolysis. The results illustrate that RuS{sub 2} is active towards oxygen reduction reaction. Although the activity of RuS{sub 2} is lower than that of Pt/C, the RuS{sub 2} catalyst outperforms commercial Pt/C in methanol tolerance and stability towards Cl{sup −}.

  13. 盐酸改性粉煤灰净化低温低浊水的试验研究%The Experimental Research on Purifying Low Temperature and Low Turbidity Water by Hydrochloric Acid Modified Fly Ash

    Institute of Scientific and Technical Information of China (English)

    刘书贤; 魏晓刚; 王伟; 杜平; 肖利萍

    2012-01-01

    由于粉煤灰具有良好的吸附性能且富含硅、铝和铁等元素,将其作为助凝剂,用盐酸对粉煤灰改性后与聚合硫酸铁PFS联合使用处理低温低浊水.在用盐酸对粉煤灰进行改性时,研究了振荡时间、振荡速度、盐酸浓度等试验因素对改性粉煤灰吸附助凝效果的影响,得出盐酸改性粉煤灰的最佳试验条件为:振荡器振荡速度80 r/min,100 mL 3.6 mol/L盐酸与5g预处理粉煤灰混合振荡3h,试验温度25℃.改性后粉煤灰的比表面积明显增加,并且粉煤灰中部分硅、铝和铁等元素溶出,转变成具有很好絮凝作用的Al3+、Fe3+和H2SiO3,粘附于粉煤灰表面,在处理低温低浊水的过程中能较好地发挥吸附助凝效果.%Becaouse of the excellent adsorption performance and high containing of silicon, aluminum and iron and other elements, fly ash by hydrochloric acid modified was used as a coagulant to purify low temperature and low turbidity water with reagent PFS. When the fly ash were modified by hydrochloric acid, the experimental factors just as duration of oscillation, speed of oscillation and hydrochloric acid concentration were researched. The best experimental conditions of hydrochloric acid modification were follows: the speed of oscillation 80r/min, 100 mL 3.6 mol/L of hydrochloric acid and 5 g the coal fly ash mixed in the oscillator for about 3 h, the experiment temperature 25 ℃. The specific surface of modified fly ash increased significantly, the elements such as silicon, aluminum and iron dissolved from fly ash and they turned into Al3+, Fe3+ and H2SiO3 (adhesion on the surface of fly ash) whose flocculation were strong. In the process of purifying low temperature and low turbidity water by hydrochloric acid modified fly ash, the adsorptive property can be exerted effectively.

  14. Role of temperature and hydrochloric acid on the formation of chlorinated hydrocarbons and polycyclic aromatic hydrocarbons during combustion of paraffin powder, polymers, and newspaper.

    Science.gov (United States)

    Takasuga, Takumi; Umetsu, Norihito; Makino, Tetsuya; Tsubota, Katsuya; Sajwan, Kenneth S; Kumar, Kurunthachalam Senthil

    2007-07-01

    Formation of chlorinated hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) were determined using a laboratory-scale incinerator when combusting materials at different temperatures, different concentrations of hydrochloric acid (HCl), and when combusting various types of polymers/newspaper. Polychlorobenzenes (PCBz), polychlorophenols (PCPhs), polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and their toxic equivalency (TEQ) and PAHs were highlighted and reported. Our results imply maximum formation of chlorinated hydrocarbons at 400 degrees C in the following order; PCBz>or=PCPhs>PCDFs>PCDDs>TEQ on a parts-per-billion level. Similarly, a maximum concentration of chlorinated hydrocarbons was noticed with an HCl concentration at 1000 ppm with the presence of paraffin powder in the following order; PAHs>PCBz>or=PCPhs>PCDFs>PCDDs>TEQ an a parts-per-billion level. PAHs were not measured at different temperatures. Elevated PAHs were noticed with different HCl concentrations and paraffin powder combustion (range: 27-32 microg/g). While, different polymers and newspaper combusted, nylon and acrylonitrile butadiene styrene (ABS) produced the maximum hydrogen cyanide (HCN) concentration, concentrations of PCDD/FS, dioxin-like polychlorinated biphenyls (DL-PCBs), and TEQ were in a decreasing order: polyvinylchloride (PVC)newspapernewspapernewspaper newspapernewspaper

  15. Improve the Properties of p-i-n α-Si:H Thin-Film Solar Cells Using the Diluted Hydrochloric Acid-Etched GZO Thin Films

    Directory of Open Access Journals (Sweden)

    Fang-Hsing Wang

    2013-01-01

    Full Text Available Gallium-doped zinc oxide (GZO thin films were deposited on glass, and the process parameters are RF power of 50 W and working pressure of 5 mTorr, and the substrate temperature was changed from room temperature to 300°C. At first, the thickness was around 300 nm by controlling the deposition time. The effects of substrate temperature on the crystallinity, lattice constant (c, carrier mobility, carrier concentration, resistivity, and optical transmission rate of the GZO thin films were studied. The 200°C-deposited GZO thin films had the best crystallinity, the larger carrier concentration and carrier mobility, and the lowest resistivity. For that, the thickness of the GZO thin films was extended to around 1000 nm. Hydrochloric (HCl acid solutions with different concentrations (0.1%, 0.2%, and 0.5% were used to etch the surfaces of the GZO thin films, which were then used as the substrate electrodes to fabricate the p-i-n α-Si:H thin-film solar cells. The haze ratio of the GZO thin films increased with increasing HCl concentration, and that would effectively enhance light trapping inside the absorber material of solar cells and then improve the efficiency of the fabricated thin-film solar cells.

  16. 盐酸浓度对酸解玉米淀粉结晶结构和性能的影响%Effects of hydrochloric acid concentration on crystalline structure and properties of corn starch

    Institute of Scientific and Technical Information of China (English)

    左迎峰; 张彦华; 杨龙; 谭海彦; 顾继友

    2013-01-01

    以玉米淀粉为原料,用盐酸对其酸解制备酸解玉米淀粉.考虑盐酸浓度对酸解玉米淀粉结构和性能的影响.通过抽滤洗涤法、X射线衍射(XRD)、旋转粘度计、差示扫描量热法(DSC)和热重分析(TGA)对酸解淀粉的回收率、结晶度、糊化粘度、糊化温度和热性能进行分析.结果表明,酸解玉米淀粉的回收率、结晶度和糊化温度随盐酸浓度的增大,先增大后减小,盐酸浓度为0.5 mol/L时,回收率、结晶度和糊化温度都达到最大值;糊化粘度随盐酸浓度的增大而迅速减小;酸解改性对玉米淀粉的热稳定性影响较小.%Acid hydrolysis corn starch was prepared by hydrochloric acid method to study the effects of hydrochloric acid concentrations on the structure and properties of acid hydrolysis com starch.. The crystallinity, gelatinization viscosity, gelatinization temperature and thermal performance of acid hydrolysis starch were analyzed by using filtration washing method, X-ray diffraction, rotational viscometer, differential scanning calorimetry and thermo gravimetric analysis, respectively. The results show that the recovery yield, crystallinity and gelatinization temperature increased first and then decreased with the increase of hydrochloric acid concentration, and reached the maximum values when hydrochloric acid concentration was 0.5 mol/L; the gelatinization viscosity rapidly decreased with increase of hydrochloric acid concentration. So the acid modification had small effect on thermal stability of corn starch.

  17. 没食子酸在含盐酸高温液态水中的稳定性%Stability of Gallic Acid in High Temperature Water with Hydrochloric Acid

    Institute of Scientific and Technical Information of China (English)

    张迎杰; 傅杰; 刘林; 吕秀阳

    2013-01-01

    The stability of gallic acid in high temperature water with hydrochloric acid was studied in a high-pressure batch reactor.The effects of initial concentration of gallic acid,concentration of hydrochloric acid and reaction temperature on the stability of gallic acid were investigated.The results indicated that HC1 concentration was an important factor to the stability of gallic acid,in which the stability of gallic acid decreased as the concentration of HC1 increased.Reaction temperature influenced the stability of gallic acid significantly.As the temperature increased,the conversion of gallic acid increased rapidly,whereas the stability of gallic acid decreased remarkably.Below 413.15 K,gallic acid was relatively stable in HC1 solutions.The kinetic data of the study obtained at different hydrochloric acid concentrations and reaction temperatures were fitted with a pesudo-first-order kinetic equation.The apparent activation energy for the decarboxylation of gallic acid at different hydrochloric acid concentration was obtained by Arrhenius equation.All the obtained apparent activation energy values were close to 112 kJ/mol and not sensitive to the HCl concentration.%采用间歇高压反应釜研究了没食子酸在含盐酸高温液态水中的稳定性.在数据重现性研究基础上,考察了没食子酸初始浓度、盐酸浓度和反应温度等对没食子酸稳定性的影响.结果表明:盐酸浓度对没食子酸的稳定性有较显著的影响,且随着盐酸浓度的增加,稳定性下降:温度对没食子酸稳定性影响十分显著,随着温度的升高,没食子酸转化速率快速增加,稳定性显著降低,但在413.15 K以下没食子酸在盐酸溶液中有较好的稳定性.采用拟一级反应动力学方程,拟合得到了不同盐酸浓度和反应温度下的反应速率常数,进而利用Arrhenius方程得到了不同盐酸浓度没食子酸脱羧反应的表观活化能,表明在盐酸存在下,没食子酸脱羧反

  18. Synthesis and characterization of a novel eco-friendly corrosion inhibition for mild steel in 1 M hydrochloric acid.

    Science.gov (United States)

    Al-Amiery, Ahmed A; Binti Kassim, Fatin A; Kadhum, Abdul Amir H; Mohamad, Abu Bakar

    2016-01-22

    The acid corrosion inhibition process of mild steel in 1 M HCl by azelaic acid dihydrazide has been investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, open circuit potential (OCP) and electrochemical frequency modulation (EFM). Azelaic acid dihydrazide was synthesized, and its chemical structure was elucidated and confirmed using spectroscopic techniques (infrared, nuclear magnetic resonance and mass spectroscopy). Potentiodynamic polarization studies indicate that azelaic acid dihydrazide is a mixed-type inhibitor. The inhibition efficiency increases with increased inhibitor concentration and reaches its maximum of 93% at 5 × 10(-3) M. The adsorption of the inhibitor on a mild steel surface obeys Langmuir's adsorption isotherm. The effect of te perature on corrosion behavior in the presence of 5 × 10(-3) M inhibitor was studied in the temperature range of 30-60 °C. The results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. To inspect the surface morphology of inhibitor film on the mild steel surface, scanning electron microscopy (SEM) was used before and after immersion in 1.0 M HCl.

  19. Operational aspect of hot water style 2-in-1 graphite hydrochloric acid furnace%热水型二合一石墨盐酸炉的运行情况

    Institute of Scientific and Technical Information of China (English)

    吕旭琦; 冯海平

    2012-01-01

    通过改造传统工艺盐酸炉为热水型二合一石墨盐酸炉,回收盐酸生产中产生的热量制热水。采用热水型溴化锂制冷机组制7℃水供生产用。工艺改造后,达到了节能减排预期目标。%The tradition graphite hydrochloric acid furnace was transformed into hot water style 2-in-1 graphite hydrochloric acid furnace.The hot water was used to produce 7℃ water.After process transformation,the ammonia refrigerating machine was stoped and the power consumption reduced,the energy conservation goals were achieved.

  20. Kinetic Approach to the Mechanism of Redox Reaction of Pyrocatechol Violet and Nitrite Ion in Aqueous Hydrochloric Acid

    Directory of Open Access Journals (Sweden)

    A. Adetoro

    2011-10-01

    Full Text Available The kinetics of the oxidation of Pyrocatechol violet (PCVH by nitrite ion (NO2- in aqueous acidic medium has been studied at 24±1ºC, I = 0.50 mol/dm3(NaCl, [H+] = 1.0×10-3 mol/dm3. The reaction is first order to [PCVH] and half order to [NO2-]. The redox reaction displayed a 1:1 stoichiometry and obeys the rate law: d[PCVH]/dt = (a + b[H+] [PCVH][NO2-]½. The second-order rate constant increases with increase in acid concentration and ionic strength. This system displayed positive salt effect while spectroscopic investigation and Michaelis-Menten plot showed evidence of intermediate complex formation in the course of the reaction. A plausible mechanism has been proposed for the reaction.

  1. 盐酸法提取污泥中蛋白质过程的研究%Study on the Processes of Protein Extraction from Sludge by Hydrochloric Acid

    Institute of Scientific and Technical Information of China (English)

    秦晓; 刘勇

    2012-01-01

    为了探索剩余污泥中蛋白质的提取方法,采用盐酸和氢氧化钠对污泥中蛋白质进行了提取,并对提取液进行了紫外光谱分析.结果证明盐酸提取法更有利于污泥中蛋白质的提取操作,并可以保证蛋白质质量.随后,实验考察了温度、污泥浓度、盐酸浓度以及操作时间对提取液中蛋白质浓度的影响情况.结果表明:蛋白质浓缩随温度呈先慢后快的增加趋势,随污泥浓度呈线性增加趋势,随盐酸浓度呈先快后慢增加趋势,适当延长时间有利于提升提取液中的蛋白质浓度.%In order to explore the methods of protein extraction from sludge, firstly, hydrochloric acid and sodium hydroxide were used to extract protein in this paper, and then the extracts were analyzed by UV spectrum. The results showed that hydrochloric acid extraction method was more conducive to the protein extraction and could ensure the protein quality. Subsequently, the effects of temperature, sludge concentration, hydrochloric acid concentration and operating time on protein concentration in the extract were experimentally investigated in detail. The results show that: the change trend of the protein concentration in the extract with temperature is slow after fast, with sludge concentration is linear, with hydrochloric acid is fast before slow, and appropriate extension of time will help to enhance the protein concentration in the extract.

  2. 盐酸戊乙奎醚治疗有机磷农药中毒临床分析%Clinical Analysis of Hydrochloric Acid Penehyclidine in Treatmentof Organophosphorus Pesticide Poisoning

    Institute of Scientific and Technical Information of China (English)

    曹振强; 汪显琪

    2012-01-01

    Objective: To investigate the efficacy and clinical significance of hydrochloric acid penehyclidine in the treatment of organophosphorus pesticide poisoning. Method: Chosing 126 cases of organophosphorus pesticide poisoning patients. Then explored the comprehensive methods of hydrochloric acid penehyclidine treatment. Result: After 3 to 5 days of comprehensive hydrochloric acid penehyclidine treatment, 122 patients escaped from danger successfully and 4 patients died. Another 15 patients responded with dry mouth , flushing face and so on, and then was cured slowly after stopping the treatment. Conclusion: Hydrochloric acid penehyclidine is characteristic of long-lasting time, simple operation and so on. It is of better clinical utility and safety, and can obviously speed up the level of consciousness, reduce treatment time and improve the treatment success rate for organophosphorus pesticide poisoning patients.%目的:探讨盐酸戊乙奎醚治疗有机磷农药中毒病症的疗效及临床意义.方法:选取我院急诊科126例有机磷农药中毒患者,探讨盐酸戊乙奎醚治疗的综合方法,并结合实际分析其效果.结果:经盐酸戊乙奎醚综合治疗3-5d后,122例患者成功脱险,死亡4例.有15例出现口干、面红等不良反应,停药后自行缓解.结论:盐酸戊乙奎醚具有持续时间长、操作简便等特点,具有更好的临床实用性和安全性,对于有机磷农药中毒患者能明显加快清醒程度,缩短时间,提高救治成功率.

  3. Formation of super-concentrated hydrochloric acid in the third phase in tertiary amine N235-PtCl62--HCl system and its influences on the Pt microemulsion extraction

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper,we have investigated the formation of the third-phase in tertiary amine(N235)-PtCl62--HCl system and the microscopic phase structural evolution of platinum-loaded organic phases before and after the occurrence of the third-phase.The third-phase is characterized by various spectroscopic techniques,and the small angle X-ray scattering(SAXS) experiments demonstrate the appearance of nano-aggregates,i.e.,water-in-oil reversed micelles,in the third phase.The experimental results indicate that(1) formation of the third phase is related to the aggregation behaviors of nano-reversed micelles in which a super-concentrated hydrochloric acid formed with the H+ to H2O molar ratio being much higher than that of the conventional 37 wt% saturated hydrochloric acid.(2) The occurrence of the super-concentrated HCl results in a great amount of H+ and Cl-ions enriched and confined within the nano-water pools of W/O reversed micelles in third phase.Therefore,the coordination behaviors of platinum complex ions in that super-concentrated hydrochloric acid are very different from their corresponding behaviors in bulk aqueous solutions.It is possible that H+ ions participate in the formation of such complexes as HmPtCl6z+ in the super-concentrated hydrochloric acid.(3) The relative contents of various HmPtCl6z+ complexes are different corresponding to the H+ ion concentrations in confined nanowater pools.The association ability of the acidified tertiary amine N235 molecules(R3NH+) with various HmPtCl6z+ complexes plays an important role in affecting the platinum extraction behaviors.

  4. Chemical Polymerization Kinetics of Poly-O-Phenylenediamine and Characterization of the Obtained Polymer in Aqueous Hydrochloric Acid Solution Using K2Cr2O7 as Oxidizing Agent

    Directory of Open Access Journals (Sweden)

    S. M. Sayyah

    2014-01-01

    Full Text Available The oxidative chemical polymerization of o-phenylenediamine (OPDA was studied in hydrochloric acid solution using potassium dichromate as oxidant at 5°C. The effects of potassium dichromate, hydrochloric acid, and monomer concentrations on the polymerization reaction were investigated. The order of reaction with respect to potassium dichromate, hydrochloric acid, and monomer concentration was found to be 1.011, 0.954, and 1.045, respectively. Also, the effect of temperature on the polymerization rate was studied and the apparent activation energy of the polymerization reaction was found to be 63.658 kJ/mol. The obtained polymer was characterized using XPS, IR, UV-visible, and elemental analysis. The surface morphology of the obtained polymers was characterized by X-ray diffraction and transmission electron microscopy (TEM. The TGA analysis was used to confirm the proposed structure and number of water molecules in each polymeric chain unit. The ac conductivity (σac of (POPDA was investigated as a function of frequency and temperature. The ac conductivity was interpreted as a power law of frequency. The frequency exponent (s was found to be less than unity and decreased with the increase of temperature, which confirms that the correlated barrier hopping model was the dominant charge transport mechanism.

  5. Treasure of the Past VI: Standard Potential of the Silver-Silver-Chloride Electrode from 0° to 95° C and the Thermodynamic Properties of Dilute Hydrochloric Acid Solutions.

    Science.gov (United States)

    Bates, R G; Bower, V E

    2001-01-01

    From electromotive-force measurements of the cell without liquid junction: [Formula: see text]through the range 0° to 95° C, calculations have been made of (1) the standard potential of the silver-silver-chloride electrode, (2) the activity coefficient of hydrochloric acid in aqueous solutions from m (molality) =0 to m=0.1 and from 0° to 90° C, (3) the relative partial molal heat content of hydrochloric acid, and (4) the relative partial molal heat capacity of hydrochloric acid. The extrapolations were made by the method of least squares with the aid of punch-card techniques. Data from at least 24 cells were analyzed at each temperature, and 81 cells were studied at 25° C. The value of the standard potential was found to be 0.22234 absolute volt at 25° C, and the standard deviation was 0.02 millivolt at 0° C, 0.01 millivolt at 25° C, and 0.09 millivolt at 95° C. The results from 0° to 60° C are compared with earlier determinations of the standard potential and other quantities derived from the electromotive force.

  6. A novel triazole-based cationic gemini surfactant: synthesis and effect on corrosion inhibition of carbon steel in hydrochloric acid

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Lingguang [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China)]. E-mail: lgahu@163.com; Xie Anjian [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Shen Yuhua [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China)

    2005-06-15

    A triazole-based cationic gemini surfactant, 3,5-bis(methylene octadecyl dimethylammonium chloride)-1,2,4-triazole (18-triazole-18) has been synthesized, and its effect on corrosion inhibition of A{sub 3} steel in 1 M HCl has been studied using the weight-loss method. The result showed that 18-triazole-18 acted as an excellent inhibitor in 1 M HCl. It was found that the adsorption mechanism of 18-triazole-18 on the steel surface in acid medium was quite different from that of cationic gemini surfactants containing dimethylene as a spacer, as well as that of conventional cationic single-chained surfactants, which is due to unique molecular structure of 18-triazole-18. 18-Triazole-18 may be adsorbed on the steel surface in acid medium through a maximum of four atoms or groups, i.e., the two nitrogen atoms of triazole ring and two quaternary ammonium head groups. Four regions of surfactant concentration could be divided to illustrate the adsorption of 18-triazole-18 on the steel surface, and four different adsorption mechanisms may take place in different regions of surfactant concentration.

  7. Trapping of hydrochloric and hydrofluoric acid at vacancies on and underneath the ice I(h) basal-plane surface.

    Science.gov (United States)

    Pinheiro Moreira, Pedro Augusto Franco; de Koning, Maurice

    2013-10-31

    We investigate the uptake of HCl and HF at lattice vacancies in ice Ih as a function of their distance to the basal-plane surface layer using density-functional theory calculations. The results for HCl display large dispersions in the binding-energy results due to the appearance of distinct dissociation states. The layer-averaged results suggest that the uptake of HCl is most favorable in the two layers just below the surface, which is consistent with available experimental indications. The behavior of HF is found to be manifestly different due to the fact that it is a weaker acid. The dispersion in the binding-energy values is significantly less compared to the case of HCl, and the average values are essentially equal to the bulk value, regardless of layer position. This suggests that, in contrast to the case of HCl, there should not be any tendency for accumulation of HF near the surface.

  8. Corrosion inhibition efficiency and surface activity of benzothiazol-3-ium cationic Schiff base derivatives in hydrochloric acid

    Energy Technology Data Exchange (ETDEWEB)

    Negm, N.A., E-mail: nabelnegm@hotmail.co [Petrochemicals Department, Egyptian Petroleum Research Institute, Nasr City, Cairo (Egypt); Elkholy, Y.M.; Zahran, M.K. [Chemistry Department, Faculty of Science, Helwan University, Helwan (Egypt); Tawfik, S.M. [Petrochemicals Department, Egyptian Petroleum Research Institute, Nasr City, Cairo (Egypt)

    2010-10-15

    Research highlights: {yields} Benzothiazolium inhibitors show high corrosion inhibition for carbon steel. {yields} Weight loss and corrosion rates decrease by increasing inhibitor dose. {yields} Inhibition mechanism suggested as physisorption mechanism supported by adsorption free energy values. {yields} The adsorption of the inhibitors obeys Langmuir isotherm. {yields} Side chains have ascending order on the corrosion inhibition of the different inhibitors. - Abstract: Two series of cationic Schiff base surfactants namely: 2-(benzylideneamino)-3-(2-oxo-2-alkoxyethyl)-1,3-benzothiazol-3-ium bromide and 2-[(4-methoxybenzylidene)amino]-3-(2-oxo-2-alkoxyethyl)-1, 3-benzothiazol-3-ium bromide were prepared and confirmed using elemental analysis, FTIR, and {sup 1}H NMR spectra. The surface activity of the synthesized Schiff bases showed their tendency towards adsorption at the interfaces. The prepared compounds were evaluated as corrosion inhibitors for carbon steel in 0.5 M HCl solution using gravimetric and polarization measurements. By fitting the gravimetric data, some thermodynamic and kinetic parameters were estimated. The adsorption of the inhibitors on the carbon steel surface obeyed Langmuir adsorption isotherm and had a physical mechanism. Polarization measurements showed that the synthesized inhibitors act as mixed inhibitors for carbon steel in the acidic media. The results of the corrosion inhibition using two different methods showed narrow differences in the obtained values between the two methods within 5%.

  9. Preparation of Butyl Chloride from Butanol and Hydrochloric Acid Using Ionic Liquids as Catalyst%离子液体催化丁醇与盐酸反应制备丁基氯

    Institute of Scientific and Technical Information of China (English)

    孙爱军; 聂毅; 李春喜; 王子镐

    2008-01-01

    The catalytic performance of some quaternary ammonium salts for the liquid phase reaction of butanol and hydrochloric acid at different conditions was studied experimentally and compared with the traditional catalyst (ZnC12). The organic ammonium catalysts investigated include ionic liquids N-butyl-N-methyl imidazolium fluobo-rate ([BMIM][BF4]) and N-butyl-N-methylimidazolium chloride ([BMIM]Cl) as well as hydrochloric salts of N-methylimidazol ([HMIM]Cl), pyridine ([Hpy]Cl) and triethylamine ([HEt3N]Cl). It is shown that the intrinsic catalytic performance of all organic ammonium salts except [Het3N]Cl is slightly superior to ZnCl2, while the se-lectivity of butyl chloride is nearly at the same level around 96%. The conversion of butanol increases slightly with temperature and the catalyst amount added while the variation of selectivity is not obvious. Based on the recycle experiments, the ionic liquids as catalyst for the reaction of butanol and hydrochloric acid can be used more than 5 times, which suggests great potential of using ionic liquids as novel catalyst for such reactions.

  10. [Suicidal poisoning due to hydrogen sulfide produced by mixing a liquid bath essence containing sulfur and a toilet bowl cleaner containing hydrochloric acid].

    Science.gov (United States)

    Kobayashi, Kanya; Fukushima, Hirofumi

    2008-04-01

    A 21-year-old man was found dead in a car. There were 9 empty bottles of 610HAP (a 440 g bottle of a liquid bath essence containing 160-195 g/kg sulfur) and 10 of Sunpole (a 500 mL bottle of a toilet bowl cleaner containing 9.5% HCl) in the car. The car doors were sealed with tape, and there was a strong smell of sulfur in and around the car. GC/MS analysis showed 0.66 microg/mL sulfide and 0.14 micromol/mL thiosulfate in the blood sample. The concentration of thiosulfate in the urine sample was normal. Police investigation concluded that the man killed himself by aspirating hydrogen sulfide that had been produced by mixing 610 HAP and Sunpole. To examine the amount of hydrogen sulfide produced, small portions of these liquids were mixed in a 560-mL volume flask. The results showed that 0.1 mL of each liquid produced 4,950 ppm of hydrogen sulfide, and 0.2 mL of each produced 10,800 ppm. According to these results, if the cabin volume is assumed to be 3,300 L, mixing 120 mL of each liquid produces a lethal level of hydrogen sulfide, i.e., 1,000 ppm. This was a rare suicide case, and it revealed the hazards of mixing of liquid bath essences containing sulfur and toilet bowl cleaners containing hydrochloric acid.

  11. 萃取净化盐酸法制备磷酸工艺研究%Study of Preparation Phosphoric Acid Process by Extraction and Purification of Hydrochloric Acid Process

    Institute of Scientific and Technical Information of China (English)

    杨站平; 闫小玲; 张树帜; 王长锐

    2014-01-01

    Based on preparation crude phosphoric acid by acid hydrolysis of ground phosphate rocks with hydrochloric acid , using process of combination of tributyl phosphate and kerosene mixed solvent extraction with chemical precipitation process to carry out purification treatment for crude phosphoric acid , after refine , concentration , removal of impurities and decolorization , food grade phosphoric product is obtained . Research results show that mass fraction of prepared product phosphoric acid is 85.2%, all indicators achieved not only meet standard requirements of industrial grade phosphoric acid , but also reach qualifications of food grade phosphoric acid .%以盐酸酸解磷矿粉制得粗磷酸为基础,采用磷酸三丁酯和煤油混合溶剂萃取与化学沉淀法相结合的工艺对粗磷酸进行净化处理,通过精制、浓缩、除杂、脱色后可制得食品级磷酸产品。研究结果表明:试验制得的产品磷酸质量分数为85.2%,各项指标不仅达到了工业级磷酸标准要求,而且达到了食品级磷酸标准要求。

  12. Microstructures of Al7.5Cr22.5Fe35Mn20Ni15 High-Entropy Alloy and Its Polarization Behaviors in Sulfuric Acid, Nitric Acid and Hydrochloric Acid Solutions

    Directory of Open Access Journals (Sweden)

    Chun-Huei Tsau

    2016-08-01

    Full Text Available This paper investigates the microstructures and the polarization behaviors of Al7.5Cr22.5Fe35Mn20Ni15 high-entropy alloy in 1M (1 mol/L deaerated sulfuric acid (H2SO4, nitric acid (HNO3, and hydrochloric acid (HCl solutions at temperatures of 30–60 °C. The three phases of the Al7.5Cr22.5Fe35Mn20Ni15 high-entropy alloy are body-centered cubic (BCC dendrites, face-centered cubic (FCC interdendrites, and ordered BCC precipitates uniformly dispersed in the BCC dendrites. The different phases were corroded in different acidic solutions. The passivation regions of the Al7.5Cr22.5Fe35Mn20Ni15 alloy are divided into three and two sub-regions in the solutions of H2SO4 and HNO3 at 30–60 °C, respectively. The passivation region of the Al7.5Cr22.5Fe35Mn20Ni15 alloy is also divided into two sub-domains in 1M deaerated HCl solution at 30 °C. The Al7.5Cr22.5Fe35Mn20Ni15 alloy has almost equal corrosion resistance in comparison with 304 stainless steel (304SS in both the 1M H2SO4 and 1M HCl solutions. The polarization behaviors indicated that the Al7.5Cr22.5Fe35Mn20Ni15 alloy possessed much better corrosion resistance than 304SS in 1M HNO3 solution. However, in 1M NaCl solution, the corrosion resistance of the Al7.5Cr22.5Fe35Mn20Ni15 alloy was less than 304SS.

  13. Dissolution kinetics of aluminum and iron from coal mining waste by hydrochloric acid☆

    Institute of Scientific and Technical Information of China (English)

    Li Cui; Yanxia Guo; Xuming Wang; Zhiping Du; Fangqin Cheng

    2015-01-01

    The extraction of aluminum from coal mining waste (CMW) is an important industrial process. The two major problems in applications are low aluminum dissolution efficiency and high iron content in the raw material, which affect the quantity and quality of products. To improve the aluminum recovery process, the leaching kinet-ics of CMW with hydrochloric acid was studied. A shrinking core model was used to investigate aluminum and iron dissolution kinetics. Based on the kinetic characteristics, a process for recovering aluminum was proposed and tested experimental y. It is found that the aluminum leaching reaction is controlled by surface reaction at low temperatures (40–80 °C) and by diffusion process at higher temperatures (90–106 °C). The iron dissolution process is dominated by surface reaction at 40–100 °C. The results show that iron could be dissolved or separated by concentrated hydrochloric acid. Fine grinding wil improve aluminum dissolution significantly.

  14. Sequential soil washing techniques using hydrochloric acid and sodium hydroxide for remediating arsenic-contaminated soils in abandoned iron-ore mines.

    Science.gov (United States)

    Jang, Min; Hwang, Jung Sung; Choi, Sang Il

    2007-01-01

    Sequential washing techniques using single or dual agents [sodium hydroxide (NaOH) and hydrochloric acid (HCl) solutions] were applied to arsenic-contaminated soils in an abandoned iron-ore mine area. We investigated the best remediation strategies to maximize arsenic removal efficiency for both soils and arsenic-containing washing solution through conducting a series of batch experiments. Based on the results of a sequential extraction procedure, most arsenic prevails in Fe-As precipitates or coprecipitates, and iron exists mostly in the crystalline forms of iron oxide. Soil washing by use of a single agent was not effective in remediating arsenic-contaminated soils because arsenic extractions determined by the Korean standard test (KST) methods for washed soils were not lower than 6mg kg(-1) in all experimental conditions. The results of X-ray diffraction (XRD) indicated that iron-ore fines produced mobile colloids through coagulation and flocculation in water contacting the soils, containing dissolved arsenic and fine particles of ferric arsenate-coprecipitated silicate. The first washing step using 0.2M HCl was mostly effective in increasing the cationic hydrolysis of amorphous ferrihydrite, inducing high removal of arsenic. Thus, the removal step of arsenic-containing flocs can lower arsenic extractions (KST methods) of washed soils. Among several washing trials, alternative sequential washing using 0.2M HCl followed by 1M HCl (second step) and 1M NaOH solution (third step) showed reliable and lower values of arsenic extractions (KST methods) of washed soils. This washing method can satisfy the arsenic regulation of washed soil for reuse or safe disposal application. The kinetic data of washing tests revealed that dissolved arsenic was easily readsorbed into remaining soils at a low pH. This result might have occurred due to dominant species of positively charged crystalline iron oxides characterized through the sequential extraction procedure. However

  15. Effects of chopping, and soaking in water, hydrochloric acidic and calcium hydroxide solutions on the nutritional value of Acacia villosa for goats

    Energy Technology Data Exchange (ETDEWEB)

    Wina, E. [Research Institute for Animal Production, Bogor (Indonesia)]. E-mail: winabudi@yahoo.com; Tangendjaja, B.; Susana, I.W.R. [Research Institute for Animal Production, Bogor (Indonesia)

    2005-08-19

    Acacia villosa, a thornless shrub legume, has potential as a feed supplement for ruminants if anti-nutritional factors, especially tannins, can be overcome. The effects of chopping and soaking the leaves on the amounts of tannin in the extracting solution and that left in the recovered leaves were studied. The tannin and non-tannin phenolics were solubilized in the extracting solution and the amount was increased with the soaking time. Soaking in calcium hydroxide solution, hydrochloric acid or water removed 41-76% of tannin and total phenolics removed from the recovered leaves. Soaking of the leaves also removed fermentable materials and reduced the gas production. In the first of two digestibility experiments, three groups of goats received one of these diets, those were: (1) sugar cane tops: unsoaked Acacia leaves (7:3), (2) sugar cane tops: water soaked Acacia leaves (7:3) and (3) sugar cane tops: water soaked Acacia leaves (7:3) + 100 g/day of cassava flour. Live weight of goats was measured every 2 weeks and a large increase in average daily gain was obtained for goats fed diet containing water soaked leaves and cassava flour (71 g/day) compared to those fed diet containing unsoaked leaves and water soaked leaves (38.9 and 44.7 g/day, respectively) (P < 0.05). In the second digestibility experiment, the three diets were: (1) sugar cane tops: unsoaked Acacia (7:3), (2) sugar cane tops water soaked Acacia (7:3), (3) sugar cane tops: calcium hydroxide soaked Acacia (7:3). A supplement of 100 g/day of cassava flour was added to each of these three diets. In both digestibility experiments, soaking improved intake and digestibility of Acacia leaves, and cassava flour increased the intake, but when all the diets contained cassava flour, there was no significant difference (P > 0.05) found in intake or digestibility between unsoaked and soaked leaves. In conclusion, soaking reduced tannin in Acacia leaves, improved digestibility and intake of Acacia leaves. In the

  16. Effect of a low-viscosity adhesive resin on the adhesion of metal brackets to enamel etched with hydrochloric or phosphoric acid combined with conventional adhesives.

    Science.gov (United States)

    Yetkiner, Enver; Ozcan, Mutlu; Wegehaupt, Florian Just; Wiegand, Annette; Eden, Ece; Attin, Thomas

    2013-12-01

    This study investigated the effect of a low-viscosity adhesive resin (Icon) applied after either hydrochloric (HCl) or phosphoric acid (H3PO4) on the adhesion of metal brackets to enamel. Failure types were analyzed. The crowns of bovine incisors (N = 20) were sectioned mesio-distally and inciso-gingivally, then randomly assigned to 4 groups according to the following protocols to receive mandibular incisor brackets: 1) H3PO4 (37%)+TransbondXT (3M UNITEK); 2) H3PO4 (37%)+Icon+TransbondXT; 3) HCl (15%)+Icon (DMG)+TransbondXT 4) HCl (15%)+Icon+Heliobond (Ivoclar Vivadent)+TransbondXT. Specimens were stored in distilled water at 37°C for 24 h and thermocycled (5000x, 5°C to 55°C). The shear bond strength (SBS) test was performed using a universal testing machine (1 mm/min). Failure types were classified according to the Adhesive Remnant Index (ARI). Contact angles of adhesive resins were measured (n = 5 per adhesive) on ceramic surfaces. No significant difference in SBS was observed, implying no difference between combinations of adhesive resins and etching agents (p = 0.712; ANOVA). The Weibull distribution presented significantly lower Weibull modulus (m) of group 3 (m = 2.97) compared to other groups (m = 5.2 to 6.6) (p group 1 (45.4 ± 7.9) > group 2 (44.2 ± 10.6) > group 3 (42.6 ± 15.5). While in groups 1, 3, and 4 exclusively an ARI score of 0 (no adhesive left on tooth) was observed, in group 2, only one specimen demonstrated score 1 (less than half of adhesive left on tooth). Contact angle measurements were as follows: Icon (25.86 ± 3.81 degrees), Heliobond (31.98 ± 3.17 degrees), TransbondXT (35 ± 2.21 degrees). Icon can be safely used with the conventional adhesives tested on surfaces etched with either HCl or H3PO4.

  17. Estudios Cinéticos de la Disolución de Hidroboracita en Soluciones de Acido Clorhídrico y Acido Sulfúrico Dissolution Kinetics of Hydroboracite in Hydrochloric Acid and Sulphuric Acid Solutions

    Directory of Open Access Journals (Sweden)

    Graciela V Morales

    2008-01-01

    Full Text Available Se realizan estudios cinéticos de la disolución de hidroboracita en soluciones de ácido clorhídrico y ácido sulfúrico en un reactor tanque agitado discontinuo de acero inoxidable, a presión atmosférica. Se investiga el efecto de la temperatura, el tamaño de partícula, la relación sólido/líquido y la concentración de ácido sobre la velocidad de disolución. Los resultados experimentales permiten observar que la velocidad de disolución aumenta con el incremento de la concentración del ácido y de la temperatura, y disminuye con el aumento del tamaño de partícula y con la relación sólido/líquido. La energía de activación aparente calculada para la disolución de hidroboracita en soluciones de ácido clorhídrico es 44.9 kJ/mol, lo cual no permite inferir cual es la etapa controlante del proceso; mientras que la energía de activación aparente calculada para la disolución de hidroboracita en soluciones de ácido sulfúrico es 14.6 kJ/mol, lo cual permite inferir que el proceso ocurre con control difusivo.The dissolution kinetics of hydroboracite in hydrochloric acid and sulphuric acid solutions was investigated. The experiments were carried out in a steel batch reactor equipped with a mechanical stirrer, at atmospheric pressure. The effect of reaction temperature, particle size, solid/liquid ratio and acid concentration on the dissolution rate was determined. It was found that the dissolution rate increased with increasing the acid concentration and reaction temperature. However, the increase of particle size and solid/liquid ratio decreased the dissolution rate. The activation energy for the hydroboracite dissolution in hydrochloric acid was calculated as 44.9 kJ/mol, which does not permit to know the process controlling step. The activation energy for the hydroboracite dissolution in sulphuric acid was found to be 14.6 kJ/mol, which indicates that the dissolution is a diffusion controlled process.

  18. Effect of Ammonium- and Phosphonium-Based Ionic Liquids on the Separation of Lactic Acid by Supported Ionic Liquid Membranes (SILMs).

    Science.gov (United States)

    Matsumoto, Michiaki; Panigrahi, Abhishek; Murakami, Yuuki; Kondo, Kazuo

    2011-05-13

    Biodegradable polymers have attracted much attention from an environmental point of view. Optically pure lactic acid that can be prepared by fermentation is one of the important raw materials for biodegradable polymer. The separation and purification of lactic acid from the fermentation broth are the major portions of the production costs. We proposed the application of supported ionic liquid membranes to recovering lactic acid. In this paper, the effect of ionic liquids, such as Aliquat 336, CYPHOS IL-101, CYPHOS IL-102, CYPHOS IL-104, CYPHOS IL-109 and CYPHOS IL-111 on the lactic acid permeation have been studied. Aliquat 336, CYPHOS IL-101 and CYPHOS IL-102 were found to be the best membrane solvents as far as membrane stability and permeation of lactic acid are concerned. CYPHOS IL-109 and CYPHOS IL-111 were found to be unsuitable, as they leak out from the pores of the supported liquid membrane (SLM), thereby allowing free transport of lactic acid as well as hydrochloric acid. CYPHOS IL-102 was found to be the most adequate (Permeation rate = 60.41%) among these ionic liquids as far as the separation of lactic acid is concerned. The permeation mechanisms, by which ionic liquid-water complexes act as the carrier of lactate and hydrochloric acid, were proposed. The experimental permeation results have been obtained as opposed to the expected values from the solution-diffusion mechanism.

  19. Effect of Ammonium- and Phosphonium-Based Ionic Liquids on the Separation of Lactic Acid by Supported Ionic Liquid Membranes (SILMs

    Directory of Open Access Journals (Sweden)

    Kazuo Kondo

    2011-05-01

    Full Text Available Biodegradable polymers have attracted much attention from an environmental point of view. Optically pure lactic acid that can be prepared by fermentation is one of the important raw materials for biodegradable polymer. The separation and purification of lactic acid from the fermentation broth are the major portions of the production costs. We proposed the application of supported ionic liquid membranes to recovering lactic acid. In this paper, the effect of ionic liquids, such as Aliquat 336, CYPHOS IL-101, CYPHOS IL-102, CYPHOS IL-104, CYPHOS IL-109 and CYPHOS IL-111 on the lactic acid permeation have been studied. Aliquat 336, CYPHOS IL-101 and CYPHOS IL-102 were found to be the best membrane solvents as far as membrane stability and permeation of lactic acid are concerned. CYPHOS IL-109 and CYPHOS IL-111 were found to be unsuitable, as they leak out from the pores of the supported liquid membrane (SLM, thereby allowing free transport of lactic acid as well as hydrochloric acid. CYPHOS IL-102 was found to be the most adequate (Permeation rate = 60.41% among these ionic liquids as far as the separation of lactic acid is concerned. The permeation mechanisms, by which ionic liquid-water complexes act as the carrier of lactate and hydrochloric acid, were proposed. The experimental permeation results have been obtained as opposed to the expected values from the solution-diffusion mechanism.

  20. Limonene as Green Inhibitor for Steel Corrosion in Hydrochloric Acid Solutions%盐酸溶液中钢铁腐蚀的绿色缓蚀剂柠檬油精

    Institute of Scientific and Technical Information of China (English)

    CHAIEB E.; BOUYANZER A.; HAMMOUTI B.; BERRABAH M.

    2009-01-01

    The inhibition of steel corrosion in hydrochloric acid solutions by limonene, which was extracted from citrus and orange fruit, was studied using measurements of mass loss, electrochemical polarisation and electrochemical impedance spectroscopy (EIS) methods. Naturally, the substance reduced the rate of corrosion. The linearity of the cathodic curves for all concentrations indicated that the law of Tafel was followed. The effectiveness of inhibition increased with the increase in concentration of limonene and this exceeded 72% at 0.220 g. L-1. The inhibition efficiency is temperature independent in the temperature range of 298-328 K. Adsorption of the substance on the surface of steel obeys the Frumkin isotherm model.

  1. Solvent extraction separation of cerium and praseodymium from hydrochloric solution with P507%P507盐酸体系萃取分离铈和镨

    Institute of Scientific and Technical Information of China (English)

    夏洁; 任钟旗; 王运东

    2012-01-01

      为了获得高纯单一的稀土元素,利用萃取法从盐酸体系中分离铈Ce3+和镨Pr3+.以P507为萃取剂,煤油为稀释剂,正辛醇为添加剂,对CeCl3和PrCl3进行萃取实验研究,考察了料液浓度和酸度、P507浓度和皂化率对稀土金属分离的影响.结果表明, Ce3+和Pr3+的萃取率随P507浓度的增大而增大,随P507皂化率提高而先增大后减小,皂化率应该保持在50%以内,以防乳化现象;在pH为3~4时,原料液质量浓度0.5g/L,皂化率40%时,0.05mol/LP507对Ce3+和Pr3+萃取率均达到99%以上,分离因子可以达到2.28;2mol/LHCl对CeCl3和PrCl3进行反萃,反萃率均可以达到100%.%  Rare earths, provided with special physical and chemical properties, are generally used in metallurgy, petrochemical industry, various functional materials and glass ceramics. Ce3+ and Pr3+ have been separated from HCl solution by extraction to obtain single rare earth using P507 as extraction agent, kerosene as diluent, and octyl alcohol as additive. The effect of concentration and saponification ratio of P507, the pH and metal concentration of feed liquid on the separation of Ce3+ and Pr3+ were studied. The results show that the saponificated P507 has a good extraction performance for Ce3+ and Pr3+. As saponification ratio increases, the extraction efficiency of Ce3+ and Pr3+ increases and then decreases. The saponification ratio should not be higher than 50% to avoid emulsification. When the pH of feed liquid keeps between 3 and 4, the mass concentration of feed liquid is 0.5 g/L, saponification ratio is 40%, the extraction efficiency of Ce3+ and Pr3+ can achieve more than 99% and separation factor 2.28. As for stripping, both Ce3+ and Pr3+ can be totally stripped from organic phase by 2 mol/L HCl.

  2. Investigation of adsorption and inhibitive effect of acid red GRE (183 dye on the corrosion of carbon steel in hydrochloric acid media

    Directory of Open Access Journals (Sweden)

    M. Abd El-raouf

    2015-09-01

    Full Text Available The adsorption and corrosion inhibitive effect of acid red GRE (183 dye on carbon steel alloy in 1 M HCl solutions was studied using various techniques. Results of weight loss, Tafel polarization measurements and electrochemical impedance spectroscopy (EIS techniques show that this compound has fairly good inhibiting properties for steel corrosion in acidic bath; with efficiency around 96% at a concentration of 50 ppm. The inhibition is of a mixed anodic–cathodic nature. Factors affecting the corrosion process have been calculated and discussed. Acid red GRE (183 dye was shown to be an inhibitor in the acidic corrosion. Inhibition efficiency increased with acid red GRE (183 dye concentration but decreased with rise in temperature, corrosion inhibition is attributed to the adsorption of acid red GRE (183 dye on the carbon steel surface via a physical adsorption mechanism. Langmuir isotherm is found to provide an accurate description of the adsorption behavior of the investigated azo compound. The nature of the protective film was investigated using SEM and EDX techniques.

  3. Influence of several nonferrous metals in the treatment of residual liquors from hydrochloric acid pickling processes. Influencia de diversos metales no ferreos en el tratamiento de lejias residuales de decapado con acido clorhidrico

    Energy Technology Data Exchange (ETDEWEB)

    Negro, C.; Cobos, M.A.; Latorre, R.; Dufour, J.; Formoso, A.; Lopez, F.

    1994-01-01

    In the oxiprecipitation of waste liquors from siderurgical processes of pickling with hydrochloric acid, several kinds of iron oxides and oxihydroxides are obtained: alpha-FeOOH, gamma-FeOOH, Fe[sub 3]O[sub 4], gamma-Fe[sub 2]O[sub 3]. Fe[sub 2]O[sub 3].1,2H[sub 2]O, etc. These products can be used like pigments in the painting industry and like raw materials for the obtaining of ferrites. Varying the operation conditions, the presence of these products can be changed greatly, obtaining different mixtures of them. The presence of non-ferrous metals catalyzes and modifies the mechanism of the reaction, yielding pure products. This simplifies their later industrial applications. The aim of this work is to determine the influence of Cu(II), Zn(II), Mo(VI) and Al(III) on the oxiprecipitation of residual liquors from hydrochloric acid pickling processes, selecting the most favourable operation conditions at which it is possible to obtain products for industrial applications.

  4. Cell cycle profiling by image and flow cytometry: The optimised protocol for the detection of replicational activity using 5-Bromo-2′-deoxyuridine, low concentration of hydrochloric acid and exonuclease III

    Science.gov (United States)

    Konečný, Petr; Frydrych, Ivo; Koberna, Karel

    2017-01-01

    The approach for the detection of replicational activity in cells using 5-bromo-2′-deoxyuridine, a low concentration of hydrochloric acid and exonuclease III is presented in the study. The described method was optimised with the aim to provide a fast and robust tool for the detection of DNA synthesis with minimal impact on the cellular structures using image and flow cytometry. The approach is based on the introduction of breaks into the DNA by the low concentration of hydrochloric acid followed by the subsequent enzymatic extension of these breaks using exonuclease III. Our data showed that the method has only a minimal effect on the tested protein localisations and is applicable both for formaldehyde- and ethanol-fixed cells. The approach partially also preserves the fluorescence of the fluorescent proteins in the HeLa cells expressing Fluorescent Ubiquitin Cell Cycle Indicator. In the case of the short labelling pulses that disabled the use of 5-ethynyl-2′-deoxyuridine because of the low specific signal, the described method provided a bright signal enabling reliable recognition of replicating cells. The optimized protocol was also successfully tested for the detection of trifluridine, the nucleoside used as an antiviral drug and in combination with tipiracil also for the treatment of some types of cancer. PMID:28426799

  5. Cell cycle profiling by image and flow cytometry: The optimised protocol for the detection of replicational activity using 5-Bromo-2'-deoxyuridine, low concentration of hydrochloric acid and exonuclease III.

    Science.gov (United States)

    Ligasová, Anna; Konečný, Petr; Frydrych, Ivo; Koberna, Karel

    2017-01-01

    The approach for the detection of replicational activity in cells using 5-bromo-2'-deoxyuridine, a low concentration of hydrochloric acid and exonuclease III is presented in the study. The described method was optimised with the aim to provide a fast and robust tool for the detection of DNA synthesis with minimal impact on the cellular structures using image and flow cytometry. The approach is based on the introduction of breaks into the DNA by the low concentration of hydrochloric acid followed by the subsequent enzymatic extension of these breaks using exonuclease III. Our data showed that the method has only a minimal effect on the tested protein localisations and is applicable both for formaldehyde- and ethanol-fixed cells. The approach partially also preserves the fluorescence of the fluorescent proteins in the HeLa cells expressing Fluorescent Ubiquitin Cell Cycle Indicator. In the case of the short labelling pulses that disabled the use of 5-ethynyl-2'-deoxyuridine because of the low specific signal, the described method provided a bright signal enabling reliable recognition of replicating cells. The optimized protocol was also successfully tested for the detection of trifluridine, the nucleoside used as an antiviral drug and in combination with tipiracil also for the treatment of some types of cancer.

  6. Study of Temperature Effect on the Corrosion Inhibition of C38 Carbon Steel Using Amino-tris(Methylenephosphonic Acid in Hydrochloric Acid Solution

    Directory of Open Access Journals (Sweden)

    Najoua Labjar

    2011-01-01

    Full Text Available Tafel polarization method was used to assess the corrosion inhibitive and adsorption behaviours of amino-tris(methylenephosphonic acid (ATMP for C38 carbon steel in 1 M HCl solution in the temperature range from 30 to 60∘C. It was shown that the corrosion inhibition efficiency was found to increase with increase in ATMP concentration but decreased with temperature, which is suggestive of physical adsorption mechanism. The adsorption of the ATMP onto the C38 steel surface was found to follow Langmuir adsorption isotherm model. The corrosion inhibition mechanism was further corroborated by the values of kinetic and thermodynamic parameters obtained from the experimental data.

  7. Alteration of the phospho- or neutral lipid content and fatty acid composition in Listeria monocytogenes due to acid adaptation mechanisms for hydrochloric, acetic and lactic acids at pH 5.5 or benzoic acid at neutral pH.

    Science.gov (United States)

    Mastronicolis, Sofia K; Berberi, Anita; Diakogiannis, Ioannis; Petrova, Evanthia; Kiaki, Irene; Baltzi, Triantafillia; Xenikakis, Polydoros

    2010-10-01

    This study provides a first approach to observe the effects on Listeria monocytogenes of cellular exposure to acid stress at low or neutral pH, notably how phospho- or neutral lipids are involved in this mechanism, besides the fatty acid profile alteration. A thorough investigation of the composition of polar and neutral lipids from L. monocytogenes grown at pH 5.5 in presence of hydrochloric, acetic and lactic acids, or at neutral pH 7.3 in presence of benzoic acid, is described relative to cells grown in acid-free medium. The results showed that only low pH values enhance the antimicrobial activity of an acid. We suggest that, irrespective of pH, the acid adaptation response will lead to a similar alteration in fatty acid composition [decreasing the ratio of branched chain/saturated straight fatty acids of total lipids], mainly originating from the neutral lipid class of adapted cultures. Acid adaptation in L. monocytogenes was correlated with a decrease in total lipid phosphorus and, with the exception of cells adapted to benzoic acid, this change in the amount of phosphorus reflected a higher content of the neutral lipid class. Upon acetic or benzoic acid stress the lipid phosphorus proportion was analysed in the main phospholipids present: cardiolipin, phosphatidylglycerol, phosphoaminolipid and phosphatidylinositol. Interestingly only benzoic acid had a dramatic effect on the relative quantities of these four phospholipids.

  8. Comparative study on solubilities of bismuth, bismuth oxide,and bismuth sulfide in hydrochloric acid-thiourea%铋、氧化铋、硫化铋在盐酸-硫脲中溶解性的比较研究

    Institute of Scientific and Technical Information of China (English)

    马哈亚·艾斯江; 巴哈尔古丽·别克吐尔逊

    2012-01-01

    在盐酸介质中及55℃加热条件下,铋与硫脲形成黄色络合物,从而建立了用分光光度法比较铋、氧化铋、硫化铋在盐酸-硫脲中溶解性的新方法.研究了反应介质、试剂浓度、加热时间、加热温度、震荡速率等因素的影响.在最佳实验条件下,溶液的质量浓度为0.04~0.24 mg/mL时符合比尔定律.相关系数R=0.999 9,检出限为1.05×10-2 μg/mL,标准偏差SD=0.003 5,相对标准偏差RSD=2.42%,摩尔吸收系数为1.515×105 L/(mol·cm),加标回收率为96.7%~98.8%.实验结果表明,铋、氧化铋、硫化铋的溶解性顺序大小为:铋>氧化铋>硫化铋.%A yellow complex is formed from bismuth and thiourea in hydrochloric acid under the heated condition of 55 °C. Thus a new method is set up to compare the solubilities of bismuth, bismuth oxide, and bismuth sulfide in hydrochloric acid-thiourea by using spectrophotometry.Effects of factors, such as reaction medium, reagent concentration, heating time, heating temperature, and oscillation speed,were studied respectively .Under the optimum experimental conditions, mass concentration of the solution is in line with Beer's law, when it is within the range of 0.04-0.24 mg/mL.The correlation coefficient (R) is 0.999 9.The detection limit is 1.05xl0-2μg/mL.The standard deviation is 0.003 5.The relative standard deviation (RSD) is 2.42%.The molar absorption coefficient is 1.515xl05 L/(mol-cm).The recovery rate of standard addition is at 96.7%~98.8%. Experimental result showed that the solubilities of bismuth,bismuth oxide,and bismuth sulfide in hydrochloric acid-thiourea is in order by size as following: Bi>Bi2O3>Bi2S3.

  9. Amino Acid Contents of Meteorite Mineral Separates

    Science.gov (United States)

    Berger, E. L.; Burton, A. S; Locke, D.

    2017-01-01

    Indigenous amino acids have been found indigenous all 8 carbonaceous chondrite groups. However, the abundances, structural, enantiomeric and isotopic compositions of amino acids differ significantly among meteorites of different groups and petrologic types. This suggests that parent-body conditions (thermal or aqueous alteration), mineralogy, and the preservation of amino acids are linked. Previously, elucidating specific relationships between amino acids and mineralogy was not possible because the samples analyzed for amino acids were much larger than the scale at which petrologic heterogeneity is observed (sub mm-scale differences corresponding to sub-mg samples). Recent advances in amino acid measurements and application of techniques such as high resolution X-ray diffraction (HR-XRD) and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) for mineralogical characterizations allow us to perform coordinated analyses on the scale at which mineral heterogeneity is observed.

  10. Characteristics of the Carbon Nanotube Coated with Polyaniline Doped with Hydrochloric Acid and Dodecylbenzene Sulfonic Acid%盐酸与DBSA共掺杂聚苯胺修饰碳纳米管性能的研究

    Institute of Scientific and Technical Information of China (English)

    张爱波; 刘刚; 薛艳丽; 郑亚萍; 赵纯颖

    2011-01-01

    The MWNTs/polyaniline composites were prepared via in-situ emulsion polymerization using hydrochloric acid and dodecylbenzene sulfonic acid as dopants. The FTIR spectra, TEM and TGA were used to characterize the morphology and performance of the composites. The TEM results show that the surface of MWNTs are coated by polyaniline composites and the thickness of the coating layer is 10~20nm. The solubility is increased in DMF, THF and chloroform. The thermal stability of the composite is highly improved at 520~750℃ and the encapsulation rate is 15.16%. The conductivity of the sample is increased from 10-7S/cm to 10-3S/cm.%采用原位乳液聚合法制备了盐酸与十二烷基苯磺酸(DBSA)共掺杂聚苯胺/MWNTs复合材料.利用FTIR、TEM和TG等对复合材料的形貌和性能进行了表征.TEM结果表明苯胺共聚物包覆于碳纳米管表面,包覆厚度为10~20nm.复合材料在DMF、THF和氯仿中的溶解性大幅度提高,在520~750℃的热稳定性明显提高,包覆率为15.16%,电导率从聚苯胺的10-7A/cm增大到10-3S/cm.

  11. Application of Stabilized Silver Nanoparticles as Thin Films as Corrosion Inhibitors for Carbon Steel Alloy in 1 M Hydrochloric Acid

    Directory of Open Access Journals (Sweden)

    Ayman M. Atta

    2013-01-01

    Full Text Available Nanometer scaled materials have attracted tremendous interest as corrosion protective films due to their high ability to form self-assembled films on the metal surfaces. It is well known that the silver nanoparticles have higher reactivity towards aqueous acidic solution. The present work aims to prepare coated silver nanoparticles to protect carbon steel alloys from aqueous acidic corrosive media. In this respect, Ag nanoparticles colloid solutions were produced through reducing AgNO3 separately with trisodium citrate in an aqueous solution or in the presence of stabilizer such as poly(ethylene glycol thiol and poly(vinyl pyrrolidone. The morphology of the modified silver nanoparticles was investigated by TEM and DLS. UV-Vis absorption spectrum was used to study the effect of HCl on the stability of the dispersed silver nanoparticles. The corrosion inhibition efficiency of the poly (ethylene glycolthiol, the self-assembled monolayers of Ag nanoparticles, was determined by polarization method and electrochemical impedance spectroscopy (EIS. Polarization curves indicated that the coated silver poly (ethylene glycolthiol acted as a mixed type inhibitor. The data of inhibition efficiencies obtained measured by polarization measurements are in good agreement with those obtained with electrochemical impedance.

  12. Separation and determination of some carboxylic acids by capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Sladkov, V.; Fourest, B

    2006-07-01

    Separation and determination of some organic acids, mono-carboxylic (formic and acetic), dicarboxylic (oxalic and tartaric), tricarboxylic (citric) acids and aromatic acids (phtalic, benzoic, mellitic and trimellitic), by capillary electrophoresis are reviewed. The method development parameters, such as separation and injection mode, are discussed. Special attention is paid to the comparison of different detection types (spectroscopic and electrochemical). The optimisation of the carrier electrolyte composition (choice of carrier electrolyte, effect of pH, ionic strength, electro-osmotic flow modifier) is treated. Different additives (alkali-earth and transition metal ions, cyclodextrins and alcohol), which are often used for improving organic acid separation, are also considered. (authors)

  13. 氯化法回收废钯-氧化铝催化剂中的钯%Recovery of Palladium from Spent Pd-Al2O3 Catalyst by Hydrochloric Acid Leaching

    Institute of Scientific and Technical Information of China (English)

    李骞; 胡龙; 饶雪飞; 悟永斌; 徐斌; 姜涛

    2015-01-01

    惣悦化铝为载体的某含钯废催化剂为原料,采用恿酸介质中添加悦化助浸剂的方案对钯恒择性浸出,并考察了焙烧,还原,浸出过程的适惚工惤条件。结果表明,钯的回收率可惣达到98%惣上。%Palladium was recovered from spent alumina-supported catalyst by the process of selective leaching using hydrochloric acid with an oxidant. The optimized conditions of roasting, reduction, leaching processes were also investigated. The results showed that the palladium recovery ratio was over 98% in the optimum condition.

  14. Experimental Investigation and Characterization of Fe and Al from Red Mud by Hydrochloric Acid%赤泥酸浸出铁、铝的工艺条件研究及其表征

    Institute of Scientific and Technical Information of China (English)

    吴烈善; 苏翠翠; 吕宏虹; 曾冬梅; 莫小荣

    2014-01-01

    The systematic study of leaching red mud with hydrochloric acid is carried out .The microstructure and phase transformation of red mud is analyzed by means of SEM and XRD .The experiment results show that the leaching ratios of Fe and Al are 82% and 30 .5% respectively under the condition that reaction temperature 80℃ ,liquid to solid ratio 6 ,hy-drochloric acid concentration 7mol/L and reaction time 3h .Microstructure of red mud is transformed from granular into layer frame shape after been leached by HCl .The hematite in red mud has been totally leached by HCl .%对广西某铝厂的赤泥进行了盐酸浸出铁、铝的工艺条件研究,并利用扫描电镜和X-衍射对赤泥酸溶前后的形貌特征及矿物物像、化学成分进行分析表征,研究结果表明,赤泥在温度为80℃、液固比为6、浓度为7 mol/L的盐酸中反应3 h ,Fe和Al的浸出率分别为82%和30.5%;酸溶前后赤泥形貌由团粒状转变为层架状,赤泥中赤铁矿矿物相被盐酸充分溶出。

  15. Synthesis of imidazoline-based dissymmetric bis-quaternary ammonium gemini surfactant and its inhibition mechanism on Q235 steel in hydrochloric acid medium

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J.; Gong, X.L.; Song, W.W.; Jiang, B.; Du, M. [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao, Shandong Province (China)

    2012-07-15

    An imidazoline-based dissymmetric bis-quaternary ammonium gemini surfactant has been synthesized. Its surface active properties at equilibrium in water at 25 C were determined. The inhibitive effect of the compound on Q235 steel in 1 M hydrochloric solution was investigated by the weight-loss method, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) analysis, and quantum chemical calculations. The results indicate that the compound has high surface properties and the inhibition efficiency (IE) increases with the increase in inhibitor concentration, which attain the maximum value around the CMC value. The imidazoline-based dissymmetric bis-quaternary ammonium acts as a mixed type inhibitor mainly inhibiting the cathodic processes and does not change the mechanism of either hydrogen evolution reaction or mild steel dissolution. The best IE is obtained at the immersion time of 144 h. The adsorption of the studied inhibitor on Q235 steel can be fitted to a Langmuir isotherm and the adsorption process is a spontaneous chemical adsorption. Quantum chemistry calculation results show that the imidazoline ring and heteroatoms of N, O, are the active sites of the inhibitors. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Separation of Aminobenzoic Acids by Gold Nanoparticle modified Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    YAN,Hongtao; LI,Tuo; GUO,Yanli

    2009-01-01

    A novel method for the separation of aminobenzoic acids by capillary electrophoresis was developed.The capillary was modified with gold nanoparticles.The effect of gold nanoparticles on the resolution and selectivity of separation was investigated.The influence of separation voltage,pH and buffer concentration on the separation of aminobenzoic acids was also examined.It was found that the presence of gold nanoparticles improved the precision of the analysis and increased the separation efficiency.Under the optimized experiment conditions,aminobenzoic acids were separated and determined.Linearity was established over the concentration range 0.5-40 μg·mL-1 with correlation coefficients of 0.9978-0.9992.The detection limits (S/N = 3) were from 0.1 to 0.5 μg·mL-1.

  17. Separation of ions in acidic solution by capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Thornton, M.

    1997-10-08

    Capillary electrophoresis (CE) is an effective method for separating ionic species according to differences in their electrophoretic mobilities. CE separations of amino acids by direct detection are difficult due to their similar electrophoretic mobilities and low absorbances. However, native amino acids can be separated by CE as cations at a low pH by adding an alkanesulfonic acid to the electrolyte carrier which imparts selectivity to the system. Derivatization is unnecessary when direct UV detection is used at 185 nm. Simultaneous speciation of metal cations such as vanadium (IV) and vanadium (V) can easily be performed without complexation prior to analysis. An indirect UV detection scheme for acidic conditions was also developed using guanidine as the background carrier electrolyte (BCE) for the indirect detection of metal cations. Three chapters have been removed for separate processing. This report contains introductory material, references, and general conclusions. 80 refs.

  18. 基于差分吸收激光雷达的一种新的对流层臭氧浓度反演算法%Butanol Extraction Combined with Dilute Hydrochloric Acid Dissolution-Atomic Fluorescence Spectrometric Method for Indirect Determination of Molybdenum in Chinese Herbal Medicine

    Institute of Scientific and Technical Information of China (English)

    范广强; 刘建国; 刘文清; 陆亦怀; 张天舒; 董云升; 赵雪松

    2012-01-01

    A method for indirectly determining the molybdenum in Chinese herbal medicine by butanol extraction and dilute hydrochloric acid dissolution was established for atomic fluorescence spectrometry. The molybdoarsenate heteropoly acid, formed in the presence of As( V) and ammonium molybdate in 0. 3 mol · L-1 sulphuric acid medium, was separated and enriched in the organic solvent, then the evaporation of organic reagent was implemented and the left residue was dissolved in dilute hydrochloric acid in which the arsenic content was determined on behalf of molybdenum. In the optimum experimental conditions, molybdenum content in 0~15 μg · L-1 range depicts a good linear relationship, the detection limit and relative standard deviation of 0. 44 μg · L-1 and 1.1% were obtained, respectively. Spiked Chinese herbal medicine samples were determined with the proposed method, and recoveries of 95. 6%—101. 3% were achieved.%差分吸收激光雷达探测对流层臭氧浓度时,气溶胶的干扰会造成较大的误差.提出了一种算法,该算法能够同时反演得到对流层臭氧浓度和气溶胶消光系数,减少气溶胶对反演结果的影响.使用实验数据,分析计算了气溶胶雷达比,气溶胶波长指数、标定点气溶胶后向散射比各种变化参数对反演结果的误差.结果表明,1km以下,各种变化参数造成的反演误差小于8%,1km以上臭氧浓度误差主要来源于信号和背景噪声,各种参数反演误差小于3%.最后给出了利用该算法得到对流层臭氧浓度和气溶胶的消光系数垂直廓线,并和传统的双波长差分算法反演结果作了比较分析.实验结果表明该算法是可行的,该算法可以减少气溶胶对差分吸收激光雷达测量结果引起的误差.

  19. Process for Separation of Petroleum Acids from Crude Oil

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A new technique for separation of petroleum acids from crude oil was proposed. The method relates to processes for treating acidic oils or fractions thereof to reduce or eliminate their acidity by addition of effective amounts of crosslinked polymeric amines such as polypropylene amine and anionic exchange resins having amino-groups. Petroleum acids contained in the mixture can be extracted by a complex solvent. The results indicate that more than 80 % of the petroleum acids are removed and the process does not cause environmental pollution because all the solvents are recovered and reused in the test.

  20. Interference effects from coexisting fatty acids on elaidic acid separation by fractionating crystallization: A model study

    DEFF Research Database (Denmark)

    Jala, Ram Chandra Reddy; Guo, Zheng; Bjerring, Thomas;

    2010-01-01

    A multi-stage temperature-programmed fractionating crystallization process was carried out to examine the effects of the presence of stearic acid (SA), oleic acid (OA), and linoleic acid (LA) on the separation of elaidic acid (EA). The results showed that the efficiency of fractionating crystalli......A multi-stage temperature-programmed fractionating crystallization process was carried out to examine the effects of the presence of stearic acid (SA), oleic acid (OA), and linoleic acid (LA) on the separation of elaidic acid (EA). The results showed that the efficiency of fractionating...

  1. Analysis of twenty phenolic compounds in human urine: hydrochloric acid hydrolysis, solid-phase extraction based on K2CO 3-treated silica, and gas chromatography tandem mass spectrometry.

    Science.gov (United States)

    Lu, Dasheng; Feng, Chao; Wang, Dongli; Lin, Yuanjie; Ip, Ho Sai Simon; She, Jianwen; Xu, Qian; Wu, Chunhua; Wang, Guoquan; Zhou, Zhijun

    2015-05-01

    This study developed a new method for the analysis of 20 phenolic compounds in human urine. The urine samples were prepared by hydrochloric acid (HCl) hydrolysis, liquid-liquid extraction (LLE), and solid-phase extraction (SPE) cleanup. We found that HCl hydrolysis is of similar effectiveness to, and much cheaper than, the traditional enzymatic method. Vanillic acid was co-eluted with butyl paraben and interfered with the determination of butyl paraben in urine. K2CO3-treated-silica-gel SPE was designed to efficiently eliminate interference from the endogenous organic acids (especially vanillic acid) in urine. After derivatization, the samples were analyzed by large-volume-injection gas chromatography-tandem mass spectrometry (LVI-GC-MS-MS). Good linearity (R (2) ≥ 0.996) was established in the range 0.1-100 ng mL(-1) for all analytes. Method detection limits (MDLs) were 0.7-9.8 pg mL(-1). Intraday (n = 5) and interday (n = 5 days) validation was performed, with satisfactory accuracy (recovery: 70-126 % and 73-107 %, respectively) and precision (RSD ≤ 19 %) at two levels (low: 0.1 and 0.5 ng mL(-1); high: 5 and 10 ng mL(-1)). The method was used in a population study and achieved more than 85 % detection for most analytes; mean analyte concentrations were in the range 0.01-185 ng mL(-1). The method is suitable for the analysis of multiple phenolic metabolites in human urine.

  2. Analytical correlation between varying corrosion parameters and corrosion rate of Al-4.5Cu/10%ZrSiO{sub 4} composite in hydrochloric acid by rare earth chloride

    Energy Technology Data Exchange (ETDEWEB)

    Oloche, O.B.; Yaro, S.A. [Department of Metallurgical Engineering Ahmadu Bello University, Zaria (Nigeria); Okafor, E.G. [Department of Metallurgical Engineering Ahmadu Bello University, Zaria (Nigeria)], E-mail: ekeneokafor@yahoo.com

    2009-03-20

    The effect of varying temperature, time and inhibitor concentration on the corrosion rate of Al-4.5Cu/ZrSiO{sub 4} composite in 0.5 M hydrochloric acid without and with lanthanide chloride salt have been investigated. 10%ZrSiO{sub 4} was used for the production of the Al-4.5Cu/zircon sand composite. The time, temperature and concentration of inhibitor were varied in the range of 6-10 h at 2 h interval, 30-75 deg. C at 15 deg. C interval and 250-1000 ppm at 250 ppm interval respectively. Factorial design, standard deviation, effect of variables at 95% confidence interval and Arrhenius kinetics approach were used to correlate the corrosion parameter and corrosion rate. Results show that increase in temperature, inhibitor concentration above 250 ppm and decrease in time enhance corrosion rate. Also, temperature and anti-corrosion agent concentration are the most important control parameters. The kinetic and statistical approaches were in good agreement.

  3. Effect of f-electron configurations on the adsorption of trivalent f-elements on tertiary pyridine resin in hydrochloric acid/alcohol mixed solvents

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Atsushi; Suzuki, Tatsuya; Aida, Masao; Ohtake, Kouhei; Fujii, Yasuhiko; Itoh, Keisuke; Hara, Mitsuo; Mitsugashira, Toshiaki

    2004-07-14

    The separation of trivalent actinides (An) from lanthanides (Ln) is difficult because of their chemical similarities although it is necessary for various fields such as nuclear fuel-cycle process. In the present study, it was observed that the trivalent An (Am{sup 3+}, Cm{sup 3+} and Cf{sup 3+}) were adsorbed on tertiary pyridine type resins far more strongly than the Ln in HCl (LiCl solution)/methanol mixed solvents and the An were separated from the Ln by using a single separation process. On the other hand, the Dowex 1 x 8 showed no adsorption in the same conditions. Therefore, there is a possibility that the adsorption of An and Ln cations is caused by the complexation of the cations with the tertiary pyridine groups of the resins, not by the ionic interaction. There seems to be some relationship between the distribution coefficients (K{sub d}) of trivalent f-elements (i.e. An and Ln) and the f-electron configurations of their cations, and their ionic size.

  4. Synthesis and characterization of a novel eco-friendly corrosion inhibition for mild steel in 1 M hydrochloric acid

    Science.gov (United States)

    Al-Amiery, Ahmed A.; Binti Kassim, Fatin A.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar

    2016-01-01

    The acid corrosion inhibition process of mild steel in 1 M HCl by azelaic acid dihydrazide has been investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, open circuit potential (OCP) and electrochemical frequency modulation (EFM). Azelaic acid dihydrazide was synthesized, and its chemical structure was elucidated and confirmed using spectroscopic techniques (infrared, nuclear magnetic resonance and mass spectroscopy). Potentiodynamic polarization studies indicate that azelaic acid dihydrazide is a mixed-type inhibitor. The inhibition efficiency increases with increased inhibitor concentration and reaches its maximum of 93% at 5 × 10−3 M. The adsorption of the inhibitor on a mild steel surface obeys Langmuir’s adsorption isotherm. The effect of temperature on corrosion behavior in the presence of 5 × 10−3 M inhibitor was studied in the temperature range of 30–60 °C. The results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. To inspect the surface morphology of inhibitor film on the mild steel surface, scanning electron microscopy (SEM) was used before and after immersion in 1.0 M HCl. PMID:26795066

  5. Synthesis and characterization of a novel eco-friendly corrosion inhibition for mild steel in 1 M hydrochloric acid

    Science.gov (United States)

    Al-Amiery, Ahmed A.; Binti Kassim, Fatin A.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar

    2016-01-01

    The acid corrosion inhibition process of mild steel in 1 M HCl by azelaic acid dihydrazide has been investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, open circuit potential (OCP) and electrochemical frequency modulation (EFM). Azelaic acid dihydrazide was synthesized, and its chemical structure was elucidated and confirmed using spectroscopic techniques (infrared, nuclear magnetic resonance and mass spectroscopy). Potentiodynamic polarization studies indicate that azelaic acid dihydrazide is a mixed-type inhibitor. The inhibition efficiency increases with increased inhibitor concentration and reaches its maximum of 93% at 5 × 10-3 M. The adsorption of the inhibitor on a mild steel surface obeys Langmuir’s adsorption isotherm. The effect of temperature on corrosion behavior in the presence of 5 × 10-3 M inhibitor was studied in the temperature range of 30-60 °C. The results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. To inspect the surface morphology of inhibitor film on the mild steel surface, scanning electron microscopy (SEM) was used before and after immersion in 1.0 M HCl.

  6. Separation Characteristics of Succinic Acid in Reactive Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Yeon Ki; Hong, Won Hi [Department of Chemical Engineering, Korea Advanced Institute of Science Technology, Taejeon (Korea)

    2000-04-01

    Succinic acid has recently been drawing much interest as a raw material for biodegradable polymer. In this study succinic acid was separated by reactive extraction with tertiary amines dissolved in various diluents. Distribution coefficients were determined as the function of TPA(tripropylamine) concentrations, diluents, and chain length of tertiary amines. The extraction capacity increased with the polarity of diluents, the concentration of TPA in organic phase and the chain length of amines. Furthermore, the coextracted water into the organic phase enhanced the solubility of succinic acid into organic phase. 12 refs., 8 figs., 2 tabs.

  7. POLONIUM SEPARATION PROCESS

    Science.gov (United States)

    Karraker, D.G.

    1959-07-14

    A liquid-liquid extraction process is presented for the recovery of polonium from lead and bismuth. According to the invention an acidic aqueous chloride phase containing the polonium, lead, and bismuth values is contacted with a tributyl phosphate ether phase. The polonium preferentially enters the organic phase which is then separated and washed with an aqueous hydrochloric solution to remove any lead or bismuth which may also have been extracted. The now highly purified polonium in the organic phase may be transferred to an aqueous solution by extraction with aqueous nitric acid.

  8. The Formation of Mathematical Model for CaCl2 Derived from The Reaction of Ulexite and Hydrochloric Acid by Using Full Factorial Desing Method

    OpenAIRE

    DURAK, Halil; GENEL, Yasar; BASHIROV, Novruz; KERIMOV, Genber

    2011-01-01

    One of the significant boron compounds which are common substance in nature is ulexite. Ulexite is a sodium calcium boron hydrate, its chemical formula is Na2O2CaO5B2O316H2O , and it is thick with in Turkey. Lots of products are derived from boron minerals. One of them is boric acid. CaCl2 is used in many fields and this compound can be obtained by different processes. The aim of this study is producing CaCl2 by forming mathematical model for CaCl2 composing in the wake of the interaction of ...

  9. The Formation of Mathematical Model for CaCl2 Derived from The Reaction of Ulexite and Hydrochloric Acid by Using Full Factorial Desing Method

    OpenAIRE

    DURAK, Halil; GENEL, Yasar; BASHIROV, Novruz; KERIMOV, Genber

    2013-01-01

    One of the significant boron compounds which are common substance in nature is ulexite. Ulexite is a sodium calcium boron hydrate, its chemical formula is Na2O2CaO5B2O316H2O , and it is thick with in Turkey. Lots of products are derived from boron minerals. One of them is boric acid. CaCl2 is used in many fields and this compound can be obtained by different processes. The aim of this study is producing CaCl2 by forming mathematical model for CaCl2 composing in the wake of the interaction of ...

  10. Electrochemical, quantum chemical and SEM investigation of the inhibiting effect and mechanism of ciprofloxacin, norfloxacin and ofloxacin on the corrosion for mild steel in hydrochloric acid

    Institute of Scientific and Technical Information of China (English)

    PANG XueHui; GUO Wenduan; LI WeiHua; XIE dianDong; HOU BaoRong

    2008-01-01

    The inhibiting effect and mechanism of 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylicacid(ciprofloxacin), 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylic acid (norfloxacin) and (-)-(S)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7oxo-7 H-pyrido(1,2,3-de)-1,4-benzoxazine-6 carboxylic acid (ofloxacin) on the corrosion of mild steel in 1 mol/L HCl have been studied using electrochemical method, quantum chemical method and SEM at 303 K. The potentiodynamic results showed that these compounds suppressed both cathodic and anodic processes of mild steel corrosion in 1 mol/L HCl. The impedance spectroscopy showed that Rp values increased, and Cdl values decreased with the rising of the working concentration. Quantum chemical calculation showed that there was a positive correlation between some inhibitors structure properties and the inhibitory efficiency. The inhibitors function through adsorption followed Langmuir isotherm, and chemisorption made more contribution to the adsorption of the inhibitors on the steel surface compared with physical adsorption. SEM analysis suggested that the metal had been protected from aggressive corrosion because of the addition of the inhibitors.

  11. Electrochemical, quantum chemical and SEM investigation of the inhibiting effect and mechanism of ciprofloxacin, norfloxacin and ofloxacin on the corrosion for mild steel in hydrochloric acid

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The inhibiting effect and mechanism of 1-cyclopropyl-6-fluoro-1,4-dihydro -4-oxo-7-(1-piperazinyl) -3- quinoline carboxylicacid(ciprofloxacin), 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylic acid (norfloxacin) and (?)-(S)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7- oxo-7 H-pyrido(1,2,3-de)-1,4- benzoxazine-6 carboxylic acid (ofloxacin) on the corrosion of mild steel in 1 mol/L HCl have been studied using electrochemical method, quantum chemical method and SEM at 303 K. The potentiodynamic results showed that these compounds suppressed both cathodic and an-odic processes of mild steel corrosion in 1 mol/L HCl. The impedance spectroscopy showed that Rp values increased, and Cdl values decreased with the rising of the working concentration. Quantum chemical calculation showed that there was a positive correlation between some inhibitors structure properties and the inhibitory efficiency. The inhibitors function through adsorption followed Langmuir isotherm, and chemisorption made more contribution to the adsorption of the inhibitors on the steel surface compared with physical adsorption. SEM analysis suggested that the metal had been protected from aggressive corrosion because of the addition of the inhibitors.

  12. The water soluble composite poly(vinylpyrrolidone–methylaniline: A new class of corrosion inhibitors of mild steel in hydrochloric acid media

    Directory of Open Access Journals (Sweden)

    R. Karthikaiselvi

    2017-02-01

    Full Text Available In recent years poly methyl aniline has been reported as one of the efficient corrosion inhibitors of mild steel in acidic media. In view of the major limitation of the insolubility of polymethyl aniline PMA, we propose to convert PMA into a water soluble composite using supporting polymer polyvinylpyrrolidone to get higher solubility and corrosion inhibition efficiency. The water soluble composite poly(vinylpyrrolidone-methyl aniline was synthesized by chemical oxidative polymerization and its inhibitive effect on mild steel in 1 M HCl has been investigated using weight loss and electrochemical techniques (potentiodynamic polarization studies and impedance spectroscopy. SEM and EDX analyses are carried out to establish a protective film formation on the metal surface.

  13. Inhibition Effects of a Synthesized Novel 4-Aminoantipyrine Derivative on the Corrosion of Mild Steel in Hydrochloric Acid Solution together with Quantum Chemical Studies

    Directory of Open Access Journals (Sweden)

    Abu Bakar Mohamad

    2013-06-01

    Full Text Available 1,5-Dimethyl-4-((2-methylbenzylideneamino-2-phenyl-1H-pyrazol-3(2H-one (DMPO was synthesized to be evaluated as a corrosion inhibitor. The corrosion inhibitory effects of DMPO on mild steel in 1.0 M HCl were investigated using electrochemical impedance spectroscopy (EIS, potentiodynamic polarization, open circuit potential (OCP and electrochemical frequency modulation (EFM. The results showed that DMPO inhibited mild steel corrosion in acid solution and indicated that the inhibition efficiency increased with increasing inhibitor concentration. Changes in the impedance parameters suggested an adsorption of DMPO onto the mild steel surface, leading to the formation of protective films. The novel synthesized corrosion inhibitor was characterized using UV-Vis, FT-IR and NMR spectral analyses. Electronic properties such as highest occupied molecular orbital energy, lowest unoccupied molecular orbital energy (EHOMO and ELUMO, respectively and dipole moment (μ were calculated and discussed. The results showed that the corrosion inhibition efficiency increased with an increase in the EHOMO values but with a decrease in the ELUMO value.

  14. A Comparative Study of the Inhibitory Effect of Gum Exudates from Khaya senegalensis and Albizia ferruginea on the Corrosion of Mild Steel in Hydrochloric Acid Medium

    Directory of Open Access Journals (Sweden)

    Paul Ocheje Ameh

    2015-01-01

    Full Text Available A comparative study of the inhibitory potentials of gum exudates from Albizia ferruginea (AF and Khaya senegalensis (KS on the corrosion of mild steel in HCl medium was investigated using weight loss and gasometric method. The active chemical constituents of the gum were elucidated using GC-MS while FTIR was used to identify the bonds/functional groups in the gums. The two gum exudates were found to be good corrosion inhibitors for mild steel in acidic medium. On comparison, maximum inhibition efficiency was found in Khaya senegalensis with 82.56% inhibition efficiency at 0.5% g/L concentration of the gum. This may be due to the fact that more compounds with heteroatoms were identified in the GCMS spectrum of KS gum compared to the AF gum. The presence of such compounds may have enhanced their adsorption on the metal surface and thereby blocking the surface and protecting the metal from corrosion. The adsorption of the inhibitors was found to be exothermic and spontaneous and fitted the Langmuir adsorption model.

  15. Inhibition effects of a synthesized novel 4-aminoantipyrine derivative on the corrosion of mild steel in hydrochloric acid solution together with quantum chemical studies.

    Science.gov (United States)

    Junaedi, Sutiana; Al-Amiery, Ahmed A; Kadihum, Abdulhadi; Kadhum, Abdul Amir H; Mohamad, Abu Bakar

    2013-06-04

    1,5-Dimethyl-4-((2-methylbenzylidene)amino)-2-phenyl-1H-pyrazol-3(2H)-one (DMPO) was synthesized to be evaluated as a corrosion inhibitor. The corrosion inhibitory effects of DMPO on mild steel in 1.0 M HCl were investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, open circuit potential (OCP) and electrochemical frequency modulation (EFM). The results showed that DMPO inhibited mild steel corrosion in acid solution and indicated that the inhibition efficiency increased with increasing inhibitor concentration. Changes in the impedance parameters suggested an adsorption of DMPO onto the mild steel surface, leading to the formation of protective films. The novel synthesized corrosion inhibitor was characterized using UV-Vis, FT-IR and NMR spectral analyses. Electronic properties such as highest occupied molecular orbital energy, lowest unoccupied molecular orbital energy (EHOMO and ELUMO, respectively) and dipole moment (μ) were calculated and discussed. The results showed that the corrosion inhibition efficiency increased with an increase in the EHOMO values but with a decrease in the ELUMO value.

  16. Effects from pretreatment of stannous fluoride versus sodium fluoride on enamel exposed to 0.1 M or 0.01 M hydrochloric acid.

    Science.gov (United States)

    Willumsen, Tiril; Ogaard, Bjørn; Hansen, Bjørn Frode; Rølla, Gunnar

    2004-10-01

    Preventing enamel erosions caused by acidic soft drinks or from vomiting during eating disorders is a challenge in current dental research. The aim of this study was to examine whether pretreatment of dental enamel with a solution of 0.4% SnF2 could prevent dissolution of human enamel exposed to solutions of 0.1 M HCl, pH 1.2 or 0.01 M HCl at pH 2.2. Human enamel was pretreated for 18 h with a solution of 0.4% SnF2 and with control solutions of 2% NaF or distilled water, and then exposed to HCl solutions. Similar experiments were performed with teeth treated for 2 min SnF2 and then 4 min HCl. The effect was monitored by scanning electron microscopy (SEM) and by chemical analysis. At pH 2.2, NaF and water treatments showed minor inhibition of enamel dissolution, whereas SnF2 inhibited demineralization significantly also after 2 min pretreatment and 4 min HCl exposure. At pH 1.2, SEM showed severe dissolution of the enamel surfaces regardless of pretreatment. As pH of stomach vomit is usually > 1.5, SnF2 may be an interesting agent for use in the treatment and prevention of dental erosions even in patients with frequent vomiting episodes.

  17. Synergistic inhibition effect of L-phenylalanine and rare earth Ce(IV) ion on the corrosion of copper in hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Daquan, E-mail: zhangdaquan@shiep.edu.cn [Department of Environmental Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Wu Huan; Gao Lixin [Department of Environmental Engineering, Shanghai University of Electric Power, Shanghai 200090 (China)

    2012-04-16

    Highlights: Black-Right-Pointing-Pointer Synergistic effect of L-phenylalanine (L-Phe) and Ce(SO{sub 4}){sub 2} on the corrosion of copper on the corrosion inhibition of copper in 0.5 M HCl solution. Black-Right-Pointing-Pointer Structure of the complex film formed by the interaction of L-phenylalanine (L-Phe) and Ce(SO{sub 4}){sub 2} on the copper surface. Black-Right-Pointing-Pointer Mechanism of the improvement of the inhibition property of amino acids by the addition of rare earth compound. - Abstract: The synergistic inhibition effect of L-phenylalanine (L-Phe) and Ce(SO{sub 4}){sub 2} on the corrosion of copper in 0.5 M HCl solution was investigated by weight-loss, electrochemical methods and surface analysis. The electrochemical results showed that L-Phe has definite inhibition effects for copper, while Ce(IV) promoted the anodic process of copper corrosion. The combination L-Phe with Ce(IV) ion produced strong synergistic effect on corrosion inhibition for copper. The maximum inhibition efficiency was 82.7% for 5 mM L-Phe + 2 mM Ce(IV). The results of EIS and potentiodynamic polarization are in good agreement. SEM showed that L-Phe and Ce(IV) can form a dense protective film on the copper surface.

  18. Effects of citric acid on separation of sillimanite from quartz

    Institute of Scientific and Technical Information of China (English)

    李晔; 雷东升; 鲁巍; 许时

    2002-01-01

    Quartz is the main gangue mineral of sillimanite. The results show that Al3+ and Fe3+ ion can activate the floatation of quartz and make the separation of quartz and sillimanite difficult when anion collector is used, and citric acid can inhibit the quartz activated by metallic ion and have slight influence on the sillimanite. X-ray photoelectronic energy spectrum analysis indicates that there are obvious electronic energy peaks on the surface of the quartz before citric acid is added into the ore pulp in presence of Al3+ and Fe3+, and after citric acid is added, the energy peak vanished. So citric acid can make Al3+ and Fe3+ on the surface of quartz solve and decrease the active points on the surface of quartz which can adsorb anion collector.

  19. 304 Cu抗菌不锈钢盐酸基酸洗工艺的研究%Research on hydrochloric acid-based pickling process of 304Cu antibacterial stainless steel

    Institute of Scientific and Technical Information of China (English)

    王冬; 邹德宁; 韩英; 薛清连

    2016-01-01

    为了明确盐酸基酸洗液对含Cu抗菌不锈钢表面氧化层的酸洗行为,采用正交试验法研究以盐酸为基础,Fe3+、H2 O2和HNO3为氧化剂的304Cu抗菌不锈钢酸洗工艺.并运用扫描电镜、透射电镜及电化学等手段分析经最佳配方酸洗后试样的表面形貌、成分及酸洗机理.结果表明:最佳酸洗工艺配方为HCl (36%~38%)120 ml/L、H2O2(30%)80 ml/L、FeCl3·6H2 O 20g/L、HNO310 ml/L,酸洗温度30℃,酸洗时间15 min.经该配方酸洗后材料表面平整度和光亮度较好,具有抗菌性能的点状ε-Cu相在基体上弥散分布.材料经酸洗去除氧化层后,仍具有足够含量的抗菌元素Cu存在.酸洗脱除氧化层过程由电荷传递过程控制,该酸洗液对不锈钢具有孔蚀诱导性,酸洗时间不宜过长.%In order to clarify pickling process of hydrochloric acid lotion against Cu⁃contained surface oxide layer of antibacterial stainless steel, the pickling process of 304Cu antibacterial stainless steel by using Fe3+, H2 O2 and HNO3 as the oxidants and taking hydrochloric acid as basis was studied by orthogonal experiment. And the surface morphology, composition and pickling mechanism of samples were analyzed by scanning electron microscopy, transmission electron microscopy and electrochemical after the best recipe pickling. The results show that the best pickling recipe is HCl (36%~38%) 120 ml/L, H2O2(30%) 80 ml/L, FeCl3· 6H2 O 20 g/L , HNO3 10 ml/L, pickling temperature is 30 ℃ and pickling for 15 min. The flatness and brightness of material surface are better after pickling, and antimicrobial properties of dot ε-Cu phase is dispersed on the substrate. After pickling to remove oxide layer of material, it still has enough content of antibacterial element Cu. Pickling process of removing oxide layer is controlled by the charge transfer process, the pickling solution of stainless steel with pitting corrosion

  20. Newly synthesized salicylidene-4,4′-dimorpholine (SDM) assembled on nickel oxide nanoparticles (NiONPs) and its inhibitive effect on mild steel in 2 N hydrochloric acid

    Energy Technology Data Exchange (ETDEWEB)

    Wadhwani, Poonam M. [Department of Chemistry, School of Sciences, Gujarat University, Ahmedabad 380009, Gujarat (India); Panchal, Vikram K., E-mail: vikram60panchal@gmail.com [R.G. Shah Science College, Vasna, Ahmedabad 382170, Gujarat (India); Shah, Nisha K. [Department of Chemistry, School of Sciences, Gujarat University, Ahmedabad 380009, Gujarat (India)

    2015-03-15

    Graphical abstract: - Highlights: • Nanoparticles with inhibitor were found to be better corrosion inhibitor than only organic compound. • A strong binding mechanism was confirmed by FTIR, PXRD. • Inhibition efficiency increases drastically for SDM assembled on NiONPs as compared to SDM. • The adsorption model obeys Langmuir adsorption isotherm. • The protective layer over the surface of mild steel has been confirmed by AFM analysis. - Abstract: Corrosion inhibition of mild steel in hydrochloric acid solution by salicylidene-4,4′-dimorpholine (SDM) and SDM assembled on nickel oxide nanoparticles (NiONPs) has been studied with gravimetric, electrochemical impedance spectroscopy (EIS) and polarization techniques. Inhibition was found to increase with increasing concentration of the inhibitors. While studying the temperature effect on corrosion behaviour of SDM and SDM assembled on NiONPs, the inhibition efficiency decreases for SDM only but increases for SDM assembled on NiONPs. The adsorption of both the inhibitors on the mild steel surface obeys the Langmuir adsorption isotherm. The activation energy as well as other thermodynamic parameters (ΔH* and ΔS*) for the inhibition process was calculated. EIS analysis results showed that the capacitive loops for SDM assembled on NiONPs were far away from blank when compared with SDM only. Polarization curve shows that the inhibitors are of mixed type. Further, the protective layer formation was confirmed from atomic force microscopy (AFM) results. Various methods such as EIS-MS, {sup 1}H NMR, XRD, FTIR, and DLS were performed for the confirmation of the structure, interaction of SDM with NiONPs and size of NiONPs.

  1. ac impedance, X-ray photoelectron spectroscopy and density functional theory studies of 3,5-bis(n-pyridyl)-1,2,4-oxadiazoles as efficient corrosion inhibitors for carbon steel surface in hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Outirite, Moha; Lagrenee, Michel; Lebrini, Mounim [Unite de Catalyse et de Chimie du Solide, UMR-CNRS 8181, ENSCL, B.P. 90108, F-59652 Villeneuve d' Ascq Cedex (France); Traisnel, Michel; Jama, Charafeddine [Laboratoire des Procedes d' Elaboration des Revetements Fonctionnels, PERF UMR-CNRS 8008, ENSCL, B.P. 90108, F-59652 Villeneuve d' Ascq Cedex (France); Vezin, Herve [Laboratoire de Chimie Organique et Macromoleculaire, UMR-CNRS 8009, USTL Bat C4, F-59655 Villeneuve d' Ascq Cedex (France); Bentiss, Fouad, E-mail: fbentiss@enscl.f [Laboratoire de Chimie de Coordination et d' Analytique, Faculte des Sciences, Universite Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco)

    2010-02-01

    The corrosion inhibition properties of a new class of oxadiazole derivatives, namely 3,5-bis(n-pyridyl)-1,2,4-oxadiazoles (n-DPOX) for C38 carbon steel corrosion in 1 M HCl medium were analysed by electrochemical impedance spectroscopy (EIS). An adequate structural model of the interface was used and the values of the corresponding parameters were calculated and discussed. The experimental results showed that these compounds are excellent inhibitors for the C38 steel corrosion in acid solution and that the protection efficiency increased with increasing the inhibitors concentration. Electrochemical impedance data demonstrate that the addition of the n-DPOX derivatives in the corrosive solution decreases the charge capacitance and simultaneously increases the function of the charge/discharge of the interface, facilitating the formation of an adsorbed layer over the steel surface. Adsorption of these inhibitors on the steel surface obeys to the Langmuir adsorption isotherm. X-ray photoelectron spectroscopy (XPS) and the thermodynamic data of adsorption showed that inhibition of steel corrosion in normal hydrochloric solution by n-DPOX is due to the formation of a chemisorbed film on the steel surface. Quantum chemical calculations using the Density Functional Theory (DFT) and the Quantitative Structure Activity Relationship (QSAR) approach were performed on n-DPOX derivatives to determine the relationship between molecular structure and their inhibition efficiencies. The results of the quantum chemical calculations and experimental inhibition efficiency were subjected to correlation analysis and indicate that their inhibition effect is closely related to E{sub HOMO}, E{sub LUMO}, and dipole moment (mu).

  2. Improvement in HPLC separation of acetic acid and levulinic acid in the profiling of biomass hydrolysate.

    Science.gov (United States)

    Xie, Rui; Tu, Maobing; Wu, Yonnie; Adhikari, Sushil

    2011-04-01

    5-Hydroxymethylfurfural (HMF) and furfural could be separated by the Aminex HPX-87H column chromatography, however, the separation and quantification of acetic acid and levulinic acid in biomass hydrolysate have been difficult with this method. In present study, the HPLC separation of acetic acid and levulinic acid on Aminex HPX-87H column has been investigated by varying column temperature, flow rate, and sulfuric acid content in the mobile phase. The column temperature was found critical in resolving acetic acid and levulinic acid. The resolution for two acids increased dramatically from 0.42 to 1.86 when the column temperature was lowered from 60 to 30 °C. So did the capacity factors for levulinic acid that was increased from 1.20 to 1.44 as the column temperature dropped. The optimum column temperature for the separation was found at 45 °C. Variation in flow rate and sulfuric acid concentration improved not as much as the column temperature did.

  3. Integrated separation process for isolation and purification of biosuccinic acid.

    Science.gov (United States)

    Kurzrock, Tanja; Schallinger, Stefan; Weuster-Botz, Dirk

    2011-01-01

    Biotechnologically produced succinic acid has the potential to displace maleic acid and its uses. Therefore, it is of high interest for the chemical, pharmaceutical, and food industry.In addition to optimized production strains and fermentation processes, an efficient separation of succinic acid from the aqueous fermentation broth is indispensable to compete with the current petrochemical production of succinic acid. Isolation and purification of succinic acid from an Escherichia coli fermentation broth were studied with two amine-based reactive extraction systems: (i) trihexylamine in 1-octanol and (ii) diisooctylamine and dihexylamine in a mixture of 1-octanol and 1-hexanol. Back extraction of succinic acid from the organic phase was carried out using an aqueous trimethylamine solution. The trimethylammonium succinate generated after back extraction was split with an evaporation-based crystallization.The focus was on process integration, for example, reuse of the applied amines for extraction and back extraction. It was shown that the maximum trimethylamine concentration for back extraction should not exceed the stoichiometric amount (2 mol trimethylamine/mol the succinic acid in the organic phase) to ensure maximal extraction yields with the reused organic phase in subsequent extractions. Moreover, mixer-settler extraction and back extraction of succinic acid were scaled up from the milliliter- to the liter-scale making use of liquid–liquid centrifuges. The overall yield was 83.5% of the succinic acid from thefermentation supernatant. The final purity of the succinic acid crystals was 99.5%. Organic phase and amines can easily be recycled and reused. © 2011 American Institute of Chemical Engineers

  4. SEPARATION OF THORIUM FROM URANIUM

    Science.gov (United States)

    Bane, R.W.

    1959-09-01

    A description is given for the separation of thorium from uranium by forming an aqueous acidic solution containing ionic species of thorium, uranyl uranium, and hydroxylamine, flowing the solution through a column containing the phenol-formaldehyde type cation exchange resin to selectively adsorb substantially all the thorium values and a portion of the uranium values, flowing a dilute solution of hydrochloric acid through the column to desorb the uranium values, and then flowing a dilute aqueous acidic solution containing an ion, such as bisulfate, which has a complexing effect upon thortum through the column to desorb substantially all of the thorium.

  5. 桑叶提取物中槲皮素和山萘酚的含量测定%Determination of quercetin and kaempferol in folium mori extract after hydrolysis by hydrochloric acid

    Institute of Scientific and Technical Information of China (English)

    蒋立娣; 宣贵达; 吴好好; 李丽萍

    2009-01-01

    To establish an method to determine the contents of quercetin and kaempferol in folium mori extract by HPLC,the flavones in folium mori extract were hydrolyted into quercetin and kaempferol with the mixed solution of methanol-hydrochloric acid.The contents of quercetin and kaempferol were determined by HPLC method,performed on Diamonsil C_u column with the mobile phase consisted of methanol -0.20% phosphoric acid solution (63·37).The flow rate was 1.0 mL·min~(-1),the UV wavelength was set at 370 nm.The linear ranges of quercetin and kaempferol were 0.84-26.8 μg·mL~(-1),0.44-14.2 μg · mL~(-1),respectively.The average recoveries of quercetin and kaempferol were 101.3%,99.5%.The method was accurate,reliable and with good reappearance for the determination of quercetin and kaempferol in folium mori extract.%建立HPLC法测定桑叶提取物中水解槲皮素和山萘酚的含量.先用甲醇-盐酸混合液(甲醇终浓度50%,盐酸终浓度2.0 mol·L~(-1))水解桑叶提取物中的黄酮类成分成槲皮素和山萘酚,以HPLC法测定槲皮素和山萘酚含量.色谱柱为Diamonsil钻石C18柱,流动相为甲醇-0.2%磷酸(63∶37,体积分数),流速为1.0 mL·min~(-1),检测波长为370 nm.结果表明槲皮素在0.84~26.8 mg·L~(-1)之间,山萘酚在0.44~14.2 mg·L~(-1)之间呈良好的线性关系,平均回收率分别为101.3%和99.5%.该测定方法准确、重复性好,可用于桑叶提取物中槲皮素和山萘酚的含量测定.

  6. 响应面法优化红薯渣果胶的提取条件%Optimization of hydrochloric acid-mediated extraction of pectin from yam pulpusing response surface methodology

    Institute of Scientific and Technical Information of China (English)

    张允; 王响; 陈劲春

    2012-01-01

    This study examined variables that influence the hydrochloric acid-extraction of pectins from yam pulp. An initial screening study tested the main parameters influencing yield and uronic acid content by one-factor-at-a-time experimental design. The solid-to-liquid ratio was determined to be 1:16. The studies of the relationship between the GalA yield and the three variables including extraction pH, temperature and the length of extraction time used response surface methodology using a Box-Behnken design. A mathematical model representing the relationship was constructed using quadratic regression orthogonal rotation combination design, and the effects of pairwise cross-interactions among the above factors on GalA yield were evaluated by response surface analysis. The optimal extraction conditions for the extraction of pectin from yam pulp were determined to be pH 1.5 at 90 % for 90 min. Under these optimal conditions, the yield of pectin reached up to 6.50%. In industry this study provide the basis of the extraction of pectins from yam pulp.%果胶提取以红薯渣为原料,果胶生产常用酸盐酸作为提取用酸,在单因素试验基础上,确定料液比为1:20,对提取液pH值,提取温度T,提取时间t3个因素采用响应面方法进行了工艺优化研究。经过响应面分析了因素之间的相互影响并建立了3因素与果胶提取率的二次回归模型。结果表明:盐酸提取果胶的最优工艺参数为:温度87℃、pH1.33、时间92min,在此最优提取条件下果胶的提取率为6.24%。这为工业利用红薯渣生产果胶提供了依据。

  7. Leachability of nitrided ilmenite in hydrochloric acid

    CSIR Research Space (South Africa)

    Swanepoel, JJ

    2010-10-01

    Full Text Available Titanium nitride in upgraded nitrided ilmenite (bulk of iron removed) can selectively be chlorinated to produce titanium tetrachloride. Except for iron, most other components present during this low temperature (ca. 200 °C) chlorination reaction...

  8. Development of PNA-Surfactant Systems for Nucleic Acid Separations

    Science.gov (United States)

    Vernille, James; Armitage, Bruce; Schneider, James

    2002-03-01

    We have been exploring the use of novel peptide nucleic acid (PNA) surfactants for use in sequence specific, scalable DNA separations. While the synthetic and physical characteristics of PNA make it a useful molecule for bioseparations, PNA shows limited water solubility. Here we describe a molecular design strategy to improve water solubility while maintaining sequence specificity. A candidate molecule has been identified which contains lysine residues and a short alkane tail. Melting temperature data show that lipid tail interactions with the DNA nucleobases have a small but significant effect on stability while the added lysines stabilize the complex in an ionic strength dependent way. We also discuss the incorporation of these surfactants into micellar systems for novel separations.

  9. Separation of gamma-aminobutyric acid from fermented broth.

    Science.gov (United States)

    Li, Haixing; Qiu, Ting; Chen, Yan; Cao, Yusheng

    2011-12-01

    Gamma-aminobutyric acid (GABA) is a non-proteinaceous amino acid that is widely distributed in nature and acts as the major inhibitory neurotransmitter in the mammalian brain. This study aimed to find a separation method for getting high-purity GABA from a fermented broth. Firstly, a fermented broth with a high content of GABA (reaching 997 ± 51 mM) was prepared by fermentation with Lactobacillus brevis NCL912. GABA purification was conducted by successive centrifugation, filtration, decoloration, desalination, ion-exchange chromatography (IEC), and crystallization. Inorganic salt (Na₂SO₄) was removed from the both by desalination with 70% ethanol solution. A ninhydrin test strip was designed for the real-time detection of GABA during IEC. The recovery rate for the whole purification process was about 50%. The purified product was characterized by thin-layer chromatography and HPLC, and its purity reached 98.66 ± 2.36%.

  10. Selective separation of sodium ions from a mixture with phenylalanine by Donnan dialysis with a profiled sulfogroup cation exchange membrane

    Science.gov (United States)

    Vasil'eva, V. I.; Goleva, E. A.

    2013-11-01

    The possibility of separating ions of metal from a mixture with ampholyte (an amino acid) by Donnan dialysis with an MK-40 sulfogroup cation exchange membrane is demonstrated. Conditions ensuring the selectivity and intensity of the mass transfer of sodium ions from a mixture with bipolar phenylalanine ions into a diffusate containing hydrochloric acid through a cation exchange membrane are found.

  11. Propanoyl(1Z-N-(2,6-dimethylphenyl-2-oxopropanehydrazonoate as inhibitor for corrosion of 6061 Al alloy15 % (v SiC(p composite in hydrochloric acid media

    Directory of Open Access Journals (Sweden)

    Achutha Kini U

    2012-10-01

    Full Text Available ABSTRACT: The corrosion inhibition effect of Propanoyl(1Z-N-(2,6-dimethylphenyl-2-oxopropanehydrazonoate (PDOH in the corrosion of 6061 Aluminium alloy-15%(v SiC(p composite in 0.5 and 1M hydrochloric acid medium at four different temperatures (30, 40, 50 and 60 ⁰C was investigated using potentio-static polarization (Tafel extrapolation and Linear polarization and weight loss methods. The results obtained reveal that PDOH is an efficient corrosion inhibitor with around 96% inhibition efficiency within the range of temperature studied. Leftward and downward shifts in Tafel plots were observed with the addition of the inhibitor, indicating that PDOH inhibits the corrosion process effectively, and that it is a cathodic inhibitor. Corrosion rate increases and inhibition efficiency decreases with increase in temperature. Results obtained by Tafel extrapolation, linear polarization, and weight loss methods are in agreement. The adsorption of the inhibitor onto the surface of the 6061 Al alloy 15 % (v SiC(p composite is found to obey Temkins' adsorption isotherm that verifies the assumption of mono-layer adsorption on a uniform homogeneous composite surface with an interaction in the adsorption layer. The inhibition is therefore governed by the physisorption mechanism.ABSTRAK: Kesan perencatan kakisan Propanoyl(1Z-N-(2,6-dimethylphenyl-2-oxopropanehydrazonoate (PDOH ke atas kakisan komposit aloi Al 6061-15%(v SiC(p dalam media asid hidroklorik 0.5 dan 1M pada suhu-suhu yang berbeza (30, 40, 50 dan 60⁰C telah dikaji menggunakan polarisasi statik-upaya (extrapolarisasi Tafel dan polarisasi Linear dan kaedah kehilangan berat. Keputusan diperolehi menunjukkan PDOH adalah perencat yang efisien dengan 96 % keupayaan perencatan bagi julat suhu yag dikaji. Anjakan ke kiri dan ke bawah plot Tafel dapat dilihat dengan penambahan perencat, menunjukkan PDOH merencatkan proses kakisan dengan berkesan, dan ia adalah perencat katodik. Dengan peningkatan suhu

  12. Separation and Structure of Chiral S-Malic Acid Hydrate

    Institute of Scientific and Technical Information of China (English)

    NIE,Jing-Jing(聂晶晶); XU,Duan-Jun(徐端钧); WU,Jing-Yun(吴景云); CHIANG,Michael Y.(蒋燕南)

    2002-01-01

    Crystals of the chiral malic acid hydrate ( C4H6O5@H2O ) were unexpectedly obtained from an ethanol ethanol/water solution containing racemic D,L-malic acid and L-asparagine. The crystal belongs to orthorhombic space group P21 21 21 with cell dimensions of a=0.5576(1), b=0.9818(2), c=1.1793(2) nm, V=0.9455(2) nm3, Z=4, μ(Mo Kα) =0.152 mm-1, F(000) =320, Dc= 1.565 g@cm-3, R =0.051, wR =0.136 for 657 observed reflections [I>2σ(I)]. The significant difference in bond distances for carboxyl groups suggests that the crystal consist of malate anion and protonized crystalline water. This is a report for direct separation of racemic mixture, i.e., without the formation of a molecular complex of raceme with a chiral separating reagent.

  13. Corrosion resistance and its mechanism of Ni-Cu-P coating and 316L stainless steel in hot hydrochloric acid solution%Ni-Cu-P镀层和316L不锈钢在热盐酸溶液中的耐蚀性及机制

    Institute of Scientific and Technical Information of China (English)

    薛亚军

    2013-01-01

    Effect of temperature and concentration on the corrosion behavior of Ni-Cu-P coating and 316L stainless steel was studied by mass loss method.The results show that the corrosion resistance of Ni-Cu-P coating is better than that of 316L stainless steel in hot hydrochloric acid solution.The effect of hydrochloric acid concentration on the corrosive rate of 316L stainless steel is greater than that of Ni-Cu-Pcoating.The corrosive rates of 316L stainless steel and Ni-Cu-P coating increase 2.7 and 0.6 times respectively while increasing hydrochloric acid concentration from 5% to 20%.For the Ni-Cu-P coating,the uniform corrosion occurs in the hydrochloric acid solution.However,the selective corrosion mechanism is found for 316L stainless steel,and the higher temperature and concentration of corrosion medium,the more serious selective corrosion.%采用质量损失法研究了温度和浓度对化学镀Ni-Cu-P镀层和316L不锈钢在盐酸溶液中的腐蚀行为.结果表明,在高温盐酸溶液中,Ni-Cu-P镀层的耐蚀性优于316L不锈钢,盐酸浓度对316L不锈钢腐蚀速率的影响大于Ni-Cu-P镀层,盐酸浓度由5%升高到20%,316L不锈钢和Ni-Cu-P镀层的腐蚀速率分别增大了2.7倍和0.6倍;在盐酸溶液中,Ni-Cu-P镀层发生均匀腐蚀,316L不锈钢发生选择性腐蚀,且温度和浓度越高,选择性腐蚀越严重.

  14. Spectrophotometric Determination of Scandium in Hydrochloric Acid Leaching Solution of Red Mud%赤泥盐酸浸出液中钪的分光光度测定

    Institute of Scientific and Technical Information of China (English)

    邓海霞; 王克勤; 王皓; 李爱秀; 张风林; 陈津

    2011-01-01

    考察了温度、时间、显色剂用量、酸度对待测溶液吸光度的影响,结果表明:温度对吸光度值不产生大的影响,在室温下测试即可;溶液显色在前8min内不稳定,其显色时间一定要达到10 min,溶液颜色保持16h不发生太大的变化;显色剂氯代磺酚C和Sc(Ⅲ)1∶1络合稳定,其溶液加入量确定为3ml;酸度对吸光度有较大的影响,待测溶液的pH值为2.0时吸光度值最大,且稳定.溶液最大吸光度波长为649 nm,工作曲线回归方程为y=0.03839x -0.0002,相关系数的平方为0.9993,Sc(Ⅲ)的质量浓度在0~1.2 mg·L-1范围内符合朗伯-比尔定律,表观摩尔吸光系数为7.78×105 L·mol -1·cm-1.本法测定赤泥盐酸浸出液中的钪,结果比较稳定,RSD(n =6)为1.45%~4.16%,加标回收率为98%~ 102%,灵敏度高、结果较满意.%The effects of temperature, time, reagent dosage, solution pH on absorbance showed that: the temperature had little effect on the absorbance, the solution could be tested at room temperature; the determination result was not stable within the first 8 min, the solution should achieve a coloration time for 10 mins, the solution color maintained 16 h did not change much; reagent chlorosulpho-phenol C and Sc( IB) 1:1 complex stability, the solution was added 3 ml; acidity had great influence on the absorbance with pH value of 2.0, the maximum absorbance, and stability. Hie maximum absorbance of solution was at 649 nm, and the standard curve regression equation: y = 0.03839* - 0.0002, the square of correlation coefficient was 0.9993, Lambert-Beer law was obeyed for Sc (JE ) in the range of 0 -1.2 rag-L"' and the apparent molar absorptivity was 7.78 xlO3 L-mol~1>cm~l. The method was applied to the determination of Sc( HI) in hydrochloric acid leaching solution of red mud, the result was stable with high sensitivity and satisfactory, RSD ( n = 6) was 1.45%-4.16% and the recovery of Sc( I) was 98% to 102%.

  15. Hexavalent chromium recovery by liquid–liquid extraction with 2-octylaminopyridine from acidic chloride media and its sequential separation from other heavy toxic metal ions

    Directory of Open Access Journals (Sweden)

    C.P. Mane

    2016-11-01

    Full Text Available A systematic study of extraction of chromium(VI with 2-octylaminopyridine (2-OAP in xylene at room temperature has been conducted. Quantitative extraction of chromium(VI was observed in the 0.4–0.8 M concentration range of hydrochloric acid. From the extracted complex species in the organic phase, chromium(VI was back extracted with 7 N ammonia (3 × 10 mL, and was determined by spectrophotometric method. Various parameters such as 2-OAP concentration, equilibrium period, effect of various diluents, aqueous: organic volume ratio, acidity and diverse ions were studied. The extraction reaction proceeds with ion-pair formation and the stoichiometry of extracted species was found to be [(2OAPH+ CrO3Cl−](org. The separation and determination of chromium(VI from associated and toxic metals in binary, ternary and multicomponent mixture were carried out. The method permits the sequential separation of chromium(VI from other toxic metals and has been used to separate and determine chromium(VI from alloys, and effluent water samples from tannery industries.

  16. Primary beneficiation of tantalite using magnetic separation and acid leaching

    Institute of Scientific and Technical Information of China (English)

    M Nete; F Koko; T Theron; W Purcell; JT Nel

    2014-01-01

    Primary beneficiation was successfully performed prior to dissolution of manganotantalite (sample A) and ferrotantalite (sample C) samples obtained from two different mines in the Naquissupa area, Mozambique. Magnetic separation removed the majority of iron and tita-nium, whereas H2SO4 leaching removed a large portion of thorium and uranium in these samples. Analytical results indicated that 64.14wt%and 72.04wt%of the total Fe and Ti, respectively, and~2wt%each of Nb2O5 and Ta2O5 were removed from sample C (ferrotantalite) using the magnetic separation method, whereas only 9.64wt%and 8.66wt%of total Fe2O3 and TiO2, respectively, and~2wt%each of Nb2O5 and Ta2O5 were removed from sample A (manganotantalite). A temperature of 50°C and a leaching time of 3 h in the presence of concentrated H2SO4 were observed to be the most appropriate leaching conditions for removal of radioactive elements from the tantalite ores. The results obtained for sample A under these conditions indicated that 64.14wt%U3O8 and 60.77wt%ThO2 were leached into the acidic solution, along with 4.45wt%and 0.99wt%of Nb2O5 and Ta2O5, respectively.

  17. Synthesis of N - Alkyl Benzimidazoles as Corrosion Inhibitors for Acidification in Hydrochloric Acid and Evaluation of Their Inhibition Performance%N-烷基苯并咪唑酸化缓蚀剂的合成及性能

    Institute of Scientific and Technical Information of China (English)

    杨鹏辉; 冀生辉

    2013-01-01

    Four kinds of N - alkyl benzimidazole corrosion inhibitors were synthesized by alkylation of 2 - methyl benzimidazole or 2 - ethyl benzimidazole. The corrosion inhibition performance of as - synthesized inhibitors was evaluated by static state weight loss test and dynamic potential scanning polarization curve measurement. It was found that properly extending carbon chain of benzimidazole helped to improve the anticorrosion ability of benzimidazoles, and corrosion inhibitor N - hexadecyl - 2 - ethyl benzimidazole showed the best corrosion inhibition performance. Besides, at 60 ℃ in 15% hydrochloric acid, the corrosion rate of N80 steel decreased with increasing concentration of the corrosion inhibitor; and the corrosion rate of the steel at a corrosion inhibitor concentration of 1.0% was 1.73g/(m2 · h) , which indicated that corrosion inhibitor N-hexadecyl-2-ethyl benzimidazole was advantageous over the first-class corrosion inhibitor for acidification. Moreover, as-synthesized corrosion inhibitors were a class of mixed-type inhibitors dominated by cathode inhibition, but their inhibition performance in HCl with a concentration of above 20 % or at a temperature of above 70 ℃ was undesirable.%苯并咪唑是一类环境友好的缓蚀剂,将其衍生物用作油气田酸化缓蚀剂的报道较少.通过烷基化反应在2-甲基苯并咪唑和2-乙基苯并咪唑的1-氮原子上分别引入十二烷基和十六烷基,合成了4种N-烷基苯并咪唑,并以其为主剂制成缓蚀剂,用静态失重法和动电位扫描极化曲线对4种复配缓蚀剂在盐酸溶液中的缓蚀性能进行了评价.结果表明:适当延长1位烷基碳链,有助于提高苯并咪唑衍生物的缓蚀能力;合成的4种N-烷基苯并咪唑中,以N-十六烷基-2-乙基苯并咪唑为主剂制成缓蚀剂d的缓蚀性能最好;在60℃,15%HCl中,N80钢的腐蚀速率随缓蚀剂d用量的增大而减小,其用量为1.0%时,N80钢腐蚀速率为1.73 g/(m2·h),优于

  18. 盐酸介质中N,N′-二(二苯基膦基)-1-苯乙胺对碳钢的缓蚀性能研究%Investigation on Corrosion Inhibition of N,N′-Bis(diphenylphosphino)-1-phenylethylamine for Carbon Steel in Hydrochloric Acid Solution

    Institute of Scientific and Technical Information of China (English)

    魏健; 谢斌; 赖川; 李玉龙; 邹立科; 樊义康

    2016-01-01

    目的:对N,N′-二(二苯基膦基)-1-苯乙胺( NPM)的合成、结构表征及其在盐酸介质中对碳钢的缓蚀性能进行研究。方法用红外光谱、元素分析和熔点测试等方法对NPM的结构进行表征,采用静态失重法、动电位极化曲线法和电化学阻抗法研究NPM在盐酸介质中对碳钢的缓蚀作用,研究腐蚀体系温度、HCl浓度、NPM浓度和腐蚀体系静置时间对NPM缓蚀率的影响,探讨NPM在碳钢表面上的吸附机理。结果动电位极化曲线法研究结果表明NPM是一种混合型缓蚀剂。 NPM的缓蚀率随NPM浓度的增加而增大,当NPM的质量浓度为140 mg/L时,NPM在25℃的1.0 mol/L HCl 溶液中的缓蚀率达到94.71%;NPM的缓蚀率随腐蚀体系温度的升高而降低,随HCl浓度的增大而减小,但随腐蚀体系静置时间的延长缓蚀率逐渐增大。 NPM在碳钢表面的吸附符合Langmuir吸附等温方程式,属于自发进行的物理和化学吸附。结论所合成的化合物NPM是一种高效的混合型有机缓蚀剂。%Objective To study the synthesis, structure characterization and inhibition performance of N,N′-bis( di-phenylphos-phino)-1-phenylethylamine ( NPM) on carbon steel in hydrochloric acid solution. Methods The structure of synthesized NPM was characterized by means of infrared spectroscopy, elemental analysis and melting point test. And the inhibitive efficiency of NPM on carbon steel in hydrochloric acid solution was investigated using the static weight loss method, potentiodynamic polarization curve and electrochemical impedance. The influences of the corrosion system temperature, NPM concentration, hydrochloric acid concen-tration and standing time of the corrosion system on the corrosion inhibition efficiency of NPM on carbon steel were studied, and the adsorption mechanism of NPM on carbon steel surface was also discussed. Results The potentiodynamic polarization curves indica-ted that NMP acted as a mixed-type inhibitor

  19. Experimental carcinogenesis on the oropharyngeal mucosa of rats with hydrochloric acid, sodium nitrate and pepsin Carcinogênese experimental na mucosa orofaríngea de ratos com ácido clorídrico, nitrato de sódio e pepsina

    Directory of Open Access Journals (Sweden)

    André Del Negro

    2008-08-01

    Full Text Available PURPOSE: To investigate the carcinogenic action of hydrochloric acid, pepsin and sodium nitrate on the oropharyngeal mucosa of rats, simulating the reflux of gastric contents. METHODS: Eighty-two Wistar rats were divided in seven groups and submitted to 2 or 3 weekly applications of hydrochloric acid, pepsin and sodium nitrate on the pharyngeal mucosa during six months. Study groups comprised 12 animals each. Rats in groups I and II were submitted to 2 (GI or 3 (GII weekly applications of 0.1N hydrochloric acid. Groups III and IV were submitted to 2 (GIII or 3 (GIV weekly applications of 0.1N hydrochloric acid solution with pepsin. Groups V and VI were submitted to 2 (GV or 3 (GVI weekly applications of 0.1N hydrochloric acid and treated with daily nitrate diluted in water. Group VII consisted of 10 animals submitted to 2 weekly applications of filtered water. RESULTS: No dysplasia, intra-epithelial neoplasia or invasive carcinomas were detected. Inflammatory changes were observed in varying degrees and mast cells were more common in Groups V and VI (p=0.006. CONCLUSION: The data of the current study could not corroborate the hypothesis that gastroesophageal and pharyngolaryngeal refluxes are carcinogenic factors to the laryngopharyngeal mucosa, and more studies are necessary in the future.OBJETIVO: Investigar a ação carcinogênica do ácido clorídrico, pepsina e nitrato de sódio na mucosa orofaríngea de ratos, simulando o refluxo do conteúdo gástrico à mucosa do faringo-laringea. MÉTODOS: Oitenta e dois ratos Wistar foram divididos em 7 grupos e submetidos a 2 ou 3 aplicações semanais de ácido clorídrico, pepsina e nitrato de sódio na mucosa orofaríngea durante 6 meses. Os grupos de estudo envolveram 12 animais cada. Os ratos nos grupos I e II foram submetidos à 2 (GI ou 3 (GII aplicações semanais de ácido clorídrico 0,1N. Nos grupos III e IV foram 2 (GIII ou 3 (GIV aplicações semanais de ácido clorídrico e pepsina. Nos

  20. Amine-oxide hybrid materials for acid gas separations

    KAUST Repository

    Bollini, Praveen

    2011-01-01

    Organic-inorganic hybrid materials based on porous silica materials functionalized with amine-containing organic species are emerging as an important class of materials for the adsorptive separation of acid gases from dilute gas streams. In particular, these materials are being extensively studied for the adsorption of CO 2 from simulated flue gas streams, with an eye towards utilizing these materials as part of a post-combustion carbon capture process at large flue gas producing installations, such as coal-fired electricity-generating power plants. In this Application Article, the utilization of amine-modified organic-inorganic hybrid materials is discussed, focusing on important attributes of the materials, such as (i) CO 2 adsorption capacities, (ii) adsorption and desorption kinetics, and (iii) material stability, that will determine if these materials may one day be useful adsorbents in practical CO 2 capture applications. Specific research needs and limitations associated with the current body of work are identified. © 2011 The Royal Society of Chemistry.

  1. Separation of mandelic acid and its derivatives with new immobilized cellulose chiral stationary phase

    Institute of Scientific and Technical Information of China (English)

    Jie ZHOU; Qian LIU; Guang-jun FU; Zhen-zhong ZHANG

    2013-01-01

    A new liquid chromatographic method has been developed for the chiral separation of the enantiomers of mandelic acid and their derivatives 2-chloromandelic acid,4-hydroxymandelic acid,4-methoxymandelic acid,and 3,4,5-trismethoxymandelic acid.The enantiomers were separated by a CHIRALPAK(R) IC (250 mm×4.6 mm,5 μm).Mandelic acid,4-methoxymandelic acid,and 3,4,5-trismethoxymandelic acid were baseline resolved (resolution factor (Rs)=2.21,Rs=2.14,and Rs=3.70,respectively).In contrast,the enantioselectivities between CHIRALPAK(R) IC and 2-chloromandelic acid and 4-hydroxymandelic acid investigated were low.By comparing the chromatographs of mandelic acid enantiomers and mandelic acid spiked with (R)-mandelic acid,it was determined that the first effluent was (R)-mandelic acid.

  2. Mutual separation of americium(III) and europium(III) using glycolamic acid and thioglycolamic acid

    Energy Technology Data Exchange (ETDEWEB)

    Suneesh, A.S.; Venkatesan, K.A.; Syamala, K.V.; Antony, M.P.; Vasudeva Rao, P.R. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Fuel Chemistry Div.

    2012-07-01

    The extractants, bis(2-ethylhexyl)diglycolamicacid (HDEHDGA) and bis(2-ethylhexy)thiodiglycolamic acid (HDEHSDGA) were synthesized and characterized by {sup 1}H and {sup 13}C NMR, mass and IR spectroscopy. The extraction behaviour of {sup (152+154})Eu(III) and {sup 241}Am(III) from nitric acid medium by a solution of HDEHDGA (or HDEHSDGA) in n-dodecane (n-DD) was studied for the mutual separation of actinides and lanthanides. The effect of various parameters such as the pH, concentrations of HDEHDGA, HDEHSDGA, sodium nitrate, N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) and diethylenetriaminepentaacetic acid (DTPA) on the separation factor (SF) of americium(III) over europium(III) and vice versa was studied, and the conditions needed for the preferential separation were optimised. The results show that HDEHDGA exhibits higher extraction for {sup (152+154)}Eu(III) and HDEHSDGA shows the superior selectivity for {sup 241}Am(III). (orig.)

  3. Design of pH Measurement and Control System Using in Process of NdFeB Waste With Hydrochloric Acid%盐酸优溶法处理NdFeB废料pH测控系统的设计

    Institute of Scientific and Technical Information of China (English)

    周雄军; 逄启寿

    2014-01-01

    The leaching principle of NdFeB waste using hydrochloric acid is introduced .The pH controlling mathematical model for acid dissolving and neutralizating process are established based on leaching mechanism .The overall designing scheme of pH control system in leaching process is put forwarded .%介绍了盐酸优溶法处理NdFeB废料的原理。结合浸出机制,建立了酸溶、中和过程的pH控制数学模型,提出了浸出过程中pH控制系统的整体设计方案。

  4. 盐酸解析与水碱洗系统的酸、水生产平衡%Hydrochloric acid analysis and alkali washing system acid, water production balance

    Institute of Scientific and Technical Information of China (English)

    林涛海; 刘胜军

    2012-01-01

    以40万t/a PVC为例,对氯化氢的消耗量与盐酸的解析量进行了物料衡算。%Take 400 kt/a PVC as an example, calculating material balance between consumption of hydrogen chloride gas and resolving amount of hydrogen acid.

  5. Separation of thorium and uranium in nitric acid solution using silica based anion exchange resin.

    Science.gov (United States)

    Chen, Yanliang; Wei, Yuezhou; He, Linfeng; Tang, Fangdong

    2016-09-30

    To separate thorium and uranium in nitric acid solution using anion exchange process, a strong base silica-based anion exchange resin (SiPyR-N4) was synthesized. Batch experiments were conducted and the separation factor of thorium and uranium in 9M nitric acid was about 10. Ion exchange chromatography was applied to separate thorium and uranium in different ratios. Uranium could be eluted by 9M nitric acid and thorium was eluted by 0.1M nitric acid. It was proved that thorium and uranium can be separated and recovered successfully by this method.

  6. 机械通气与盐酸氨溴索联合治疗老年急性呼吸窘迫综合症的临床效果%Mechanical Ventilation with Hydrochloric Acid Ammonia Bromine Cable Joint is the Clinical Effect of Treatment of Senile Acute Respiratory Distress Syndrome

    Institute of Scientific and Technical Information of China (English)

    张鹏

    2016-01-01

    目的:客观评价机械通气与盐酸氨溴索联合治疗老年急性呼吸窘迫综合症的临床效果。方法随机选择该院2012年1月—2015年12月接收的55例老年急性呼吸窘迫综合症患者(A组),同期选择55例老年急性呼吸窘迫综合症患者(B组)作对照,分别予以机械通气与盐酸氨溴索联合治疗、机械通气单纯治疗。结果 A组入选患者有效率81.82%,B组54.55%(P﹤0.05)。结论就老年急性呼吸窘迫综合症患者而言,选择机械通气与盐酸氨溴索联合治疗方案效果突出。%Objective To objectively evaluate mechanical ventilation with hydrochloric acid ammonia bromine cable joint is the clinical effect of treatment of senile acute respiratory distress syndrome. Methods Random selection etween January 2012 and December 2015 received 55 cases of elderly patients with acute respiratory distress syndrome (group A), at the same time choose 55 cases of elderly patients with acute respiratory distress syndrome (group B) were compared, respective-ly to mechanical ventilation with hydrochloric acid ammonia bromine cable joint treatment, mechanical ventilation therapy alone. Results In group A patients effective rate was 81.82%, 54.55% in group B (P﹤ 0.05). Conclusion In terms of el-derly patients with acute respiratory distress syndrome, mechanical ventilation and hydrochloric acid ammonia bromine joint treatment effect is prominent.

  7. [Separation mechanism of chiral stationary phase based on quinine and crown ether for the direct stereoselective separation of amino acids].

    Science.gov (United States)

    Wu, Haixia; Wang, Dongqiang; Zhao, Jianchao; Ke, Yanxiong; Liang, Xinmiao

    2016-01-01

    A novel chiral stationary phase combining quinine and crown ether (QN-CR CSP) was developed to separate amino acid enantiomers. This CSP showed good enantioselectivity for some amino acids. Since the synergistic effect of ion exchange and complexation in chiral recognition of amino acids, a new adsorption isotherm was built. Using the method of frontal analysis by characteristic point (FACP), the adsorption isotherms of tryptophan (Trp) under different mobile phase conditions were determined and fitted the proposed adsorption isotherm model well. With the increase of the competition between metal cationic and amino to crown ether, the equilibrium constant of complexing adsorption was found increased. The chiral separation ability was decreased. The adsorption isotherm improved the understanding of the retention behavior of amino acids on QN-CR CSP, which was also benefit to optimize the structure of the stationary phase.

  8. Separation of lactic acid from acetic acid using a four-zone SMB.

    Science.gov (United States)

    Lee, Ho-Joon; Xie, Yi; Koo, Yoon-Mo; Wang, Nien-Hwa Linda

    2004-01-01

    A simulated moving bed (SMB) process has been developed to separate l-(+)-lactic acid from acetic acid, a major impurity in the fermentation broth of Lactobacillus rhamnosus. Poly(4-vinylpyridine) resin (PVP) was selected as the adsorbent. Adsorption isotherms and mass transfer parameters of the organic acids were estimated from single-column frontal tests. Experimental results show that the Langmuir isotherms obtained from the frontal tests can be used in the design of an SMB process to achieve 99.9% purity and over 93% yield of lactic acid. The column profiles and effluent histories, however, deviate from rate model predictions based on the Langmuir isotherms. They agree more closely with the predictions based on a modified Langmuir isotherm for lactic acid. The standing wave design method for systems with modified Langmuir isotherms is developed in this study. Rate model simulations show that the process based on the modified design method can achieve high purity (>99.9%) and high yield (>99.9%). For this nonlinear system, accurate isotherm model and model parameters are needed in the design, and the zone flow rates must be closely monitored and controlled in order to ensure high purity and high yield in the SMB process.

  9. Study of nano-Ti02 thin films prepared by sol-gel in the ethanol-hydrochloric acid-water system%乙醇-盐酸-水体系中溶胶-凝胶法制备纳米TiO2薄膜的研究

    Institute of Scientific and Technical Information of China (English)

    孟丹; 王和义; 刘秀华; 丁兰岚

    2011-01-01

    以Ti (OBu)4为前驱体,设计单因素优选实验,通过溶胶凝胶-浸渍提拉法在玻璃基片上制备TiO2纳米薄膜,研究了无水乙醇、浓盐酸、超纯水对其结构和性能的影响,获得了纳米TiO2薄膜的最佳制备条件.%The nano-Ti02 films on glass was prepared from Ti( OBu)4 precursor via the sol-gel and dip-coating method. The effects of anhydrous ethanol, hydrochloric acid and ultra-pure water on structures and performances of TiO2 films were investigated by single factor optimization,and the optimum preparation conditions of TiO2 thin films were obtained.

  10. Separation of complex mixtures of amino acids for biorefinery applications using electrodialysis

    NARCIS (Netherlands)

    Kattan-Readi, O.M.; Girones nogue, M.; Nijmeijer, D.C.

    2013-01-01

    The potential of electrodialysis (ED) for the separation of amino acids (zwitterionic molecules that exhibit a specific charge behavior dependent on pH) has been demonstrated in the past. However, even though successful for the separation of specific amino acids, ED is not applicable for the separat

  11. Separation Sr and Ba From Fission Products Using Sr-spec Resin Column

    Institute of Scientific and Technical Information of China (English)

    WANG; Xiu-feng

    2013-01-01

    Sr and Ba are the IIA group elements,with the same outer electronic structure,and the very similar properties,so separation of the two elements becomes very difficult.The traditional separation method of Sr and Ba in fission products is repeated precipitation of BaCl2·H2O in hydrochloric acid-ether medium.Four times repeated precipitation steps are needed to ensure the decontamination factor of Sr to be better

  12. Introduction of structural affinity handles as a tool in selective nucleic acid separations

    Science.gov (United States)

    Willson, III, Richard Coale (Inventor); Cano, Luis Antonio (Inventor)

    2011-01-01

    The method is used for separating nucleic acids and other similar constructs. It involves selective introduction, enhancement, or stabilization of affinity handles such as single-strandedness in the undesired (or desired) nucleic acids as compared to the usual structure (e.g., double-strandedness) of the desired (or undesired) nucleic acids. The undesired (or desired) nucleic acids are separated from the desired (or undesired) nucleic acids due to capture by methods including but not limited to immobilized metal affinity chromatography, immobilized single-stranded DNA binding (SSB) protein, and immobilized oligonucleotides. The invention is useful to: remove contaminating genomic DNA from plasmid DNA; remove genomic DNA from plasmids, BACs, and similar constructs; selectively separate oligonucleotides and similar DNA fragments from their partner strands; purification of aptamers, (deoxy)-ribozymes and other highly structured nucleic acids; Separation of restriction fragments without using agarose gels; manufacture recombinant Taq polymerase or similar products that are sensitive to host genomic DNA contamination; and other applications.

  13. In-line and selective phase separation of medium-chain carboxylic acids using membrane electrolysis.

    Science.gov (United States)

    Xu, Jiajie; Guzman, Juan J L; Andersen, Stephen J; Rabaey, Korneel; Angenent, Largus T

    2015-04-21

    We had extracted n-caproate from bioreactor broth. Here, we introduced in-line membrane electrolysis that utilized a pH gradient between two chambers to transfer the product into undissociated n-caproic acid without chemical addition. Due to the low maximum solubility of this acid, selective phase separation occurred, allowing simple product separation into an oily liquid containing ∼90% n-caproic and n-caprylic acid.

  14. Separation of cis-fatty acids from saturated and trans-fatty acids by nanoporous polydicyclopentadiene membranes.

    Science.gov (United States)

    Gupta, Abhinaba; Bowden, Ned B

    2013-02-01

    This article describes the separation of mixtures of fatty acid salts using a new organic solvent nanofiltration membrane based on polydicyclopentadiene (PDCPD). Mixtures of free fatty acids could not be separated by the membranes because they permeated at similar rates. When triisobutylamine was added to the fatty acids, the cis-fatty acid salts (oleic, petroselinic, vaccenic, linoleic, and linolenic acid) had slower permeation though the membranes than saturated (stearic acid) and trans-fatty acid (elaidic acid) salts. The reason for the difference in permeation was due to the formation of stable salt pairs between the amine and fatty acids that increased their cross-sectional areas. The fatty acid salts derived from saturated and trans-fatty acids were smaller than the critical area cutoff for the PDCPD membranes, so they readily permeated. In contrast, the fatty acid salts derived from the cis-fatty acids had critical areas larger than critical area cutoff of the PDPCD membranes and had slowed permeation. The partitioning coefficients of fatty acids and fatty acid salts were investigated to demonstrate that they were not responsible for the difference in permeation. The use of pressure was investigated to greatly accelerate the permeation through the membranes. For a solvent mixture of 35/65 (v/v) toluene/hexanes, the permeation of solvent was approximately 39 L m(-2) h(-1). This value is similar to values reported for permeation through membranes used in industry. The separation of a mixture of fatty acids based on the composition of soybean oil was investigated using pressure. The saturated fatty acid salts were almost completely removed from the cis-fatty acid salts when iBu(3)N was used as the amine to form the salt pairs. The separation of the cis-fatty acids found in soybean oil was investigated with Pr(3)N as the amine. The oleic acid salt (oleic acid has one cis double bond) preferentially permeated the membrane while the linoleic (two cis double bonds

  15. STUDY ON THE SEPARATION OF GLUTAMIC ACID BY ION—EXCHANGE

    Institute of Scientific and Technical Information of China (English)

    ShenJiyu; WangQinyu

    1995-01-01

    The feasibility of recovering glutamic acid by ion exchange method with macroporous resins was investigated.Their adsorption properties in stati state and the effective factors,such as pH,concentration of eeed and the ratio of ammonium ion to glutamic acid,were systematically explored.The best condition of separating glutamic acid from mother liquid were obtained.

  16. Separation and recovery of nucleic acids with improved biological activity by acid-degradable polyacrylamide gel electrophoresis.

    Science.gov (United States)

    Kim, Yoon Kyung; Kwon, Young Jik

    2010-05-01

    One of the fundamental challenges in studying biomacromolecules (e.g. nucleic acids and proteins) and their complexes in a biological system is isolating them in their structurally and functionally intact forms. Electrophoresis offers convenient and efficient separation and analysis of biomacromolecules but recovery of separated biomacromolecules is a significant challenge. In this study, DNAs of various sizes were separated by electrophoresis in an acid-degradable polyacrylamide gel. Almost 100% of the nucleic acids were recovered after the identified gel bands were hydrolyzed under a mildly acidic condition and purified using anion exchange resin. Further concentration by centrifugal filtration and a second purification using ion exchange column chromatography yielded 44-84% of DNA. The second conventional (non-degradable) gel electrophoresis confirmed that the nucleic acids recovered from acid-degradable gel bands preserved their electrophoretic properties through acidic gel hydrolysis, purification, and concentration processes. The plasmid DNA recovered from acid-degradable gel transfected cells significantly more efficiently than the starting plasmid DNA (i.e. improved biological activity via acid-degradable PAGE). Separation of other types of nucleic acids such as small interfering RNA using this convenient and efficient technique was also demonstrated.

  17. In situ separation of lactic acid from fermentation broth using ion exchange resins.

    Science.gov (United States)

    Ataei, Seyed Ahmad; Vasheghani-Farahani, Ebrahim

    2008-11-01

    Lactic acid fermentation is an end product inhibited reaction. In situ separation of lactic acid from fermentation broth using ion exchange resins was investigated and compared with conventional fermentation system. Amberlite resin (IRA-400, Cl-) was used to separate lactic acid from fermentation broth and pH was controlled online with an automatic pH controller. The effect of process variables on lactic acid production by Lactobacillus casei in whey permeate was studied. The maximum productivity was obtained at pH=6.1, T=37 degrees C and impeller speed=200 rpm. The maximum concentration of lactic acid at optimum condition was found to be 37.4 g/L after 38 h of fermentation using in situ separation system. The productivity of in situ separation system was five times increased in comparison with conventional system.

  18. Selective separation of indium by iminodiacetic acid chelating resin

    Energy Technology Data Exchange (ETDEWEB)

    Fortes, M.C.B.; Benedetto, J.S. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Martins, A.H. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Metalurgica e de Materiais]. E-mail: ahmartin@demet.ufmg.br

    2007-04-15

    - Indium can be recovered by treating residues, flue dusts, slags, and metallic intermediates in zinc smelting. This paper investigates the adsorption characteristics of indium and iron on an iminodiacetic acid chelating resin, Amberlite{sup R} IRC748 (Rohm and Haas Co.-USA). High concentrations of iron are always present in the aqueous feed solution of indium recovery. In addition, the chemical behaviour of iron in adsorptive systems is similar to that of indium. The metal concentrations in the aqueous solution were based on typical indium sulfate leach liquor obtained from zinc hydrometallurgical processing in a Brazilian plant. The ionic adsorption experiments were carried out by the continuous column method. Amberlite{sup R} IRC748 resin had a high affinity for indium under acidic conditions. Indium ions adsorbed onto the polymeric resin were eluted with a 0.5 mol/dm{sup 3} sulphuric acid solution passed through the resin bed in the column. 99.5% pure indium sulfate aqueous solution was obtained using the iminodiacetic acid chelating resin Amberlite{sup R} IRC748. (author)

  19. Selective separation of indium by iminodiacetic acid chelating resin

    Directory of Open Access Journals (Sweden)

    M. C. B. Fortes

    2007-06-01

    Full Text Available Indium can be recovered by treating residues, flue dusts, slags, and metallic intermediates in zinc smelting. This paper investigates the adsorption characteristics of indium and iron on an iminodiacetic acid chelating resin, Amberlite®IRC748 (Rohm and Haas Co.-USA. High concentrations of iron are always present in the aqueous feed solution of indium recovery. In addition, the chemical behaviour of iron in adsorptive systems is similar to that of indium. The metal concentrations in the aqueous solution were based on typical indium sulfate leach liquor obtained from zinc hydrometallurgical processing in a Brazilian plant. The ionic adsorption experiments were carried out by the continuous column method. Amberlite®IRC748 resin had a high affinity for indium under acidic conditions. Indium ions adsorbed onto the polymeric resin were eluted with a 0.5mol/dm³ sulphuric acid solution passed through the resin bed in the column. 99.5% pure indium sulfate aqueous solution was obtained using the iminodiacetic acid chelating resin Amberlite®IRC748.

  20. Determination of tellurium in ores, concentrates and related materials by graphite-furnace atomic-absorption spectrometry after separations by iron collection and xanthate extraction.

    Science.gov (United States)

    Donaldson, E M; Leaver, M E

    1990-02-01

    A method for determining approximately 0.01 mug/g or more of tellurium in ores, concentrates, rocks, soils and sediments is described. After sample decomposition and evaporation of the solution to incipient dryness, tellurium is separated from > 300 mug of copper by co-precipitation with hydrous ferric oxide from an ammoniacal medium and the precipitate is dissolved in 10M hydrochloric acid. Alternatively, for samples containing 300 mug of copper, the salts are dissolved in 10M hydrochloric acid. Tellurium in the resultant solutions is reduced to the quadrivalent state by heating and separated from iron, lead and various other elements by a single cyclohexane extraction of its xanthate complex from approximately 9.5M hydrochloric acid in the presence of thiosemicarbazide as a complexing agent for copper. After washing with 10M hydrochloric acid followed by water to remove residual iron, chloride and soluble salts, tellurium is stripped from the extract with 16M nitric acid and finally determined, in a 2% v/v nitric acid medium, by graphite-furnace atomic-absorption spectrometry at 214.3 nm in the presence of nickel as matrix modifier. Small amounts of gold and palladium, which are partly co-extracted as xanthates if the iron-collection step is omitted, do not interfere. Co-extraction of arsenic is avoided by volatilizing it as the bromide during the decomposition step. The method is directly applicable, without the co-precipitation step, to most rocks, soils and sediments.

  1. Possible prebiotics and gallic acid separations from jackfruit seed extract

    Directory of Open Access Journals (Sweden)

    Kulchanat Prasertsit

    2015-06-01

    Full Text Available A large amount of jackfruit seeds can be extracted for possible prebiotics and phenolics (gallic acid and purified by crystallization and solid phase extraction (SPE, respectively. The studied parameters for crystallization were mixing speed, crystallizing temperature and cooling rate while the studied parameters for SPE were feed concentration, feed flow rate and length to diameter ratio (L/D of the extraction column. The optimal condition for the crystallization provided the crystal yield of 0.028 g crystal /g dry extract at 100 rpm mixing speed, 58°C crystallizing temperature and 1°C /min cooling rate. Molecular weight analysis of the crystals indicated that the crystals can be fructo-oligosaccharide or raffinose. The optimal condition for SPE obtaining gallic acid 92 percent yield was at 4% w/v feed concentration with 3 mL/min flow rate and L/D of 15.3. Finally a high temperature can degrade both possible prebiotic and gallic acid.

  2. Complex Leaching Process of Scheelite in Hydrochloric and Phosphoric Solutions

    Science.gov (United States)

    Liu, Liang; Xue, Jilai; Liu, Kang; Zhu, Jun; Wang, Zengjie

    2016-09-01

    The complex leaching process of synthetic scheelite and scheelite concentrate in hydrochloric and phosphoric solutions has been investigated for improving process efficiency. A higher leaching rate, compared with the classic acid leaching process, can be obtained through the synergy of HCl and H3PO4 with appropriate W/P mole ratio, temperature, and acid concentration. For synthetic scheelite, the optimum leaching conditions were W/P mole ratio 7:1, temperature 50°C, HCl 0.72 mol/L, and stirring speed 600 rpm; for scheelite concentrate, W/P mole ratio 7:1, temperature 80°C, HCl 2.16 mol/L, and stirring speed 1000 rpm. The leaching rates under the optimized conditions can reach up to 98% or even higher. FTIR spectra analysis confirmed that the leachate composition remained as H3[PW12O40] in the range of varying W/P mole ratios, so the PO4 3- in acidic solution and phosphorus content in the leaching product could be better controlled. The function 1 - (1 - X)1/3 against leaching time was applied to fit the experimental data, and the apparent activation energy, E a, was calculated as 60.65 kJ/mol. The results would be valuable for effectively using scheelite as a raw material resource for sustainable tungsten production.

  3. Separation of Acetic Acid from Aqueous Solution using Various Organic Solvents

    Directory of Open Access Journals (Sweden)

    Md. Zaved Hossain Khan

    2014-01-01

    Full Text Available 800x600 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 In the study a model has been developed to separate the acetic acid from aqueous solution by liquid-liquid extraction and find out the proper solvent for this separation. Various solvents such as n-butanol, iso butanol, amyl alcohol and ethyl acetate are used for separation of acetic acid from water. The binodal curves (mutual solubility curves for acetic acid distributed between water and an organic solvent were obtained by titrating known mixtures of two components (water and solvents with the third component acetic acid to the point of first appearance of permanent turbidity. In order to determine the tie-lines, the absorbance of the coexisting phases, obtained by the separation of ternary mixtures within the binodal curve are needed to be determined. The absorbance of each point had been determined by a UV spectrophotometer. Distribution diagrams are obtained by plotting weight percent of acetic acid in solvent phase against the weight percent of acetic acid in water phase. Selectivity diagrams are also obtained by plotting (wt. % of acetic acid / (percent of acetic acid + percent of water in solvent phase against the same quantity in the diluent phase. The separation factor is determined numerically from the tie-line data.

  4. Magnetically separable nanoferrite-anchored glutathione: Aqueous homocoupling of arylboronic acids under microwave irradiation

    Science.gov (United States)

    A highly active, stable and magnetically separable glutathione based organocatalyst provided good to excellent yields to symmetric biaryls in the homocoupling of arylboronic acids under microwave irradiation. Symmetrical biaryl motifs are present in a wide range of natural p...

  5. SEPARATION OF POLONIUM, PROTACTINIUM OR MIXTURES THEREOF IN AQUEOUS SOLUTION FROM BISMUTH, LEAD, ZIRCONIUM AND/OR COLUMBIUM VALUES

    Science.gov (United States)

    Van Winkle, Q.; Kraus, K.A.

    1959-10-27

    A process is presented for separating polonium, protactinium, or mixtures thereof in aqueous solution from bismuth, zirconium, lead, and niobium values contained in the solution. The method comprises providing hydrochloric acid in the solution in a concentration of at least 5N. contacting the aqueous solution with a substantially waterimmiscible organic solvent such as diisopropyl ketone, and separating the aqueous phase containing the bismuth, zirconium, lead, and niobium from the organic extract phase containing the polonium, protactinium, or mixture thereof.

  6. Novel additives for the separation of organic acids by ion-pair chromatography

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This paper proposes the use of novel surfactant additives for the separation of organic acids by ion-pair chromatography and studies the influences of surfactants on the chromatographic separation behaviors.Researches have been carried out on both silica gel matrix and polymer supporters in order to compare the two ordinary kinds of stationary phases,and the phenomenon is similar. Separation is based on differences in the stabilities of analyte-additive complexes in solution.Retention times of analytes c...

  7. Separation of salvianic acid A from the fermentation broth of engineered Escherichia coli using macroporous resins.

    Science.gov (United States)

    Bai, Chen-Long; Zhao, Guang-Rong

    2015-08-01

    Salvianic acid A (also known as danshensu) is a plant-derived polyphenolic acid, and has a variety of physiological and pharmacological activities. Our laboratory previously constructed an unprecedented artificial biosynthetic pathway in Escherichia coli and established the fermentation process to produce salvianic acid A. Here, we developed an efficient method for separating salvianic acid A from the fermentation broth of engineered Escherichia coli by macroporous resins. Among ten tested macroporous resins, the static and dynamic adsorption/desorption experiments demonstrated that X5 resin was the best to separate salvianic acid A from fermentation broth. Other parameters during static and dynamic procedures were also investigated. Under the optimum separation conditions, the average adsorption capacity of SAA were 10.66±0.54 mg/g dry resin and the desorption ratio was 85.6±4.1%. The purity and recovery yield of salvianic acid A in the final dry product were 90.2±1.5 and 81.5±2.3%, respectively. The results show that adsorption separation with macroporous resin X5 was an efficient method to prepare salvianic acid A from fermentation broth. This work will benefit the development and application of plant-derived salvianic acid A and its derivatives. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Separation of Aliphatic and Aromatic Carboxylic Acids by Conventional and Ultra High Performance Ion Exclusion Chromatography.

    Science.gov (United States)

    Mansour, Fotouh R; Kirkpatrick, Christine L; Danielson, Neil D

    2013-06-01

    An ion exclusion chromatography (IELC) comparison between a conventional ion exchange column and an ultra-high performance liquid chromatography (UHPLC) dynamically surfactant modified C18 column for the separation of an aliphatic carboxylic acid and two aromatic carboxylic acids is presented. Professional software is used to optimize the conventional IELC separation conditions for acetylsalicylic acid and the hydrolysis products: salicylic acid and acetic acid. Four different variables are simultaneously optimized including H2SO4 concentration, pH, flow rate, and sample injection volume. Thirty different runs are suggested by the software. The resolutions and the time of each run are calculated and feed back to the software to predict the optimum conditions. Derringer's desirability functions are used to evaluate the test conditions and those with the highest desirability value are utilized to separate acetylsalicylic acid, salicylic acid, and acetic acid. These conditions include using a 0.35 mM H2SO4 (pH 3.93) eluent at a flow rate of 1 mL min(-1) and an injection volume of 72 μL. To decrease the run time and improve the performance, a UHPLC C18 column is used after dynamic modification with sodium dodecyl sulfate. Using pure water as a mobile phase, a shorter analysis time and better resolution are achieved. In addition, the elution order is different from the IELC method which indicates the contribution of the reversed-phase mode to the separation mechanism.

  9. A study of the clinical effect of combining use of budesonide and hydrochloric acid ammonia bromine using of ultrasonic atomization inhalation on treatment of infantile capillary bronchitis%布地奈德和盐酸氨溴索联合使用超声雾化吸入治疗婴幼儿毛细支气管炎的疗效观察

    Institute of Scientific and Technical Information of China (English)

    王海丽

    2014-01-01

    Objective To study the clinical effect of combining use of budesonide and hydrochloric acid ammonia bromine using ultrasonic atomization on treatment of infantile capillary bronchitis. Methods 80 cases of patients in our hospital were selected,randomly divided into experimental group and control group,each 40 cases,the experimental group were given basic treatment plus budesonide and ambroxol hydrochloride using ultrasonic atomizing inhalation,Compared the disappeared time of clinical symptoms and signs and the cure rate of the two groups. Results The time of clinical symptoms and signs in the experimental group were shorter than that of the observation group,the cure rate in the experimental group was significantly higher than the control group. Conclusion Using budesonide and hydrochloric acid ammonia bromine with ultrasonic atomization inhalation on treatment of infantile capillary bronchitis,can effectively shorten the time of dyspnea,suppress wheezing (such as clinical symptoms and signs of time,and improve the cure rate.The clinical application of the treatment is safe and convenient,is worth to clinical promotion.%目的:探讨布地奈德和盐酸氨溴索合用使用超声雾化治疗婴幼儿毛细支气管炎的临床效果。方法选80例来我院就诊的患儿随机分为实验组和对照组,各40例,实验组在采取基础治疗外加用布地奈德+盐酸氨溴索使用超声雾化吸入治疗,对比两组患儿临床症状、体征消失时间以及治愈率。结果实验组临床症状、体征时间均比观察组时间短,并且治愈率也明显高于对照组。结论布地奈德和盐酸氨溴索联合使用超声雾化吸入治疗婴幼儿毛细支气管炎,可以有效缩短患儿呼吸困难、憋喘等临床症状和体征缓解时间,并且提高治愈率,对于临床应用安全方便,值得临床推广。

  10. Response Surface Methodology for Optimization of Extraction Process for Soluble Dietary Fiber from Grape Pomace with Hydrochloric Acid%响应面法优化葡萄皮渣中可溶性膳食纤维的酸法提取工艺

    Institute of Scientific and Technical Information of China (English)

    杜彬; 李凤英; 范长军; 朱凤妹

    2011-01-01

    目的:利用响应面法对葡萄皮渣中可溶性膳食纤维的酸法提取工艺进行优化。方法:在单因素试验基础上选取试验因素与水平,根据Box-Behnken试验设计原理采用四因素三水平的响应面分析法,依据回归分析确定各工艺条件的影响因素,以可溶性膳食纤维得率为响应值作响应面和等高线图。结果:在分析各个因素的显著性和交互作用后,得出葡萄皮渣可溶性膳食纤维提取的最佳工艺为盐酸的浓度0.40mol/L、提取温度75℃、提取时间90min、料液比1:12(g/mL),在此工艺条件下可溶性膳食纤维得率为47.56mg/g。结论:响应面回归方程与实验结果拟合性好,此模型合理可靠,可用于实际预测。%Objective: To optimize the extraction of soluble dietary fiber(SDF) from grape pomace with hydrochloric acid.Methods: One-factor-at-a-time experiments,mathematical modeling based on Box-Behnken experimental design and multiple regression analysis and response surface analysis were carried out to investigate the individual and interactive effects of various process conditions on extraction yield of SDF and their significance.Response surface and contour plots were drawn with extraction yield of SDF as a function.Results: The optimal conditions for SDF extraction were 0.40 mol/L hydrochloric acid as extraction solvent at a material-to-liquid ratio of 1:12(g/mL) and 75 ℃ for an extraction duration of 90 min.Under the optimal extraction conditions,the yield of SDF was up to 47.56 mg/g,which was close to the model-predicted value.Conclusion: The developed regression equation can be well fitted with experimental results and is reasonable,reliable and applicable for actual prediction.

  11. Gas chromatography of volatile fatty acids. Method involving separation from biological material by vacuum distillation.

    Science.gov (United States)

    Tyler, J E; Dibdin, G H

    1975-02-19

    A method is described for the quantitation of C2-C5 volatile fatty acids present in biological tissues. It involved recovery of the acids from their biological matrix by vacuum micro-distillation at room temperature, followed by gas phase separation of aqueous solutions on orthophosphoric acid-modified Phasepak Q columns. The subsequent gas chromatographic procedure resolved iso from normal isomers and showed a linear response for each volatile acid over the range 10-400 ng. There was no evidence of ghosting, isomer peak broadening, or peak tailing. Relative molar response values were shown to be linear with carbon number for all the volatile fatty acids studied.

  12. Enrichment and separation of chlorogenic acid from the extract of Eupatorium adenophorum Spreng by macroporous resin.

    Science.gov (United States)

    Liu, Boyan; Dong, Beitao; Yuan, Xiaofan; Kuang, Qirong; Zhao, Qingsheng; Yang, Mei; Liu, Jie; Zhao, Bing

    2016-01-01

    A simple and efficient chromatographic method for separation of chlorogenic acid from Eupatorium adenophorum Spreng extract was developed. The adsorption properties of nine macroporous resins were evaluated. NKA-II resin showed much better adsorption/desorption properties. The adsorption of chlorogenic acid on NKA-II resin at 25°C was well fitted to Langmuir isotherm model and pseudo-second-order kinetic model. The dynamic adsorption and desorption experiments were carried out on columns packed with NKA-II resin to optimize the separation process. The content of chlorogenic acid in the product increased to 22.17%, with a recovery yield of 82.41%.

  13. Acid natural clinoptilolite: structural properties against adsorption/separation of n-paraffins.

    Science.gov (United States)

    Rivera, Aramis; Farías, Tania; de Ménorval, Louis Charles; Autié-Castro, Giselle; Yee-Madeira, Hernany; Contreras, José Luis; Autié-Pérez, Miguel

    2011-08-01

    The employment of an acid natural clinoptilolite (AZH-1) in the adsorption and separation of n-paraffins has been evaluated. Natural clinoptilolite, NZ, was the raw material used to prepare the sodium-exchanged clinoptilolite (AZ) starting from which the AZH-1 sample was obtained by acid treatment. The structural stability of the samples after the applied treatments was demonstrated. The nitrogen adsorption experiments indicated that the acid sample has a homogeneous porous distribution and a considerable increase in the micropore volume with respect to NZ and AZ. The employment of the inverse gas chromatography at infinite dilution (IGCID) allowed studying the adsorption and separation of n-paraffin mixtures on AZH-1. It was also confirmed that the diffusion on AZH-1 took place in an unblocked structure through the A channel of ten members with minimal interactions. The IGCID results demonstrated the capacities of the acid Cuban natural zeolite in the adsorption and separation of n-paraffin mixtures.

  14. Fluorescent Boronic Acid Polymer Grafted on Silica Particles for Affinity Separation of Saccharides

    Science.gov (United States)

    2014-01-01

    Boronic acid affinity gels are important for effective separation of biological active cis-diols, and are finding applications both in biotech industry and in biomedical research areas. To increase the efficacy of boronate affinity separation, it is interesting to introduce repeating boronic acid units in flexible polymer chains attached on solid materials. In this work, we synthesize polymer brushes containing boronic acid repeating units on silica gels using surface-initiated atom transfer radical polymerization (ATRP). A fluorescent boronic acid monomer is first prepared from an azide-tagged fluorogenic boronic acid and an alkyne-containing acrylate by Cu(I)-catalyzed 1,3-dipolar cycloaddition reaction (the CuAAC click chemistry). The boronic acid monomer is then grafted to the surface of silica gel modified with an ATRP initiator. The obtained composite material contains boronic acid polymer brushes on surface and shows favorable saccharide binding capability under physiological pH conditions, and displays interesting fluorescence intensity change upon binding fructose and glucose. In addition to saccharide binding, the flexible polymer brushes on silica also enable fast separation of a model glycoprotein based on selective boronate affinity interaction. The synthetic approach and the composite functional material developed in this work should open new opportunities for high efficiency detection, separation, and analysis of not only simple saccharides, but also glycopeptides and large glycoproteins. PMID:24444898

  15. Research on Application of HPLC in Measuring Concentration of Hydrochloric Acid Palmatine in Rat Serum%高效液相色谱-荧光检测法在大鼠血清中盐酸黄藤素浓度测定中的应用研究

    Institute of Scientific and Technical Information of China (English)

    周小虎

    2015-01-01

    目的:建立大鼠血清中盐酸黄藤素浓度的反相高效液相色谱-荧光检测方法,并应用于大鼠口服盐酸黄藤素制剂后药物体内药动学过程测定。方法色谱条件:Diamonsil C18柱流动相:0.01mol/L 磷酸二氢钾缓冲液-乙腈(40:60);流速:1.0mL/min;荧光检测波长:λEx =310 nm,λEm =360 nm。动物实验:给予6只 wistar 大鼠口服盐酸黄藤素片,尾静脉取血测定血药浓度,数据经3P97药动学软件包处理,计算药物体内药动学参数。结果黄藤素线性回归方程为:C =6.1050A ×10-4+7.3×10-3(r =0.9997),盐酸黄藤素血清浓度在0.04mg/L -0.4mg/L 范围内与峰面积呈良好的线性关系。低、中、高3个浓度日内及日间精密度试验 RSD 均小于10%。稳定性良好(RSD =1.77%)。盐酸黄藤素在大鼠体内表现为两室模型药动学过程。按30mg/kg 剂量灌胃给药,测得血药浓度达峰时间为(0.30±0.04)h,血药峰浓度为15.27μg/L,消除速率常数为0.2031(1/h)。结论本研究建立的高效液相色谱-荧光检测大鼠血清中盐酸黄藤素浓度方法灵敏度高,专属性强,稳定性好,能快速、准确地测定大鼠血清中盐酸黄藤素浓度,适用于盐酸黄藤素新制剂大鼠体内过程实验的血清药物浓度测定。%s:Objective Establish reversed -phase high -performance liquid chromatography – fluorescence detection method of the hy -drochloric acid palmatine concentration in rat serum , and apply it in measuring the pharmacokinetics process in the medicine after the rat takes the hydrochloric acid palmatine preparations orally .Methods Chromatographic condition: Diamonsil C18 , mobile phase: 0.01mol /L monopotassium phosphate buffer solution :acetonitrile (40:60); flow velocity: 1.0mL/min; fluorescence detection wave length :λEx =310nm,λEm =360nm.Animal experiment: let 6 wistar rats

  16. SEPARATION OF HAFNIUM FROM ZIRCONIUM

    Science.gov (United States)

    Overholser, L.B.; Barton, C.J. Sr.; Ramsey, J.W.

    1960-05-31

    The separation of hafnium impurities from zirconium can be accomplished by means of organic solvent extraction. The hafnium-containing zirconium feed material is dissolved in an aqueous chloride solution and the resulting solution is contacted with an organic hexone phase, with at least one of the phases containing thiocyanate. The hafnium is extracted into the organic phase while zirconium remains in the aqueous phase. Further recovery of zirconium is effected by stripping the onganic phase with a hydrochloric acid solution and commingling the resulting strip solution with the aqueous feed solution. Hexone is recovered and recycled by means of scrubbing the onganic phase with a sulfuric acid solution to remove the hafnium, and thiocyanate is recovered and recycled by means of neutralizing the effluent streams to obtain ammonium thiocyanate.

  17. Aliphatic carboxylic acids as new modifiers for separation of 2,4-dinitrophenyl amino acids by micellar liquid chromatography.

    Science.gov (United States)

    Boichenko, Alexander P; Kulikov, Artem U; Loginova, Lidia P; Iwashchenko, Anna L

    2007-07-20

    The possibilities of isocratic separation of 2,4-dinitrophenyl derivatives of 12 amino acids that considerably differ in hydrophobicity by micellar mobile phases with different organic modifiers have been discussed. For the first time aliphatic carboxylic acids have been used as modifiers of micellar eluent in micellar liquid chromatography with C18 columns. Elution strength of hybrid micellar phases on the basis of sodium dodecylsulfate and aliphatic carboxylic acids increases in sequence: aceticacid. The effect of sodium dodecylsulfate micelles on aliphatic carboxylic acids has been characterized by their micellar-induced shifts of ionization constants. The use of aliphatic carboxylic acids as modifiers of SDS micellar eluents provides better overall resolution of 2,4-dinitrophenyl-amino acids in comparison with aliphatic alcohols.

  18. Determination of silver in miscellaneous copper materials in hydrochloric acid medium by ammonia leaching-flame atomic absorption spectrometry%氨水浸取-盐酸介质火焰原子吸收光谱法测定杂铜物料中的银

    Institute of Scientific and Technical Information of China (English)

    肖红新

    2014-01-01

    The sample is dissolved in aqua regia and silver is leached by ammonia ,most other metallic elements are precipitated at the same time ,eliminating the interference .In 10%hydrochloric acid medium ,under the set equip-ment working conditions ,silver content was determined by flame atomic absorption spectrometry .The relatively stand-ard deviation of the determination results is less than 1 %.%采用王水溶解样品,氨水浸取银,同时沉淀分离大部分其他金属元素,消除其他元素干扰;在10%的盐酸介质中,在设定的仪器工作条件下,采用火焰原子吸收光谱法测定杂铜物料中的银。该方法简单快速、准确可靠,测定结果相对标准偏差小于1%。

  19. Separation of Six Pyridoncarboylxic Acid Derivatives by Micellar and Microemulsion Electrokinetic Chromatography

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Micellar and microemulsion electrokinetic chromatography (MEKC & MEEKC) separation of six closely structural pyridoncarboylxic acid derivatives were studied and compared. Both anionic surfactant sodium dodecyl sulfate (SDS) and cationic surfactant hexadecyl-trimethyl ammonium bromide (CTAB) were used to form micellar and microemulsion as pseudostation phases, respectively. The effects of the separation conditions on retention time and selectivity were studied. Good resolutions were obtained in selected systems, indicating that there is markably different selectivity between SDS and CTAB systems.

  20. Separation of Erucic Acid from Rape-Seed Oil Using Supercritical Carbon Dioxide with Entrainer

    Institute of Scientific and Technical Information of China (English)

    云志; 钱仁渊; 等

    2002-01-01

    Separation of erucic acid from rape-seed oil using supercritical carbon dioxide with entrainer was carried on a pilot column with an inner diameter 14 mm and an effective total height 2.2m.Experiments were focused on the effects of entrainers.i.e.acetone.ethanol and ethyl acetate,on the extraction.It is showed that entrainers made selectivity lower,but separation time shorter.

  1. Review and assessment of technologies for the separation of cesium from acidic media

    Energy Technology Data Exchange (ETDEWEB)

    Orth, R.J.; Brooks, K.P.; Kurath, D.E.

    1994-09-01

    A preliminary literature survey has been conducted to identify and evaluate methods for the separation of cesium from acidic waste. The most promising solvent extraction, precipitation, and ion exchange methods, along with some of the attributes for each method, are listed. The main criteria used in evaluating the separation methods were as follows: (1) good potential for cesium separation must be demonstrated (i.e., cesium decontamination factors on the order of 50 to 100). (2) Good selectivity for cesium over bulk components must be demonstrated. (3) The method must show promise for evolving into a practical and fairly simple process. (4) The process should be safe to operate. (5) The method must be robust (i.e., capable of separating cesium from various acidic waste types). (6) Secondary waste generation must be minimized. (7) The method must show resistance to radiation damage. The most promising separation methods did not necessarily satisfy all of the above criteria, thus key areas requiring further development are suggested for each method. The report discusses in detail these and other areas requiring further development, as well as alternative solvent extraction, precipitation, ion exchange, and {open_quote}other{close_quote} technologies that, based on current information, show less promise for the separation of cesium from acidic wastes because of significant process limitations. When appropriate, the report recommends areas of future development.

  2. Modification of HZSM- 5 Zeolite by Hydrochloric Acid and Catalytic Performance of Mo - based Catalyst for Methane Dehydroaromatization Reaction%盐酸改性HZSM-5及Mo-基催化剂的MDA反应活性

    Institute of Scientific and Technical Information of China (English)

    王红霞; 赵婷婷

    2012-01-01

    采用盐酸溶液在303K对HZSM-5分子筛进行预处理,并以处理后的分子筛制备相应的Mo-基催化剂.分子筛和催化剂采用XRD和NH3-TPD等手段进行表征,利用甲烷无氧芳构化(MDA)反应评价Mo-基催化剂的催化活性.结果表明,指定实验条件下的盐酸处理在一定程度上降低了分子筛的结晶度,降低了分子筛上的B酸量,改性后的Mo-基催化剂在MDA反应中表现很好的稳定性.%The pretreatment with HC1 solution at 303 K was applied to modify HZSM -5 zeolite, and the Mobased catalysts were prepared by using the modified HZSM -5 zeolite as support and tested for catalytic performance of methane dehydroaromatization reaction. The modified Mo - based catalysts show a higher stability than that of Mo/HZSM - 5 catalyst prepared with unmodified with HZSM - 5 zeolite. The effect of acid treatment on the structure and acidity of HZSM - 5 zeolite and Mo - based catalysts were studied by XRD and NH3 - TPD methods. The results show that the acid treatment to HZSM - 5 at given experimental conditions led to a decrease in the crystallinity of HZSM -5 zeolite and the number of the Brnsted acid sites to a certain degree.

  3. Large-scale separation of amino acids by continuous displacement chromatography

    Energy Technology Data Exchange (ETDEWEB)

    DeCarli, J.P. II; Carta, G.; Byers, C.H.

    1989-10-01

    Continuous annular chromatography (CAC) is a developing technology that allows truly continuous chromatographic separations. Previous work has demonstrated the utility of this technology for the separation of various materials by isocratic elution on a bench scale. Novel applications and improved operation of the process were studied in this work, demonstrating that CAC is a versatile apparatus which is capable of separations at high throughput. Three specific separation systems were investigated. Pilot-scale separations at high loadings were performed using an industrial sugar mixture as an example of scale-up for isocratic separations. Bench-scale experiments of a low concentration metal ion mixture were performed to demonstrate stepwise elution, a chromatographic technique which decreases dilution and increases sorbent capacity. Finally, the separation of mixtures of amino acids by ion exchange was investigated to demonstrate the use of displacement development on the CAC. This technique, which perhaps has the most potential, when applied to the CAC allowed simultaneous separation and concentration of multicomponent mixtures on a continuous basis. Mathematical models were developed to describe the CAC performance and optimize the operating conditions. For all the systems investigated, the continuous separation performance of the CAC was found to be very nearly the same as the batchwise performance of conventional chromatography. The technology appears, thus, to be very promising for industrial applications.

  4. Controllable Phase Separation by Boc-Modified Lipophilic Acid as a Multifunctional Extractant

    Science.gov (United States)

    Tao, Kai; Adler-Abramovich, Lihi; Gazit, Ehud

    2015-12-01

    While phase separation of immiscible liquid-liquid systems has become increasingly significant in diverse areas, the irreversible nature limits their further application in controllable extraction-concentration or capture-release fields. There is a need for the development of simple, efficient and reversible methods for numerous research and industrial extraction and separation applications. We envisioned Boc-modified lipophilic acids as a simple model for such use based on the studies of the multi-phase transitions of Boc-modified supramolecular polymeric systems. Here, we demonstrate that in the presence of Boc-7-aminoheptanoic acid (Boc-7), phase separation occurs in mixtures of miscible organic solvent and water. The separation behavior was confirmed by differential colorimetric development in aqueous and organic phases using methyl orange staining assays. Component substitution experiments verified that the phase separation results from the subtle balance between the aggregation and the solvation forces of Boc-7, and is reversible by adjusting the solution pH. Owing to the intrinsic hydrophobic properties of the organic phase and the hydrogen bonding-forming ability of the carboxyl group of Boc-7, the phase separation system captures and releases Sudan Red, fluorescein, and streptavidin in a controllable manner. Consequently, a reversible and simple phase separation system can be designed as a multifunctional extractant.

  5. Scaleable production and separation of fermentation-derived acetic acid. Final CRADA report.

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, S. W.; Energy Systems

    2010-02-08

    Half of U.S. acetic acid production is used in manufacturing vinyl acetate monomer (VAM) and is economical only in very large production plants. Nearly 80% of the VAM is produced by methanol carbonylation, which requires high temperatures and exotic construction materials and is energy intensive. Fermentation-derived acetic acid production allows for small-scale production at low temperatures, significantly reducing the energy requirement of the process. The goal of the project is to develop a scaleable production and separation process for fermentation-derived acetic acid. Synthesis gas (syngas) will be fermented to acetic acid, and the fermentation broth will be continuously neutralized with ammonia. The acetic acid product will be recovered from the ammonium acid broth using vapor-based membrane separation technology. The process is summarized in Figure 1. The two technical challenges to success are selecting and developing (1) microbial strains that efficiently ferment syngas to acetic acid in high salt environments and (2) membranes that efficiently separate ammonia from the acetic acid/water mixture and are stable at high enough temperature to facilitate high thermal cracking of the ammonium acetate salt. Fermentation - Microbial strains were procured from a variety of public culture collections (Table 1). Strains were incubated and grown in the presence of the ammonium acetate product and the fastest growing cultures were selected and incubated at higher product concentrations. An example of the performance of a selected culture is shown in Figure 2. Separations - Several membranes were considered. Testing was performed on a new product line produced by Sulzer Chemtech (Germany). These are tubular ceramic membranes with weak acid functionality (see Figure 3). The following results were observed: (1) The membranes were relatively fragile in a laboratory setting; (2) Thermally stable {at} 130 C in hot organic acids; (3) Acetic acid rejection > 99%; and (4

  6. 盐酸介质磷钒钼黄直接光度法快速测定钒浸出液中的磷%Rapid phosphorus analysis in vanadium- leached solution using direct absorbance measurement in hydrochloric acid media phosphorus - vanadium - molybdenum yellow system

    Institute of Scientific and Technical Information of China (English)

    刘继宁; 马庆; 刘忠文; 党岚

    2001-01-01

    Compared with analytical characteristics and interfering factors for different media, hydrochloric acid was chosen as media in direct absorbance measurement to analyse phosphorus of Vanadium - leached solution.In this method, ammonium sodium was chosen as chromogenic agent, under the conditions that: the coloration acidity is 1.2 N, λ = 430 nm, ε = 1 300. We concluded that when phosphorus content is between 0 ~ 400 μg,Beer' s law is obeyed; when phosphorus content is lower limit 1.67 μg(3s), the coexistence components don' t interfere with phosphorus; when phosphorus content is 50 ~ 350 μg, the adding standard sample rate of recovery is 97.76% ~ 102. 1%; when phosphorus content is 100 μg, eleven times analyses are made and given. RSD =1.52% and X = 100. 48 μ-g.%研究了不同介质中钒钼黄法的分析特性和干扰因素,选定盐酸介质建立了快速分析钒浸出液中磷的直接光度法.该方法用钼酸钠作显色剂,显色酸度1.2 N,λ=430 nm,ε=1300,0~400μg线性良好;检测下限1.67μg(3s),共存组分无干扰,50~350μg加标回收率97.6%~102.1%,100μg中重复11次分析,RSD=1.52%,X=100.48μg.

  7. Design of simulated moving bed for separation of fumaric acid with a little fronting phenomenon.

    Science.gov (United States)

    Choi, Jae-Hwan; Kang, Mun-Seok; Lee, Chung-Gi; Wang, Nien-Hwa Linda; Mun, Sungyong

    2017-03-31

    The production of fumaric acid through a biotechnological pathway has grown in importance because of its potential value in related industries. This has sparked an interest in developing an economically-efficient process for separation of fumaric acid (product of interest) from acetic acid (by-product). This study aimed to develop a simulated moving bed (SMB) chromatographic process for such separation in a systematic way. As a first step for this work, commercially available adsorbents were screened for their applicability to the considered separation, which revealed that an Amberchrom-CG71C resin had a sufficient potential to become an adsorbent of the targeted SMB. Using this adsorbent, the intrinsic parameters of fumaric and acetic acids were determined and then applied to optimizing the SMB process under consideration. The optimized SMB process was tested experimentally, from which the yield of fumaric-acid product was found to become lower than expected in the design. An investigation about the reason for such problem revealed that it was attributed to a fronting phenomenon occurring in the solute band of fumaric acid. To resolve this issue, the extent of the fronting was evaluated quantitatively using an experimental axial dispersion coefficient for fumaric acid, which was then considered in the design of the SMB of interest. The SMB experimental results showed that the SMB design based on the consideration of the fumaric-acid fronting could guarantee the attainment of both high purity (>99%) and high yield (>99%) for fumaric-acid product under the desorbent consumption of 2.6 and the throughput of 0.36L/L/h. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Separation of free fatty acids from high free fatty acid crude palm oil using short-path distillation

    Science.gov (United States)

    Japir, Abd Al-Wali; Salimon, Jumat; Derawi, Darfizzi; Bahadi, Murad; Yusop, Muhammad Rahimi

    2016-11-01

    The separation of free fatty acids (FFAs) was done by using short-path distillation (SPD). The separation parameters was at their boiling points, a feed amount of 2.3 mL/min, an operating pressure of 10 Torr, a condenser temperature of 60°C, and a rotor speed of 300 rpm. The physicochemical characteristics of oil before and after SPD were determined. The results showed that FFA % of 8.7 ± 0.3 and 0.9 ± 0.1 %, iodine value of 53.1 ± 0.4 and 52.7 ± 0.5 g I2/100 g, hydroxyl value of 32.5 ± 0.6 and 13.9 ± 1.1 mg KOH/g, unsaponifiable value of 0.31 ± 0.01 and 0.20 ± 0.15%, moisture content of 0.31 ± 0.01 and 0.24 ± 0.01 % for high free fatty acid crude palm oil before and after distillation, respectively. Gas chromatography (GC) results showed that the major fatty acids in crude palm oil (CPO) were palmitic acid (44.4% - 45%) followed by oleic acid (39.6% - 39.8%). In general, high free fatty acid crude palm oil after molecular distillation (HFFA-CPOAM) showed admirably physicochemical properties.

  9. Simultaneous isocratic separation of phenolic acids and flavonoids using micellar liquid chromatography.

    Science.gov (United States)

    Hadjmohammadi, Mohammad Reza; Nazari, S Saman S J

    2013-12-01

    The simultaneous isocratic separation of a mixture of five phenolic acids and four flavonoids (two important groups of natural polyphenolic compounds with very different polarities) was investigated in three different RPLC modes using a hydro-organic mobile phase, and mobile phases containing SDS at concentrations below and above the critical micellar concentration (submicellar LC and micellar LC (MLC), respectively). In the hydro-organic mode, methanol and acetonitrile; in the submicellar mode methanol; and in the micellar mode, methanol and 1-propanol were examined individually as organic modifiers. Regarding the other modes, MLC provided more appropriate resolutions and analysis time and was preferred for the separation of the selected compounds. Optimization of separation in MLC was performed using an interpretative approach for each alcohol. In this way, the retention of phenolic acids and flavonoids were modeled using the retention factors obtained from five different mobile phases, then the Pareto optimality method was applied to find the best compatibility between analysis time and quality of separation. The results of this study showed some promising advantages of MLC for the simultaneous separation of phenolic acids and flavonoids, including low consumption of organic solvent, good resolution, short analysis time, and no requirement of gradient elution.

  10. Separation and concentration of lanthanoids using microcapsules containing acidic organophosphorus compounds as an extractant

    Energy Technology Data Exchange (ETDEWEB)

    Kamio, Eiji; Kondo, Kazuo [Doshisha Univ., Department of Chemical Engineering and Materials Science, Kyoto (Japan)

    2002-06-01

    In this study, we measured the extraction equilibria of lanthanoids with microcapsules containing acidic organophosphorus compound as an extractant and discuss their mutual separation by using a column packed with the microcapsules. The extraction equilibria of lanthanoids into the microcapsules containing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (EHPNA) were elucidated and the extraction equilibrium constants were calculated by slope-analysis method. It was suggested that the lanthanoid ions are extracted in the microcapsules in a high loading state. Furthermore, the adsorption behavior of lanthanoids into the column packed with the microcapsules containing EHPNA was observed. It was found that adsorption and elution of lanthanoids are briefly achieved by selecting pH of the feed aqueous solution. However, it was impossible to separate them only in adsorption or elution operation. So, the mutual separation of lanthanoids was investigated using the adsorption column connected to the development column containing microcapsules. By selecting pH of the eluent, each metal was separated mutually in more than 95% of purity. The metal ions in the eluent from the development column could be concentrated by treating it with a column packed with the microcapsules containing di(2-ethylhexyl) phosphoric acid (D2EHPA). Considering these information, it will be possible to design a continuous extracting, separating and concentrating reactor of lanthanoids using a column packed with the microcapsules. (author)

  11. Microsystems for anion exchange separation of radionuclides in nitric acid media

    Energy Technology Data Exchange (ETDEWEB)

    Losno, M.; Brennetot, R.; Mariet, C. [DEN/Service d' Etudes Analytiques et de Reactivite des Surfaces - SEARS, CEA, Centre de Saclay, Universite Paris-Saclay, F-91191, Gif sur Yvette (France); Ferrante, I.; Descroix, S. [MMBM Group, Institut Curie Research Center, CNRS UMR 168, Paris (France)

    2016-07-01

    An efficient and reproducible photo-polymerized poly(ethylene glycol methacrylate methacrylate-co- allyl methacrylate) monolith was synthesized and a photo-grafting process based on the ene-thiol click-chemistry has been performed to give anion exchange properties to the monolith. Since their introduction in the early 1990's polymethacrylate monoliths have emerged as a powerful alternative for microscale separations or sample treatment. Their relatively simple implementation in columns with small internal diameters makes them particularly attractive for the new chromatographic challenges of complex matrices analysis and on-chip separations. Despite their relatively poor ion-exchange capacity due to their highly porous structure, their use as anion exchangers is of large interest for nuclear analysis as numerous separations are based on this process. This paper presents a systematic study of the synthesis of the polymeric porous monolith and the versatile and robust functionalization method developed for the specific strong acidic media used in radiochemical procedures. The robustness of the stationary phase was tested in concentrated nitric acid. It appears that the C-S bond formed via thiol-ene chemistry is strong enough to be used to graft function of interest for separation in strong nitric acid medium. The photo-grafted anion exchanger, a quaternary ammonium, presents sufficient resistance to be used for radionuclide separation in [HNO{sub 3}]=5 mol.L{sup -1}so the next step is its integration in the cyclo olefin copolymer (COC) micro-system.

  12. 盐酸液中钇(Ⅲ)和铕(Ⅲ)的P507溶剂萃取平衡分析%Equilibrium analysis of solvent extraction of yttrium(Ⅲ)and europium(Ⅲ)from hydrochloric acid with P507

    Institute of Scientific and Technical Information of China (English)

    付念新; 隋智通; Mikiya TANAKA

    2011-01-01

    为了精确预测非理想条件下稀土金属溶剂萃取的平衡分配比,研究了溶于Shellsol D70中的P507溶剂对盐酸液中钇(Ⅲ)和铕(Ⅲ)的萃取平衡,建立化学基模型,并通过非线性最小二乘法确定萃取平衡常数.所建模型涉及了在低酸度区的离子交换反应和高酸度区的溶剂化萃取反应;模型还考虑了稀土金属与Cl-的配位反应,并用萃取剂的有效浓度代替[(HR)2],进而分别对水相和有机相(HR2)的非理想性加以修正.对稀土单元体系,在较宽的初始浓度范围内(稀土浓度最高至0.1 mol/L,盐酸浓度0.07-3.00 mol/L,萃取剂浓度0.25-1.00 mol/L),由模型计算的稀土分配比与实验测得的数据吻合良好,验证了模型的有效性.对于稀土二元体系,该模型能以良好的精度对平衡分配比进行工程预测.%For the accurate prediction of equilibrium distribution ratios of rare earth metals during solvent extraction under non-ideal conditions,the extraction equilibria of yttrium(Ⅲ)and europium(Ⅲ)from the hydrochloric acid solutions with P507 in Shellsoi D70 were studied.A chemically-based model was established and the extraction equilibrium constants were determined by the nonlinear least squares method.The proposed model involves the cation exchange reaction and the solvation extraction in the low and high acidity regions,respectively.In the model,the nonideality of the aqueous phase and(HR)2 was corrected by considering the complexation of the metals with(Cl-)and by replacing[(HR)2]with its effective concentration,respectively.This model was verified by fair agreement between the calculated metal distribution ratios and those experimentally obtained in the single metal systems.The feed concentrations for the systems are in wide ranges of the metal(up to 0.1 mol/L),hydrochloric acid(0.07-3.00 mol/L)and the extractant(0.25-1.00 mol/L).The model enables the engineering prediction of the equilibrium distribution ratios with good

  13. SEPARATION OF T-MAZ ETHOXYLATED SORBITAN FATTY ACID ESTERS BY SUPERCRITICAL FLUID CHROMATOGRAPHY

    Science.gov (United States)

    The application of supercritical fluid chromatography (SFC) to the analysis of T-MAZ ethoxylated sorbitan fatty acid esters is described. FC separation methods utilize a density programming technique and a 50 um I.D. capillary column. his work demonstrates that capillary column S...

  14. cis,cis-Muconic acid: separation and catalysis to bio-adipic acid for nylon-6,6 polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Vardon, Derek R.; Rorrer, Nicholas A.; Salvachúa, Davinia; Settle, Amy E.; Johnson, Christopher W.; Menart, Martin J.; Cleveland, Nicholas S.; Ciesielski, Peter N.; Steirer, K. Xerxes; Dorgan, John R.; Beckham, Gregg T.

    2016-01-01

    cis,cis-Muconic acid is a polyunsaturated dicarboxylic acid that can be produced renewably via the biological conversion of sugars and lignin-derived aromatic compounds. Subsequently, muconic acid can be catalytically converted to adipic acid -- the most commercially significant dicarboxylic acid manufactured from petroleum. Nylon-6,6 is the major industrial application for adipic acid, consuming 85% of market demand; however, high purity adipic acid (99.8%) is required for polymer synthesis. As such, process technologies are needed to effectively separate and catalytically transform biologically derived muconic acid to adipic acid in high purity over stable catalytic materials. To that end, this study: (1) demonstrates bioreactor production of muconate at 34.5 g L-1 in an engineered strain of Pseudomonas putida KT2440, (2) examines the staged recovery of muconic acid from culture media, (3) screens platinum group metals (e.g., Pd, Pt, Rh, Ru) for activity and leaching stability on activated carbon (AC) and silica supports, (4) evaluates the time-on-stream performance of Rh/AC in a trickle bed reactor, and (5) demonstrates the polymerization of bio-adipic acid to nylon-6,6. Separation experiments confirmed AC effectively removed broth color compounds, but subsequent pH/temperature shift crystallization resulted in significant levels of Na, P, K, S and N in the crystallized product. Ethanol dissolution of muconic acid precipitated bulk salts, achieving a purity of 99.8%. Batch catalysis screening reactions determined that Rh and Pd were both highly active compared to Pt and Ru, but Pd leached significantly (1-9%) from both AC and silica supports. Testing of Rh/AC in a continuous trickle bed reactor for 100 h confirmed stable performance after 24 h, although organic adsorption resulted in reduced steady-state activity. Lastly, polymerization of bio-adipic acid with hexamethyldiamine produced nylon-6,6 with comparable properties to its petrochemical counterpart

  15. Separation and purification of hyaluronic acid by glucuronic acid imprinted microbeads

    Energy Technology Data Exchange (ETDEWEB)

    Akdamar, H.Acelya; Sarioezlue, Nalan Yilmaz [Department of Biology, Anadolu University, Eskisehir (Turkey); Ozcan, Ayca Atilir; Ersoez, Arzu [Department of Chemistry, Anadolu University, Eskisehir (Turkey); Denizli, Adil [Department of Chemistry, Hacettepe University, Ankara (Turkey); Say, Ridvan, E-mail: rsay@anadolu.edu.tr [Department of Chemistry, Anadolu University, Eskisehir (Turkey); BIBAM (Plant, Drug and Scientific Researches Center), Anadolu University, Eskisehir (Turkey)

    2009-05-05

    The purification of hyaluronic acid (HA) is relatively significant to use in biomedical applications. The structure of HA is formed by the repetitive units of glucuronic acid and N-acetyl glucosamine. In this study, glucuronic acid-imprinted microbeads have been supplied for the purification of HA from cell culture (Streptococcus equi). Histidine-functional monomer, methacryloylamidohistidine (MAH) was chosen as the metal-complexing monomer. The glucuronic acid-imprinted poly(ethyleneglycoldimethacrylate-MAH-Copper(II)) [p(EDMA-MAH-Cu{sup 2+})] microbeads have been synthesized by typical suspension polymerization procedure. The template glucuronic acid has been removed by employing 5 M methanolic KOH solution. p(EDMA-MAH-Cu{sup 2+}) microbeads have been characterized by elemental analysis, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) images and swelling studies. Moreover, HA adsorption experiments have been performed in a batch experimental set-up. Purification of HA from cell culture supernatant has been also investigated by determining the hyaluronidase activity using purified HA as substrate. The glucuronic acid imprinted p(EDMA-MAH-Cu{sup 2+}) particles can be used many times with no significant loss in adsorption capacities. Also, the selectivity of prepared molecular imprinted polymers (MIP) has been examined. Results have showed that MIP particles are 19 times more selective for glucuronic acid than N-acetylglucose amine.

  16. Separation and Concentration of Indium from Leaching Solution Containing Indium, Antimony and Iron Ions

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Processing conditions of effectively separating indium from the leaching solution of a smelting antimony slag were studied. For the leaching solution containing indium and antimony and iron ions, indium was separated by extracting with HDEHP-kerosine solution, washing antimony and iron ions with oxalic acid solution and stripping indium with a dilute solution of hydrochloric acid. InCl3 solution with purity above 90% is obtained. Indium can be enriched through a circulation of stripping with a dilute HCl solution. The concentration of InCl3 solution is about 25~30 g/L.

  17. Separate and Concentrate Lactic Acid Using Combination of Nanofiltration and Reverse Osmosis Membranes

    Science.gov (United States)

    Li, Yebo; Shahbazi, Abolghasem; Williams, Karen; Wan, Caixia

    The processes of lactic acid production include two key stages, which are (a) fermentation and (b) product recovery. In this study, free cell of Bifidobacterium longum was used to produce lactic acid from cheese whey. The produced lactic acid was then separated and purified from the fermentation broth using combination of nanofiltration and reverse osmosis membranes. Nanofiltration membrane with a molecular weight cutoff of 100-400 Da was used to separate lactic acid from lactose and cells in the cheese whey fermentation broth in the first step. The obtained permeate from the above nanofiltration is mainly composed of lactic acid and water, which was then concentrated with a reverse osmosis membrane in the second step. Among the tested nanofiltration membranes, HL membrane from GE Osmonics has the highest lactose retention (97±1%). In the reverse osmosis process, the ADF membrane could retain 100% of lactic acid to obtain permeate with water only. The effect of membrane and pressure on permeate flux and retention of lactose/lactic acid was also reported in this paper.

  18. Nanofiltration, bipolar electrodialysis and reactive extraction hybrid system for separation of fumaric acid from fermentation broth.

    Science.gov (United States)

    Prochaska, Krystyna; Staszak, Katarzyna; Woźniak-Budych, Marta Joanna; Regel-Rosocka, Magdalena; Adamczak, Michalina; Wiśniewski, Maciej; Staniewski, Jacek

    2014-09-01

    A novel approach based on a hybrid system allowing nanofiltration, bipolar electrodialysis and reactive extraction, was proposed to remove fumaric acid from fermentation broth left after bioconversion of glycerol. The fumaric salts can be concentrated in the nanofiltration process to a high yield (80-95% depending on pressure), fumaric acid can be selectively separated from other fermentation components, as well as sodium fumarate can be conversed into the acid form in bipolar electrodialysis process (stack consists of bipolar and anion-exchange membranes). Reactive extraction with quaternary ammonium chloride (Aliquat 336) or alkylphosphine oxides (Cyanex 923) solutions (yield between 60% and 98%) was applied as the final step for fumaric acid recovery from aqueous streams after the membrane techniques. The hybrid system permitting nanofiltration, bipolar electrodialysis and reactive extraction was found effective for recovery of fumaric acid from the fermentation broth. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Separation of aliphatic carboxylic acids and benzenecarboxylic acids by ion-exclusion chromatography with various cation-exchange resin columns and sulfuric acid as eluent.

    Science.gov (United States)

    Ohta, Kazutoku; Ohashi, Masayoshi; Jin, Ji-Ye; Takeuchi, Toyohide; Fujimoto, Chuzo; Choi, Seong-Ho; Ryoo, Jae-Jeong; Lee, Kwang-Pill

    2003-05-16

    The application of various hydrophilic cation-exchange resins for high-performance liquid chromatography (sulfonated silica gel: TSKgel SP-2SW, carboxylated silica gel: TSKgel CM-2SW, sulfonated polymethacrylate resin: TSKgel SP-5PW, carboxylated polymethacrylate resins: TSKgel CM-5PW and TSKgel OA-Pak A) as stationary phases in ion-exclusion chromatography for C1-C7 aliphatic carboxylic acids (formic, acetic, propionic, butyric, isovaleric, valeric, isocaproic, caproic, 2-methylhexanoic and heptanoic acids) and benzenecarboxylic acids (pyromellitic, trimellitic, hemimellitic, o-phthalic, m-phthalic, p-phthalic, benzoic, salicylic acids and phenol) was carried out using diluted sulfuric acid as the eluent. Silica-based cation-exchange resins (TSKgel SP-2SW and TSKgel CM-2SW) were very suitable for the ion-exclusion chromatographic separation of these benzenecarboxylic acids. Excellent simultaneous separation of these benzenecarboxylic acids was achieved on a TSKgel SP-2SW column (150 x 6 mm I.D.) in 17 min using a 2.5 mM sulfuric acid at pH 2.4 as the eluent. Polymethacrylate-based cation-exchange resins (TSKgel SP-5PW, TSKgel CM-5PW and TSKgel OA-Pak A) acted as advanced stationary phases for the ion-exclusion chromatographic separation of these C1-C7 aliphatic carboxylic acids. Excellent simultaneous separation of these C1-C7 acids was achieved on a TSKgel CM-5PW column (150 x 6 mm I.D.) in 32 min using a 0.05 mM sulfuric acid at pH 4.0 as the eluent.

  20. Effect of Schiff base as corrosion inhibitor on AZ31 magnesium alloy in hydrochloric acid solution%席夫碱作为缓蚀剂对盐酸溶液中AZ31镁合金的影响

    Institute of Scientific and Technical Information of China (English)

    S. THIRUGNANASELVI; S. KUTTIRANI; Amali Roseline EMELDA

    2014-01-01

    Schiff base derived from the condensation reaction of analar grade 1-amino-2-naphthol 4-sulphonic acid with cinnamaldehyde was prepared under microwave condition. The Schiff base was analysed by infrared spectroscopy. This Schiff base as a corrosion inhibitor of AZ31 magnesium alloy in 0.05 mol/L HCl solution was studied. The inhibition effect of the Schiff base compound (4Z)-4-(3-phenyl allylidene amino)-3-hydroxy naphthalene-1-sulfonic acid (AC) on AZ31 magnesium alloy corrosion was studied using mass loss, potentiodynamic polarization technique, electrochemical impedance spectroscopy methods. The potentiodynamic polarization curve shows that Schiff base AC inhibits both anodic and cathodic reactions at all concentration, which indicates it is a mixed type inhibitor. EIS results indicate that as the additive concentration is increased, the polarization resistance increases whereas double-layer capacitance decreases. The adsorption of AC on the AZ31 magnesium alloy surface in 0.05 mol/L HCl obeys the Langmuir adsorption isotherm.%在微波条件下,通过高纯度1-氨基-2萘酚4-磺酸与肉桂醛的缩合反应制备席夫碱(4Z)-4-(3-苯基烯丙叉氨基)-3-羟基萘-1-磺酸(AC)。采用红外光谱对制备的席夫碱进行分析。研究席夫碱作为缓蚀剂对AZ31镁合金在0.05 mol/L 盐酸中的缓蚀作用。通过质量损失法、动电位极化法和电化学交流阻抗谱(EIS)研究席夫碱化合物在 AZ31镁合金腐蚀过程中的抑制作用。动电位极化曲线表明:席夫碱在所有浓度下能抑制阳极和阴极反应,是一种混合型缓蚀剂。EIS结果表明:随着添加剂浓度的增加,极化电阻增加而双电层电容减少。在0.05 mol/L盐酸中,席夫碱AC对AZ31镁合金表面的吸附符合Langmuir吸附等温式。

  1. 胺碘酮和普罗帕酮治疗阵发性室上性心动过速的疗效对照研究%Controlled study on effect of amiodarone and hydrochloric acid propafenone on paroxysmal supraventricular tachycardia

    Institute of Scientific and Technical Information of China (English)

    霍秋玉

    2012-01-01

    Objective To observe the clinical efficacy and safety of intravenous amiodarone and hydrochloric acid propafenone in treating paroxysmal supraventricular tachycardia. Methods Eighty patients with paroxysmal supraventricular tachycardia were divieded into group A and B randomly (40 cases in each group). Group A received amiodarone, while group B received hydrochloric acid propafenone. The effective rate of cardioversion, cardioversion time, adverse reactions and the heart rate change were compared. Results The effective rate in group A was higher than that in group B, but the difference was not statistically significant. The cardioversion time in group A was obviously longer than that in group B (P<0. 01). The heart rates in the two groups after treatment decreased obviously (P<0.01), while the heart rate in group A was obviously lower than that in group B (P<0. 01). The incidence of adverse reactions in group A was lower than that in group B, but the difference was not statistically significant. Conclusion There are advantages of both amiodarone and propafenone in the treatment of paroxysmal supraventricular tachycardia. Propafenone is applicable to acute tachycardia, but adverse reactions should be taken into consideration. The amiodarone is effective in the treatment of paroxysmal supraventricular tachycardia in spite of the slow onset.%目的 比较静脉注射胺碘酮和普罗帕酮治疗阵发性室上心动过速的临床疗效及安全性.方法 将80例室上心动过速患者随机分为A、B 2组,各40例,A组给予胺碘酮注射液治疗,B组给予普岁帕酮注射液治疗,比较2组复律成功率、复律时间、不良反应及用药前后心率的变化.结果 A组复律成功率高于B组,但差异无统计学意义(P>0.05),而复律时间显著长于B组(P<0.01);2组治疗后心率均较治疗前显著下降(P<0.01),但治疗后A组心率显著低于B组(P<0.01).A组不良反应发生率低于B组,但差异无统计学意义.结论

  2. Separative determination of ascorbic acid analogs contained in mushrooms by high-performance liquid chromatography.

    Science.gov (United States)

    Okamura, M

    1998-02-01

    Analogs (6-deoxyascorbic acid, erythroascorbic acid, and associated glycosides) of L-ascorbic acid (AA) contained in mushrooms were allowed to react with hydrazine to form osazones, and the conditions for separative determination by HPLC using a Zorbax SIL column were examined. Separation was started using solvent system 1 (ethylacetate/n-hexane/acetone/acetic acid, 50:50:1:1, v/v) as the mobile phase, and switching after 15 min to solvent system 2 (ethylacetate/acetone/acetic acid, 100:1:1, v/v). Detection was performed by absorbance at 500 nm. Because these analogs showed different formation rates for osazone, calibration curves were prepared for each substance. The recovery rate in the load test was 93-105%. By this method, AA and the analogs contained in eight species of edible mushrooms have been determined. The results revealed that: (1) the main constituents of all mushrooms are AA analogs rather than AA itself; (2) only one species contained AA in a very small amount (2 mumol/kg); (3) the types of AA analogs present differed according to the species of mushrooms, and (4) the total amount of AA analogs was between ca. 100-500 mumol/kg (2-9 mg per 100 g, converted to AA). In addition, a new AA analog was found in Pleurotus ostreatus and identified as 5-O-(alpha-D-xylopyranosyl)-D-erythroascorbic acid in structural analyses by NMR and other methods.

  3. 脂肪胺类化合物在盐酸介质中对工业纯铝缓蚀作用的研究%An investigation on the inhibition effect of aliphatic amines for aluminium in hydrochloric acid

    Institute of Scientific and Technical Information of China (English)

    帅长庚; 邓淑珍; 宋玉苏; 银继伟

    2001-01-01

    The corrosion of industrial pure aluminium in 1.0 mol.dm-3hydrochloride acid is investigated in the absence and presence of various amines,both by weight loss and electrochemistry.To begin with,the inhibition efficiency is found to follow the order: Hexamethylenetetramine>Diethylamine>n-Butylamine. With the increasing of the dipping time, the inhibition efficiency decreases gradually. The three amines, as the mixed inhibitors, has a great effect on the progress of cathodal and anodic corrosion of Al and can form a film by the adsorption on the surface of Al to protect Al from corrosion.%通过失重法、电化学方法分别研究了正丁胺、二乙胺、乌洛托品在1.0mol.dm-3HCl中对铝的缓蚀作用,并对其机理进行了探讨.研究结果表明:3种化合物对工业纯铝均具有一定的缓蚀作用.缓蚀效果:乌洛托品>二乙胺>正丁胺,随着时间的延长,它们的缓蚀效率逐渐降低.3种化合物均可在工业纯铝表面吸附成膜,抑制铝的腐蚀,为混合型缓蚀剂.

  4. Application of statistical design for the optimization of amino acid separation by reverse-phase HPLC.

    Science.gov (United States)

    Gheshlaghi, R; Scharer, J M; Moo-Young, M; Douglas, P L

    2008-12-01

    Modified resolution and overall separation factors used to quantify the separation of complex chromatography systems are described. These factors were proven to be applicable to the optimization of amino acid resolution in reverse-phase (RP) HPLC chromatograms. To optimize precolumn derivatization with phenylisothiocyanate, a 2(5-1) fractional factorial design in triplicate was employed. The five independent variables for optimizing the overall separation factor were triethylamine content of the aqueous buffer, pH of the aqueous buffer, separation temperature, methanol/acetonitrile concentration ratio in the organic eluant, and mobile phase flow rate. Of these, triethylamine concentration and methanol/acetonitrile concentration ratio were the most important. The methodology captured the interaction between variables. Temperature appeared in the interaction terms; consequently, it was included in the hierarchic model. The preliminary model based on the factorial experiments was not able to explain the response curvature in the design space; therefore, a central composite design was used to provide a quadratic model. Constrained nonlinear programming was used for optimization purposes. The quadratic model predicted the optimal levels of the variables. In this study, the best levels of the five independent variables that provide the maximum modified resolution for each pair of consecutive amino acids appearing in the chromatograph were determined. These results are of utmost importance for accurate analysis of a subset of amino acids.

  5. Acid Separation, Catalytic Oxidation and Coagulation for ATC Waste Liquid Treatment

    Institute of Scientific and Technical Information of China (English)

    DING Xiaoling; JIA Chunning

    2005-01-01

    It is difficult to treat 2-amino-thiazoline-4-carboxylic acid (ATC) waste liquid effectively at present for its characteristics of high chemical oxygen demand (COD), high salinity and low biodegradability. In order to solve this problem, this paper presents several kinds of physical-chemical treatment unit techniques, including acid separation, catalytic oxidation and coagulation. First of all, acid separation was adopted to precipitate relevant organics at isoelectric point. When the temperature and pH value of acid separation were controlled at about 5 ℃ and 2.2 respectively, the COD removal rate could reach 27.6%. Secondly, oxidation was used to break chemical constitution of refractory organics. The optimal reaction parameters of catalytic oxidation should be 20 ℃, pH adjusted to 5.0 and [Fe2+] 300 mg/L. Then with 5% H 2O 2 added and after one-hour reaction, the COD removal rate could achieve about 52%. Finally, coagulation was adopted to remove a portion of refractory organics, and 15% polymeric molysite flocculant was the best for the coagulation, and the COD removal rate could reach about 15%. Therefore, the proposed feasible process of physical-chemical pretreatment for ATC waste liquid could have about 70% COD removed in total.

  6. Evaluation of Chromogenic Reaction Ability of Hydrochloric Acid (Sulfuric Acid)-vanillin by the Colorimetry for Determining Tea Catechins Aggregates%茶叶儿茶素总量比色测定的盐酸(硫酸)香草醛显色反应能力评价

    Institute of Scientific and Technical Information of China (English)

    单虹丽; 卿钰; 杜晓; 刘东娜

    2012-01-01

    Chromogenic reaction level of catechins from the green tea and the black tea with hydrochloric acid (sulfuric acid-vanillin)-vanillin was determined in this paper. By determining and comparing the reaction coefficient, accuracy and precision, the color reaction ability of catechins reacted with acid vanillin was evaluated. The results showed that the reaction system was sensitive to catechins with a high linear correlation(R2HA =0.9976 ±0.001 4, R2SA =0.9978 ±0.001 8). It was also seen that the chromogenic reaction coefficients from both systems were less than the Roberts coefficient (145.68) obtained from the empirical formula for calculating catechins aggregates. The recoveries from both system were more than 94.22 % and all the variation coefficient of precision were less than 0.08 %. This showed that both systems could determinate tea catechins aggregates. The chromogenic capability of tea catechins from different sources with acid-Vanillin was very different from each other (F = 37. 434 > F0.01(1,5) =6.61). This results showed that two kinds of reaction systems could objectively reflect tea catechins aggregates. However, both recoveries and variation coefficient from the empirical formula were instable and the total catechins aggregates was higher than the reality.%测定了茶叶儿茶素及绿茶、红茶中的儿茶素与盐酸(硫酸)-香草醛的显色反应水平,通过对反应系数、准确度、精密度测定和比较,评价了儿茶素与酸性香草醛的显色反应能力.结果表明:两种酸性体系对儿茶素反应灵敏,且呈高度线性相关(R2盐酸=0.9976±0.0014,R2硫酸=0.9978±0.0018);显色反应系数上,盐酸法为34.77±10.00(绿茶)、83.83±20.13(红茶);硫酸法为39.65±8.97(绿茶)、86.68±19.87(红茶),均低于茶叶儿茶素总量经验计算公式中Roberts系数(145.68).盐酸-香草醛显色反应体系的回收率为94.22%±3.33%(绿茶)、99.71%±1.39%(红茶),精密度的变异系数为0.08

  7. High-speed separation and detection of amino acids in laver using a short capillary electrophoresis system.

    Science.gov (United States)

    Wang, Wei; Ma, Lihong; Yao, Fenzeng; Lin, Xiuli; Xu, Kaixuan

    2015-01-01

    A high-speed separation method of capillary MEKC with LIF detection had been developed for separation and determination of amino acids in laver. The CE system comprised a manual slotted-vial array (SVA) for sample introduction that could improve the separation efficiency by reducing injection volume. Using a capillary with 80 mm effective separation length, the separation conditions for amino acids were optimized. Applied with the separation electric field strength of 300 V/cm, the ten amino acids could be completely separated within 2.5 min with 10 mol/L Na2HPO4-NaOH buffer (pH = 11.5) including 30 mmol/L SDS. Theoretical plates for amino acids ranged from 72,000 to 40,000 (corresponding to 1.1-2.0 μm plate heights) and the detection limits were between 25 and 80 nmol/L. Finally, this method was applied to analyze the composition of amino acids in laver and eight known amino acids could be found in the sample. The contents of five amino acids, tyrosine, glutamic acid, glycine, lysine, and aspartic acid that could be completely separated in real sample were determined. The recoveries ranged from 82.3% to 123% that indicated the good reliability for this method in laver sample analysis.

  8. Reactive Separation of Gallic Acid: Experimentation and Optimization Using Response Surface Methodology and Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    K. Rewatkar

    2017-04-01

    Full Text Available Gallic acid is a major phenolic pollutant present in the wastewater generated from cork boiling, olive mill, and pharmaceutical industries. Experimental and statistical modelling using response surface methodology (RSM and artificial neural network (ANN were carried out for reactive separation of gallic acid from aqueous stream using tri-nbutyl phosphate (TBP in hexanol. TBP has a more significant effect on extraction efficiency as compared to temperature and pH. The optimum conditions of 2.34 g L–1, 65.65 % v/v, 19 oC, and 1.8 of initial concentration of gallic acid, concentration of TBP, temperature, and pH, respectively, were obtained using RSM. Under optimum conditions, extraction efficiency of 99.45 % was obtained for gallic acid. The ANN and RSM results were compared with experimental unseen data. Error analysis suggested the better performance of ANN for extraction efficiency predictions.

  9. In-capillary derivatization and capillary electrophoresis separation of amino acid neurotransmitters from brain microdialysis samples.

    Science.gov (United States)

    Denoroy, Luc; Parrot, Sandrine; Renaud, Louis; Renaud, Bernard; Zimmer, Luc

    2008-09-26

    A new in-capillary derivatization method with naphtalene-2,3-dicarboxyaldehyde (NDA)/CN(-) has been developed for capillary electrophoresis with laser-induced fluorescence detection of brain microdialysate amino acids. Samples are sandwiched between two plugs of reagent mixture at the capillary inlet and subsequently separated. Highest derivatization yields are obtained by using a reagent to sample plug length ratio equal to 4, performing a first electrophoretic mixing followed by a zero potential amplification step before applying the separation voltage and using a NaCN to NDA concentration ratio equal to 1. This new single-step methodology allows the analysis of amino acid neurotransmitters in rat brain microdialysis samples.

  10. Fast enantioselective separation of clevidipine and a dihydropyridine substituted acid by SFC on Chiralpak AD.

    Science.gov (United States)

    Gyllenhaal, O

    2001-01-01

    Conditions for the fast separation of the enantiomers of a dihydropyridine substituted acid on a 50 x 4.6 mm ID short Chiralpak AD column with 2-propanol modified carbon dioxide as the mobile phase are presented. A high throughout of samples can be accomplished through the continuous sample loading of the loop of the injector. If a continuous data collection was used 10 separations could be performed in about 5 min with a precision of 0.6% RSD for the area ratio (n = 10). The parent drug clevidipine can also be analyzed and its enantiomeric composition determined after alkaline hydrolysis into its acid, either through hydrolysis followed by extraction to dichloromethane or by direct analysis of the hydrolysis media. About 1 min is required for each run. Using 0.1 M of methanolic sodium hydroxide 2 min are sufficient for the hydrolysis, and, including weighing, only 5 min are required to analyze clevidipine.

  11. Separation of glycols from dilute aqueous solutions via complexation with boronic acids

    Energy Technology Data Exchange (ETDEWEB)

    Randel, L.A.; King, C.J.

    1991-07-01

    This work examines methods of separating low molecular weight glycols from dilute aqueous solution. Extraction into conventional solvents is generally not economical, since, in the literature reviewed, distribution ratios for the two- to four-carbon glycols are all less than one. Distribution ratios can be increased, however, by incorporating into the organic phase an extracting agent that will complex with the solute of interest. The extracting agent investigated in this work is 3-nitrophenylboronic acid (NPBA). NPBA, a boric acid derivative, reversibly complexes with many glycols. The literature on complexation of borate and related compounds with glycols, including mechanistic data, measurement techniques, and applications to separation processes, provides information valuable for designing experiments with NPBA and is reviewed herein. 88 refs., 15 figs., 24 tabs.

  12. Separation of americium and curium from complex chemical and radiochemical mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Bochkarev, V.A.; Martynov, N.P.; Slivin, V.G.; Trikanov, A.E.; Fedyaeva, N.V.

    1988-11-01

    This work describes a method for separation and radiochemical purification of nanogram levels of americium and curium from complex chemical and radiochemical mixtures containing tens of milligrams of elements such as aluminum, iron, magnesium, calcium, barium, titanium, potassium, and others, microgram levels of uranium, neptunium, and plutonium, and fission products. Extraction coefficients of americium and curium from these elements are measured. The separation from the macrocomponents was carried out by extraction of americium and curium with butyric acid in the presence of sulfosalicylic acid. Uranium, neptunium, and plutonium were separated from hydrochloric acid solutions, while the rare earth elements were separated from lithium chloride solutions using a column of anion exchange resin AV-17. Alpha measurements were carried out on americium and curium deposited electrolytically on tantalum cathodes. The chemical yield of americium and curium was identical of greater than or equal to 94%, separation time approx. 8 h.

  13. Determination of the base composition of deoxyribonucleic acid by measurement of the adenine/guanine ratio

    Science.gov (United States)

    Kirk, J. T. O.

    1967-01-01

    A method is described for determination of the base composition (as guanine+cytosine or adenine+thymine content) of DNA by accurate measurement of the adenine/guanine ratio. The DNA is hydrolysed with 0·03n-hydrochloric acid for 40min. to release the purines. The hydrolysate is subjected to ion-exchange chromatography on Zeo-Karb 225. Apurinic acids are eluted with 0·03n-hydrochloric acid and then guanine and adenine are eluted separately with 2n-hydrochloric acid. Guanine and adenine are each collected as a single fraction, and the amount of base in each case is determined by measuring the volume and the extinction at suitable wavelengths. For use in the calculations, millimolar extinction coefficients in 2n-hydrochloric acid of 12·09 for adenine at 262mμ, and 10·77 for guanine at 248mμ, were determined with authentic samples of bases. The method gives extremely reproducible results: from 12 determinations with calf thymus DNA the adenine/guanine molar ratio had a standard deviation of 0·011; this corresponds to a standard deviation in guanine+cytosine content of 0·2% guanine+cytosine. PMID:5626094

  14. Determination of the base composition of deoxyribonucleic acid by measurement of the adenine-granine ratio.

    Science.gov (United States)

    Kirk, J T

    1967-11-01

    A method is described for determination of the base composition (as guanine+cytosine or adenine+thymine content) of DNA by accurate measurement of the adenine/guanine ratio. The DNA is hydrolysed with 0.03n-hydrochloric acid for 40min. to release the purines. The hydrolysate is subjected to ion-exchange chromatography on Zeo-Karb 225. Apurinic acids are eluted with 0.03n-hydrochloric acid and then guanine and adenine are eluted separately with 2n-hydrochloric acid. Guanine and adenine are each collected as a single fraction, and the amount of base in each case is determined by measuring the volume and the extinction at suitable wavelengths. For use in the calculations, millimolar extinction coefficients in 2n-hydrochloric acid of 12.09 for adenine at 262mmu, and 10.77 for guanine at 248mmu, were determined with authentic samples of bases. The method gives extremely reproducible results: from 12 determinations with calf thymus DNA the adenine/guanine molar ratio had a standard deviation of 0.011; this corresponds to a standard deviation in guanine+cytosine content of 0.2% guanine+cytosine.

  15. PERVAPORATION SEPARATION OF WATER-ACETIC ACID MIXTURES THROUGH AN-co-AA MEMBRANES TREATED WITH RARE EARTH METAL IONS

    Institute of Scientific and Technical Information of China (English)

    SHEN Zhiquan; ZHANG Fuyao; ZHANG Yifeng

    1995-01-01

    Pervaporation separation of water-acetic acid mixtures through Poly (AN-co-AA)membranes and rare earth metal ions treated Poly(AN-co-AA)membranes was investigated for the first time. The results showed that the treatment with rare earth metal ions could greatly improve the characteristics of the separation of water-acetic acid mixtures.

  16. Chemically modified polymeric resins for separation of cations, organic acids, and small polar moleculea by high performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Morris, John B. [Iowa State Univ., Ames, IA (United States)

    1993-07-01

    This thesis is divided into 4 parts: a review, ion chromatography of metal cations on carboxylic resins, separation of hydrophilic organic acids and small polar compounds on macroporous resin columns, and use of eluent modifiers for liquid chromatographic separation of carboxylic acids using conductivity detection.

  17. Effect of Micelle Composition on Acidic Drugs Separation Behavior by Micellar Electrokinetic Capillary Chromatography

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Micellar electrokinetic capillary chromatography (MECC) separation of four acidic drugs similar in structure was studied. Both anionic surfactant sodium dodecyl sulfate (SDS) and nonionic surfactant Tween 20 were used to form single micelles and mixed micelles as pseudostationary phases. The effects of the composition of micellar solution on retention behaviors were studied. The results indicate that there is markedly different selectivity among SDS, Tween 20 and the mixed micelles systems.

  18. Capillary electrophoresis separation of human milk neutral and acidic oligosaccharides derivatized with 2-aminoacridone.

    Science.gov (United States)

    Galeotti, Fabio; Coppa, Giovanni V; Zampini, Lucia; Maccari, Francesca; Galeazzi, Tiziana; Padella, Lucia; Santoro, Lucia; Gabrielli, Orazio; Volpi, Nicola

    2014-03-01

    Human milk is a unique fluid in glycobiology due to the presence of many free structurally complex oligosaccharides emerging as important dietary factors during early life and having many biological and protective functions. Methods that allow accurate profiling of oligosaccharide mixtures in this complex biological fluid with quantification of the four known genetically determined groups are welcomed. A high-voltage CE separation and detection at 254 nm of 17 neutral and acidic human milk oligosaccharide (HMO) standard along with lactose derivatized with 2-aminoacridone, using a BGE containing 20% methanol as an organic modifier and borate, able to form on-capillary anionic borate-polyol complexes, is reported. This CE approach was able to separate both neutral HMOs and acidic HMOs, with the sialic acid residue, also in the presence of lactose in high content. This method was applied to the four secretory groups individually extracted by a rapid and simple preparative step. LODs were found ranging from ∼50 to 700 fmol. We were able to measure HMO content also in the presence of excess fluorophore, or interference from proteins, peptides, salts, and other impurities normally present in this complex biological fluid. Overall, CE equipped with a UV detector is a common analytical approach and this simple CE separation offers high resolution and sensitivity for the differentiation of human milk samples related to genetic groups and days of lactation by considering that important changes in HMO content are a reflection of the lactation day.

  19. The selective conversion of glutamic acid in amino acid mixtures using glutamate decarboxylase--a means of separating amino acids for synthesizing biobased chemicals.

    Science.gov (United States)

    Teng, Yinglai; Scott, Elinor L; Sanders, Johan P M

    2014-01-01

    Amino acids (AAs) derived from hydrolysis of protein rest streams are interesting feedstocks for the chemical industry due to their functionality. However, separation of AAs is required before they can be used for further applications. Electrodialysis may be applied to separate AAs, but its efficiency is limited when separating AAs with similar isoelectric points. To aid the separation, specific conversion of an AA to a useful product with different charge behavior to the remaining compounds is desired. Here the separation of L-aspartic acid (Asp) and L-glutamic acid (Glu) was studied. L-Glutamate α-decarboxylase (GAD, Type I, EC 4.1.1.15) was applied to specifically convert Glu into γ-aminobutyric acid (GABA). GABA has a different charge behavior from Asp therefore allowing a potential separation by electrodialysis. Competitive inhibition and reduced operational stability caused by Asp could be eliminated by maintaining a sufficiently high concentration of Glu. Immobilization of GAD does not reduce the enzyme's initial activity. However, the operational stability was slightly reduced. An initial study on the reaction operating in a continuous mode was performed using a column reactor packed with immobilized GAD. As the reaction mixture was only passed once through the reactor, the conversion of Glu was lower than expected. To complete the conversion of Glu, the stream containing Asp and unreacted Glu might be recirculated back to the reactor after GABA has been removed. Overall, the reaction by GAD is specific to Glu and can be applied to aid the electrodialysis separation of Asp and Glu.

  20. Hexavalent chromium recovery by liquid–liquid extraction with 2-octylaminopyridine from acidic chloride media and its sequential separation from other heavy toxic metal ions

    OpenAIRE

    C.P. Mane; S.V. Mahamuni; S. S. Kolekar; Han, S. H.; M. A. ANUSE

    2016-01-01

    A systematic study of extraction of chromium(VI) with 2-octylaminopyridine (2-OAP) in xylene at room temperature has been conducted. Quantitative extraction of chromium(VI) was observed in the 0.4–0.8 M concentration range of hydrochloric acid. From the extracted complex species in the organic phase, chromium(VI) was back extracted with 7 N ammonia (3 × 10 mL), and was determined by spectrophotometric method. Various parameters such as 2-OAP concentration, equilibrium period, effect of variou...

  1. Spectrophotometric determination of bismuth in concentrates and non-ferrous alloys by the iodide method after separations by diethyldithiocarbamate and xanthate extraction.

    Science.gov (United States)

    Donaldson, E M

    1978-03-01

    A method for determining 0.0001-1% of bismuth in copper, molybdenum, lead, zinc and nickel sulphide concentrates is described. After sample decomposition, bismuth is separated from matrix and other elements, except lead and thallium(III), by chloroform extraction of its diethyldithiocarbamate complex, pH 11.5-12.0, from a sodium hydroxide medium containing citric acid, tartaric acid, EDTA and potassium cyanide as complexing agents. Following back-extraction of bismuth into 12M hydrochloric acid and reduction of thallium to the univalent state, bismuth is separated from co-extracted lead and thallium by chloroform extraction of its xanthate from a 2.5M hydrochloric acid-tartaric acid-ammonium chloride medium. Bismuth is then determined spectrophotometrically, at 337 or 460 nm, as the iodide. Interference from lead, which is co-extracted in mug-amounts as the xanthate and causes high results at 337 nm, is eliminated by washing the extract with a hydrochloric acid solution of the same composition as the medium used for extraction. The proposed method is also applicable to lead-, tin- and copper-base alloys.

  2. Effects of hydrochloric acid modification on the channel characteristics, composition, surface potential and cation exchange behavior of natural clinoptilolite%盐酸改性对天然斜发沸石孔道特征、成分、表面电位及阳离子交换性能的影响

    Institute of Scientific and Technical Information of China (English)

    霍汉鑫; 林海; 董颖博; 刘泉利; 曹丽霞; 程皝; 汪涵; 傅川

    2015-01-01

    采用不同浓度盐酸对天然斜发沸石进行改性,并系统地研究了改性沸石的孔道特征、化学成分、表面电位及阳离子交换性能的变化.盐酸改性后,沸石晶体结构破坏较小,表面变得疏松粗糙,K+、Na+、Ca2+和Mg2+元素含量均小幅下降;表面负电荷增加,阳离子交换容量减小;比表面积和总孔体积均有所提高,最高分别从原沸石的35.97 m2·g -1和0.0761 m3·g-1提高至64.46 m2·g-1和0.1156 m3·g-1.盐酸改性对沸石微孔、介孔和大孔的分布影响明显.从迟滞回线形状判断沸石孔道类型均为不均匀狭缝型孔道,盐酸改性不会改变沸石孔道类型.%ABSTRACT Natural clinoptilolite was modified by different concentrations of hydrochloric acid. Systemic investigations were performed on the channel characteristics, chemical composition, surface potential, and cation exchange behavior of the modified clinoptilolite. It is found that the surface of the modified clinoptilolite becomes loose and rough, the contents of K+, Na+, Ca2+, and Mg2+ slightly decrease, the surface negative charges increases, and the cation exchange capacity decreases to some extent. The specif-ic surface area and total pore volume are improved and the maximum values of them increase from 35.97 m2·g-1 and 0.0761 m3·g-1 to 64.46 m2·g-1 and 0.1156 m3·g-1 , respectively. The distribution of micropores, mesopores, and macropores is obviously impacted, and the type of zeolite cavities is determined to be uneven slits by the hysteresis loop shape, indicating that this acid modification cannot change zeolite cavities.

  3. On-line Determination of Hydrochloric Acid in Process Effluent ...

    African Journals Online (AJOL)

    Prof Van Staden

    The results obtained with the proposed system were compared with the results obtained from ..... The null hypothesis which assumes that the quantities from two different ... 14 R.H. Taylor, J. Ruzicka and G.D. Christian, Talanta, 1992, 39, 285.

  4. Boronic Acid-Based Approach for Separation and Immobilization of Glycoproteins and Its Application in Sensing

    Science.gov (United States)

    Wang, Xiaojin; Xia, Ning; Liu, Lin

    2013-01-01

    Glycoproteins influence a broad spectrum of biological processes including cell-cell interaction, host-pathogen interaction, or protection of proteins against proteolytic degradation. The analysis of their glyco-structures and concentration levels are increasingly important in diagnosis and proteomics. Boronic acids can covalently react with cis-diols in the oligosaccharide chains of glycoproteins to form five- or six-membered cyclic esters. Based on this interaction, boronic acid-based ligands and materials have attracted much attention in both chemistry and biology as the recognition motif for enrichment and chemo/biosensing of glycoproteins in recent years. In this work, we reviewed the progress in the separation, immobilization and detection of glycoproteins with boronic acid-functionalized materials and addressed its application in sensing. PMID:24141187

  5. Boronic Acid-Based Approach for Separation and Immobilization of Glycoproteins and Its Application in Sensing

    Directory of Open Access Journals (Sweden)

    Lin Liu

    2013-10-01

    Full Text Available Glycoproteins influence a broad spectrum of biological processes including cell-cell interaction, host-pathogen interaction, or protection of proteins against proteolytic degradation. The analysis of their glyco-structures and concentration levels are increasingly important in diagnosis and proteomics. Boronic acids can covalently react with cis-diols in the oligosaccharide chains of glycoproteins to form five- or six-membered cyclic esters. Based on this interaction, boronic acid-based ligands and materials have attracted much attention in both chemistry and biology as the recognition motif for enrichment and chemo/biosensing of glycoproteins in recent years. In this work, we reviewed the progress in the separation, immobilization and detection of glycoproteins with boronic acid-functionalized materials and addressed its application in sensing.

  6. Phase separation behavior of fusidic acid and rifampicin in PLGA microspheres.

    Science.gov (United States)

    Gilchrist, Samuel E; Rickard, Deborah L; Letchford, Kevin; Needham, David; Burt, Helen M

    2012-05-01

    The purpose of this study was to characterize the phase separation behavior of fusidic acid (FA) and rifampicin (RIF) in poly(d,l-lactic acid-co-glycolic acid) (PLGA) using a model microsphere formulation. To accomplish this, microspheres containing 20% FA with 0%, 5%, 10%, 20%, and 30% RIF and 20% RIF with 30%, 20% 10%, 5%, and 0% FA were prepared by solvent evaporation. Drug-polymer and drug-drug compatibility and miscibility were characterized using laser confocal microscopy, Raman spectroscopy, XRPD, DSC, and real-time video recordings of single-microsphere formation. The encapsulation of FA and RIF alone, or in combination, results in a liquid-liquid phase separation of solvent-and-drug-rich microdomains that are excluded from the polymer bulk during microsphere hardening, resulting in amorphous spherical drug-rich domains within the polymer bulk and on the microsphere surface. FA and RIF phase separate from PLGA at relative droplet volumes of 0.311 ± 0.014 and 0.194 ± 0.000, respectively, predictive of the incompatibility of each drug and PLGA. When coloaded, FA and RIF phase separate in a single event at the relative droplet volume 0.251 ± 0.002, intermediate between each of the monoloaded formulations and dependent on the relative contribution of FA or RIF. The release of FA and RIF from phase-separated microspheres was characterized exclusively by a burst release and was dependent on the phase exclusion of surface drug-rich domains. Phase separation results in coalescence of drug-rich microdroplets and polymer phase exclusion, and it is dependent on the compatibility between FA and RIF and PLGA. FA and RIF are mutually miscible in all proportions as an amorphous glass, and they phase separate from the polymer as such. These drug-rich domains were excluded to the surface of the microspheres, and subsequent release of both drugs from the microspheres was rapid and reflected this surface location.

  7. Micellar LC Separation of Sesquiterpenic Acids and Their Determination in Valeriana officinalis L. Root and Extracts

    Directory of Open Access Journals (Sweden)

    Artem U. Kulikov

    2012-01-01

    Full Text Available A simple micellar liquid chromatography (MLC method was developed and validated according to ICH Guidelines for the determination of sesquiterpenic acids (valerenic, hydroxyvalerenic, and acetoxyvalerenic acids in root and rhizome extract from Valeriana officinalis L. and valerian dry hydroalcoholic extract. Samples were analyzed on Nucleosil C18 column (150mm×4.6mm, 5 μm using an isocratic mobile phase which consisted of Brij 35 (5% (w/v aqueous solution; pH 2.3±0.1 by phosphoric acid and 1-butanol (6% (v/v; UV detection was at 220 nm. Micellar mobile phase using allows to fully separate valerenic acids within 25 minutes. Linearity for hydroxyvalerenic, acetoxyvalerenic, and valerenic acids was 1.9–27.9, 4.2–63.0, and 6.1–91·3 μg.mL−1, and limit of detection was 0.14, 0.037, and 0.09 μg·mL−1, respectively. Intraday and interday precisions were not less than 2% for all investigated compounds. The proposed method was found to be reproducible and convenient for quantitative analysis of sesquiterpenic acids in valerian root and related preparations.

  8. On-Chip Microfluidic Components for In Situ Analysis, Separation, and Detection of Amino Acids

    Science.gov (United States)

    Zheng, Yun; Getty, Stephanie; Dworkin, Jason; Balvin, Manuel; Kotecki, Carl

    2013-01-01

    The Astrobiology Analytical Laboratory at GSFC has identified amino acids in meteorites and returned cometary samples by using liquid chromatography-electrospray ionization time-of-flight mass spectrometry (LCMS). These organic species are key markers for life, having the property of chirality that can be used to distinguish biological from non-biological amino acids. One of the critical components in the benchtop instrument is liquid chromatography (LC) analytical column. The commercial LC analytical column is an over- 250-mm-long and 4.6-mm-diameter stainless steel tube filled with functionized microbeads as stationary phase to separate the molecular species based on their chemistry. Miniaturization of this technique for spaceflight is compelling for future payloads for landed missions targeting astrobiology objectives. A commercial liquid chromatography analytical column consists of an inert cylindrical tube filled with a stationary phase, i.e., microbeads, that has been functionalized with a targeted chemistry. When analyte is sent through the column by a pressurized carrier fluid (typically a methanol/ water mixture), compounds are separated in time due to differences in chemical interactions with the stationary phase. Different species of analyte molecules will interact more strongly with the column chemistry, and will therefore take longer to traverse the column. In this way, the column will separate molecular species based on their chemistry. A lab-on-chip liquid analysis tool was developed. The microfluidic analytical column is capable of chromatographically separating biologically relevant classes of molecules based on their chemistry. For this analytical column, fabrication, low leak rate, and stationary phase incorporation of a serpentine microchannel were demonstrated that mimic the dimensions of a commercial LC column within a 5 10 1 mm chip. The microchannel in the chip has a 75- micrometer-diameter oval-shaped cross section. The serpentine

  9. The CGC enantiomer separation of 2-arylcarboxylic acid esters by using β-cyclodextrin derivatives as chiral stationary phases.

    Science.gov (United States)

    Shi, Xueyan; Liu, Feipeng; Mao, Jianyou

    2016-03-17

    Chiral 2-arylcarboxylic acid esters are important intermediates in preparation of enantioenriched 2-arylpropionic acids type Non-steroidal anti-inflammatory drugs (NSAIDs). Enantiomer separation of 2-arylcarboxylic acid esters is crucial for evaluation of the asymmetric synthesis efficiency and the enantiomer excess of chiral 2-arylcarboxylic acid derivatives. The capillary gas chromatography (CGC) enantiomer separation of 17 pairs of 2-arylcarboxylic acid esters enantiomers was conducted by using seven different β-cyclodextrin derivatives (CDs) as chiral stationary phases. It was found that for the 7 pairs of 2-phenylpropionates enantiomers, CDs with both alkyl and acyl substituents especially 2,6-di-O-pentyl-3-O-butyryl-β-cyclodextrin exhibited better enantiomer separation abilities than the other CDs examined. For the 7 pairs of 2-(4-substituted phenyl)propionates enantiomers, 2,3,6-tri-O-methyl-β-cyclodextrin possessed better enantiomer separation abilities than the other CDs. Among the 3 pairs of 2-phenylbutyrates enantiomers examined, only methyl 2-phenylbutyrate enantiomers could be separated by three CDs among the 7 CDs tested, while enantiomers of ethyl 2-phenylbutyrate and isopropyl 2-phenylbutyrate couldn't be separated by any of the 7 CDs tested. Besides the structures of CDs, the structures of 2-arylcarboxylic acid esters including different ester moieties, substituents of phenyl, and different carboxylic acids moieties in 2-arylcarboxylic acid esters also affected the enantiomer separation results greatly. The CGC enantiomer separation results of 2-arylcarboxylic acid esters on different CDs are useful for solving the enantiomer separation problem of 2-arylcarboxylic acid esters.

  10. Synergistic effects on enantioselectivity of zwitterionic chiral stationary phases for separations of chiral acids, bases, and amino acids by HPLC.

    Science.gov (United States)

    Hoffmann, Christian V; Pell, Reinhard; Lämmerhofer, Michael; Lindner, Wolfgang

    2008-11-15

    In an attempt to overcome the limited applicability scope of earlier proposed Cinchona alkaloid-based chiral weak anion exchangers (WAX) and recently reported aminosulfonic acid-based chiral strong cation exchangers (SCX), which are conceptionally restricted to oppositely charged solutes, their individual chiral selector (SO) subunits have been fused in a combinatorial synthesis approach into single, now zwitterionic, chiral SO motifs. The corresponding zwitterionic ion-exchange-type chiral stationary phases (CSPs) in fact combined the applicability spectra of the parent chiral ion exchangers allowing for enantioseparations of chiral acids and amine-type solutes in liquid chromatography using polar organic mode with largely rivaling separation factors as compared to the parent WAX and SCX CSPs. Furthermore, the application spectrum could be remarkably expanded to various zwitterionic analytes such as alpha- and beta-amino acids and peptides. A set of structurally related yet different CSPs consisting of either a quinine or quinidine alkaloid moiety as anion-exchange subunit and various chiral or achiral amino acids as cation-exchange subunits enabled us to derive structure-enantioselectivity relationships, which clearly provided strong unequivocal evidence for synergistic effects of the two oppositely charged ion-exchange subunits being involved in molecular recognition of zwitterionic analytes by zwitterionic SOs driven by double ionic coordination.

  11. Homochiral metal-organic frameworks based on amino acid ligands for HPLC separation of enantiomers.

    Science.gov (United States)

    Zhang, Jun-Hui; Nong, Rui-Yu; Xie, Sheng-Ming; Wang, Bang-Jin; Ai, Ping; Yuan, Li-Ming

    2017-07-05

    Natural amino acids are well known to form coordination polymers with transition metal ions. In this study, six homochiral metal-organic frameworks constructed from Zn(2+) or Co(2+) ions and various enantiopure amino acid (L-tyrosine, L-histidine, L-tryptophan and L-glutamic acid), namely [Zn(L-tyr)]n (L-tyrZn), [Zn4 (btc)2 (Hbtc)(L-His)2 (H2 O)4 ]·1.5H2 O, {[Zn2 (L-trp)2 (bpe)2 (H2 O)2 ]·2H2 O·2NO3 }n , [Co2 (L-Trp)(INT)2 (H2 O)2 (ClO4 )], [Co2 (sdba)((L-Trp)2 ] and [Co(L-Glu)(H2 O)·H2 O]∞ , were synthesized according to the methods previously reported in the literature. The six homochiral MOFs were explored as the chiral stationary phases for high-performance liquid chromatographic separation of enantiomers using hexane/isopropanol or hexane/dichloromethane as mobile phase. Various types of enantiomers such as alcohols, amines, ketones, ethers, organic acids, etc. can be resolved on these homochiral MOF columns. The results revealed that the enantioseletivities of homochiral MOFs based on amino acids as chiral bridging ligands used as stationary phases are practical in HPLC. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Quantification of Multi Elements in Geological Samples by Inductively Coupled Plasma-Mass Spectrometry with Pressurized Decomposition-Hydrochloric Acid Extraction%封闭压力酸溶-盐酸提取-电感耦合等离子体质谱法测定地质样品中的多元素

    Institute of Scientific and Technical Information of China (English)

    张保科; 温宏利; 王蕾; 马生凤; 巩爱华

    2011-01-01

    Rock, soil, sediments and other geological samples can be effectively decomposed by acid under high temperature and pressure, and be measured by Inductively Coupled Plasma-Mass Spectrometry ( ICP-MS ). The recoveries of most elements were satisfactory, except for the results of Zr, Hf, REEs, Rb, Th, and U. In this paper, the traditional pressurized acid digestion method has been improved as the sample was extracted by hydrochloric acid instead of nitric acid. 46 elements in the National Standard Materials of rock, soil and sediments can be accurately determined by this improved method. Sample weight was increased from 25 mg to 100m and digestion time was extended from 12 h to 48 h,which effectively resolved the problems including the representation of the samples and inadequate results for Rb, Sr, REEs and other elements dissolved by HN03. The results of many experiments showed that the 44 elements measured were consistent with standard values except for As and V elements, according to Cl interference in ICP-MS. Detection limits of the improved method were 0. 01 -0. 85 μg/g, with a precision RSD( n = 10 ) of 0. 73% -13. 1% and an accuracy RE( n = 10 )of less than 10%. The improved method is accurate, reliable and suitable for avariety of different types of geological samples.%高温、高压封闭压力酸溶可有效分解岩石、土壤、沉积物等地质样品,采用电感耦合等离子体质谱法(ICP-MS)进行测定,大部分元素可得到满意的回收率;但Zr、Hf、REEs、Rb、Th、U等元素用硝酸复溶困难,测定结果不准确.本文对传统的封闭压力酸溶方法进行改进,用盐酸复溶提取代替硝酸复溶提取,ICP-MS法测定岩石、土壤、沉积物等国家一级标准物质中Li、Be、Cr、Mn、Co、Ni、Cu、Zn、Ga、Rb、Sr、Mo、Cd、In、Cs、Ba、Ti、Zr、Nb、Sn、Sb、W、Hf、Ta、Tl、Pb、Bi、Th、U以及稀土元素(REEs)等46个元素.将原方法中的称样量25 mg加大至100 mg,溶样时间由12 h

  13. Determination of Strong Acidic Drugs in Biological Matrices: A Review of Separation Methods

    Directory of Open Access Journals (Sweden)

    Lingli Mu

    2014-01-01

    Full Text Available Strong acidic drugs are a class of chemical compounds that normally have high hydrophilicity and large negative charges, such as organophosphatic compounds and organosulphonic compounds. This review focuses on sample preparation and separation methods for this group of compounds in biological matrices in recent years. A wide range of separation techniques, especially chromatographic method, are presented and critically discussed, which include liquid chromatography (e.g., ion-pair and ion-exchange chromatography, capillary electrophoresis (CE, and other types. Due to the extremely low concentration level of target analytes as well as the complexity of biological matrices, sample pretreatment methods, such as dilute and shoot methods, protein precipitation (PP, liquid-liquid extraction (LLE, solid-phase extraction (SPE, degradation, and derivatization strategy, also play important roles for the development of successful analytical methods and thus are also discussed.

  14. Fast isotopic separation of (10) B and (11) B boric acid by capillary zone electrophoresis.

    Science.gov (United States)

    Kamencev, Mikhail; Yakimova, Nina; Moskvin, Leonid; Kuchumova, Irina; Tkach, Kirill; Malinina, Yulia

    2016-11-01

    Fast isotopic separation of (10) B and (11) B boric acid by CZE was demonstrated. The BGE contained 25 mM phenylalanine and 5 mM putrescine (рН 8.95). The running conditions were +25 kV at 20°C with indirect photometric detection at 210 nm. Baseline separation was achieved in less than 9 min. RSD of migration times and corrected peak areas were less than 0.5 and 3%, respectively (n = 5). Linearity was demonstrated in the range 0.2-2 mM for (11) B and 0.2-0.5 mM for (10) B. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Separation and PurificationHomologous Compounds byof Dodecanedioic Acid from Its Falling Film Crystallization

    Institute of Scientific and Technical Information of China (English)

    李裕; 刘有智; 齐雪琴

    2004-01-01

    Separation and purification of dodecanedioic acid (DDDA) from its homologous compounds were studied experimentally by falling film crystallization (FFC). The influences of various operation parameters, including crystallizing time, flow rate of melt and temperature of glycerine bath, on purity of DDDA and crystallizing rate were investigated. Over 99% (by mole) DDDA was obtained for a feed composition of 96% (by mole). The main factors affecting the separation efficiency are flow rate of melt and temperature of glycerine bath. The crystallizing layer of DDDA was further purified by sweating and blasting. A set of optimized operation data are provided for better understanding the mechanism of heat and mass transfer in FFC, and for further industrial application of DDDA purification process.

  16. Separation of water and oil by poly (acrylic acid)-coated stainless steel mesh prepared by radiation crosslinking

    Energy Technology Data Exchange (ETDEWEB)

    Nho, Young Chang; Shin, Jung Woong; Park, Jong Seok; Lim, Young Mook; Jeun, Joon Pyo; Kang, Phil Hyun [Research Division for Industry and Environment, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2015-05-15

    The stainless steel mesh coated with poly(acrylic acid) hydrogel was fabricated and applied for the separation of water and oil. The stainless steel mesh was immersed in aqueous poly (acrylic acid) solution, and then irradiated by radiation to introduce poly(acrylic acid) hydrogel on the surface of mesh by crosslinking. It was possible to separate oil and water from mixtures of oil/water effectively using the hydrogel-coated mesh. The effect of irradiation dose, coating thickness, size of mesh on the separation efficiency was examined.

  17. Behaviour of Tributylamine as Entrainer for the Separation of Water and Acetic Acid with Reactive Extractive Distillation

    Institute of Scientific and Technical Information of China (English)

    雷志刚; 李成岳; 陈标华

    2003-01-01

    A new separation method, reactive extractive distillation, was put forward for separating water and acetic acid. The separation mechanism was analyzed through infrared spectra technique. Isobaric vapor-liquid equilibrium (VLE) data at 101.33 kPa for the binary or ternary systems consisting of water, acetic acid and tributylamine were measured. The activity coefficients were correlated by using Wilson, NRTL, and UNIQUAC Equations.The VLE experiment showed that tributylamine could enhance the relative volatility of water to acetic acid. An extractive distillation experiment was carried out and proved that tributylamine was a good extractive solvent.

  18. [Separation of zoledronic acid and its related substances by ion-pair reversed-phase high performance liquid chromatography].

    Science.gov (United States)

    Zhang, Xiaoqing; Jiang, Ye; Xu, Zhiru

    2004-07-01

    A rapid and simple ion-pair reversed-phase high performance liquid chromatographic method (HPLC) has been established for the routine analysis of zoledronic acid and its related substances. The chromatographic conditions were optimized based on the satisfactory separation of zoledronic acid from imidazol-1-ylacetic acid, their retention times and peak shape. The excellent separation of zoledronic acid from its related substances, including the remaining imidazol-1-ylacetic acid used in the synthesis of zoledronic acid and other impurities of oxidation and decomposition, was achieved within 9 min on a Hypersil C8 column with UV detection at 220 nm. The mobile phase was a mixture of methanol (20%) and 5 mmo/L phosphate buffer (80%) that contains 6 mmol/L tetrabutylammonium bromide. The resolution factor of zoledronic acid from its adjacent peak was more than 2.5. This is a simple and rapid method for the routine assay of zoledronic acid.

  19. An ion-exchange method for selective separation of palladium, platinum and rhodium from solutions obtained by leaching automotive catalytic converters.

    Science.gov (United States)

    Gaita, R; Al-Bazi, S J

    1995-02-01

    An ion-exchange method has been developed for the separation of palladium, platinum and rhodium from a solution that is highly acidic and contains a considerable amount of lead, aluminum, iron and cerium, obtained by leaching a used honeycomb type automotive catalytic converter. A column of Amberlite IRA-93 anion-exchange resin was found appropriate to recover platinum metals from the pregnant solution. Selective stripping of these metals from the resin was achieved by eluting rhodium first with 6.0M hydrochloric acid, then palladium with a 1% ammonia solution at ambient temperature, and platinum with 5% of the reagent at elevated temperatures. Optimum conditions for leaching these metals from the catalyst were 5.0M hydrochloric acid and 0.4M sodium chlorate at 70 degrees C. This method can be applied to both analytical as well as large scale operations. It is simple, economical, and relatively safe for human exposure and the environment.

  20. Effect of temperature on acid-base equilibria in separation techniques. A review.

    Science.gov (United States)

    Gagliardi, Leonardo G; Tascon, Marcos; Castells, Cecilia B

    2015-08-19

    Studies on the theoretical principles of acid-base equilibria are reviewed and the influence of temperature on secondary chemical equilibria within the context of separation techniques, in water and also in aqueous-organic solvent mixtures, is discussed. In order to define the relationships between the retention in liquid chromatography or the migration velocity in capillary electrophoresis and temperature, the main properties of acid-base equilibria have to be taken into account for both, the analytes and the conjugate pairs chosen to control the solution pH. The focus of this review is based on liquid-liquid extraction (LLE), liquid chromatography (LC) and capillary electrophoresis (CE), with emphasis on the use of temperature as a useful variable to modify selectivity on a predictable basis. Simplified models were evaluated to achieve practical optimizations involving pH and temperature (in LLE and CE) as well as solvent composition in reversed-phase LC.

  1. Vapour and acid components separation from gases by membranes principles and engineering approach to membranes development

    Science.gov (United States)

    Kagramanov, G. G.; Storojuk, I. P.; Farnosova, E. N.

    2016-09-01

    The modern commercially available polymer membranes and membrane modules for purification of gases, containing acid components, simultaneously with dehumidification of treated gas streams, were developed and commercialized in the very end of XXth century. The membranes basic properties - selectivity (separation factor) and permeation flow rates - are relatively far from satisfying the growing and modern-scale industrial need in purification technologies and corresponding equipments. The attempt to formulate the basic principles, scientific and engineering approaches to the development of prospective membranes for the purification of gases, especially such as natural and oil gases, from acid components, simultaneously with drying them, was being made. For this purpose the influence of various factors - polymer nature, membrane type, structure, geometrical and mass-transfer characteristics, etc. - were studied and analyzed in order to formulate the basic principles and demands for development of membranes, capable to withstand successfully the sever conditions of exploitation.

  2. Extraction, separation, and intramolecular carbon isotope characterization of athabasca oil sands acids in environmental samples.

    Science.gov (United States)

    Ahad, Jason M E; Pakdel, Hooshang; Savard, Martine M; Simard, Marie-Christine; Smirnoff, Anna

    2012-12-04

    Here we report a novel approach to extract, isolate, and characterize high molecular weight organic acids found in the Athabasca oil sands region using preparative capillary gas chromatography (PCGC) followed by thermal conversion/elemental analysis-isotope ratio mass spectrometry (TC/EA-IRMS). A number of different "naphthenic acids" surrogate standards were analyzed as were samples from the bitumen-rich unprocessed McMurray Formation, oil sands process water, groundwater from monitoring wells, and surface water from the Athabasca River. The intramolecular carbon isotope signature generated by online pyrolysis (δ(13)C(pyr)) showed little variation (±0.6‰) within any given sample across a large range of mass fractions separated by PCGC. Oil sand, tailings ponds, and deep McMurray Formation groundwater were significantly heavier (up to ∼9‰) compared to surface water and shallow groundwater samples, demonstrating the potential use of this technique in source apportionment studies.

  3. Electrochemical membrane reactor: In situ separation and recovery of chromic acid and metal ions

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Jeeshan; Tripathi, Bijay P.; Saxena, Arunima; Shahi, Vinod K. [Electro-Membrane Processes Division, Central Salt and Marine Chemicals Research Institute, Bhavnagar 364002, Gujarat (India)

    2007-08-01

    An electrochemical membrane reactor with three compartments (anolyte, catholyte and central compartment) based on in-house-prepared cation- and anion-exchange membrane was developed to achieve in situ separation and recovery of chromic acid and metal ions. The physicochemical and electrochemical properties of the ion-exchange membrane under standard operating conditions reveal its suitability for the proposed reactor. Experiments using synthetic solutions of chromate and dichromate of different concentrations were carried out to study the feasibility of the process. Electrochemical reactions occurring at the cathode and anode under operating conditions are proposed. It was observed that metal ion migrated through the cation-exchange membrane from central compartment to catholyte and OH{sup -} formation at the cathode leads to the formation of metal hydroxide. Simultaneously, chromate ion migrated through the anion-exchange membrane from central compartment to the anolyte and formed chromic acid by combining H{sup +} produced their by oxidative water splitting. Thus a continuous decay in the concentration of chromate and metal ion was observed in the central compartment, which was recovered separately in the anolyte and catholyte, respectively, from their mixed solution. This process was completely optimized in terms of operating conditions such as initial concentration of chromate and metal ions in the central compartment, the applied cell voltage, chromate and metal ion flux, recovery percentage, energy consumption, and current efficiency. It was concluded that chromic acid and metal ions can be recovered efficiently from their mixed solution leaving behind the uncharged organics and can be reused as their corresponding acid and base apart from the purifying water for further applications. (author)

  4. Simulation of a Wet Sulfuric Acid Process (WSA for Utilization of Acid Gas Separated from Omani Natural Gas

    Directory of Open Access Journals (Sweden)

    Ahmed Jawad Ali Al-Dallal

    2013-06-01

    Full Text Available In this study, a proposed process for the utilization of hydrogen sulphide separated with other gases from omani natural gas for the production of sulphuric acid by wet sulphuric acid process (WSA was studied. The processwas simulated at an acid gas feed flow of 5000 m3/hr using Aspen ONE- V7.1-HYSYS software. A sensitivity analysis was conducted to determine the optimum conditions for the operation of plant. This included primarily the threepacked bed reactors connected in series for the production of sulphur trioxidewhich represented the bottleneck of the process. The optimum feed temperature and catalyst bed volume for each reactor were estimated and then used in the simulation of the whole process for two cases namely 4 and 6 mole% SO2 stream fed to the first catalytic reactor. The 4mole% SO2 gaves the highest conversion (98% compared with 6 mole% SO2 (94.7%. A valuable quantity of heat was generated from the process. This excess heat could also be transformed into power in a turbine or used as a heating media in neighbouring process units.

  5. Enantioselective separation and transformation of metalaxyl and its major metabolite metalaxyl acid in tomato and cucumber.

    Science.gov (United States)

    Li, Yuanbo; Dong, Fengshou; Liu, Xingang; Xu, Jun; Chen, Xiu; Han, Yongtao; Cheng, Youpu; Jian, Qiu; Zheng, Yongquan

    2013-11-01

    Many studies have shown the enantioselective transformation of metalaxyl in soil and animals, but little is known about the enantioselective biotransformation of metalaxyl in plants. In this study, a sensitive and convenient chiral liquid chromatography-tandem mass spectrometry method was developed for simultaneous measurement of the enantiomers of metalaxyl and its major metabolite, metalaxyl acid, in tomato and cucumber. Separation was by reversed-phase chromatography on a Chiralcel OD-RH column under isocratic conditions using acetonitrile-water (60/40, v/v) as mobile phase. The proposed method was successfully applied to investigate the possible enantioselective transformation of metalaxyl as well as the formation of metalaxyl acid in tomato and cucumber. In both vegetables, the (-)-R-enantiomer was preferentially degraded, resulting in relative enrichment of the (+)-S-enantiomer. Furthermore, formation of the metalaxyl acid enantiomers was also shown to be enantioselective, with the R-metalaxyl acid formed at a faster rate. This is the first evidence of enantioselective transformation of metalaxyl in vegetables, and the results should be considered in future environmental risk and food safety evaluations. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Separation of phenolic acids from natural plant extracts using molecularly imprinted anion-exchange polymer confined ionic liquids.

    Science.gov (United States)

    Bi, Wentao; Tian, Minglei; Row, Kyung Ho

    2012-04-06

    Polymer-confined ionic liquids were used for the separation of phenolic acids from natural plant extract by utilizing an anion-exchange mechanism. They were synthesized using molecular imprinting technique to reduce non-directional ion-ion interactions during anion-exchange and other interactions with interference substances that could decrease selectivity. A suitable sorbent for phenolic acid separation could be identified based on the adsorption behaviors of phenolic acids on different polymer-confined ionic liquids. Thus, the developed ionic liquid-based molecularly imprinted anion-exchange polymer (IMAP) achieved high recovery rates by solid-phase extraction of phenolic acids from Salicornia herbacea L. extract: 90.1% for protocatechuic acid, 95.5% for ferulic acid and 96.6% for caffeic acid. Moreover, the phenolic acids were separable from each other by repeated solid phase extraction cycles. The proposed method could be used to separate other phenolic acids or organic acids from complex samples. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Chemical composition and bioactivity properties of size-fractions separated from a vermicompost humic acid.

    Science.gov (United States)

    Canellas, Luciano P; Piccolo, Alessandro; Dobbss, Leonardo B; Spaccini, Riccardo; Olivares, Fábio L; Zandonadi, Daniel B; Façanha, Arnoldo R

    2010-01-01

    Preparative high performance size-exclusion chromatography (HPSEC) was applied to humic acids (HA) extracted from vermicompost in order to separate humic matter of different molecular dimension and evaluate the relationship between chemical properties of size-fractions (SF) and their effects on plant root growth. Molecular dimensions of components in humic SF was further achieved by diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY-NMR) based on diffusion coefficients (D), while carbon distribution was evaluated by solid state (CP/MAS) (13)C NMR. Seedlings of maize and Arabidopsis were treated with different concentrations of SF to evaluate root growth. Six different SF were obtained and their carbohydrate-like content and alkyl chain length decreased with decreasing molecular size. Progressive reduction of aromatic carbon was also observed with decreasing molecular size of separated fractions. Diffusion-ordered spectroscopy (DOSY) spectra showed that SF were composed of complex mixtures of aliphatic, aromatic and carbohydrates constituents that could be separated on the basis of their diffusion. All SF promoted root growth in Arabidopsis and maize seedlings but the effects differed according to molecular size and plant species. In Arabidopsis seedlings, the bulk HA and its SF revealed a classical large auxin-like exogenous response, i.e.: shortened the principal root axis and induced lateral roots, while the effects in maize corresponded to low auxin-like levels, as suggested by enhanced principal axis length and induction of lateral roots. The reduction of humic heterogeneity obtained in HPSEC separated size-fractions suggested that their physiological influence on root growth and architecture was less an effect of their size than their content of specific bioactive molecules. However, these molecules may be dynamically released from humic superstructures and exert their bioactivity when weaker is the humic conformational stability as that obtained

  8. 甜橙键合态芳香组分的酶(酸)解解离方法研究%Study on the Separation Method of Bound Flavour Component from Sweet Orange by Enzyme(Acid)

    Institute of Scientific and Technical Information of China (English)

    孙爱东; 葛毅强; 阎红; 倪元颖; 蔡同一

    2001-01-01

    In this paper, the separation of free and bound flavour component from orange juice by Amberlite XAD-2 absorption and methanol elution is processed, followed by simultaneous enzyme catalysis extraction using glucosidase and hydrochloric acid to release the potential flavour component from orange juice. The suitable resolve method is decided by the comparison of flavour components of different reaction fashions.%以甜橙为研究对象,通过采用Amberlite XAD-2树脂吸附溶剂解吸法,对橙汁的游离态与键合态芳香组分进行分离,然后酶(酸)解键合态组分,释放橙汁中的潜在芳香组分。通过对酶(酸)解反应方式释放的芳香组分的比较,确定适宜的解离方法。

  9. Synthesis of ino Acid Derived β-Cyclodextrins Used in Chiral Separation by Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    戴荣继; 佟斌; 魏征; 顾峻岭; 邓玉林; 李明愉; 傅若农

    2004-01-01

    Six new kinds of ino acid derived β-cyclodextrins were synthesized to improve their water solubility and chiral separation properties. They are heptakis{2,6-di-O-[3-L-(1-isopropyl carboxyl methyl ino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Val-β-CD), heptakis{2,6-di-O-[3-L-(1-benzyl carboxyl methyl ino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Phe-β-CD), heptakis{2,6-di-O-[3-(D, L-1-benzyl carboxyl methyl ino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. D,L-Phe-β-CD), heptakis{2,6-di-O-[3-(L-1-hydroxymethyl carboxyl methyl ino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Ser-β-CD), heptakis{2,6-di-O-[3-(L-1-carboxylmethyl carboxyl methyl ino)- 2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Asp-β-CD), heptakis{2,6-di-O-[3-(L-2-carboxyl tetrethylene ino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Pro-β-CD). Their chemical structures were certified using FTIR and 1H NMR. Except for L-Phe-β-CD and D,L-Phe-β-CD, that are in soluble in water, the other ino acid derived β-CDs all have good water solubility. D,L-tyrosine and promethazine were baselinely separated by L-Val-β-CD in capillary electrophoresis.

  10. Separation of cis/trans fatty acid isomers on gas chromatography compared to the Ag-TLC method

    Energy Technology Data Exchange (ETDEWEB)

    Ravi Kiran, C.; Reshma, M. V.; Sundaresan, A.

    2013-05-01

    The present study investigates the separation of the cis/ trans isomers of fatty acids on the 75 m SP2560 column under different gas chromatographic (GC) conditions including an isothermal program and a time-temperature program. The time-temperature program showed improved separation of cis/trans isomers of C{sub 1}4:1, C{sub 1}6:1, C{sub 1}8:1, C{sub 1}8:2 and C{sub 1}8:3 fatty acids along with short chain fatty acids compared to the isothermal program. The separation of trans/trans isomers of C{sub 1}8:1 fatty acids including elaidic acid (C{sub 1}8:1 .9t) and vaccenic acid (C{sub 1}8:1 {Delta}11t) was difficult with the time-temperature program. The thin layer chromatography impregnated with silver nitrate (Ag- TLC) method was performed to separate cis/trans fractions and GC analysis was carried out with the trans fraction. But GC analysis showed a co-elution of trans isomers of C{sub 1}8:1 fatty acid. Thus the study shows that a time-temperature programmed GC method with the highly polar cyanopropyl column is sufficient to resolve trans fatty acids along with short chain fatty acids when a large number of samples has to be analyzed. (Author) 33 refs.

  11. Liquid anion-exchange separation of vanadium from malonate media

    Energy Technology Data Exchange (ETDEWEB)

    Rao, R.R.; Khopkar, S.M. (Indian Inst. of Technology, Dept. of Chemistry, Bombay (India))

    1992-06-01

    Vanadium (IV) and (V) can be quantitatively extracted with 0.2 mol/l Amberlite LA-2 in xylene at pH 3.0 from 0.02 mol/l malonic acid, stripped with 0.5 mol/l hydrochloric acid, and determined spectrophotometrically. Five other liquid anion exchangers (Amberlite LA-1, Primene JM-T, Aliquat 336S, TOA and TIOA) were examined as possible extractants. The extraction of vanadium(IV) was found to be quantitative only with Amberlite LA-2, while that of vanadium(V) was quantitative with Amberlite LA-1 and LA-2, Primene JM-T and Aliquat 336S. Eight common solvents were tested as diluents; of these hexane, cyclohexane, benzene, and xylene were found to be satisfactory. Vanadium was separated from elements that do not form anionic complexes with malonic acid by selective extraction, from those that form weak complexes by washing the organic extract with water, and from metals that form strong malonato complexes by selective stripping with hydrochloric, nitric, or sulphuric acid. The method has been applied to the determination of vanadium in steel, coal fly ash and fuel oil. The precision of measurement is within {+-}5% and the detection limit of the method for vanadium is 0.5 mg/kg. (orig.).

  12. Synthesis of Homoveratric Acid-Imprinted Polymers and Their Evaluation as Selective Separation Materials

    Directory of Open Access Journals (Sweden)

    Mariusz Dana

    2011-05-01

    Full Text Available A bulk polymerization method was used to easily and efficiently prepare homo-veratric acid (3,4-dimethoxyphenylacetic acid-imprinted polymers from eight basic monomers: 2-vinylpyridine, 4-vinylpyridine, 1-vinylimidazole, N-allylaniline, N-allylpiperazine, allylurea, allylthiourea, and allylamine, in the presence of homoveratric acid as a template in N,N-dimethylformamide as a porogen. The imprinted polymer prepared from allylamine had the highest affinity to the template, showing an imprinting factor of 3.43, and allylamine polymers MIP8/NIP8 were selected for further studies. Their binding properties were analyzed using the Scatchard method. The results showed that the imprinted polymers have two classes of heterogeneous binding sites characterized by two pairs of Kd, Bmax values: Kd(1 = 0.060 μmol/mL, Bmax(1 = 0.093 μmol/mg for the higher affinity binding sites, and Kd(2 = 0.455 μmol/mL, Bmax(2 = 0.248 μmol/mg for the lower affinity binding sites. Non-imprinted polymer has only one class of binding site, with Kd = 0.417 μmol/mL and Bmax = 0.184 μmol/mg. A computational analysis of the energies of the prepolymerization complexes was in agreement with the experimental results. It showed that the selective binding interactions arose from cooperative three point interactions between the carboxylic acid and the two methoxy groups in the template and amino groups in the polymer cavities. Those results were confirmed by the recognition studies performed with the set of structurally related compounds. Allylamine polymer MIP8 had no affinity towards biogenic amines. The obtained imprinted polymer could be used for selective separation of homoveratric acid.

  13. Alkaline battery containing a separator of a cross-linked copolymer of vinyl alcohol and unsaturated carboxylic acid

    Science.gov (United States)

    Hsu, L. C.; Philipp, W. H.; Sheibley, D. W.; Gonzalez-Sanabria, O. D. (Inventor)

    1985-01-01

    A battery separator for an alkaline battery is described. The separator comprises a cross linked copolymer of vinyl alcohol units and unsaturated carboxylic acid units. The cross linked copolymer is insoluble in water, has excellent zincate diffusion and oxygen gas barrier properties and a low electrical resistivity. Cross linking with a polyaldehyde cross linking agent is preferred.

  14. Separating Tumorigenicity from Bile Acid Regulatory Activity for Endocrine Hormone FGF19.

    Science.gov (United States)

    Zhou, Mei; Wang, Xueyan; Phung, Van; Lindhout, Darrin A; Mondal, Kalyani; Hsu, Jer-Yuan; Yang, Hong; Humphrey, Mark; Ding, Xunshan; Arora, Taruna; Learned, R Marc; DePaoli, Alex M; Tian, Hui; Ling, Lei

    2014-06-15

    Hepatocellular carcinoma (HCC), one of the leading causes of cancer-related death, develops from premalignant lesions in chronically damaged livers. Although it is well established that FGF19 acts through the receptor complex FGFR4-β-Klotho (KLB) to regulate bile acid metabolism, FGF19 is also implicated in the development of HCC. In humans, FGF19 is amplified in HCC and its expression is induced in the liver under cholestatic and cirrhotic conditions. In mice, ectopic overexpression of FGF19 drives HCC development in a process that requires FGFR4. In this study, we describe an engineered FGF19 (M70) that fully retains bile acid regulatory activity but does not promote HCC formation, demonstrating that regulating bile acid metabolism is distinct and separable from tumor-promoting activity. Mechanistically, we show that FGF19 stimulates tumor progression by activating the STAT3 pathway, an activity eliminated by M70. Furthermore, M70 inhibits FGF19-dependent tumor growth in a rodent model. Our results suggest that selectively targeting the FGF19-FGFR4 pathway may offer a tractable approach to improve the treatment of chronic liver disease and cancer.

  15. Application of Convective Interaction Media (CIM) disk monolithic columns for fast separation and monitoring of organic acids.

    Science.gov (United States)

    Vodopivec, M; Podgornik, A; Berovic, M; Strancar, A

    2000-11-01

    The separation of organic acids on the anion-exchange monolithic support, commercially available as Convective Interaction Media (CIM), is presented in this study. It is demonstrated that citric, isocitric, pyruvic, fumaric, malic, and alpha-ketoglutaric acid can be successfully separated using a CIM monolithic column of suitable user-adjustable length. The effect of the mobile phase composition on the separation is investigated. CIM monolithic columns of adjustable length from 3 to 18 mm are compared regarding the resolution and the back pressure. It is shown that the CIM monolithic column of 12 mm in length enables a good separation of all six organic acids within 3 min and exhibits a linear dependence of back pressure versus flow rate. The resolution and the dynamic binding capacity are found to be flow-unaffected. A filtrated sample of bioprocess supernatant is analyzed without previous pretreatment, which indicates the possibility of online monitoring of small molecules during the bioprocess using CIM monolithic columns.

  16. Enantioselective separation of amino acids as biomarkers indicating life in extraterrestrial environments.

    Science.gov (United States)

    Pietrogrande, Maria Chiara

    2013-10-01

    chemical reactor. Liquid-based separation systems have been used in space missions. In particular, microchip capillary electrophoresis, based on microfluidic lab-on-a-chip systems, enables high-performance chemical analysis of amino acids with low mass and volume equipment and low power and reagent consumption. Coupling with laser-induced fluorescence detectors results in ultra-low limits of detection. This critical review describes applications of the on-board instruments used in the Rosetta mission to comets and in the more recent Mars exploration program, i.e., the Mars Science Laboratory and ExoMars missions.

  17. Adsorption and Separation of Aromatic Amino Acids from Aqueous Solutions Using Metal-Organic Frameworks.

    Science.gov (United States)

    Jonckheere, Dries; Steele, Julian A; Claes, Birgit; Bueken, Bart; Claes, Laurens; Lagrain, Bert; Roeffaers, Maarten B J; De Vos, Dirk E

    2017-09-06

    Metal-organic frameworks (MOFs) are investigated for the adsorption of aromatic amino acids l-phenylalanine (l-Phe), l-tryptophan (l-Trp), and l-tyrosine (l-Tyr) from aqueous solutions. After screening a range of water-stable MOFs, the hydrophobic Zr-MOF MIL-140C emerged as the best performing material, exhibiting uptakes of 15 wt % for l-Trp and 20 wt % for l-Phe. These uptakes are 5-10 wt % higher than those of large-pore zeolites Beta and Y. Both single-compound and competitive adsorption isotherms for l-Phe and l-Trp were experimentally obtained at the natural pH of these amino acid mixtures (pH 6.5-7) without additional pH modification. We find that the hydrophobic nature of MIL-140C and the capacity of l-Trp to form hydrogen bonds favor the uptake of l-Trp with its larger indole moiety compared to the smaller phenyl side group of l-Phe. On the basis of literature and vibrational analysis, observations of hydrogen-bonded l-Trp within the MIL-140C framework are evidenced by red- and blue-shifted -NH vibrations (3400 cm(-1)) in Fourier transform infrared spectroscopy, which were attributed to types N-Hl-Trp···πMIL-140C and N-Hl-Trp···OMIL-140C, respectively. MIL-140C is shown to be recycled at least three times for both aromatic amino acids without any loss of adsorption capacity, separation performance, or crystallinity. Desorption of aromatic amino acids proceeds easily in aqueous ethanol. Substantial coadsorption of negatively charged amino acids l-glutamate and l-aspartate (l-Glu and l-Asp) was observed from a model solution for wheat straw protein hydrolysate at pH 4.3. On the basis of these results, we conclude that MIL-140C is an interesting material for the recovery of essential aromatic amino acids l-Tyr, l-Phe, and l-Trp and of l-Glu and l-Asp from waste protein hydrolysates.

  18. Expression of NGF in the respiratory tract mucosa of the repetitive oesphageal stimulation by hydrochloric acid in guinea pig%神经生长因子在多次盐酸灌注食管气道高反应豚鼠肺组织中的表达

    Institute of Scientific and Technical Information of China (English)

    李芹子; 孔灵菲; 张宝辉; 张姝娜; 孙淑华

    2010-01-01

    目的 观察多次盐酸灌注豚鼠食管对呼吸道黏膜内神经生长因子(nerve growth factor,NGF)物质表达的影响.方法 将20只豚鼠按随机数字表法分为2组,每组10只.①模型组:用盐酸氯胺酮将豚鼠轻度麻醉,将5F胃管插入豚鼠食管至食管中下端,灌注含0.5%胃蛋白酶的盐酸(0.1 mol/L,8滴/min,20 min/d),连续灌注14 d;②对照组:用PBS代替盐酸灌注食管,方法同上.用免疫组织化学方法测定两组豚鼠肺组织NGF的免疫反应变化;用免疫印迹法(Western blotting)检测肺组织NGF的免疫反应变化;Metamoph图像分析系统对结果进行分析.结果 免疫组织化学结果显示(染色反应强度用灰度值表示):模型组豚鼠气管和细支气管黏膜内NGF物质阳性反应的平均灰度值明显地低于对照组[(108.46±9.89)vs(135.86±4.01)](P<0.01).Western blotting显示NGF在模型组豚鼠的肺内平均相对光密度值明显强于对照组[(1.415±0.155)vs(0.550±0.039)](P<0.01).结论 多次盐酸灌注豚鼠食管后呼吸道黏膜内NGF物质表达明显增多,提示NGF可能参与胃食管反流性呼吸系统疾病的发病过程.%Objective To observe the expression of nerve growth factor(NGF)in respiratory tract mueosa of the repetitive esophageal stimulation by hydrochloric acid(HCl)in guinea pigs.Methods Twenty adult guinea pigs were randomly divided into two groups(n=10):①HCl model group:On the day of experimentation,guinea pigs were maintained under ketamine anesthesia.A 5F catheter was inserted through the mouth and into the lumen of the middle and lower oesophagus.The oesophagus of each animal was perfused with HCl-P for 20 min/d for 14 d.②PBS control group:The oesophagus of each animal was perfused with PBS.The alterations of NGF immunoreactivity were investigated by immunohistochemical and Western blotting method and analyzed by the Metamoph analysisi system.Results Immunohistochemistry demonstrated that the mean grey values of NGF positive

  19. Separation and purification of γ-aminobutyric acid from fermentation broth by flocculation and chromatographic methodologies.

    Science.gov (United States)

    Gao, Qiang; Duan, Qiang; Wang, Depei; Zhang, Yunze; Zheng, Chunyang

    2013-02-27

    To date, the multifunctional γ-aminobutyric acid (GABA) is mainly produced by microbial fermentation in industry. The purpose of this study was to find an effective method for separation and purification of 31.2 g/L initial GABA from the fermentation broth of Enterococcus raffinosus TCCC11660. To remove the impurities from fermentation broth, flocculation pretreatment using chitosan and sodium alginate was first implemented to facilitate subsequent filtration. Ultrafiltration followed two discontinuous diafiltration steps to effectively remove proteins and macromolecular pigments, and the resulting permeate was further decolored by DA201-CII resin at a high decoloration ratio and GABA recovery. Subsequently, ion exchange chromatography (IEC) with Amberlite 200C resin and gradient elution were applied for GABA separation from glutamate and arginine. Finally, GABA crystals of 99.1% purity were prepared via warm ethanol precipitation twice. Overall, our results reveal that the successive process including flocculation, filtration, ultrafiltration, decoloration, IEC, and crystallization is promising for scale-up GABA extraction from fermentation broth.

  20. An improved extraction chromatographic resin for the separation of uranium from acidic nitrate media

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, M.L.; Horwitz, E.P.; Sajdak, L.R.; Chiarizia, R. [Chemistry Division, Argonne National Laboratory, 60439 Argonne, IL (United States)

    2001-07-06

    The preparation and characterization of a new extraction chromatographic resin exhibiting extraordinarily strong retention of hexavalent uranyl ion over a wide range of nitric acid concentrations and very high selectivity for U(VI) over Fe(III) and numerous other cations is described. This new material (designated U/TEVA-2) comprises a novel liquid stationary phase consisting of an equimolar mixture of diamyl amylphosphonate (DA[AP]) and Cyanex 923{sup registered} (a commercially available trialkyl-phosphine oxide, TRPO) sorbed on silanized silica or Amberchrom CG-71. Cyanex 923 is shown to be preferable to a related TRPO, Cyanex 925{sup registered}, due to its lower viscosity and higher selectivity for U(VI) over Fe(III). The retention of uranyl nitrate by the U/TEVA-2 resin, as measured by the k' values (number of free column values to peak maximum) is >5000 from approximately 0.1 to 8 M HNO{sub 3}. The ability of the new resin to strongly and selectively retain U(VI) from such a wide range of acid concentrations, along with its favorable physical properties, make it a good candidate for application in the separation and preconcentration of U(VI) from complex environmental, biological, and nuclear waste samples for subsequent determination.

  1. An improved extraction chromatographic resin for the separation of uranium from acidic nitrate media.

    Science.gov (United States)

    Dietz, M L; Horwitz, E P; Sajdak, L R; Chiarizia, R

    2001-07-01

    The preparation and characterization of a new extraction chromatographic resin exhibiting extraordinarily strong retention of hexavalent uranyl ion over a wide range of nitric acid concentrations and very high selectivity for U(VI) over Fe(III) and numerous other cations is described. This new material (designated U/TEVA-2) comprises a novel liquid stationary phase consisting of an equimolar mixture of diamyl amylphosphonate (DA[AP]) and Cyanex 923((R)) (a commercially available trialkyl-phosphine oxide, TRPO) sorbed on silanized silica or Amberchrom CG-71. Cyanex 923 is shown to be preferable to a related TRPO, Cyanex 925((R)), due to its lower viscosity and higher selectivity for U(VI) over Fe(III). The retention of uranyl nitrate by the U/TEVA-2 resin, as measured by the k' values (number of free column values to peak maximum) is >5000 from approximately 0.1 to 8 M HNO(3). The ability of the new resin to strongly and selectively retain U(VI) from such a wide range of acid concentrations, along with its favorable physical properties, make it a good candidate for application in the separation and preconcentration of U(VI) from complex environmental, biological, and nuclear waste samples for subsequent determination.

  2. Separation of DR synthesized Ti-Mg Alloy by dissolution of waste by-products in acid media

    CSIR Research Space (South Africa)

    Mushove, T

    2010-06-01

    Full Text Available Of DR Synthesized Ti-Mg Alloy By Dissolution Of Waste By-Products In Acid Media. The dissolution experiments were done in a Julabo SW23 waterbath shaker, with 300 ml flasks. Acid solution of predetermined molarity was charged into a flask and heated... - 200rpm Inorganic Acid Leach time - 40mins temperature - 90oC Organic Acid leach time - 2.5hrs temperature - 60oC Filtration leach residues XRD Dissolution efficiencies Separate TiO2, Ti-20Mg alloy and MgO powders were leached in the same...

  3. SEPARATION OF SATURED AND UNSATURATED FATTY ACIDS FROM PALM FATTY ACIDS DISTILLATES IN CONTINUOUS MULTISTAGE COUNTERCURRENT COLUMNS WITH SUPERCRITICAL CARBON DIOXIDE AS SOLVENT: A PROCESS DESIGN METHODOLOGY

    Directory of Open Access Journals (Sweden)

    Nélio Teixeira MACHADO

    1997-12-01

    Full Text Available In this work the separation of multicomponent mixtures in counter-current columns with supercritical carbon dioxide has been investigated using a process design methodology. First the separation task must be defined, then phase equilibria experiments are carried out, and the data obtained are correlated with thermodynamic models or empirical functions. Mutual solubilities, Ki-values, and separation factors aij are determined. Based on this data possible operating conditions for further extraction experiments can be determined. Separation analysis using graphical methods are performed to optimize the process parameters. Hydrodynamic experiments are carried out to determine the flow capacity diagram. Extraction experiments in laboratory scale are planned and carried out in order to determine HETP values, to validate the simulation results, and to provide new materials for additional phase equilibria experiments, needed to determine the dependence of separation factors on concetration. Numerical simulation of the separation process and auxiliary systems is carried out to optimize the number of stages, solvent-to-feed ratio, product purity, yield, and energy consumption. Scale-up and cost analysis close the process design. The separation of palmitic acid and (oleic+linoleic acids from PFAD-Palm Fatty Acids Distillates was used as a case study.

  4. Simultaneous separation and quantitative determination of monosaccharides, uronic acids, and aldonic acids by high performance anion-exchange chromatography coupled with pulsed amperometric detection in corn stover prehydrolysates

    Directory of Open Access Journals (Sweden)

    Xing Wang

    2012-11-01

    Full Text Available A method for simultaneous separation and quantitative determination of arabinose, galactose, glucose, xylose, xylonic acid, gluconic acid, galacturonic acid, and glucuronic acid was developed by using high performance anion-exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD. The separation was performed on a CarboPacTM PA-10 column (250 mm × 2 mm with a various gradient elution of NaOH-NaOAc solution as the mobile phase. The calibration curves showed good linearity (R2 ≥ 0.9993 for the monosaccharides, uronic acids, and aldonic acids in the range of 0.1 to 12.5 mg/L. The detection limits (LODs and the quantification limits (LOQs were 4.91 to 18.75 μg/L and 16.36 to 62.50 μg/L, respectively. Relative standard deviations (RSDs of the retention times and peak areas for the seven consecutive determinations of an unknown amount of mixture were 0.15% to 0.44% and 0.22% to 2.31%, respectively. The established method was used to separate and determine four monosaccharides, two uronic acids, and two aldonic acids in the prehydrolysate from dilute acid steam-exploded corn stover within 21 min. The spiked recoveries of monosaccharides, uronic acids, and aldonic acids ranged from 91.25% to 108.81%, with RSDs (n=3 of 0.04% ~ 6.07%. This method was applied to evaluate the quantitative variation of sugar and sugar acid content in biomass prehydrolysates.

  5. Boric acid as a mobile phase additive for high performance liquid chromatography separation of ribose, arabinose and ribulose.

    Science.gov (United States)

    De Muynck, Cassandra; Beauprez, Joeri; Soetaert, Wim; Vandamme, Erick J

    2006-01-01

    A new high performance liquid chromatographic (HPLC) method is described for the analysis of ribose, arabinose and ribulose mixtures obtained from (bio)chemical isomerization processes. These processes gain importance since the molecules can be used for the synthesis of antiviral therapeutics. The HPLC method uses boric acid as a mobile phase additive to enhance the separation on an Aminex HPX-87K column. By complexing with boric acid, the carbohydrates become negatively charged, thus elute faster from the column by means of ion exlusion and are separated because the complexation capacity with boric acid differs from one carbohydrate to another. Excellent separation between ribose, ribulose and arabinose was achieved with concentrations between 0.1 and 10 gL(-1) of discrete sugar.

  6. Removal of humic acid from aqueous solution by magnetically separable polyaniline: adsorption behavior and mechanism.

    Science.gov (United States)

    Wang, Jiahong; Bi, Lijuan; Ji, Yanfen; Ma, Hongrui; Yin, Xiaolong

    2014-09-15

    Magnetically separable polyaniline (Fe3O4@SiO2-PANI) was prepared by in situ chemical polymerization of aniline on the surface of silica-coated Fe3O4 nanoparticles, and characterized by FTIR spectroscopy, powder X-ray diffraction, elemental analysis, transmission electron microscopy, vibrating sample magnetometry and X-ray photoelectron spectroscopy. Characterization results showed that Fe3O4@SiO2-PANI with amino groups of 1.78 mmol/g and the average diameter of 21.6 nm are superparamagnetic. Adsorption behavior of Fe3O4@SiO2-PANI nanoparticles for humic acid (HA) was investigated by batch experiments and adsorption kinetic tests. HA adsorption amount on the adsorbent decreased with increasing solution pH and the presence of Ca(2+) resulted in the enhanced HA adsorption. HA adsorption on Fe3O4@SiO2-PANI could be well described by Langmuir model and the maximum adsorption amount of the adsorbent for HA at 25°C was 36.36 mg/g. HA adsorption process on the adsorbent obey pseudo-second-order kinetics and the adsorption rates decrease with increasing initial HA concentration. The XPS analysis verified that HA adsorption over the adsorbent could be attributed to the surface complexation between the disassociated HA molecules and the protonated nitrogen of polyaniline on the adsorbent. HA loaded adsorbent could be magnetically separated and easily desorbed in 0.01 mol/L NaOH solution. Regeneration tests indicated that Fe3O4@SiO2-PANI could be used repeatedly. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Solubility and phase separation of benzocaine and salicylic acid in 1,4-dioxane-water mixtures at several temperatures.

    Science.gov (United States)

    Peña, M Angeles; Bustamante, Pilar; Escalera, Begoña; Reíllo, Aurora; Bosque-Sendra, Juan Manuel

    2004-11-15

    The solubilities of benzocaine and salicylic acid were determined in water-dioxane mixtures at several temperatures (5-40 degrees C for benzocaine and 10-40 degrees C for salicylic acid). The solubility curves as a function of dioxane ratio showed a maximum at 90% dioxane at all temperatures. Above 25 degrees C, the homogeneous mixture splits into two liquid immiscible phases. For benzocaine, the initial dioxane concentration range at which phase separation takes place increased with temperature (50-60% at 25 degrees C, 50-70% at 30-35 degrees C and 40-70% at 40 degrees C). For salicylic acid, the dioxane concentration required for phase separation (40-60% dioxane) did not change with temperature. Phase separation was not related to solid phase changes (polymorphism or solvates). The phase composition and drug extraction at the drug-rich phase were determined. The apparent enthalpies of the solution process were a nonlinear function of the dioxane ratio for both drugs. The apparent enthalpy of solution of benzocaine was larger than that expected at the upper limit of phase separation (70% dioxane), whereas for salicylic acid the apparent enthalpy of solution decreased abruptly at the region corresponding to phase separation (40-70% dioxane). Both drugs showed a nonlinear pattern of enthalpy-entropy compensation.

  8. Separation of Long and Short Chain Fatty Acids as Naphthacyl and Substituted Phenacyl Esters by High Performance Liquid Chromatography.

    Science.gov (United States)

    High performance liquid chromatography of various C2 - C24 fatty acids was run on their p-bromophenacyl, p-nitrophenacyl, p-chlorophenacyl, and 2--naphthacyl esters. All the separations were accomplished using reversed phase columns with the eluent consisting of an acetonitrile:water gradient. For all derivatives tested the separations were well defined and analogous although certain esters eluted together as one peak. Quantitative results indicate that the limit of detection in the present study was two picograms of n-caproic acid and 10 picograms of

  9. Impact of citric acid and calcium ions on acid solubilization of mechanically separated turkey meat: effect on lipid and pigment content.

    Science.gov (United States)

    Hrynets, Y; Omana, D A; Xu, Y; Betti, M

    2011-02-01

    Increased demand for poultry products has resulted in an increased availability of by-products, such as the neck, back, and frame, that can be processed into mechanically separated poultry meat. The major problems with mechanically separated poultry meat are its high lipid content, color instability, and high susceptibility to lipid oxidation. The present work was undertaken to determine the effect of different concentrations of citric acid and calcium ions on protein yield, color characteristics, and lipid removal from protein isolates prepared using an acid-aided extraction process. Six levels of citric acid (0, 2, 4, 6, 8, and 10 mmol/L) and 2 levels of calcium chloride (0 and 8 mmol/L) were examined. The entire experiment was replicated 3 times, resulting in 36 extractions (3 × 6 × 2). The highest (P citric acid. In general, all the combinations removed an average of 90.8% of the total lipids from mechanically separated turkey meat, ranging from 86.2 to 94.7%. The lowest amount (1.14%) of total lipids obtained was for samples treated with 4 mmol/L of citric acid. Maximum removal of neutral lipids (96.5%) and polar lipids (96.4%) was attained with the addition of 6 and 2 mmol/L of citric acid, respectively. Polar lipid content was found to be significantly (P = 0.0045) affected by the presence of calcium chloride. The isolated proteins were less (P citric acid. Addition of calcium chloride had a negative effect on total pigment content. The study revealed that acid extractions with the addition of citric acid resulted in substantial removal of lipids and pigments from mechanically separated turkey meat, improved stability of the recovered proteins against lipid oxidation, and appreciable protein recovery yields.

  10. Diglycolamic acid anchored on polyamine matrix for the mutual separation of Eu(III) and Am(III)

    Energy Technology Data Exchange (ETDEWEB)

    Suneesh, A.S.; Syamala, K.V.; Venkatesan, K.A.; Antony, M.P.; Vasudeva Rao, P.R. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Fuel Chemistry Div.

    2016-04-01

    Diglycolamic acid was anchored on a polyamine matrix and the product (PA-DGAH) was characterized by ion-exchange capacity measurement, TG-DTA and FT-IR spectroscopy. The extraction behavior of Am(III) and Eu(III) in PA-DGAH was studied from dilute nitric acid medium to examine the feasibility using the anchored adsorbent for their mutual separation. The effect of various parameters such as the duration of equilibration, concentration of europium, nitric acid and diethylenetriaminepentaacetic acid (DTPA) in aqueous phase on the distribution coefficient (K{sub d}) of Am(III) and Eu(III) was studied. The distribution coefficient decreased with increase in the concentration of nitric acid. Rapid extraction of metal ions in the initial stages of equilibration followed by the establishment of equilibrium occurred within 4 h. The data on the rate of uptake of Am(III) and Eu(III) were fitted into pseudo-first order and pseudo-second order rate equation. The extraction isotherm was fitted to Langmuir and Freundlich adsorption models and the apparent europium extraction capacity was determined. The mechanism of extraction was elucidated and the conditions needed for efficient separation of Am(III) from Eu(III) was optimized using DTPA. The study indicated the possibility of using PA-DGAH for the separation of Eu(III) from Am(III) with high separation factors.

  11. Production of 61Cu using natural cobalt target and its separation using ascorbic acid and common anion exchange resin.

    Science.gov (United States)

    Das, Sujata Saha; Chattopadhyay, Sankha; Barua, Luna; Das, Malay Kanti

    2012-02-01

    (61)Cu was produced by (nat)Co(α, xn)(61)Cu reaction. (61)Cu production yield was 89.5 MBq/μAh (2.42 mCi/μAh) at the end of irradiation (EOI). A simple radiochemical separation method using anion exchange resin and ascorbic acid has been employed to separate the product radionuclide from inactive target material and co-produced non-isotopic impurities. The radiochemical separation yield was about 90%. Radiochemical purity of (61)Cu was >99% 1 h after EOI. Final product was suitable for making complex with N(2)S(2) type of ligands.

  12. Kinetic study on reactive extraction for chiral separation of phenylsuccinic acid enantiomers

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The kinetics of the extraction of phenylsuccinic acid(PSA) enantiomers by hydroxypropyl-β-cyclodextrin(HP-β-CD) in a modified Lewis cell was studied,in which HP-β-CD dissolved in 0.1 mol L-1 NaH2PO4/H3PO4 buffer solution(pH = 2.5) was selected as the chiral extractant.PSA enantiomers were extracted from organic phase to aqueous phase in the extraction module.The theory of extraction accompanied by a chemical reaction has been used to obtain the intrinsic kinetics of this extraction module.The different parameters affecting the extraction rate such as agitation speed,interfacial area,initial concentration of PSA enantiomers in organic phase as well as HP-β-CD concentration in aqueous phase were separately studied.The experimental results demonstrate that the extraction reactions are fast.The reactions were found to be first order with respect to PSA and second order with respect to HP-β-CD with forward rate constants of 3.4 × 10-2 m6 mol-2 s-1 for R-PSA and 9.96 × 10?3 m6 mol-2 s-1 for S-PSA.These data will be useful in the design of extraction processes.

  13. Artificial Photosynthetic Reaction Center Exhibiting Acid-Responsive Regulation of Photoinduced Charge Separation

    Energy Technology Data Exchange (ETDEWEB)

    Pahk, Ian [Arizona State Univ., Tempe, AZ (United States). School of Molecular Sciences; Kodis, Gerdenis [Arizona State Univ., Tempe, AZ (United States). School of Molecular Sciences; Fleming, Graham R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Molecular Biophysics and Integrated Bioimaging Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemistry and QB3 Inst.; Moore, Thomas A. [Arizona State Univ., Tempe, AZ (United States). School of Molecular Sciences; Moore, Ana L. [Arizona State Univ., Tempe, AZ (United States). School of Molecular Sciences; Gust, Devens [Arizona State Univ., Tempe, AZ (United States). School of Molecular Sciences

    2016-09-16

    Charge separation (CS) is the primary light-driven reaction in photosynthesis whereas onphotochemical quenching (NPQ) is a photoprotective regulatory mechanism employed by many photosynthetic organisms to dynamically modulate energy flow within the photosynthetic apparatus in response to fluctuating light conditions. Activated by decreases in lumen pH produced during periods of high photon flux, NPQ induces rapid thermal dissipation of excess excitation energy. As a result, the rate of CS decreases, thereby limiting the accumulation of potentially deleterious reactive intermediates and byproducts. In this article, a molecular triad that functionally mimics the effects of NPQ associated with an artificial photosynthetic reaction center is described. Steady-state absorption and emission, time-resolved fluorescence, and transient absorption spectroscopies have been used to demonstrate a 1 order of magnitude reduction in the CS quantum yield via reversible protonation of an excited-state-quenching molecular switch moiety. As in the natural system, the populations of unquenched and quenched states and therefore the overall yields of CS were found to be dependent on acid concentration.

  14. Advanced Acid Gas Separation Technology for the Utilization of Low Rank Coals

    Energy Technology Data Exchange (ETDEWEB)

    Kloosterman, Jeff

    2012-12-31

    Air Products has developed a potentially ground-breaking technology – Sour Pressure Swing Adsorption (PSA) – to replace the solvent-based acid gas removal (AGR) systems currently employed to separate sulfur containing species, along with CO{sub 2} and other impurities, from gasifier syngas streams. The Sour PSA technology is based on adsorption processes that utilize pressure swing or temperature swing regeneration methods. Sour PSA technology has already been shown with higher rank coals to provide a significant reduction in the cost of CO{sub 2} capture for power generation, which should translate to a reduction in cost of electricity (COE), compared to baseline CO{sub 2} capture plant design. The objective of this project is to test the performance and capability of the adsorbents in handling tar and other impurities using a gaseous mixture generated from the gasification of lower rank, lignite coal. The results of this testing are used to generate a high-level pilot process design, and to prepare a techno-economic assessment evaluating the applicability of the technology to plants utilizing these coals.

  15. Preparation of molecularly imprinted cross-linked chitosan/glutaraldehyde resin for enantioselective separation of L-glutamic acid.

    Science.gov (United States)

    Monier, M; El-Sokkary, A M A

    2010-08-01

    In the present study, separation of L-glutamic acid from dilute aqueous solution by solid-phase extraction based on molecular imprinting technique using cross-linked chitosan/glutaraldehyde resin was investigated. L-Glutamic acid imprinted cross-linked chitosan (LGIC) was prepared by cross-linking of chitosan by glutaraldehyde cross-linker, in the presence of L-glutamic acid. Non-imprinted cross-linked chitosan (NIC) as control was also prepared by the same procedure in the absence of template molecules. The morphological structures of both LGIC and NIC were examined by scanning electron microscope (SEM). LGIC particles were applied to determine the optimum operational condition for l-glutamic acid separation from dilute aqueous solution. In adsorption step, optimum pH and retention time were 5.5 and 100 min, while corresponding values in extraction step were 2.5 and 60 min, respectively. The adsorption isotherms indicated that the maximum adsorption capacities of L- and D-glutamic acid on LGIC were 42+/-0.8 and 26+/-1.2mg/g, respectively, while in case of NIC, both L- and D-glutamic acid present the same maximum adsorption capacity 7+/-0.6 mg/g, which confirm that the molecular imprinting technique creates an enantioselectivity of LGIC toward L-glutamic acid. In addition, chiral resolution of l-, d-glutamic acid racemic mixture was carried out using column of LGIC. Copyright 2010 Elsevier B.V. All rights reserved.

  16. Extraction and separation studies of platinum(IV) with N-n-octylaniline.

    Science.gov (United States)

    Lokhande, T N; Anuse, M A; Chavan, M B

    1998-11-01

    N-n-octylaniline in xylene is used for the extractive separation of platinum(IV) from acidic media. Platinum(IV) was extracted quantitatively with 10 ml of 3% reagent in xylene from 0.5 to 10 and 2.5 to 10 M hydrochloric and sulphuric acid, respectively. It was stripped from organic phase with water and estimated photometrically with stannous chloride. The effect of metal ion, acids, reagent concentration and of various foreign ions has been investigated. The method affords binary separation of platinum(IV) from iron(III), cobalt(II), nickel(II) and copper(II), and is applicable to the analysis of synthetic mixtures and alloys. The method is fast, accurate and precise.

  17. PREPARATION OF ASYMMETRIC POLYETHERKETONE FLAT AND HOLLOW FIBER MEMBRANES FOR GAS SEPARATION USING ACETIC ACID BASED COAGULANTS

    Institute of Scientific and Technical Information of China (English)

    Ji-ping Yang; Philip J. Brown

    2008-01-01

    Membranes for gas separation have developed significantly in the last twenty years, however, there is still a need for high temperature and chemically resistant membranes that exhibit good selectivity and gas permeability. Our study examines the fundamental properties of polyetherketone (PEK, a thermally stable and chemically resistant polymer)membranes prepared using concentrated sulphuric acid (98% H2SO4) as the solvent. Non-solvents used in the work included acetic acid, ethanol, methanol, glycerol, and water. The concentration of the polymer solutions was chosen to be 20%. The membrane structures were examined using SEM, and the gas separation properties were measured using a lab-scale test rig.The results show that formation and control of membrane structures are complicated, and many preparation parameters affect membrane morphology and performance. Using appropriate conditions skinned sponge-like structured hollow fiber membranes could be made from PEK by using acetic acid as the internal coagulant. PEK hollow fibers spun from 20%PEK/H2SO4 solutions with 50% aqueous acetic acid as internal coagulant had selectivity for hydrogen/methane of around 40, implying a solution diffusion separation mechanism for gas separation without the need for fiber coating or after post-treatments.

  18. Chiral separation of the clinically important compounds fucose and pipecolic acid using CE: determination of the most effective chiral selector.

    Science.gov (United States)

    Hadjistasi, Christoforos A; Stavrou, Ioannis J; Stefan-Van Staden, Raluca-Ioana; Aboul-Enein, Hassan Y; Kapnissi-Christodoulou, Constantina P

    2013-09-01

    In this study, simple electrophoretic methods were developed for the chiral separation of the clinically important compounds fucose and pipecolic acid. In recent years, these analytes, and particularly their individual enantiomers, have attracted considerable attention due to their role in biological functions and disorders. The detectability and sensitivity of pipecolic acid and fucose were improved by reacting them with fluorenylmethyloxycarbonyl chloride (FMOC-Cl) and 5-amino-2-naphthalene-sulfonic acid (ANSA), respectively. The enantioseparation conditions were optimized by initially investigating the type of the chiral selector. Different chiral selectors, such as polymeric surfactants and cyclodextrins, were used and the most effective ones were determined with regard to resolution and analysis time. A 10-mM β-cyclodextrin was able to separate the enantiomers of ANSA-DL-fucose and the polymeric surfactant poly(sodium N-undecanoyl-LL-leucine-valinate) was able to separate the enantiomers of FMOC-DL-pipecolic acid, with resolution values of 3.45 and 2.78, respectively. Additional parameters, such as the concentration and the pH of the background electrolyte (BGE), the concentration of the chiral selector, and the addition of modifiers were examined in order to optimize the separations. The addition of the chiral ionic liquid D-alanine tert-butyl ester lactate into the BGE was also investigated, for the first time, in order to improve resolution of the enantiomers.

  19. Separation of middle rare earths by solvent extraction using 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester as an extractant

    Institute of Scientific and Technical Information of China (English)

    Danilo; Fontana; Loris; Pietrelli

    2009-01-01

    The extraction of the trivalent middle rare earths from chloride media by kerosene solutions of 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester as an extractant was studied. The separation factors between the elements using solution simulating wastes from NiMH spent batteries have been evaluated: the order of the extractive ability of extractant can be confirmed in ThGdEuSm.

  20. Fluorescent boronic acid terminated polymer grafted silica particles synthesized via click chemistry for affinity separation of saccharides

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhifeng, E-mail: 897061147@qq.com; Deng, Peihong; Tang, Siping; Li, Junhua

    2014-07-01

    Boronic acids are important for effective separation of biological active cis-diols. For the purpose of constructing a new type of saccharide-sensitive material which can not only provide convenient separation but also improve the access of boronic acid to guest molecules, the fluorogenic boronic acid terminated, thermo-sensitive polymers (BA-polyNIPAm) were grafted to an alkyne modified silica gel through the exploitation of click chemistry. The BA-polyNIPAm grafted silica gel (BA-polyNIPAm-SG) was characterized by FT-IR, fluorescence spectra, fluorescence microscopy, elemental analysis (EA), thermal gravimetric analysis (TGA), scanning electron microscope (SEM) and so on. BA-polyNIPAm-SG displayed affinity binding ability for saccharides under physiological pH value and allowed saccharides to be conveniently separated from solution. The maximum binding capacities for fructose and glucose are 83.2 μmol/g and 70.4 μmol/g polymer, respectively. The intensity of fluorescence emission of BA-polyNIPAm-SG increased with the increasing of fructose concentration. The present study provides a new kind of composite material which contains moveable and flexible grippers for recognizing and binding guest molecules. - Highlights: • Fluorogenic boronic acid terminated polymers were conjugated to silica particle. • The prepared material can conveniently separate saccharides from solution. • The prepared material displays increased fluorescence emission upon binding fructose.

  1. Improved dating of the human/chimpanzee separation in the mitochondrial DNA tree: heterogeneity among amino acid sites.

    Science.gov (United States)

    Adachi, J; Hasegawa, M

    1995-06-01

    The internal branch lengths estimated by distance methods such as neighbor-joining are shown to be biased to be short when the evolutionary rate differs among sites. The variable-invariable model for site heterogeneity fits the amino acid sequence data encoded by the mitochondrial DNA from Hominoidea remarkably well. By assuming the orangutan separation to be 13 or 16 Myr old, a maximum-likelihood analysis estimates a young date of 3.6 +/- 0.6 or 4.4 +/- 0.7 Myr (+/- 1 SE) for the human/chimpanzee separation, and these estimates turn out to be robust against differences in the assumed model for amino acid substitutions. Although some uncertainties still exist in our estimates, this analysis suggests that humans separated from chimpanzees some 4-5 Myr ago.

  2. Method for the chemical separation of GE-68 from its daughter Ga-68

    Science.gov (United States)

    Fitzsimmons, Jonathan M.; Atcher, Robert W.

    2010-06-01

    The present invention is directed to a generator apparatus for separating a daughter gallium-68 radioisotope substantially free of impurities from a parent gernanium-68 radioisotope, including a first resin-containing column containing parent gernanium-68 radioisotope and daughter gallium-68 radioisotope, a source of first eluent connected to said first resin-containing column for separating daughter gallium-68 radioisotope from the first resin-containing column, said first eluent including citrate whereby the separated gallium is in the form of gallium citrate, a mixing space connected to said first resin-containing column for admixing a source of hydrochloric acid with said separated gallium citrate whereby gallium citrate is converted to gallium tetrachloride, a second resin-containing column for retention of gallium-68 tetrachloride, and, a source of second eluent connected to said second resin-containing column for eluting the daughter gallium-68 radioisotope from said second resin-containing column.

  3. Experimental and Model Studies on Continuous Separation of 2-Phenylpropionic Acid Enantiomers by Enantioselective Liquid-Liquid Extraction in Centrifugal Contactor Separators.

    Science.gov (United States)

    Feng, Xiaofeng; Tang, Kewen; Zhang, Pangliang; Yin, Shuangfeng

    2016-03-01

    Multistage enantioselective liquid-liquid extraction (ELLE) of 2-phenylpropionic acid (2-PPA) enantiomers using hydroxypropyl-β-cyclodextrin (HP-β-CD) as extractant was studied experimentally in a counter-current cascade of centrifugal contactor separators (CCSs). Performance of the process was evaluated by purity (enantiomeric excess, ee) and yield (Y). A multistage equilibrium model was established on the basis of single-stage model for chiral extraction of 2-PPA enantiomers and the law of mass conservation. A series of experiments on the extract phase/washing phase ratio (W/O ratio), extractant concentration, the pH value of aqueous phase, and the number of stages was conducted to verify the multistage equilibrium model. It was found that model predictions were in good agreement with the experimental results. The model was applied to predict and optimize the symmetrical separation of 2-PPA enantiomers. The optimal conditions for symmetric separation involves a W/O ratio of 0.6, pH of 2.5, and HP-β-CD concentration of 0.1 mol L(-1) at a temperature of 278 K, where eeeq (equal enantiomeric excess) can reach up to 37% and Yeq (equal yield) to 69%. By simulation and optimization, the minimum number of stages was evaluated at 98 and 106 for eeeq > 95% and eeeq > 97%.

  4. PDMS microchip coated with polydopamine/gold nanoparticles hybrid for efficient electrophoresis separation of amino acids.

    Science.gov (United States)

    Liang, Ru-Ping; Meng, Xiang-Ying; Liu, Chun-Ming; Qiu, Jian-Ding

    2011-11-01

    In this paper, a novel, simple, economical and environmentally friendly method based on in situ chemically induced synthesis strategy was designed and developed for the modification of a poly(dimethylsiloxane) (PDMS) microchip channel with polydopamine/gold nanoparticles (PDA/Au NPs) to create a hydrophilic and biofouling resistant surface. Dopamine as a reductant and a monomer, and HAuCl(4) as an oxidant to trigger dopamine polymerization and the source of metallic nanoparticles, were filled into the PDMS microchannel to yield in situ a well-distributed and robust PDA/Au NP coating. Au NPs were highly and uniformly dispersed in/on the PDA matrix with a narrow size distribution, as verified by scanning electron microscopy and UV-vis spectra. Compared with the native PDMS microchannel, the modified surfaces exhibited much better wettability, high stability and suppressed electroosmotic mobility, and less nonspecific adsorption towards biomolecules. The water contact angle and EOF of PDA/Au NP-coated PDMS microchip were measured to be 13° and 4.17×10(-4) cm(2)/V s, compared to those of 111° and 5.33×10(-4) cm(2)/V s from the native one, respectively. Fast and efficient separations of five amino acids such as arginine, proline, histidine, valine and threonine suggested greatly improved electrophoretic performance of the PDA/Au NP-functionalized PDMS microchips. This one-step procedure offers an effective approach for a biomimetic surface design on microfluidic chips, which is promising in high-throughput and complex biological analysis. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Membrane fractionation of herring marinade for separation and recovery of fats, proteins, amino acids, salt, acetic acid and water

    DEFF Research Database (Denmark)

    Fjerbæk Søtoft, Lene; Lizarazu, Juncal Martin; Razi Parjikolaei, Behnaz;

    2015-01-01

    containing sugars, amino acids and smaller peptides and a NF permeate containing salt and acetic acid ready for reuse. 42% of the spent marinade is recovered to substitute fresh water and chemicals. The Waste water amount is reduced 62.5%. Proteins are concentrated 30 times, while amino acids and smaller......In the production of marinated herring, nearly one ton of acidic saline marinade is produced per 1.5 tons herring fillet. This spent marinade contains highly valuable compounds such as proteins and amino acids. Membranes are suited to recover these substances. In this work, six membrane stages...... are employed: microfiltration (MF) (0.2 lm), ultrafiltration (UF) (50, 20, 10 and 1 kDa) and nanofiltration (NF). The most promising stages are 50 kDa UF and NF based on SDS–PAGE analyses and total amino acid concentration. The 50 kDa stage produces a protein concentrate (>17 kDa). NF produces a retentate...

  6. Separation of chlorogenic acid and concentration of trace caffeic acid from natural products by pH-zone-refining countercurrent chromatography.

    Science.gov (United States)

    Lu, Yuanyuan; Dong, Genlai; Gu, Yanxiang; Ito, Yoichiro; Wei, Yun

    2013-07-01

    Chlorogenic acid and caffeic acid were selected as test samples for separation by the pH-zone-refining countercurrent chromatography (CCC). The separation of these test samples was performed with a two-phase solvent system composed of methyl-tert-butyl-ether/acetonitrile/water at a volume ratio of 4:1:5 v/v/v where trifluoroacetic acid (TFA; 8 mM) was added to the organic stationary phase as a retainer and NH4 OH (10 mM) to the aqueous mobile phase as an eluter. Chlorogenic acid was successfully separated from Flaveria bidentis (L.) Kuntze (F. bidentis) and Lonicerae Flos by pH-zone-refining CCC, a slightly polar two-phase solvent system composed of methyl-tert-butyl-ether/acetonitrile/n-butanol/water at a volume ratio of 4:1:1:5 v/v/v/v was selected where TFA (3 mM) was added to the organic stationary phase as a retainer and NH4 OH (3 mM) to the aqueous mobile phase as an eluter. A 16.2 mg amount of chlorogenic acid with the purity of 92% from 1.4 g of F. bidentis, and 134 mg of chlorogenic acid at the purity of 99% from 1.3 g of crude extract of Lonicerae Flos have been obtained. These results suggest that pH-zone-refining CCC is suitable for the isolation of the chlorogenic acid from the crude extracts of F. bidentis and Lonicerae Flos.

  7. Physicochemical and electrochemical characterization of battery separator prepared by radiation induced grafting of acrylic acid onto microporous polypropylene membranes

    Directory of Open Access Journals (Sweden)

    2009-05-01

    Full Text Available Mutual radiation grafting technique was used to graft acrylic acid on micrometer thick micro-porous polypropylene membrane using high-energy gamma radiation. Grafting could not be achieved in aqueous acrylic acid solution. The presence of Mohr’s salt effectively retarded the homopolymerization of acrylic acid but did not lead to grafting enhancement. Mohr’s salt in presence of acids was found to be effective in enhancing the grafting yield. Contact angle measurement studies of the grafted and radiation treated polypropylene showed that initial grafting as well as radiation treatment of poly(propylene in aqueous medium and in presence of Mohr’s salt enhances its affinity towards the grafting solution. The enhancement in the polar component of surface energy of treated polypropylene membrane is the primary cause of grafting enhancement. The membranes grafted to an extent of ~20% were found to perform comparably with the battery separator presently being used by battery industry.

  8. Survey of knowledge of hazards of chemicals potentially associated with the advanced isotope separation processes

    Energy Technology Data Exchange (ETDEWEB)

    Chester, R.O.; Kirkscey, K.A.; Randolph, M.L.

    1979-09-01

    Hazards of chemical potentially associated with the advanced isotope separation processes are estimated based on open literature references. The tentative quantity of each chemical associated with the processes and the toxicity of the chemical are used to estimate this hazard. The chemicals thus estimated to be the most potentially hazardous to health are fluorine, nitric acid, uranium metal, uranium hexafluoride, and uranium dust. The estimated next most hazardous chemicals are bromine, hydrobromic acid, hydrochloric acid, and hydrofluoric acid. For each of these chemicals and for a number of other process-associated chemicals the following information is presented: (1) any applicable standards, recommended standards and their basis; (2) a brief discussion to toxic effects including short exposure tolerance, atmospheric concentration immediately hazardous to life, evaluation of exposures, recommended control procedures, chemical properties, and a list of any toxicology reviews; and (3) recommendations for future research.

  9. Gas chromatographic separation of fatty acid esters of cholesterol and phytosterols on an ionic liquid capillary column.

    Science.gov (United States)

    Hammann, Simon; Vetter, Walter

    2015-12-15

    Steryl esters are high molecular weight compounds (600-700g/mol) regularly present as a minor lipid class in animal and plant lipids. Different sterol backbones (e.g., cholesterol, β-sitosterol and brassicasterol) which can be esterified with various fatty acids can result in highly complex steryl ester patterns in food samples. The gas chromatographic (GC) analysis of intact steryl esters is challenging, since high elution temperatures are required for their elution. On nonpolar GC phases, steryl esters with fatty acids with differing degree of unsaturation (e.g., oleate and linoleate) cannot be separated and there are only few polar columns available with sufficient temperature stability. In this study, we used gas chromatography with mass spectrometry (GC/MS) and analyzed intact steryl esters on a commercial room temperature ionic liquid (RTIL) column which was shortened to a length of 12m. The column separated the steryl esters both by total carbon number and by degree of unsaturation of the fatty acid. For instance, cholesteryl esters with stearic acid (18:0), oleic acid (18:1n-9), linoleic acid (18:2n-6) and α-linolenic acid (18:3n-3) could be resolved (R≥1.3) from each other. By analysis of synthesized standard substances, the elution orders for different steryl backbones and different fatty acids on a given sterol backbone could be determined. Analysis of spreads and plant oils allowed to determine retention times for 37 steryl esters, although a few co-elutions were observed. The ionic liquid column proved to be well-suited for the analysis of intact steryl esters.

  10. High-performance liquid chromatographic separation of carminic acid, alpha- and beta-bixin, and alpha- and beta-norbixin, and the determination of carminic acid in foods.

    Science.gov (United States)

    Lancaster, F E; Lawrence, J F

    1996-05-03

    During a study of natural food colours, a simple and reliable high-performance liquid chromatography system was developed for use with cochineal and annato. An isocratic mobile phase, consisting of methanol and 6% aqueous acetic acid, resolved bixin and norbixin, while a gradient system was used to separate carminic acid and the annato compounds. The carminic acid contents of cochineal extract, carmine and carmine hydrosoluble were determined using an isocratic mobile phase (40:60, v/v). The detection limit for carminic acid in the various products was approximately 100 ng/g. Carminic acid was determined quantitatively in fruit beverages, yogurt and candies. It was demonstrated that, because of decomposition, carminic acid was not suitable for use in candies when manufacturing temperatures above 100 degrees C were required. Most membrane filters are not suitable for use with cochineal solutions, but a cellulose membrane filter did not adsorb carminic acid and was used successfully to remove impurities from water-based cochineal products and food extracts containing carminic acid.

  11. Separation of DR synthesized Ti-Mg Alloy by dissolution of waste by-products in acid media

    CSIR Research Space (South Africa)

    Mushove, T

    2010-06-01

    Full Text Available Of DR Synthesized Ti-Mg Alloy By Dissolution Of Waste By-Products In Acid Media. The dissolution experiments were done in a Julabo SW23 waterbath shaker, with 300 ml flasks. Acid solution of predetermined molarity was charged into a flask and heated... conditions as TiO2-Mg to:- ? investigate how they would behave in the leaching reagents reviewed. ? note how well the Ti-Mg separation process could be achieved by each reagent. Figure 2: Effect of H2SO4 concentration Figure 3: Effect of HCL...

  12. Separation and Detection of Lanthanide Ions with Nitrilotri (methylenephosphonic) Acid as Complexing Agent and Eluent by IPC

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A mixture containing eleven lanthanide ions was separated and detected on an anion-exchange co-lumn by ion chromatography with indirect photometry detection (IPC).An aqueous solution of 1.5×10-2mol/L nitrilotri(methylenephosphonic) acid and 2.5×10-3mol/L tiron was used as the eluent in which the former served as complexing agent and eluent,the latter played as color reagent and eluent.The effects of acidity,concentration and composition of eluent on the retention behavior of the analytes and detection sensitivity are discussed.

  13. STUDY OF COMPOSITE MEMBRANE OF CELLULOSE ACETATE OR POLYVINYL ALCOHOL BLENDED WITH METHYLMETHACRYLATE-ACRYLIC ACID COPOLYMER FOR PERVAPORATION SEPARATION

    Institute of Scientific and Technical Information of China (English)

    Huan-lin Chen; Jun Tan; Mo-e Liu; Chang-luo Zhu

    1999-01-01

    In this paper, methylmethacrylate-acrylic acid MMA-AA hydrophilic and hydrophobic copolymers were prepared by copolymerization for preparing membrane materials. The composite membrane of cellulose acetate (CA) blended with MMA-AA hydrophobic copolymer was used for the separation of methanol from pentane-methanol mixture. When the methanol concentration was only 1 wt%, the permeate flux still maintained at 350 g/m2h and separation factor was as big as 800. The composite membrane of PVA (polyvinyl alcohol) blended with MMA-AA hydrophilic copolymer was used for the separation of ethanolwater mixture. The permeate flux was increased to 975 g/m2h at 74℃ and the separation factor reached 3000at 25℃. The PVA/MMA-AA blended membrane surface modified by ammonia plasma was also investigated for separating ethanol-water mixture. Both permeate flux and separation factor of the membrane was improved. However, there was no obvious difference of plasma treatment time in the interval of 20~40 min.

  14. [Separation, purification and structural characterization of acidic polysaccharide from Microcystic aeruginosa].

    Science.gov (United States)

    Wang, Xida; Wu, Guorong; Chen, Jingyao; Wang, Jian'an

    2003-12-01

    Acidic polysccharide was extracted by boiling water from Microcystic aeruginosa, isolated and purified by DEAE-52 gel column. IR, UV, HPLC and 13C-NMR were used for the structural analysis. Results showed that MAAP was a new acidic polysaccharide, it's molecular weigh was 2.0028 x 10(5), and it's chain was composed of a-glycoside linkage. The component of MAAP was identified as rhamnose, xylose, arabinose, galactose and galacturonic acid.

  15. Enhancing separation of histidine from amino acids via free-flow affinity electrophoresis with gravity-induced uniform hydrodynamic flow.

    Science.gov (United States)

    Pang, Bo; Shao, Jing; Zhang, Jie; Geng, Jia-Zhen; Fan, Liu-Yin; Cao, Cheng-Xi; Hou, Jing-Li

    2012-03-01

    In this paper, a novel mode of free-flow affinity electrophoresis (FFAE) was developed to indirectly enhance the separation of free-flow electrophoresis (FFE). In the mode of FFAE, a Ni(II) with high electric charge density and histidine (His) is chosen as a model ligand and target solute, respectively. Through the controlling of experimental conditions (10 mM pH 6.0 Na(2)HPO(4)-NaH(2)PO(4) with 2.0 mM NiCl(2)·6H(2)O background buffer), Ni(II) can combine with His and the combination leads to the high electric charge density of affinity complex of His-Ni(II) in contrast to the low density of free His molecule. But the ligand has weak interaction with uninterested amino acids. Thus, the mobility of His existing as His-Ni(II) is greatly increased from 14.5×10(-8) m(2) V(-1) s(-1) to 30.2 × 10(-8) m(2) V(-1) s(-1), while those mobilities of uninterested amino acids are almost constant. By virtue of the mode, we developed the FFAE procedure and conducted the relevant experiments. The experiments demonstrated the following merits of the FFAE technique: (i) clear enhancement of separation between the target solute of His and uninterested amino acids; (ii) simplicity, and (iii) low cost. Furthermore, the technique was used for the continuous separation of His from its complex sample, and the purity of His was near to 100%. All of the results demonstrate the feasibility of affinity separation in FFE. The developed FFAE may be used in the separation and pretreatment of some biological molecules (e.g. peptides).

  16. Cation-exchange high-performance liquid chromatography: Separation of highly basic proteins using volatile acidic solvents

    NARCIS (Netherlands)

    Eijnden-van Raaij, A.J.M. van den; Koornneef, I.; Oostwaard, Th.M.J.; Laat, S.W. de; Zoelen, E.J.J. van

    1987-01-01

    The chromatographic behavior of a number of globular proteins was studied on a Bio-Sil TSK CM-2-SW weak cation exchange HPLC column under acidic conditions. A linear gradient of O-I M NH₄Ac in I M HOAc, inducing a convex pH gradient from 2.4-4.8, resulted in an excellent separation of highly basic p

  17. Substituted ethan phosphonic acid esters as reagents for the separation of molybdenum from rhenium by solvent extraction.

    Science.gov (United States)

    Jordanov, N; Mareva, S; Borisov, G; Jordanov, B

    1968-02-01

    New esters of the ethan phosphonic acids have been synthesized and their extraction properties studied with respect to Mo(VI), Re(VII), Fe(III),Au(III),Tl(III) and Sb(V). A possibility is shown for the analytical separation of molybdenum from rhenium (beta = 700). The state of these new extraction agents in carbon tetrachloride solution, and the mechanism of the extraction processes, have been investigated by means of infrared spectra.

  18. Separation and conductimetric detection of C1-C7 aliphatic monocarboxylic acids and C1-C7 aliphatic monoamines on unfunctionized polymethacrylate resin columns.

    Science.gov (United States)

    Ohta, Kazutoku; Towata, Atsuya; Ohashi, Masayoshi; Takeuchi, Toyohide

    2004-06-11

    The application of unfunctionized polymethacrylate resin (TSKgel G3000PWXL) as a stationary phase in liquid chromatography with conductimetric detection for C1-C7 aliphatic monocarboxylic acids (formic acid, acetic acid, propionic acid, butyric acid, isovaleric acid, valeric acid, 3,3-dimethylbutyric acid, 4-methylvaleric acid, hexanoic acid, 2-methylhexanoic acid, 5-methylhexanoic acid and heptanoic acid) and C1-C7 aliphatic monoamines (methylamine, ethylamine, propylamine, isobutylamine, butylamine, isoamylamine, amylamine, 1,3-dimethylbutylamine, hexylamine, 2-heptylamine and heptylamine) was attempted with C8 aliphatic monocarboxylic acids (2-propylvaleric acid, 2-ethylhexanoic acid, 2-methylheptanoic acid and octanoic acid) and C8 aliphatic monoamines (1,5-dimethylhexylamine, 2-ethylhexylamine, 1-methylheptylamine and octylamine) as eluents, respectively. Using 1 mM 2-methylheptanoic acid at pH 4.0 as the eluent, excellent separation and relatively high sensitive detection for these C1-C7 carboxylic acids were achieved on a TSKgel G3000PWXL column (150 mm x 6 mm i.d.) in 60 min. Using 2 mM octylamine at pH 11.0 as the eluent, excellent separation and relatively high sensitive detection for these C1-C7 amines were also achieved on the TSKgel G3000PWXL column in 60 min.

  19. Separation of phenolic acids and flavonoids from Trollius chinensis Bunge by high speed counter-current chromatography.

    Science.gov (United States)

    Qin, Yanhua; Liang, Yizeng; Ren, Dabing; Qiu, Ximin; Li, Xi

    2015-09-15

    In this work, eleven compounds were successfully separated from Trollius chinensis Bunge by using a two-step high-speed counter-current chromatography (HSCCC) method. NRTL-SAC (nonrandom two-liquid segment activity coefficient) method, a newly developed solvent system selection strategy, was applied to screening the suitable biphasic liquid systems. Hexane/ethyl acetate/ethanol/water (3:7:3:7, v/v) solvent system was used in the first step, while the hexane/ethyl acetate/methanol/water (1:2:1:2, 1:4:1:4, 1:9:1:9, v/v) systems were employed in the second step. The chemical structures of the separated compounds were identified by UV, high resolution ESI-MS and MS/MS data. The separated compounds are 3,4-dihydroxyphenylethanol (1), vanillic acid (2), orientin (3), vitexin (4), veratric acid (5), 2″-O-(3‴, 4‴-dimethoxybenzoyl) orientin (6), 2″-O-feruloylorientin (7), 2″-O-feruloylvitexin (8), 2″-O-(2‴-methylbutyryl) vitexin (9), 2″-O-(2‴-methylbutyryl) isoswertiajaponin (10), 2″-O-(2‴-methylbutyryl) isoswertisin (11). The results demonstrate that HSCCC is a powerful tool for the separation of compounds from extremely complex samples.

  20. Production of {sup 61}Cu using natural cobalt target and its separation using ascorbic acid and common anion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    Das, Sujata Saha; Chattopadhyay, Sankha; Barua, Luna [Radiopharmaceuticals Laboratory, Board of Radiation and Isotope Technology (BRIT), Variable Energy Cyclotron Centre (VECC), Kolkata 700064 (India); Das, Malay Kanti, E-mail: mkdas@vecc.gov.in [Radiopharmaceuticals Laboratory, Board of Radiation and Isotope Technology (BRIT), Variable Energy Cyclotron Centre (VECC), Kolkata 700064 (India)

    2012-02-15

    {sup 61}Cu was produced by {sup nat}Co({alpha}, xn){sup 61}Cu reaction. {sup 61}Cu production yield was 89.5 MBq/{mu}Ah (2.42 mCi/{mu}Ah) at the end of irradiation (EOI). A simple radiochemical separation method using anion exchange resin and ascorbic acid has been employed to separate the product radionuclide from inactive target material and co-produced non-isotopic impurities. The radiochemical separation yield was about 90%. Radiochemical purity of {sup 61}Cu was >99% 1 h after EOI. Final product was suitable for making complex with N{sub 2}S{sub 2} type of ligands. - Highlights: Black-Right-Pointing-Pointer High purity, no-carrier added {sup 61}Cu produced from natural cobalt target. Black-Right-Pointing-Pointer {sup 61}Cu separated from impurities using anion exchange resin and ascorbic acid. Black-Right-Pointing-Pointer {sup 61}Cu preparation was successfully used to label N{sub 2}S{sub 2}-type of ligand.

  1. Adsorptive Separation and Recovery of Organic Compounds from Purified Terephthalic Acid Plant Effluent

    NARCIS (Netherlands)

    Khachane, P.K.; Heesink, A. Bert M.; Versteeg, G.F.; Pangarkar, V.G.

    2003-01-01

    Several organic impurities formed in the p-xylene oxidation process for manufacture of terephthalic acid are carried into the aqueous effluent from the crystallization section of PTA plant of crystallizers for purified terephthalic acid (PTA). These compounds impose a burden on the effluent treatmen

  2. Adsorptive Separation and Recovery of Organic Compounds from Purified Terephthalic Acid Plant Effluent

    NARCIS (Netherlands)

    Khachane, P.K.; Heesink, A. Bert M.; Versteeg, G.F.; Pangarkar, V.G.

    2003-01-01

    Several organic impurities formed in the p-xylene oxidation process for manufacture of terephthalic acid are carried into the aqueous effluent from the crystallization section of PTA plant of crystallizers for purified terephthalic acid (PTA). These compounds impose a burden on the effluent treatmen

  3. Physical chemistry and engineering of membranes for fat - fatty acid separations

    NARCIS (Netherlands)

    Keurentjes, J.

    1991-01-01

    Fatty acids have to be removed from non-mineral oil for several purposes. In the refining of edible oils and fats they have to be removed as a contaminant. In the enzymatic hydrolysis of oils, a high content in fatty acids results in a reduced conversion rate. In order to maintain a suffici

  4. Influence of acid-induced conformational variability on protein separation in reversed phase high performance liquid chromatography.

    Science.gov (United States)

    Bobály, Balázs; Tóth, Eszter; Drahos, László; Zsila, Ferenc; Visy, Júlia; Fekete, Jenő; Vékey, Károly

    2014-01-17

    Influence of acid concentration in the mobile phase on protein separation was studied in a wide concentration range using trifluoroacetic acid (TFA) and formic acid (FA). At low, 0.001-0.01 (v/v%) TFA concentration and appropriate solvent strength proteins elute before the column's dead time. This is explained by the proteins having a structured, but relatively extended conformation in the eluent; and are excluded from the pores of the stationary phase. Above ca. 0.01-0.05 (v/v%) TFA concentration proteins undergo further conformational change, leading to a compact, molten globule-like structure, likely stabilized by ion pairing. Proteins in this conformation enter the pores and are retained on the column. The results suggest a pore exclusion induced separation related to protein conformation. This effect is influenced by the pH and type of acid used, and is likely to involve ion-pair formation. The TFA concentration needed to result in protein folding (and therefore to observe retention on the column) depends on the protein; and therefore can be utilized to improve chromatographic performance. Conformation change was monitored by circular dichroism spectroscopy and mass spectrometry; and it was shown that not only TFA but FA can also induce molten globule formation.

  5. Separation and Identification of Fatty Acid in the Seed Oils of Two New Species of Celosia Cristata L.

    Institute of Scientific and Technical Information of China (English)

    WENG Debao; WANG Haifeng

    2002-01-01

    The seed oils of two new species of Celosia cristata L., C. Argentea L. Var. Crispa Kuntze (Yellow flower) and C. Cristata L. Cv. Spicata ( Red flower), were extracted with organic solvent and the fatty acides (Fas) in seed oils were separated and identificated by gas chromatography (GC). They all contained 10 kinds of FA including 4 trace Fas, respectively. Two new Fas of odd number of carbons in the seed oils, pentadecanoic acid( C15:0) and heptadecenoic acid (C17:1 ), were found. The compositions of main Fas in the seed oils were palmitic 20.61%, 23.50%; stearic 1.87 %; 2.39 %; oleic 20.77 %, 19.93% ;linoleic 51.39%, 45.99%; linolenic 1.54%, 1.86% and arachidonic 3.20%, 3.42%, respectively.

  6. Separation and immobilization of Sr and Cs contained in acidic media by using inorganic ion-exchangers. Literature survey

    Energy Technology Data Exchange (ETDEWEB)

    Yamagishi, Isao [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-07-01

    The present study deals with the survey of inorganic ion-exchangers suitable for separation and immobilization of Sr and Cs contained in acidic high-level liquid waste. The stabilities of published waste forms and their preparation processes were evaluated from the standpoint of conversion of exchangers containing Sr and Cs into appropriate waste forms. The essential results are below. (1) For separation and immobilization of Cs, crystalline silicotitanate seems to be the most promising exchanger. Insoluble ferrocyanides and phosphates are not suitable for immobilization without additives. Mordenite is inexpensive and commercially available but it would dissolve in highly acidic media. (2) For selective separation of Sr, there is no promising exchanger up to now. It is necessary either to modify separation condition or to synthesize a novel exchanger. (3) Soluble salts, glasses and ceramics are proposed as a storage or disposal form of separated Sr and Cs. Ceramics sintered by hot-pressing are favorable waste forms of inorganic ion-exchangers but their leachabilities and thermal conductivities are largely influenced by qualities of products. Crystallinity of a sintered exchanger depends on its composition. Exchanges of low Cs contents are often converted into amorphous materials whose chemical stabilities depend on solubilities of components of exchangers. (4) A new exchanger to be synthesized is crystalline and selective toward Sr and Cs. One meq/g is enough for Sr and Cs capacities, which are restricted by thermal and transmutation effects. Composition of the exchanger should be selected from the point of a scenario of separation and disposal. The solubilities of SiO{sub 2}, TiO{sub 2}, ZrO{sub 2}, Nb{sub 2}O{sub 5} and Ta{sub 2}O{sub 5} are low in acidic media and those of Al{sub 2}O{sub 3}, TiO{sub 2} and ZrO{sub 2}, in disposal circumstances. (5) Future works are optimization of separation scheme including development of exchangers, simplification of

  7. Enantiomeric separation of free L- and D-amino acids in hydrolyzed protein fertilizers by capillary electrophoresis tandem mass spectrometry.

    Science.gov (United States)

    Sánchez-Hernández, Laura; Serra, Nuria Sierras; Marina, María Luisa; Crego, Antonio L

    2013-05-29

    Two capillary electrophoresis-tandem mass spectrometry (CE-MS(2)) methods were optimized in this work using cyclodextrins (CDs) as chiral selectors in order to determine the degree of racemization of the free amino acids contained in different hydrolyzed protein fertilizers used as plant biostimulants. The methodologies developed were characterized by the specificity of MS(2) experiments enabling the identification of all protein amino acids, except for cysteine. The enantiomeric separation of up to 14 amino acids was achieved with resolutions above 1.0 and limits of detection between 0.02 and 0.8 μM. The methods were applied to the analysis of complex samples such as hydrolyzed protein fertilizers to evaluate the presence of d-amino acids after different kinds of hydrolysis treatments. The results corroborated the absence or almost negligible presence of enantiomeric conversions of the L-amino acids into D-amino acids in the case of fertilizers obtained by enzymatic hydrolysis, as well as the high racemization rate for those obtained through a chemical hydrolysis.

  8. Features of separation on polymeric reversed phase for two classes of higher saturated fatty acids esters

    Science.gov (United States)

    Deineka, V. I.; Lapshova, M. S.; Zakharenko, E. V.; Deineka, L. A.

    2013-11-01

    The principles of sorption on polymeric reversed phase (PRP) YMS C30 for members of the two classes of esters formed by higher saturated fatty acids, i.e., lutein diesters ( I) and triacylglycerols ( II), are investigated. It is shown that the logarithm of the retention factor increases nonlinearly with an increase of the length of the acid radical, although the retention on PRP is higher in the case of I and lower in the case of II, compared to their retention on traditional monomeric reversed phase (MRP) Kromasil-100 5C18; however, the equivalence of the contributions to the retention of I that correspond to an identical change in acids, does not depend on the length of the hydrocarbon radical of the second acid. It is noted that the Van't Hoff plot for PRP contains a curve break, indicating a change in the retention mechanism upon a rise in temperature.

  9. Adsorptive Separation and Recovery of Organic Compounds from Purified Terephthalic Acid Plant Effluent

    OpenAIRE

    Khachane, P.K.; Heesink, A. Bert M.; Versteeg, G. F.; Pangarkar, V.G.

    2003-01-01

    Several organic impurities formed in the p-xylene oxidation process for manufacture of terephthalic acid are carried into the aqueous effluent from the crystallization section of PTA plant of crystallizers for purified terephthalic acid (PTA). These compounds impose a burden on the effluent treatment plant. Due to the presence of these impurities the recycle of aqueous effluent from crystallization section of PTA plant to the PTA crystallizer is not possible. The aim of this study is to check...

  10. tRNA acceptor-stem and anticodon bases embed separate features of amino acid chemistry.

    Science.gov (United States)

    Carter, Charles W; Wolfenden, Richard

    2016-01-01

    The universal genetic code is a translation table by which nucleic acid sequences can be interpreted as polypeptides with a wide range of biological functions. That information is used by aminoacyl-tRNA synthetases to translate the code. Moreover, amino acid properties dictate protein folding. We recently reported that digital correlation techniques could identify patterns in tRNA identity elements that govern recognition by synthetases. Our analysis, and the functionality of truncated synthetases that cannot recognize the tRNA anticodon, support the conclusion that the tRNA acceptor stem houses an independent code for the same 20 amino acids that likely functioned earlier in the emergence of genetics. The acceptor-stem code, related to amino acid size, is distinct from a code in the anticodon that is related to amino acid polarity. Details of the acceptor-stem code suggest that it was useful in preserving key properties of stereochemically-encoded peptides that had developed the capacity to interact catalytically with RNA. The quantitative embedding of the chemical properties of amino acids into tRNA bases has implications for the origins of molecular biology.

  11. Determination of tin in ores, iron, steel and non-ferrous alloys by atomic-absorption spectrophotometry after separation by extraction as the iodide.

    Science.gov (United States)

    Donaldson, E M

    1980-06-01

    A simple and moderately rapid method for determining 0.001% or more of tin in ores, concentrates and tailings, iron, steel and copper-, zinc-, aluminium-, titanium- and zirconium-base alloys is described. After sample decomposition, tin is separated from the matrix elements, except arsenic, by toluene extraction of its iodide from a 3M sulphuric acid-1.5M potassium iodide medium containing tartaric and ascorbic acids. It is finally back-extracted into a nitric-sulphuric acid solution containing hydrochloric acid to prevent the formation of an insoluble tin-arsenic compound and the resultant solution is evaporated to dryness. Tin is subsequently determined by atomic-absorption spectrophotometry in a nitrous oxide-acetylene flame, at 235.4 nm in a 10% hydrochloric-0.5% tartaric acid medium containing 250 mug of potassium per ml. Co-extracted arsenic does not interfere. Results obtained by this method are compared with those obtained spectrophotometrically with gallein after the separation of tin by iodide extraction.

  12. Recovery of Pd(II) from hydrochloric solution using polyallylamine hydrochloride-modified Escherichia coli biomass.

    Science.gov (United States)

    Park, Jiyeong; Won, Sung Wook; Mao, Juan; Kwak, In Seob; Yun, Yeoung-Sang

    2010-09-15

    A new type of biosorbent able to bind anionic metals was developed by cross-linking of waste biomass Escherichia coli with polyallylamine hydrochloride (PAH). The PAH-modified biomass was investigated for the removal and recovery of Pd(II), in the chloro-complex form, from aqueous solution. The performance of the PAH-modified biomass was evaluated in terms of the following parameters: the solution pH, contact time and initial metal concentration. In the pH edge experiments, the uptake of Pd(II) increased with increasing pH. Pd(II) biosorption proceeded rapidly in the first 10 min, with almost complete equilibrium being achieved within 60 min. Moreover, the isotherm data showed that the maximum uptakes of Pd(II) were 265.3mg/g at pH 3 and 212.9 mg/g at pH 2, respectively. After incineration of the Pd-loaded PAH-modified biomass, metallic palladium was recovered in the ash. X-ray photoelectron spectroscopy (XPS) results confirmed that the palladium was recovered in two valency states: zero-valent and divalent palladium (as PdO). Therefore, we concluded that PAH-modified biomass is a useful and cost-effective biosorbent for the recovery of anionic precious metals as chloro-complex solutions containing hydrochloric acid produced from metal refining processes.

  13. Method for separating constituents from solution employing a recyclable Lewis acid metal-hydroxy gel

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, D.H.

    1995-12-31

    This invention permits radionuclides, heavy metals, and organics to be extracted from solution by scavenging them with an amorphous gel. In the preferred embodiment, a contaminated solution (e.g. from soil washing, decontamination, or groundwater pumping) is transferred to a reaction vessel. The contaminated solution is contacted by the sequestering reagent which might contain for example, aluminate and EDTA anions in a 2.5 M NaOH solution. The pH of the reagent bearing solution is lowered on contact with the contaminated solution, or for example by bubbling carbon dioxide through it, causing an aluminum hydroxide gel to precipitate as the solution drops below the range of 1.8 to 2.5 molar NaOH (less than pH 14). This precipitating gel scavenges waste contaminants as it settles through solution leaving a clean supernatant which is then separated from the gel residue by physical means such as centrifugation, or simple settling. The gel residue containing concentrated contaminants is then redissolved releasing contaminants for separations and processing. This is a critical point: the stabilized gel used in this invention is readily re-dissolved by merely increasing the pH above the gels phase transition to aqueous anions. Thus, concentrated contaminants trapped in the gel can be released for convenient separation from the sequestering reagent, and said reagent can then be recycled.

  14. Synthesis and Photophysical Characterization of an Artificial Photosynthetic Reaction Center Exhibiting Acid-Responsive Regulation of Charge Separation

    Science.gov (United States)

    Pahk, Ian

    Non-photochemical quenching (NPQ) is a photoprotective regulatory mechanism essential to the robustness of the photosynthetic apparatus of green plants. Energy flow within the low-light adapted reaction centers is dynamically optimized to match the continuously fluctuating light conditions found in nature. Activated by compartmentalized decreases in pH resulting from photosynthetic activity during periods of elevated photon flux, NPQ induces rapid thermal dissipation of excess excitation energy that would otherwise overwhelm the apparatus's ability to consume it. Consequently, the frequency of charge separation decreases and the formation of potentially deleterious, high-energy intermediates slows, thereby reducing the threat of photodamage by disallowing their accumulation. Herein is described the synthesis and photophysical analysis of a molecular triad that mimics the effects of NPQ on charge separation within the photosynthetic reaction centers. Steady-state absorption and emission, time-resolved fluorescence, and transient absorption spectroscopies were used to demonstrate reversible quenching of the first singlet excited state affecting the quantum yield of charge separation by approximately one order of magnitude. As in the natural system, the populations of unquenched and quenched states and, therefore, the overall yields of charge separation were found to be dependent upon acid concentration.

  15. Amplification of electrolyte uptake in the absorptive glass mat (AGM) separator for valve regulated lead acid (VRLA) batteries

    Science.gov (United States)

    Kumar, Vijay; Kameswara Rao, P. V.; Rawal, Amit

    2017-02-01

    Absorptive glass mat (AGM) separators are widely used for valve regulated lead acid (VRLA) batteries due to their remarkable fiber and structural characteristics. Discharge performance and recharge effectiveness of VRLA batteries essentially rely on the distribution and saturation levels of the electrolyte within the AGM separator. Herein, we report an analytical model for predicting the wicking characteristics of AGM battery separators under unconfined and confined states. The model of wicking behavior of AGM is based upon Fries and Dreyer's approach that included the effect of gravity component which was neglected in classic Lucas-Washburn's model. In addition, the predictive model of wicking accounted for realistic structural characteristics of AGM via orientation averaging approach. For wicking under confined state, the structural parameters have been updated under defined level of compressive stresses based upon the constitutive equation derived for a planar network of fibers in AGM under transverse loading conditions. A comparison has been made between the theoretical models and experimental results of wicking behavior under unconfined and confined states. Most importantly, the presented work has highlighted the questionable validity of classic Lucas-Washburn model for predicting the wicking characteristics of AGM separator over longer time duration.

  16. Separation of cis/trans fatty acid isomers on gas chromatography compared to the Ag-TLC method

    Directory of Open Access Journals (Sweden)

    Sundaresan, A.

    2013-03-01

    Full Text Available The present study investigates the separation of the cis/trans isomers of fatty acids on the 75 m SP2560 column under different gas chromatographic (GC conditions including an isothermal program and a time-temperature program. The time-temperature program showed improved separation of cis/trans isomers of C14:1, C16:1, C18:1, C18:2 and C18:3 fatty acids along with short chain fatty acids compared to the isothermal program. The separation of trans/trans isomers of C18:1 fatty acids including elaidic acid (C18:1 ∆9t and vaccenic acid (C18:1 ∆11t was difficult with the time-temperature program. The thin layer chromatography impregnated with silver nitrate (Ag- TLC method was performed to separate cis/trans fractions and GC analysis was carried out with the trans fraction. But GC analysis showed a co-elution of trans isomers of C18:1 fatty acid. Thus the study shows that a time-temperature programmed GC method with the highly polar cyanopropyl column is sufficient to resolve trans fatty acids along with short chain fatty acids when a large number of samples has to be analyzed.El presente estudio investiga la separación de isómeros cis/trans de ácidos grasos mediante cromatografía de gases (GC utilizando una columna de SP2560 de 75 m y diferentes condiciones que incluyen un programa isotérmico y una programación temperatura-tiempo. La programación temperatura- tiempo mostró una mejor separación de isómeros cis / trans de los ácidos grasos C14:1, C16:1, C18:1, C18:2 y C18:3 con los ácidos grasos de cadena corta en comparación con el programa isotermo. La separación de los isómeros trans/trans de los ácidos grasos C18:1 incluyendo ácido elaídico (C18:1 Δ9t y ácido vaccénico (C18:1Δ11t fué difícil mediante programación temperatura-tiempo. La cromatografía en capa fina impregnada con nitrato de plata (Ag-TLC se realizó para separar fracciones cis/trans y el análisis de la fracciones se llevó a cabo mediante GC. El an

  17. Antagonists of chemoattractants reveal separate receptors for cAMP, folic acid and pterin in Dictyostelium

    NARCIS (Netherlands)

    Haastert, Peter J.M. van; Wit, René J.W. de; Konijn, Theo M.

    1982-01-01

    Adenosine 3’,5’-monophosphate (cAMP), folic acid and pterin are chemoattractants in the cellular slime molds. The cAMP analog, 3’-amino-cAMP, inhibits a chemotactic reaction to cAMP at a concentration at which the analog is chemotactically inactive. The antagonistic effect of 3’-amino-cAMP on the ch

  18. The use of L-lysine decarboxylase as a means to separate amino acids by electrodialysis

    NARCIS (Netherlands)

    Teng, Y.; Scott, E.L.; Zeeland, van A.N.T.; Sanders, J.P.M.

    2011-01-01

    Amino acids (AA's) are interesting materials as feedstocks for the chemical industry as they contain chemical functionalities similar to conventional petrochemicals. This offers the possibility to circumvent process steps, energy and reagents. AA's can be obtained by the hydrolysis of potentially

  19. Nitric acid-organic mixtures surveyed for use in separation by anion exchange methods

    Science.gov (United States)

    Bloomquist, C. A. A.; Faris, J. P.; Stewart, D. C.

    1968-01-01

    Column elution-spectrographic analysis technique compares certain solvents directly to the methanol system, using inert rare earths instead of actinides. Distribution ratios for americium between 90 percent solvent, 10 percent 5 M nitric acid and Dowex 1 nitrate form resin for a large group of organics miscible in water was determined.

  20. Ionic Liquid and HP-β-CD Modified Capillary Zone Electrophoresis to Separate Hyperoside, Luteolin and Chlorogenic Acid

    Institute of Scientific and Technical Information of China (English)

    Yue Ling WANG; Zhong Bo HU; Zhuo Bin YUAN

    2006-01-01

    Ionic liquid (1-ethyl-3-methylimidazolium tetrafluoroborate, 1E-3MI-TFB) and HP-β-CD as modifier was added to the buffer to separate hyperoside, luteolin and chlorogenic acid.Experiments explored the effect of concentration of 1E-3MI-TFB and HP-β-CD on separation.The results indicated that 1.0 mmol/L HP-β-CD and 1‰ (v/v) 1E-3MI-TFB added to the buffer simultaneous y could achieve a good compromise of resolution and analysis time. Capillary experiments and UV spectra indicated that there was interaction between 1E-3MI-TFB and analytes.

  1. Enantiomer separation of acidic chiral compounds on a quinine-silica/zirconia hybrid monolith by capillary electrochromatography.

    Science.gov (United States)

    Tran, Le Ngoc; Park, Jung Hag

    2015-05-29

    A weak anion-exchanger chiral selector, quinine-incorporated silica/zirconia hybrid monolithic (QUI-S/ZHM) capillary column was prepared by sol-gel technology. The performance of the QUI-S/ZHM column was investigated for enantioresolution of a set of acidic chiral drugs and dinitrobenzoyl (DNB)-amino acids by capillary electrochromatography in aqueous organic mobile phases composed of acetonitrile (ACN) and triethylammonium acetate (TEAA) buffer. Effects of several parameters including the ACN content, concentration and pH of the mobile phase on the chiral separation were examined. Baseline resolutions of all the compounds were obtained in the mobile phase consisting of 70:30 ACN/TEAA (10mM, pH 6) under applied voltage of -10kV at 25°C within 20min.

  2. SEPARATION OF p-AMINOBENZOIC ACID BY REACTIVE EXTRACTION. 1. MECHANISM AND INFLUENCING FACTORS

    Directory of Open Access Journals (Sweden)

    DAN CASCAVAL

    2008-09-01

    Full Text Available The comparative study on the reactive extraction of p-aminobenzoic acid with Amberlite LA-2 and D2EHPA in two solvents with different polarity (n-heptane and dichloromethane indicated that the extractant type and solvent polarity control the extraction mechanism. Thus, the reactive extraction with Amberlite LA-2 occurs by means of the interfacial formation of an aminic adduct with three extractant molecules in low-polar solvent, or of an salt with one extractant molecule in higher polar solvent. Similarly, the extraction with D2EHPA is based on the formation of an acidic adduct with two extractant molecules in n-heptane, or of a salt with one extractant molecule in dichloromethane. The most efficient extraction has been reached for the combination Amberlite LA-2-dichloromethane.

  3. Selective recognition and separation of amino acids by molecularly imprinted polymers

    OpenAIRE

    Trikka, F.A.; Papi, R. M.; Kyriakidis, D A

    2008-01-01

    Journal URL: http://www.springer.at/amino_acids Molecularly imprinted polymers (MIPs) are smart tailored-made materials used for the sensitive and selective recognition of small molecules and=or biologically important substances. The target molecule acting as a molecular template is copolymerized with an excess of afunctional monomer and a cross-linker. The template is entrapped in the formed polymer and following its removal complementary cavities in structure and in properties to the ...

  4. Extraction and separation of titanium(IV with D2EHPA and PC-88A from aqueous perchloric acid solutions

    Directory of Open Access Journals (Sweden)

    PURSHOTTAM M. DHADKE

    2002-07-01

    Full Text Available The liquid-liquid extraction of Ti(IV from perchlorate media using, di(2-ethylhexyl phosphoric acid (D2EHPA and 2-ethylhexyl prosphonic acid mono-2-ethylhexyl ester (PC-88A in toluene as the extractant was studied. Quantitative extraction of Ti(IV was observed in the lower acidity range of 0.01 to 0.1 mol dm-3 with 0.003 mol dm-3 D2EHPA and 0.01 mol dm-3 PC-88A in toluene, respectively, and in the higher acidity range of 9.0 to 10.0 mol dm-3 with 0.1 mol dm-3 D2EHPA and PC-88A in toluene. Ti(IV was completely stripped from the metal loaded organic phase of both the extractants with 3 % H2O2 in 1 M H2SO4 and determined spectrophotometrically. The stoichiometry of the extracted species was determined on the basis of slope analysis. The extraction in the lower acidity range was found to proceed by a cation-exchange mechanism with the extracted species being TiOR2·2HR, while in the higher acidity range it was by solvation with the extracted species being Ti(OH3ClO4·4HR. Separation of Ti(IV was also carried out from some associated metals like Fe(III, Al(III, V(V, Ce(IV, Mg(II and Mn(II. The developed methods were extended for the determination of Ti(IV in real samples like ilmenite, magnetite and red mud in order to show the practical utility of the extractants.

  5. 49 CFR 173.158 - Nitric acid.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Nitric acid. 173.158 Section 173.158... Nitric acid. (a) Nitric acid exceeding 40 percent concentration may not be packaged with any other material. (b) Nitric acid in any concentration which does not contain sulfuric acid or hydrochloric acid as...

  6. Separation and quantitation of phycobiliproteins using phytic acid in capillary electrophoresis with laser-induced fluorescence detection.

    Science.gov (United States)

    Viskari, Pertti J; Colyer, Christa L

    2002-10-01

    The similar electrophoretic mobilities and sizes of several of the phycobiliproteins, which are derived from the photosynthetic apparatus of cyanobacteria and eukaryotic algae, render their separation and quantitation a challenging problem. However, we have developed a suitable capillary electrophoresis (CE) method that employs a phytic acid-boric acid buffer and laser-induced fluorescence (LIF) detection with a single 594 nm He-Ne laser. This method takes advantage of the remarkably high quantum yields of these naturally fluorescent proteins, which can be attributed to their linear tetrapyrrole chromophores covalently bound to cysteinyl residues. As such, limits of detection of 1.18 x 10(-14), 5.26 x 10(-15), and 2.38 x 10(-15) mol/l were obtained for R-phycoerythrin, C-phycocyanin, and allophycocyanin proteins, respectively, with a linear dynamic range of eight orders of magnitude in each case. Unlike previously published CE-LIF methods, this work describes the separation of all three major classes of phycobiliproteins in under 5 min. Very good recoveries, ranging from 93.2 to 105.5%, were obtained for a standard mixture of the phycobiliproteins, based on seven-point calibration curves for both peak height and peak area. It is believed that this development will prove useful for the determination of phycobiliprotein content in naturally occurring cyanobacteria populations, thus providing a useful tool for understanding biological and chemical oceanographic processes.

  7. A humic acid stationary phase for the high performance liquid chromatography separation of buckminsterfullerenes: Theoretical and practical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Casadei, Nicolas [Equipe des Sciences Separatives et Biopharmaceutiques (2SB)-EA 3924, Laboratoire de Chimie Analytique, Faculte de Medecine Pharmacie, Place Saint Jacques, 25030 Besancon Cedex (France); Thomassin, Mireille [Equipe des Sciences Separatives et Biopharmaceutiques (2SB)-EA 3924, Laboratoire de Chimie Analytique, Faculte de Medecine Pharmacie, Place Saint Jacques, 25030 Besancon Cedex (France); Guillaume, Yves-Claude [Equipe des Sciences Separatives et Biopharmaceutiques (2SB)-EA 3924, Laboratoire de Chimie Analytique, Faculte de Medecine Pharmacie, Place Saint Jacques, 25030 Besancon Cedex (France)]. E-mail: yves.guillaume@univ-fcomte.fr; Andre, Claire [Equipe des Sciences Separatives et Biopharmaceutiques (2SB)-EA 3924, Laboratoire de Chimie Analytique, Faculte de Medecine Pharmacie, Place Saint Jacques, 25030 Besancon Cedex (France)

    2007-04-11

    The influence of the mobile phase composition and column temperature on the chromatographic separation of five buckminsterfullerenes (C60, C70, C76, C78, C84) on a stationary phase based on silica gel with chemically bonded humic acid (Bonded humic acid column (BHAC)) was studied. The retention behavior of the fullerenes was measured under isocratic conditions with different mobile phase compositions, ranging from 0.05-0.70 (v/v) of toluene in cyclohexane. The column temperature was analysed in the range 35-75 deg. C. The retention factors of the five fullerenes do not depend linearly on the toluene fraction but follow a quadratic relationship. The best chromatographic conditions for baseline separation of the five fullerenes were selected. The retention of the fullerenes on the HA stationary phase was strongly affected by temperature. Positive values of thermodynamic parameters (changes of enthalpy and entropy) were due to the abnormal solubility behaviour of fullerenes in toluene in the temperature range 35-75 deg. C. The information obtained in this work makes this BHAC very simple to prepare and low cost, useful for fullerene research applications.

  8. Chiral separation of benzothiazole derivatives of amino acids using capillary zone electrophoresis.

    Science.gov (United States)

    Nováková, Zuzana; Pejchal, Vladimír; Fischer, Jan; Česla, Petr

    2017-02-01

    A method for the separation of enantiomers of leucine and phenylalanine benzothiazole derivatives as potential antimicrobial agents was developed using capillary zone electrophoresis with a dual cyclodextrin (CD) system. The best resolution of enantiomers was achieved in 100 mmol/L phosphate background electrolyte (pH 3.5) with the dual CD system consisting of 10 mmol/L of β-CD with 10 mmol/L of 2-hydroxypropyl-β-cyclodextrin for leucine derivative and 10 mmol/L of 2-hydroxypropyl-γ-cyclodextrin for phenylalanine derivative, respectively. Under the optimal conditions, the highest enantioresolution of 1.25 was achieved in a noncoated-fused silica capillary at 17°C and 24 kV applied voltage.

  9. Electro-membrane reactor for separation and in situ ion substitution of glutamic acid from its sodium salt

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Mahendra; Tripathi, Bijay P. [Electro-Membrane Processes Division, Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial Research (CSIR), G. B. Marg, Bhavnagar 364002, Gujarat (India); Shahi, Vinod K. [Electro-Membrane Processes Division, Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial Research (CSIR), G. B. Marg, Bhavnagar 364002, Gujarat (India)], E-mail: vkshahi@csmcri.org

    2009-08-30

    An electro-membrane reactor with four compartments (EMR-4) (anolyte, catholyte and comp. 1 and 2) based on in-house-prepared cation- and anion-exchange membrane (CEM and AEM, respectively) was developed to achieve separation and recovery of glutamic acid (GAH) from its sodium salt by in situ ion substitution and acidification. The physicochemical and electrochemical properties of CEM and AEM were characterized and its suitability was assessed in operating environment. The separation of GA{sup -} from the mixture of nonionic organic compounds and further ion substitution was achieved by EMR-4. But the higher energy consumption (5.75 kWh/kg of GAH produced), low current efficiency (50.5%) and recovery of GAH (57.2%) in this process were main obstacles for the industrial exploration of the process. Latter, electro-membrane reactor with three compartments (EMR-3) (anolyte, catholyte and central compartment) was developed based on CEMs for only in situ ion substitution of GANa to achieve GAH, in which GA{sup -} was not allowed for electro-migration from its feed compartment. CE and recovery of GAH were close to 73% and 96% that indicate the suitability of the EMR-3 process for industrial application over the EMR-4. It was concluded that EMR-3 was efficient as compared to EMR-4 for separation and recovery of GAH from fermentation broth by in situ ion substitution in eco-friendly manner.

  10. Molecular dynamics investigation of separation of hydrogen sulfide from acidic gas mixtures inside metal-doped graphite micropores.

    Science.gov (United States)

    Huang, Pei-Hsing

    2015-09-21

    The separation of poisonous compounds from various process fluids has long been highly intractable, motivating the present study on the dynamic separation of H2S in acidic-gas-mixture-filled micropores. The molecular dynamics approach, coupled with the isothermal-isochoric ensemble, was used to model the molecular interactions and adsorption of H2S/CO2/CO/H2O mixtures inside metal-doped graphite slits. Due to the difference in the adsorption characteristics between the two distinct adsorbent materials, the metal dopant in the graphitic micropores leads to competitive adsorption, i.e. the Au and graphite walls compete to capture free adsorbates. The effects of competitive adsorption, coupled with changes in the gas temperature, concentration, constituent ratio and slit width on the constituent separation of mixtures were systematically studied. The molecule-wall binding energies calculated in this work (those of H2S, H2O and CO on Au walls and those of H2O, CO and CO2 on graphite walls) show good agreement with those obtained using density functional theory (DFT) and experimental results. The z-directional self-diffusivities (Dz) for adsorbates inside the slit ranged from 10(-9) to 10(-7) m(2) s(-1) as the temperature was increased from 10 to 500 K. The values are comparable with those for a typical microporous fluid (10(-8)-10(-9) m(2) s(-1) in a condensed phase and 10(-6)-10(-7) m(2) s(-1) in the gaseous state). The formation of H-bonding networks and hydrates of H2S is disadvantageous for the separation of mixtures. The results indicate that H2S can be efficiently separated from acidic gas mixtures onto the Au(111) surface by (i) reducing the mole fraction of H2S and H2O in the mixtures, (ii) raising the gas temperature to the high temperature limit (≥400 K), and (iii) lowering the slit width to below the threshold dimension (≤23.26 Å).

  11. Separation of Be and Al for AMS using single-step column chromatography

    Science.gov (United States)

    Binnie, Steven A.; Dunai, Tibor J.; Voronina, Elena; Goral, Tomasz; Heinze, Stefan; Dewald, Alfred

    2015-10-01

    With the aim of simplifying AMS target preparation procedures for TCN measurements we tested a new extraction chromatography approach which couples an anion exchange resin (WBEC) to a chelating resin (Beryllium resin) to separate Be and Al from dissolved quartz samples. Results show that WBEC-Beryllium resin stacks can be used to provide high purity Be and Al separations using a combination of hydrochloric/oxalic and nitric acid elutions. 10Be and 26Al concentrations from quartz samples prepared using more standard procedures are compared with results from replicate samples prepared using the coupled WBEC-Beryllium resin approach and show good agreement. The new column procedure is performed in a single step, reducing sample preparation times relative to more traditional methods of TCN target production.

  12. Ion Exchange and Thin Layer Chromatographic Separation and Identification of Amino Acids in a Mixture: An Experiment for General Chemistry and Biotechnology Laboratories

    Science.gov (United States)

    Brunauer, Linda S.; Caslavka, Katelyn E.; Van Groningen, Karinne

    2014-01-01

    A multiday laboratory exercise is described that is suitable for first-year undergraduate chemistry, biochemistry, or biotechnology students. Students gain experience in performing chromatographic separations of biomolecules, in both a column and thin layer chromatography (TLC) format. Students chromatographically separate amino acids (AA) in an…

  13. Ion Exchange and Thin Layer Chromatographic Separation and Identification of Amino Acids in a Mixture: An Experiment for General Chemistry and Biotechnology Laboratories

    Science.gov (United States)

    Brunauer, Linda S.; Caslavka, Katelyn E.; Van Groningen, Karinne

    2014-01-01

    A multiday laboratory exercise is described that is suitable for first-year undergraduate chemistry, biochemistry, or biotechnology students. Students gain experience in performing chromatographic separations of biomolecules, in both a column and thin layer chromatography (TLC) format. Students chromatographically separate amino acids (AA) in an…

  14. Zwitterionic chiral stationary phases based on cinchona and chiral sulfonic acids for the direct stereoselective separation of amino acids and other amphoteric compounds.

    Science.gov (United States)

    Zhang, Tong; Holder, Emilie; Franco, Pilar; Lindner, Wolfgang

    2014-06-01

    An extensive series of free amino acids and analogs were directly resolved into enantiomers (and stereoisomers where appropriate) by HPLC on zwitterionic chiral stationary phases (Chiralpak ZWIX(+) and Chiralpak ZWIX(-)). The interaction and chiral recognition mechanisms were based on the synergistic double ion-paring process between the analyte and the chiral selectors. The chiral separation and elution order were found to be predictable for primary α-amino acids with apolar aliphatic side chains. A systematic investigation was undertaken to gain an insight into the influence of the structural features on the enantiorecognition. The presence of polar and/or aromatic groups in the analyte structure is believed to tune the double ion-paring equilibrium by the involvement of the secondary interaction forces such as hydrogen bonding, Van der Waals forces and π-π stacking in concert with steric parameters. The ZWIX chiral columns were able to separate enantiomers and stereoisomers of various amphoteric compounds with no need for precolumn derivatization. Column switching between ZWIX(+) and ZWIX(-) is believed to be an instrumental tool to reverse or control the enantiomers elution order, due to the complementarity of the applied chiral selectors.

  15. Advanced Acid Gas Separation Technology for Clean Power and Syngas Applications

    Energy Technology Data Exchange (ETDEWEB)

    Amy, Fabrice [Air Products and Chemicals Inc., Allentown, PA (United States); Hufton, Jeffrey [Air Products and Chemicals Inc., Allentown, PA (United States); Bhadra, Shubhra [Air Products and Chemicals Inc., Allentown, PA (United States); Weist, Edward [Air Products and Chemicals Inc., Allentown, PA (United States); Lau, Garret [Air Products and Chemicals Inc., Allentown, PA (United States); Jonas, Gordon [Air Products and Chemicals Inc., Allentown, PA (United States)

    2015-06-30

    Air Products has developed an acid gas removal technology based on adsorption (Sour PSA) that favorably compares with incumbent AGR technologies. During this DOE-sponsored study, Air Products has been able to increase the Sour PSA technology readiness level by successfully operating a two-bed test system on coal-derived sour syngas at the NCCC, validating the lifetime and performance of the adsorbent material. Both proprietary simulation and data obtained during the testing at NCCC were used to further refine the estimate of the performance of the Sour PSA technology when expanded to a commercial scale. In-house experiments on sweet syngas combined with simulation work allowed Air Products to develop new PSA cycles that allowed for further reduction in capital expenditure. Finally our techno economic analysis of the use the Sour PSA technology for both IGCC and coal-to-methanol applications suggests significant improvement of the unit cost of electricity and methanol compared to incumbent AGR technologies.

  16. DILUTE SOLUTION BEHAVIOR OF CHITOSAN IN DIFFERENT ACID SOLVENTS

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; WANG Lihua; QIN Wen

    1994-01-01

    Dilute solution behavior of chitosan was studied in formic acid, acetic acid,lactic acid and hydrochloric acid aqueous solution under different pH values. The reduced viscosities, ηsp/C,of chitosan solutions were dependent on the properties of acid and pH value of solvents. For a given chitosan concentration, ηsp/C decreased with the increase of acid concentration, or decreasing pH of solvent, indicating shielding effect of excessive acid similar to adding salt into solution. The stabilities of dilute chitosan solution in formic acid and lactic acid were better than that in acetic acid and hydrochloric acid.

  17. Combination of electromembrane extraction and liquid-phase microextraction in a single step: Simultaneous group separation of acidic and basic drugs

    DEFF Research Database (Denmark)

    Huang, Chuixiu; Seip, Knut Fredrik; Gjelstad, Astrid

    2015-01-01

    as the SLM for LPME, basic and acidic drugs were extracted and separated simultaneously from a low pH sample by EME and LPME, respectively. After 15 min of extraction, basic drugs (citalopram and sertraline) were exhaustively extracted, whereas the recoveries for acidic drugs (ketoprofen and ibuprofen) were...

  18. Separation Of Cadmium(II, Cobalt(II And Nickel(II By Transport Through Polymer Inclusion Membranes With Phosphonium Ionic Liquid As Ion Carrier / Separacja Jonów Kadmu(II, Kobaltu(II I Niklu(II W Procesie Transportu Przez Polimerowe Membrany Inkluzyjne Zawierające Fosfoniową Ciecz Jonową W Roli Przenośnika

    Directory of Open Access Journals (Sweden)

    Pospiech B.

    2015-12-01

    Full Text Available This paper presents study on the facilitated transport of cadmium(II, cobalt(II and nickel(II ions from aqueous chloride solutions through polymer inclusion membranes (PIMs with phosphonium ionic liquid. Cyphos IL 101 (trihexyl(tetradecyl phosphonium chloride was used as a selective carrier for synthesis of cellulose triacetate membranes containing o-nitrophenyl pentyl ether (ONPPE as a plasticizer. Effect of different parameters such as hydrochloric acid concentration in the source phase as well as ion carrier concentration in the polymer membrane on metal ions transport has been investigated. Cd(II was transported preferably from hydrochloric acid solutions containing Co(II and Ni(II through PIM containing 18.8 wt.% CTA and 26.0 wt.% Cyphos 101 and 55.1 wt.% ONPPE into 0.5 M HNO3 as the receiving phase. The obtained results suggest that there is a possibility of application of this membrane with Cyphos IL 101 as ion carrier for separation of Cd(II over Co(II and Ni(II from hydrochloric acid solutions.

  19. Countercurrent Chromatographic Separation of Lipophilic Ascorbic Acid Derivatives and Extract from Kadsura Coccinea Using Hydrophobic Organic-Aqueous Two-Phase Solvent Systems.

    Science.gov (United States)

    Shinomiya, Kazufusa; Li, Heran; Kitanaka, Susumu; Ito, Yoichiro

    2009-01-01

    Countercurrent chromatographic (CCC) separation of lipophilic ascorbic acid derivatives and the crude extract from Kadsura Coccinea was performed using the type-J multilayer coil planet centrifuge with a hydrophobic organic-aqueous two-phase solvent system composed of n-hexane/ethyl acetate/ethanol/aqueous 0.1% trifluoroacetic acid at the volume ratio of (5 : 5 : 6 : 2). The lipophilic ascorbic acid derivatives were separated in the order of L-ascrobyl 2,6-dibutyrate, L-ascorbyl 6-palmitate and L-ascorbyl 6-stearate by eluting the lower phase as the mobile phase, and L-ascorbyl 2,6-dipalmitate was separated by eluting the upper phase at the opposite direction. The above solvent system was then applied to the CCC separation of the extract prepared from K. coccinea. With lower phase mobile, the extract was mainly separated into two peaks corresponding to lignans and triterpenoids accordingly. The HPLC analysis of the fractions showed that the former peak contained Kadsulignan N, Schizandrin H and Neokadsuranin as lignans, and the latter peak, Micranoic acid A, Neokadsuranic acid B and beta-Sitosterol as triterpenoids. The overall results indicate that the hydrophobic organic-aqueous two-phase solvent system used in the present studies was useful for the CCC separation of lignans and triterpenoids present in the natural products.

  20. Novel energy saving strategy for separating acetic acid – water in extractive distillation with N-methyl acetamide as entrainer

    Science.gov (United States)

    You, Xinqiang; Peng, Changjun; Liu, Honglai

    2017-09-01

    The design of homogeneous extractive distillation for acetic acid (AA) dehydration with N-methyl acetamide (NMA) as entrainer was investigated. It belongs to the classification of 0.0-1. The main challenge is that NMA and AA will lead to another pinch point, probably leading to energy cost and total annual cost (TAC) increase. Through analyzing thermodynamic insight, we have proposed a new strategy: low recycling entrainer purity for the extractive distillation of class 0.0-1 with no univolatility line existing. The strategy could save energy cost by avoiding the approach of the pinch point between AA and NMA. We have run sequence iterative optimization method for the process optimization. The total eleven variables are optimized. Results show that energy consumption and TAC are reduced by 50.6% and 52.1%, respectively. The results also reveal that a suitable shift of the feed tray locations improves the efficiency of the separation, even when less entrainer is used.

  1. The Effect of Oil and Filer Contents on the Porosity of Lead Acid Battery Separators Produced From Polyethylene

    Directory of Open Access Journals (Sweden)

    Zyad Rafa'a Zair

    2005-01-01

    Full Text Available In this investigation a high density polyethylene (HDPE was used as a substitute to polyvinylchloride in the production of lead acid battery separators. This has been achieved by preparing mixtures of different percentages of the feed materials which include a high density polyethylene (HDPE locally produced, filler materials such as silica and oils such as dioctylphthalate (DOP or paraffin which were added to the mixture to improve the final properties of the separator. The materials were compounded by two roll-mills under the same conditions. The following parameters are involved: 1- Studying the use of a high density polyethylene as a binder to film components with (15-30 wt.%. 2- Studying the use of finely divided silica sand with (25-45 wt.% as a medium to oil adsorption.- Studying the use of two type plasticizers (Paraffin or DOP with (35-55 wt. %. as a creative medium to films porosity.The best results of the feed materials in the mixture were selected so as to give the highest porosity using 15 wt. % PE, 30 wt. % filler, and 55 wt. % oil. It has been found that the films with DOP oil give higher porosity.

  2. Sequential separation of lanthanides, thorium and uranium using novel solid phase extraction method from high acidic nuclear wastes.

    Science.gov (United States)

    Kesava Raju, Ch Siva; Subramanian, M S

    2007-06-25

    A novel grafted polymer for selective extraction and sequential separation of lanthanides, thorium and uranium from high acidic wastes has been developed by grafting Merrifield chloromethylated (MCM) resin with octyl(phenyl)-N,N-diisobutylcarbamoyl-methylphosphine oxide (CMPO) (MCM-CMPO). The grafting process is well characterized using FT-IR spectroscopy, (31)P and (13)C CPMAS (cross-polarized magic angle spin) NMR spectroscopy and CHNPS elemental analysis. The influence of various physico-chemical parameters during metal ion extraction by the resin phase are studied and optimized by both static and dynamic methods. The resin shows very high sorption capacity values of 0.960mmolg(-1) for U(VI), 0.984mmolg(-1) for Th(IV), 0.488mmolg(-1) for La(III) and 0.502mmolg(-1) for Nd(III) under optimum HNO(3) medium, respectively. The grafted polymer shows faster rate exchange kinetics (extraction) and greater preconcentration ability, with reusability exceeding 20 cycles. During desorption process, sequential separation of the analytes is possible with varying eluting agents. The developed grafted resin has been successfully applied in extracting Th(IV) from high matrix monazite sand, U(VI) and Th(IV) from simulated nuclear spent fuel mixtures. All the analytical data is based on triplicate analysis and measurements are within 3.5% rsd reflecting the reproducibility and reliability of the developed method.

  3. CZE separation of amitrol and triazine herbicides in environmental water samples with acid-assisted on-column preconcentration.

    Science.gov (United States)

    Arribas, Alberto Sánchez; Moreno, Mónica; Bermejo, Esperanza; Zapardiel, Antonio; Chicharro, Manuel

    2011-01-01

    A simple analytical scheme for the detection and quantification of amitrol and triazine herbicides (atrazine, ametryn and atraton) and degradation product (2-hydroxyatrazine) in environmental water samples by CZE is reported. On-column preconcentration of analytes from untreated water samples (mineral, spring, tap and river water) is accomplished by introducing an acid plug (200 mM citrate of pH 2.0) after the sample and then proceeding with the CZE separation, using 100 mM formiate buffer of pH 3.5 as running buffer and 25.0 KV as separation voltage. UV detection at 200 nm provides LODs from 50 to 300 nM in untreated samples and they were lowered tenfold by sample preconcentration by evaporation. Calculated recoveries were typically higher than 90%. Minimal detectable concentration of the electroactive amitrol could be decreased about 20-fold when electrochemical detection was employed by monitoring the amperometric signal at +800 mV using a carbon paste electrode (LOD of 9.6 nM, 0.81 μg/L, versus 170 nM, 14.3 μg/L, using amperometric and UV detection, respectively) in untreated water samples. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Processing and size range separation of pristine and magnetic poly(l-lactic acid) based microspheres for biomedical applications.

    Science.gov (United States)

    Correia, D M; Sencadas, V; Ribeiro, C; Martins, P M; Martins, P; Gama, F M; Botelho, G; Lanceros-Méndez, S

    2016-08-15

    Biodegradable poly(l-lactic acid) (PLLA) and PLLA/CoFe2O4 magnetic microspheres with average sizes ranging between 0.16-3.9μm and 0.8-2.2μm, respectively, were obtained by an oil-in-water emulsion method using poly(vinyl alcohol) (PVA) solution as the emulsifier agent. The separation of the microspheres in different size ranges was then performed by centrifugation and the colloidal stability assessed at different pH values. Neat PLLA spheres are more stable in alkaline environments when compared to magnetic microspheres, both types being stable for pHs higher than 4, resulting in a colloidal suspension. On the other hand, in acidic environments the microspheres tend to form aggregates. The neat PLLA microspheres show a degree of crystallinity of 40% whereas the composite ones are nearly amorphous (17%). Finally, the biocompatibility was assessed by cell viability studies with MC3T3-E1 pre-osteoblast cells.

  5. Extraction and separation of U(VI and Th(IV from hydrobromic acid media using Cyanex-923 extractant

    Directory of Open Access Journals (Sweden)

    Ghag Snehal M.

    2010-01-01

    Full Text Available A systematic study of the solvent extraction of uranium(VI and thorium(IV from hydrobromic acid media was performed using the neutral phosphine oxide extractant Cyanex-923 in toluene. These metal ions were found to be quantitatively extracted with Cyanex-923 in toluene in the acidity range 5x10-5-1x10-4 M and 5x10-5-5x10-3 M, respectively, and they are stripped from the organic phase with 7.0 M HClO4 and 2.0- 4.0 M HCl, respectively. The effect of the equilibrium period, diluents, diverse ions and stripping agent on the extraction of U(VI and Th(IV was studied. The stoichiometry of the extracted species of these metal ions was determined based on the slope analysis method. The extraction reactions proceed by solvation and their probable extracted species found in the organic phase were UO2Br2•2Cyanex-923 and ThBr4•2Cyanex-923. Based on these results, a sequential procedure for their separation from each other was developed.

  6. Mandelic acid chiral separation utilizing a two-phase partitioning bioreactor built by polysulfone microspheres and immobilized enzymes.

    Science.gov (United States)

    Wang, Xinyu; Cui, Yanjun; Chen, Xia; Zhu, Hao; Zhu, Weiwei; Li, Yanfeng

    2015-03-01

    A novel two-phase partitioning bioreactor (TPPB) modified by polysulfone (PSF) microspheres and immobilized enzyme (novozym-435) was formed, and the resulting TPPB was applied into mandelic acid chiral separation. The PSF microspheres containing n-hexanol (named PSF/hexanol microspheres) was prepared by using the phase inversion method, which was used as the organic phase. Meanwhile, the immobilized enzyme novozym-435 was used as a biocatalyst. The water phase was composed of the phosphate buffer solution (PBS). (R, S)-Methyl mandelate was selected as the substrate to study enzymatic properties. Different reaction factors have been researched, such as pH, reaction time, temperature and the quantity of biocatalyst and PSF/hexanol microspheres added in. Finally, (S)-mandelic acid was obtained with an 80 % optical purity after 24 h in the two-phase partitioning bioreactor. The enantiomeric excess (eep) values were very low in the water phase, in which the highest eep value was only 46 %. The eep of the two-phase partitioning bioreactor had been enhanced more obviously than that catalyzed in the water phase.

  7. Amberlite XAD-4 functionalized with succinic acid for the solid phase extractive preconcentration and separation of uranium(VI).

    Science.gov (United States)

    Metilda, P; Sanghamitra, K; Mary Gladis, J; Naidu, G R K; Prasada Rao, T

    2005-01-15

    Amberlite XAD-4 resin has been functionalized with succinic acid by coupling it with dibromosuccinic acid after acetylation. The resulting resin has been characterized by FT-IR, elemental analysis and TGA and has been used for preconcentrative separation of uranium(VI) from host of other inorganic species prior to its determination by spectrophotometry. The optimum pH value for quantitative sorption of uranium(VI) in both batch and column modes is 4.5-8.0 and desorption can be achieved by using 5.0ml of 1.0moll(-1) HCl. The sorption capacity of functionalized resin is 12.3mgg(-1). Calibration graphs were rectilinear over the uranium(VI) concentrations in the range 5-200mugl(-1). Five replicate determinations of 50mug of uranium(VI) present in 1000ml of solution gave a mean absorbance of 0.10 with a relative standard deviation of 2.56%. The detection limit corresponding to three times the standard deviation of the blank was found to be 2mugl(-1). Various cationic and anionic species at 200-fold amounts do not interfere during the preconcentration of 5.0mug of uranium(VI) present in 1000ml (batch) or 100ml (column) of sample solution. Further, adsorption kinetic and isotherm studies were also carried out by a batch method to understand the nature of sorption of uranium(VI) with the succinic acid functionalized resin. The accuracy of the developed solid phase extractive preconcentration method in conjunction with Arsenazo III procedure was tested by analyzing marine sediment (MESS-3) and soil (IAEA soil-7) reference material. Further, the above procedure has been successfully employed for the analysis of soil and sediment samples.

  8. Application of hydrochloric cyclopentolate eye drops in the mydriasis test and optometry for children with hyperopia

    Directory of Open Access Journals (Sweden)

    Hong-Ping Yin

    2016-02-01

    Full Text Available AIM:To observe and study the comprehensive application effect of hydrochloric cyclopentolate eye drops in the mydriasis test and optometry for children with hyperopia.METHODS:Eighty-four children with hyperopia who were intervened with mydriasis test and optometry in our hospital from February 2014 to March 2015 were selected as the research object,and they were intervened with mydriasis test and optometry by tropicamide or hydrochloric cyclopentolate eye drops. The diopter, pupil diameter and residual regulation before administration and at different time after administration of the two methods were compared,and the detected results of the two groups with different severity degree were compared too.RESULTS:The diopter, pupil diameter and residual regulation before administration of the two eye drops had no significant differences(all P>0.05,while the residual regulation after using hydrochloric cyclopentolate eye drops at 20, 40, 60min and 24h were all smaller than those after using tropicamide(all PP>0.05. The pupil diameter of the two groups at 48h after administration both had no significant differences to those before administration(all P>0.05.CONCLUSION:The comprehensive application effect of hydrochloric cyclopentolate eye drops in the mydriasis test and optometry of children with hyperopia is better,and its paralysis effect for ciliaris is obvious.

  9. Study of the separation of zirconium and hafnium from nitric solutions by solvent extraction

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, Janubia Cristina B.S.; Rocha, Laura R.T.; Morais, Carlos Antonio de, E-mail: jcbsa@cdtn.br, E-mail: lrtr@cdtn.br, E-mail: cmorais@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, BH (Brazil)

    2013-07-01

    This paper describes the study of the separation of Zr and Hf in nitric and hydrochloric media by solvent extraction technique. As aqueous phase, solutions prepared from the Zr and Hf hydroxides and the liquor generated from the product of the alkaline fusion of the zircon were used. The content of Zr and Hf in these solutions were 15 g/L and 0.6 g/L Hf respectively, and its acidity was varied between 1.0 and 10 mol/L. The effect of the acid extractants (DEHPA, IONQUEST®801 and CYANEX®272), solvating extractants (TBP and CYANEX®923) and basic extractants (PRIMENE®JTM, ALAMINE®336 and ALIQUAT®336), all of them diluted in dodecane, was investigated. In the solutions of the basic extractants, 5.0% of tridecanol was added as a modifier agent. Among the extractants investigated, the TBP in a nitric medium showed the best performance in the separation of the Zr/Hf. For acid extractants a high extraction was observed, however, with low selectivity. With the basic extractants no metals extraction was observed under the conditions investigated. The best results were obtained with the liquor generated from the product of alkaline fusion of zircon at acidity 7.0 mol/L and nitrate concentration of 9.2 mol/L. Under these conditions an extraction percentage of 91.6% for Zr and of 12.1% for Hf and a separation factor of Zr/Hf of 79.3 was obtained. (author)

  10. Separation and partial characterization of enzymes catalyzing delta-aminolevulinic acid formation in Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Rieble, S; Beale, S I

    1991-09-01

    Formation of the universal tetrapyrrole precursor, delta-aminolevulinic acid (ALA), from glutamate via the five-carbon pathway requires three enzymes: glutamyl-tRNA synthetase, glutamyl-tRNA reductase, and glutamate-1-semialdehyde (GSA) aminotransferase. All three enzymes were separated from extracts of the unicellular cyanobacterium Synechocystis sp. PCC 6803, and two of them, glutamyl-tRNA synthetase and GSA aminotransferase, were partially characterized. After an initial high speed centrifugation and differentiatial ammonium sulfate fractionation of cell extract, the enzymes were separated by successive affinity chromatography on Reactive Blue 2-Sepharose and 2',5'-ADP-agarose. All three enzyme fractions were required to reconstitute ALA formation from glutamate. The apparent native molecular masses of glutamyl-tRNA synthetase and GSA aminotransferase were determined by gel filtration chromatography to be 63 and 98 kDa, respectively. Neither glutamyl-tRNA synthetase nor GSA aminotransferase activity was affected by hemin concentrations up to 10 and 30 microM, respectively, and neither activity was affected by protochlorophyllide concentrations up to 2 microM. GSA aminotransferase was inhibited 50% by 0.5 microM gabaculine. The gabaculine inhibition was reversible for up to 1 h after its addition, if the gabaculine was removed by gel filtration before the enzyme was incubated with substrate. However, irreversible inactivation was obtained by preincubating the enzyme at 30 degrees C either for several hours with gabaculine alone or for a few minutes with both gabaculine and GSA. Neither pyridoxal phosphate nor pyridoxamine phosphate significantly affected the activity of GSA aminotransferase at physiologically relevant concentrations, and neither of these compounds reactivated the gabaculine-inactivated enzyme. It was noted that the presence of pyridoxamine phosphate in the ALA assay mixture produced a false positive color reaction even in the absence of enzyme.

  11. Effect of thermal annealing on a novel polyamide–imide polymer membrane for aggressive acid gas separations

    KAUST Repository

    Vaughn, Justin T.

    2012-05-01

    A fluorinated, 6FDA based polyamide-imide is investigated for the purification of CH 4 from CO 2 and H 2S containing gas streams. Dense polymer films were thermally annealed and showed that increased annealing temperatures at constant annealing time caused transport behavior that does not resemble physical aging. Free volume increased after annealing at 200°C for 24h relative to annealing at 150°C for the same time. CO 2 and CH 4 permeabilities and diffusivities did not decrease as a result of the higher annealing temperature, and in fact, were shown to increase slightly. A change to the intrinsic microstructure that cannot be described by simple, densification based physical aging is hypothesized to be the reason for this trend. Furthermore, annealing increased CO 2 induced plasticization resistance and a temperature of 200°C was shown to have the greatest effect on plasticization suppression. Annealing at 200°C for 24h suppressed pure gas CO 2 plasticization up to 450psia. Fluorescence spectroscopy revealed increased intramolecular charge transfer, which is presumably due to increased electron conjugation over the N-phenyl bond. Additionally, intermolecular charge transfer increased with thermal annealing, as inferred from fluorescence intensity measurements and XRD patterns. 50/50 CO 2/CH 4 mixed gas permeation measurements reveal stable separation performance up to 1000psia. Ternary mixed gas feeds containing toluene/CO 2/CH 4 and H 2S/CO 2/CH 4 show antiplasticization, but more importantly, selectivity losses due to plasticization did not occur up to 900psia of total feed pressure. These results show that the polyamide-imide family represents a promising class of separation materials for aggressive acid gas purifications. © 2012 Elsevier B.V.

  12. Partition chromatography separation using trilaurylamine adsorbed on a solid support. Behaviour of the uranyl ion; Separations par chromatographie de partage au moyen de trilaurylamine adsorbee sur support solide comportement de l'ion uranyle

    Energy Technology Data Exchange (ETDEWEB)

    Petit-Bromet, M. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1968-07-01

    The extractive phase is made up of a TLA solution in cyclohexanol adsorbed on a solid poly-trifluorochloroethylene support (sold commercially as voltalef or KEL-F). The mixture obtained is homogeneous and can be used for partition chromatography. For a solution of hydrochloric acid stronger than 1 M, the amine is quantitatively in the form of the chlorohydrate. The partition curve for U(VI) between the 2 N hydrochloric acid aqueous phase and the organic TLA phase has two steps which can be explained by assuming that two complexes exist in the organic phase. The equilibrium constants for extraction have been determined. The homogeneity of the voltalef-amine mixture has made it possible to build up a column with reproducible characteristics. Under the operational conditions adopted, the height of the equivalent theoretical plate is about 3 mm. A plot of all the curves giving the variations in the partition function of U(VI), Fe(III), Cu(II), Sr(II) and Cs(I) as a function of the hydrochloric acid concentration makes it possible to predict the conditions under which these elements may be separated. [French] La phase extractive est constituee d'une solution de TLA dans le cyclohexanol adsorbe sur un support solide de polytrifluorochloroethylene (commercialise sous le nom de voltalef ou KEL-F). Le melange obtenu est homogene et peut etre utilise en chromatographie de partage. Pour une concentration d'acide chlorhydrique en solution superieure a 1 M, l'amine est quantitativement sous forme de chlorhydrate. La courbe de partage de U(VI) entre la phase aqueuse d'acide chlorhydrique 2 N et la phase organique de TLA presente deux paliers que l'on peut interpreter en admettant l'existence de deux complexes en phase organique. Les constantes des equilibres d'extraction ont ete determinees. L'homogeneite du melange voltalef-amine a permis de constituer une colonne.dont les caracteristiques sont reproductibles. Dans les conditions de

  13. Separating nano graphene oxide from the residual strong-acid filtrate of the modified Hummers method with alkaline solution

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xuebing, E-mail: xuebinghu2010@gmail.com [Key Laboratory of Inorganic Membrane, Jingdezhen Ceramic Institute, Jingdezhen 333001 (China); Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 201800 (China); Yu, Yun, E-mail: yunyush@mail.sic.ac.cn [Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 201800 (China); Wang, Yongqing; Zhou, Jianer [Key Laboratory of Inorganic Membrane, Jingdezhen Ceramic Institute, Jingdezhen 333001 (China); Song, Lixin [Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 201800 (China)

    2015-02-28

    Graphical abstract: By adding an alkaline (NaOH or KOH) solution, the unprecipitated nano graphene oxide undergoes fast aggregation from the residual strong-acid filtrate of the modified Hummers method and forms the stable floccules when the pH value of the filtrate is about 1.7. The acid–base interaction with the surface functional groups of the carbon layers plays a role in the aggregation of the unprecipitated nano graphene oxide. - Highlights: • The novel and high-efficient method for separating graphene oxide was showed. • Graphene oxide undergoes aggregation and forms the floccules when pH value is ∼1.7. • The acid–base interaction plays a role in the aggregation of graphene oxide. - Abstract: In the modified Hummers method for preparing graphene oxide, the yellow slurry can be obtained. After filtering through a quantitative filter paper, the strong-acid filtrate containing the unprecipitated nano graphene oxide was gained. The corresponding filtrate was added gradually with an alkaline (NaOH or KOH) solution at room temperature. The unprecipitated nano graphene oxide could undergo fast aggregation when the pH value of the filtrate was about 1.7 and formed the stable floccules. X-ray diffraction analysis shows the dominant peak of the floccules is about 11°, which accords to the peak of graphene oxide. Spectra of X-ray photoelectron spectroscopy confirm the presence in the floccules of an abundance of oxygen functional groups and the purified graphene oxide floccules can be obtained. Atomic force microscopy measurement shows the graphene oxide floccules consists of sheet-like objects, mostly containing only a few layers (about 5 layers). Zeta potential analysis demonstrates the surface charge of the graphene oxide is pH-sensitive and its isoelectric point is ∼1.7. The flocculation mechanism of graphene oxide ascribes to the acid–base interaction with the surface functional groups of the carbon layers.

  14. Development of an automatic method for americium and plutonium separation and preconcentration using an multisyringe flow injection analysis-multipumping flow system.

    Science.gov (United States)

    Fajardo, Yamila; Ferrer, Laura; Gómez, Enrique; Garcias, Francesca; Casas, Monserrat; Cerdà, Víctor

    2008-01-01

    A new procedure for automatic separation and preconcentration of 241Am and 239+240Pu from interfering matrixes using transuranide (TRU)-resin is proposed. Combination of the multisyringe flow injection analysis and multipumping flow system techniques with the TRU-resin allows carrying out the sampling treatment and separation in a short time using large sample volumes. Americium is eluted from the column with 4 mol L(-1) hydrochloric acid, and then plutonium is separated via on-column Pu(IV) reduction to Pu(III) with titanium(III) chloride. The corresponding alpha activities are measured off-line, with a relative standard deviation of 3% and a lower limit of detection of 0.004 Bq mL(-1), by using a multiplanchet low-background proportional counter.

  15. Investigation on enantiomeric separations of fluorenylmethoxycarbonyl amino acids and peptides by high-performance liquid chromatography using native cyclodextrins as chiral stationary phases.

    Science.gov (United States)

    Tang, Y; Zukowski, J; Armstrong, D W

    1996-09-06

    A systematic study was carried out to investigate enantiomeric separations of fluorenylmethoxycarbonyl (FMOC) amino acids and their peptides. Twenty amino acids were derivatized by 9-fluorenylmethyl chloroformate (FMOC-Cl) and its analogues, FMOC-glycyl-Cl and FMOC-beta-alanyl-Cl. All derivatives were chromatographed on native beta- and gamma-cyclodextrin columns using acetonitrile as the main mobile phase component. The results indicated that glycyl and beta-alanyl groups between FMOC and amino acid moieties enhanced chiral selectivities of amino acid derivatives. The addition of modifiers, triethylamine, acetic acid and methanol, into the mobile phase caused alterations in retention, enantiorecognition and elution order. The structures of amino acids and the type of chiral stationary phase employed exhibited significant impacts on chiral resolutions. It is also found that the number and position of glycyl moieties affect the retentions and enantioselectivities of FMOC derivatized glycyl containing peptides.

  16. Spring flood pH decline in northern Sweden: Towards an operational model separating natural acidity from anthropogenic acidification

    Energy Technology Data Exchange (ETDEWEB)

    Laudon, H.

    1999-10-01

    The spring flood is a defining feature of the ecosystem in northern Sweden. In this region, spring flood is an occasion for dramatic hydrochemical changes that profoundly effect the biodiversity of the aquatic ecosystem. Spring flood is also the period most susceptible to anthropogenic acidification. A belief in the anthropogenic component to pH decline during spring flood has been an important factor in spending over half a billion crowns to lime surface waters in Northern Sweden during the last decade. The natural component of episodic pH decline during spring flood, however, has received less attention. The main objective of this work is to present an operational model for separating and quantifying the anthropogenic and natural contributions of episodic acidification during high flow events in Northern Sweden. The key assumptions in this model are that baseflow ANC has not been affected by anthropogenic acidification, that DOC has not changed due to modern land-use practice and that natural dilution during hydrological episodes can be quantified. The limited data requirements of 10-15 stream water samples before and during spring flood make the model suitable for widespread use in environmental monitoring programs. This makes it possible to distinguish trends of human impact as well as natural pH decline in space and time. Modeling results from northern Sweden demonstrate that the natural driving mechanisms of dilution and organic acidity were the dominant factors in the episodic acidification of spring flood in the region. The anthropogenic contribution to spring pH decline was similar in size to the natural contribution in only two of the more than 30 events where this model was applied. Natural factors alone were found to cause pH values below 4.5 in some streams. Anthropogenic sources of acidity can be superimposed on this natural dynamics. In the sites studied, the magnitude of the anthropogenic ANC decline was correlated to the winter deposition of

  17. Enantiomeric separations of amino alcohols by packed-column SFC on Hypercarb with L-(+)-tartaric acid as chiral selector.

    Science.gov (United States)

    Gyllenhaal, Olle; Karlsson, Anders

    2002-12-31

    The use of L-(+)-tartaric acid as a chiral mobile phase additive (CMPA) has been investigated in a packed-column SFC system. The CMPA, carbon dioxide, and methanol, containing a high concentration of aliphatic amine additive, were used as the mobile phase and Hypercarb as support [Gyllenhaal O., Karlsson A., SFC of metoprolol and other amino alcohols on Hypercarb (in preparation)]. Good enantioselectivities were obtained for tertiary amine homologues of 2-amino alcohols, used as beta-adrenoreceptor-blocking drugs. Moderate selectivities were observed for aromatic compounds having a second substituent in the ortho-position. The overall retention was influenced by the aromaticity of the analytes as well as the presence of free electron pairs in the molecule. Increased concentrations of CMPA gave higher retention and also increased the enantioselectivity. The practical utility of this present enantioselective system was demonstrated on one batch of (S)-metoprolol that was N-methylated with methyl iodide. The enantiomeric separation was accomplished within 10 min.

  18. Separation of basic drug enantiomers by capillary electrophoresis using chicken alpha1-acid glycoprotein: insight into chiral recognition mechanism.

    Science.gov (United States)

    Matsunaga, Hisami; Sadakane, Yutaka; Haginaka, Jun

    2003-08-01

    Recombinant chicken alpha(1)-acid glycoprotein (alpha(1)-AGP) was prepared by the Escherichia coli expression system and completely deglycosylated alpha(1)-AGP (cd-alpha(1)-AGP) was obtained by treatments of native alpha(1)-AGP with a mixture of endoglycosidase and N-glycosidase. The average molecular masses of chicken alpha(1)-AGP, cd-alpha(1)-AGP and recombinant alpha(1)-AGP were estimated to be about 29 200, 21 700 and 20 700, respectively, by matrix-assisted laser desorption-time of flight-mass spectrometry. We compared the chiral recognition ability of chicken alpha(1)-AGP, cd-alpha(1)-AGP and recombinant alpha(1)-AGP using them as chiral selectors in capillary electrophoresis. The chicken alpha(1)-AGP showed higher resolution for eperisone, pindolol and tolperisone than cd-alpha(1)-AGP or recombinant alpha(1)-AGP. Recombinant alpha(1)-AGP still showed chiral recognition for three basic drugs tested. By addition of propranolol as a competitor in the separation solution in CE, no enantioseparations of three basic drugs were observed with chicken alpha(1)-AGP, cd-alpha(1)-AGP or recombinant alpha(1)-AGP. These results reveal that the protein domain of the chicken alpha(1)-AGP is responsible for the chiral recognition ability, and that the chiral recognition site(s) for basic drugs exists on the protein domain.

  19. Increments to chiral recognition facilitating enantiomer separations of chiral acids, bases, and ampholytes using Cinchona-based zwitterion exchanger chiral stationary phases.

    Science.gov (United States)

    Wernisch, Stefanie; Pell, Reinhard; Lindner, Wolfgang

    2012-07-01

    The intramolecular distances of anion and cation exchanger sites of zwitterionic chiral stationary phases represent potential tuning sites for enantiomer selectivity. In this contribution, we investigate the influence of alkanesulfonic acid chain length and flexibility on enantiomer separations of chiral acids, bases, and amphoteric molecules for six Cinchona alkaloid-based chiral stationary phases in comparison with structurally related anion and cation exchangers. Employing polar-organic elution conditions, we observed an intramolecular counterion effect for acidic analytes which led to reduced retention times but did not impair enantiomer selectivities. Retention of amphoteric analytes is based on simultaneous double ion pairing of their charged functional groups with the acidic and basic sites of the zwitterionic selectors. A chiral center in the vicinity of the strong cation exchanger site is vital for chiral separations of bases. Sterically demanding side chains are beneficial for separations of free amino acids. Enantioseparations of free (un-derivatized) peptides were particularly successful in stationary phases with straight-chain alkanesulfonic acid sites, pointing to a beneficial influence of more flexible moieties. In addition, we observed pseudo-enantiomeric behavior of quinine and quinidine-derived chiral stationary phases facilitating reversal of elution orders for all analytes. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Ab initio investigations of the dynamic and thermodynamic properties of atmospherically relevant strong acids

    OpenAIRE

    Partanen, Lauri

    2017-01-01

    Sulfuric and hydrochloric acids participate in several important chemical processes occurring in the atmosphere. Due to its tendency to react with water molecules, sulfuric acid is an important factor in cloud formation and related phenomena. Hydrochloric acid is heavily implicated in stratospheric ozone depletion because of its role as a temporary reservoir for chlorine radicals. In this thesis, the thermodynamics and dynamics of these two acids are investigated. The dynamic part focuse...

  1. Separation of some mono-, di- and tri-unsaturated fatty acids containing 18 carbon atoms by high-performance liquid chromatography and photodiode array detection.

    Science.gov (United States)

    Czauderna, M; Kowalczyk, J

    2001-08-25

    Positional and geometric isomers of mono-, di- and tri-unsaturated fatty acids containing 18 carbon atoms were separated on commercially available reversed-phase columns in gradient systems composed of acetonitrile and water, utilizing photodiode array detection. The biological samples were hydrolyzed with 2 M NaOH for 35-40 min at 85-90 degrees C. After cooling, the hydrolysates were acidified with 4 M HCl and the free fatty acids were extracted with dichloromethane. The organic solvent was removed in a gentle stream of argon. The fatty acids were determined after pre-column derivatization with dibromacetophenone in the presence of triethylamine. The reaction components were mixed and reacted for 2 h at 50 degrees C. Separations of derivatized fatty acids were performed on two C18 columns (Nova Pak C18, 4 microm, 250x4.6 mm, Waters) by binary or ternate gradient programs and UV detection at 254 and 235 nm. The geometric and positional isomers of some unsaturated fatty acids were substantially retained on the C18 columns and were distinct from some saturated fatty acids, endogenous substances in biological samples or background interference. Only slight separation of critical pairs of cis-9 C18:1/cis-11 C18:1 and cis-6 C18:1/trans-11 C18:1 was obtained. A ternate gradient program can be used for complete fractionation of a mixture of conjugated linoleic acid isomers (CLA) from cis-9, cis-12 and trans-9, trans-12 isomers of C18:2. The CLA isomers in the effluent were monitored at 235 nm. The CLA isomers were differentiated from saturated and unsaturated fatty acids using a photodiode array detector. The utility of the method was demonstrated by evaluating the fatty acid composition of duodenal digesta, rapeseed and maize oils.

  2. Hafnium extraction from acidic chloride solutions by Cyanex 923

    Energy Technology Data Exchange (ETDEWEB)

    El-Ammouri, E.; Distin, P.A. [McGill Univ., Montreal (Canada)

    1996-08-01

    Hafnium extraction from hydrochloric acid/lithium chloride solutions into Cyanex 923 in kerosene has been studied. Variables investigated were hydrochloric acid, total chloride and hafnium concentrations in the aqueous phase, and extractant/modifier (isodecanol) levels in the organic phase. Hafnium is considered to load as the tetrachloride complex forming a disolvate with Cyanex 923. Results are compared with equivalent data for zirconium extraction. 14 refs., 7 figs., 2 tabs.

  3. Carboxymethyl-β-cyclodextrin for Chiral Separation of Amino Acids Derivatized with Fluorescene-5-isothiocyanate by Capillary Electrophoresis and Laser-induced Fluorescence Detection

    Institute of Scientific and Technical Information of China (English)

    Yu Yun CHEN; Wei WANG; Wei Ping YANG; Zhu Jun ZHANG

    2004-01-01

    A method using carboxymethyl-β-cyclodextrin(CM-β-CD) as selector for chiral separation of amino acids by capillary electrophoresis and laser-induced fluorescence detection was studied. Resolution was better than that obtained byβ-CD or HP-β-CD.

  4. Corrosão de cerâmicas à base de Si3N4 em soluções aquosas de HCl 0,1 N Corrosion of Si3N4 ceramics in 0.1 N hydrochloric acid solution

    Directory of Open Access Journals (Sweden)

    F. Vernilli Júnior

    1999-06-01

    Full Text Available O comportamento à corrosão de cerâmicas à base de Si3N4 contendo misturas de Y2O3/SiO2 e RE2O3/SiO2 como aditivos nas proporções de 14 e 21% em volume ambos na estequiometria dos dissilicatos Y2Si2O7 e RE2Si2O7, respectivamente, foi estudado em soluções aquosas de HCl 0,1N a 100 °C. A resistência à corrosão foi avaliada pela perda de massa das amostras e análise química das soluções após os testes. As análises por microscopia eletrônica das amostras atacadas revelou que basicamemte a fase vítrea intergranular foi dissolvida pela solução ácida, deixando um esqueleto de grãos de b-Si3N4 entrelaçados.The corrosion resistance of Si3N4 ceramics with 14 and 21 vol.% of Y2O3/SiO2 and RE2O3/SiO2 mixtures as additive, both in the stoichiometry of disilicates Y2 Si2O7 and RE2Si2O7, respectively, has been investigated in 0.1N HCl solutions. Samples were prepared by a two step gas pressure sintering process, under a final N2 pressure of 10 MPa and a maximum temperature of 1850 °C for 30 min. The corrosion resistance was evaluated by the mass change of polished samples and chemical analysis of the solutions after the tests. Analysis by electron microscopy showed that the glassy intergranular phase is dissolved by the acid solution, leaving a skeleton of interlinked b -Si3N4 grains.

  5. Chromatographic separation of cerium(Ⅲ) in L-valine medium using poly[dibenzo-18-crown-6

    Institute of Scientific and Technical Information of China (English)

    SABALE Sandip R; MOHITE Baburao S

    2009-01-01

    A column chromatographic method has been developed for the separation and determination of cerium(Ⅲ) using poly[dibenzo-18-crown-6]. The separation was carried out in L-valine medium. The adsorption of cerium(Ⅲ) was quantitative from 1×10-1 to 1×10-4 mol/L L-valine. Amongst the various eluents, 1.0-8.0 mol/L hydrochloric acid, 1.0-8.0 mol/L hydrobromic acid, 1.0-8.0 mol/L perchloric acid, 1.0-2.0 mol/L sulfuric acid and 4.0-5.0 mol/L acetic acid, were found to be the efficient eluents for cerium(Ⅲ). The capacity of poly[dibenzo-18-crown-6] for cerium(Ⅲ) was (0.428±0.01) mmol/g. The method was applied to the separation of cerium(Ⅲ) from associated elements link uranium(Ⅵ) and thorium(Ⅳ). It was also applied for the determination of cerium(Ⅲ) in geological samples. The method is simple, rapid and selective with good reproducibility (approximately±2% ).

  6. Solid-liquid extraction of Gd(Ⅲ) and separation possibilities of rare earths from phosphoric acid solutions using Tulsion CH-93 and Tulsion CH-90 resins

    Institute of Scientific and Technical Information of China (English)

    S.Radhika; V.Nagaraju; B.Nagaphani Kumar; M.Lakshmi Kantam; B.Ramachandra Reddy

    2012-01-01

    Solid-liquid extraction of gadolinium was investigated from phosphoric acid medium using commercial amino phosphonic acid resin,Tulsion CH-93.The experimental conditions studied included equilibration time,acid concentration,mass of the resin,metal concentration,loading and elution.The percent extraction of Gd(Ⅲ) was studied as a function of phosphoric acid (0.05-3 mol/L) using Tulsion CH-93 resin.The corresponding lgD vs.equilibrium pH plot gave straight line with a slope of 1.8.The percent extraction decreased with acid concentration increasing,conforming ion exchange mechanism.Under observed experimental conditions the loading capacity of Tulsion CH-93 for gadolinium was 10.6 mg/g.Among several eluants screened,the quantitative elution of Gd(Ⅲ) from loaded Tulsion CH-93 was obtained with ammonium oxalate (0.15 mol/L).The extraction behavior of commonly associated metals with gadolinium was studied as a function of phosphoric acid concentration.Tulsion CH-93 resin showed selective extraction towards heavy rare earths (Lu and Yb) which could be separated from other rare earths at 3 mol/L H3PO4,similar to wet phosphoric acid (3-5 mol/L).On the other hand Gd(Ⅲ) and other rare earths were studied with chelating resin Tulsion CH-90.Light rare earths were highly extracted and these could be separated from heavy rare earths and Gd.

  7. (S)-1-(4-Dimethylaminophenylcarbonyl)-3-aminopyrrolidine: a derivatization reagent for enantiomeric separation and sensitive detection of chiral carboxylic acids by LC/ESI-MS/MS.

    Science.gov (United States)

    Ogawa, Shoujiro; Tadokoro, Hiroaki; Sato, Maho; Hanawa, Takehisa; Higashi, Tatsuya

    2013-12-01

    A novel derivatization reagent, (S)-1-(4-dimethylaminophenylcarbonyl)-3-aminopyrrolidine (1-DAPAP), was developed for increasing the detection sensitivity and enantiomeric separation of chiral carboxylic acids by liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS). 1-DAPAP reacted with carboxylic acids at room temperature within 5min in the presence of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The epimerization (racemization) during the derivatization reaction was negligible. The resulting derivatives were highly responsive during the ESI-MS operating in the positive-ion mode and gave a characteristic product ion during the MS/MS, which enabled the sensitive detection using selected reaction monitoring; the detection responses of the 1-DAPAP-derivatives were increased by 10-1100-fold over the intact carboxylic acids and the limits of detection ranged from 0.97 and 5.2fmol on the column. The 1-DAPAP-derivatization was also effective for the enantiomeric separation of chiral carboxylic acids; the resolution values were 1.2-4.3 for the evaluated carboxylic acids. The derivatization procedure was successfully applied to biological sample analyses; the derivatization followed by LC/ESI-MS/MS enabled the separation and detection of trace amounts of ibuprofen and naproxen in human saliva with a simple pretreatment and small sample volume.

  8. Ion-exclusion chromatographic separations of C1-C6 aliphatic carboxylic acids on a sulfonated styrene-divinylbenzene co-polymer resin column with 5-methylhexanoic acid as eluent.

    Science.gov (United States)

    Ohta, Kazutoku; Towata, Atsuya; Ohashi, Masayoshi

    2003-05-16

    The application of C7 aliphatic carboxylic acids (heptanoic, 2-methylhexanoic, 5-methylhexanoic and 2,2-dimethyl-n-valeric acids) as eluents in ion-exclusion chromatography with conductimetric detection for C1-C6 aliphatic carboxylic acids (formic, acetic, propionic, isobutyric, butyric, isovaleric, valeric, isocaproic and caproic acids) was carried out using a highly sulfonated styrene-divinylbenzene co-polymer resin (TSKgel SCX) in the H+ form as a stationary phase. When using 0.05 mM sulfuric acid at pH 4.0 as the eluent, peak shapes of hydrophobic carboxylic acids (isovaleric, valeric, isocaproic and caproic acids) were tailed strongly. In contrast, when using 1 mM these C7 carboxylic acids at pH ca. 4 as the eluents, although system peaks (vacant peaks) corresponding to these C7 carboxylic acids appeared, peak shapes of these hydrophobic acids were improved drastically. Excellent simultaneous separation and relatively high sensitive conductimetric detection for these C1-C6 aliphatic carboxylic acids were achieved in 25 min on the TSKgel SCX column (150 x 6 mm I.D.) using 1 mM 5-methylhexanoic acid at pH 4.0 as the eluent.

  9. Study on separation of chlorobenzene and acetic acid azeotrope by distillation-crystallization hybrid separation process%蒸馏-结晶耦合工艺分离乙酸-氯苯共沸体系的研究

    Institute of Scientific and Technical Information of China (English)

    宋闯

    2015-01-01

    本文主要对蒸馏-结晶耦合工艺分离共沸体系进行研究。以乙酸-氯苯为研究对象,对耦合工艺的原理和实验装置进行研究设计。通过对回流比,结晶终温,降温速率和发汗等工艺条件的考察,得出蒸馏-结晶耦合工艺分离乙酸-氯苯共沸体系的最佳条件,即:最佳回流比为2,结晶终温为-6℃,降温速率为0.2618℃/min.,发汗时间为2.5h。%This paper mainly studies that binary azeotrope system has been separated by the distillation-crystallization hybrid separa-tion process .Taken chlorobenzene and acetic acid for researching objects,the principle of hybrid separation process was studied and the experimental equipment was designed.By studing of the reflux ratio, final crystallization temperatures,the cooling rate and sweating, opti-mum conditions of separating chlorobenzene-acetic acid azeotrope by distillation-crystallization hybrid separation process were determined. The best reflux ratio was 2, the final crystallization temperature was -6℃, the cooling rate was 0.2618℃/min, sweating time was 2.5h.

  10. Simultaneous and selective decarboxylation of L-serine and deamination of L-phenylalanine in an amino acid mixture--a means of separating amino acids for synthesizing biobased chemicals.

    Science.gov (United States)

    Teng, Yinglai; Scott, Elinor L; Witte-van Dijk, Susan C M; Sanders, Johan P M

    2016-01-25

    Amino acids (AAs) obtained from the hydrolysis of biomass-derived proteins are interesting feedstocks for the chemical industry. They can be prepared from the byproduct of biofuel production and agricultural wastes. They are rich in functionalities needed in petrochemicals, providing the opportunity to save energy, reagents, and process steps. However, their separation is required before they can be applied for further applications. Electrodialysis (ED) is a promising separation method, but its efficiency needs to be improved when separating AAs with similar isoelectric points. Thus, specific conversions are required to form product with different charges. Here we studied the enzymatic conversions which can be used as a means to aid the ED separation of neutral AAs. A model mixture containing L-serine, L-phenylalanine and L-methionine was used. The reactions of L-serine decarboxylase and L-phenylalanine ammonia-lyase were employed to specifically convert serine and phenylalanine into ethanolamine and trans-cinnamic acid. At the isoelectric point of methionine (pH 5.74), the charge of ethanolamine and trans-cinnamic acid are +1 and -1, therefore facilitating potential separation into three different streams by electrodialysis. Here the enzyme kinetics, specificity, inhibition and the operational stabilities were studied, showing that both enzymes can be applied simultaneously to aid the ED separation of neutral AAs.

  11. Identification of candidate amino acids involved in the formation of pink-red pigments in onion (Allium cepa L.) juice and separation by HPLC.

    Science.gov (United States)

    Lee, Eun Jin; Yoo, Kil Sun; Patil, Bhimanagouda S

    2010-10-01

    The formation of pink-red pigments ("pinking") by various amino acids was investigated by reacting amino acids with compounds present in onion juice. The unknown pink-red pigments were generated and separated using high-performance liquid chromatography (HPLC) and a diode array detector (DAD) in the range of 200 to 700 nm. To generate pink-red pigments, we developed several reaction systems using garlic alliinase, purified 1-propenyl-L-cysteine sulfoxide (1-PeCSO), onion thiosulfinate, natural onion juice, and 21 free amino acids. The compound 1-PeCSO was a key compound associated with pinking in the presence of both the alliinase and amino acids. Numerous naturally occurring pink-red pigments were detected and separated from pink onion juice using the HPLC-DAD system at 515 nm. Most free amino acids, with the exceptions of histidine, serine, and cysteine, formed various pink-red pigments when reacted with onion thiosulfinate. This observation indicated that onion pinking is caused not by a single pigment, but by many. Furthermore, more than one color compound could be produced from a single amino acid; this explains, in part, why there were many pink-red compound peaks in the chromatogram of discolored natural onion juice. We presumed that the complexity of the pink-red pigments was due to the involvement of more than 21 natural amino acids as well as several derivatives of the color products produced from each amino acid. We observed that the pinking process in onion juice is very similar to that of the greening process in crushed garlic, emphasizing that both thiosulfinate from flavor precursors and free amino acids are absolutely required for the discoloration.

  12. Separation of transition metals on a poly-iminodiacetic acid grafted polymeric resin column with post-column reaction detection utilising a paired emitter-detector diode system.

    Science.gov (United States)

    Barron, Leon; O'Toole, Martina; Diamond, Dermot; Nesterenko, Pavel N; Paull, Brett

    2008-12-05

    The selectivity, retention and separation of transition metals on a short (2 mm x 50 mm) column packed with a poly-iminodiacetic acid functionalised polymer 10 microm resin (Dionex ProPac IMAC-10) are presented. This stationary phase, typically used for the separation of proteins, is composed of long chain poly-iminodiacetic acid groups grafted to a hydrophilic layer surrounding a 10 microm polymeric bead. Through the use of a combination of a multi-step pH and picolinic acid gradient, the separation of magnesium, iron, cobalt, cadmium, zinc, lead and copper was possible, followed by post-column reaction with 4-(2-pyridylazo) resorcinol (PAR) and absorbance detection at 510 nm using a novel and inexpensive optical detector, comprised of two light emitting diodes with one acting as a light source and the other as a detector. Column efficiency for selective transition metals was in excess of N=10,000, with the baseline separation of seven metal cations in <3 min possible under optimised conditions. Detection limits of between 5 and 81 microg/L were possible based upon a 50 microL injection volume.

  13. Separation of small molecular peptides with the same amino acid composition but different sequences by high performance liquid chromatography-electrospray ionization-mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Peptidomics has emerged as a new discipline in recent years. Mass spectrometry (MS) is the most universal and efficient tool for structure identification of proteins and peptides. However,there is a limitation for the identification of peptides with the same amino acid composition but different se-quences because these peptides have identical mass spectra of molecular ions. This paper presents a high performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) method for the separation of small molecular peptides with the same amino acid composition but dif-ferent sequences. Two tripeptides of Gly-Ser-Phe and Gly-Phe-Ser were used as a model sample. The separation behavior has been investigated and the separation conditions have been optimized. Under the optimum conditions,good repeatability was achieved. The developed method could provide a helpful reference for the separation of other peptides with the same amino acid composition but different sequences in the study of proteomics and peptidomics.

  14. Comparison of the Separation Performances of Cinchona Alkaloid-Based Zwitterionic Stationary Phases in the Enantioseparation of β2- and β3-Amino Acids

    Directory of Open Access Journals (Sweden)

    István Ilisz

    2014-12-01

    Full Text Available The enantiomers of twelve unusual β2- and β3-homoamino acids containing the same side-chains were separated on chiral stationary phases containing a quinine- or quinidine-based zwitterionic ion-exchanger as chiral selector. The effects of the mobile phase composition, the nature and concentration of the acid and base additives and temperature on the separations were investigated. The changes in standard enthalpy, ∆(∆H°, entropy, ∆(∆S°, and free energy, ∆(∆G°, were calculated from the linear van’t Hoff plots derived from the ln α vs. 1/T curves in the studied temperature range (10–50 °C. The values of the thermodynamic parameters depended on the nature of the selectors, the structures of the analytes, and the positions of the substituents on the analytes. A comparison of the zwitterionic stationary phases revealed that the quinidine-based ZWIX(−™ column exhibited much better selectivity for both β2- and β3-amino acids than the quinine-based ZWIX(+™ column, and the separation performances of both the ZWIX(+™ and ZWIX(−™ columns were better for β2-amino acids. The elution sequence was determined in some cases and was observed to be R < S and S < R on the ZWIX(+™ and ZWIX(−™ columns, respectively.

  15. Effects of pH mismatch between the two dimensions of reversed-phase×reversed-phase two-dimensional separations on second dimension separation quality for ionogenic compounds-I. Carboxylic acids.

    Science.gov (United States)

    Stoll, Dwight R; O'Neill, Kelly; Harmes, David C

    2015-02-27

    Two persistent impediments to wider adoption of two-dimensional liquid chromatography (2D-LC) are the perceptions that 2D methods are generally less sensitive than 1D ones, and that coupling of certain separation modes in a 2D system is difficult because of the negative impact of the effluent of the first separation on the second separation. In this work we address these problems in the specific case where reversed-phase separations are used in both dimensions of a 2D-LC system, but the pH is varied such that the ionization state of carboxylic acid analytes is different (i.e., neutral or negatively charged, in eluents buffered at pH 2 or 7) in the two columns. We first demonstrate that the effect of first dimension ((1)D) effluent on the performance of second dimension ((2)D) separation of ionogenic solutes is much more serious than it is for neutral compounds where the pH of the eluent does not play a role in retention. We have systematically varied the properties of the sample solution injected into the (2)D column (i.e., the (1)D effluent), as well as the (2)D eluent, with the goal of establishing guidelines for conditions that yield acceptable (2)D performance. We find that the organic solvent content of the (1)D effluent and (2)D eluent is not as important as the buffer concentrations in these two solutions, and that the greater the ratio of buffer concentration in the (1)D effluent relative to the (2)D eluent, the smaller the volume one can inject into the (2)D column before dramatic peak splitting occurs. We have then used the information from these simple experiments to guide both 1D experiments that mimic the (2)D separation, and actual 2D separations, to demonstrate that online adjustment of the properties of the (1)D effluent by dilution with a buffered solvent prior to injection into the (2)D column is a very effective solution to the pH mismatch problem. We find that when the buffer capacity of the diluent is high enough to effectively titrate the (1)D

  16. Scalable enantioseparation of amino acid derivatives using continuous liquid-liquid extraction in a cascade of centrifugal contactor separators

    NARCIS (Netherlands)

    Schuur, Boelo; Hallett, Andrew J.; Winkelman, Jozef G.M.; Vries, Johannes G. de; Heeres, Hero J.

    2009-01-01

    Using a cascade of six centrifugal contactor separators in a countercurrent liquid-liquid extraction mode allowed the separation of one of the enantiomers of 3,5-dinitrobenzoyl-leucine in 55% yield and 98% ee using a catalytic amount of a chiral host compound based on a cinchona alkaloid, This metho

  17. Fabrication of Silica Nanospheres Coated Membranes: towards the Effective Separation of Oil-in-Water Emulsion in Extremely Acidic and Concentrated Salty Environments.

    Science.gov (United States)

    Chen, Yuning; Liu, Na; Cao, Yingze; Lin, Xin; Xu, Liangxin; Zhang, Weifeng; Wei, Yen; Feng, Lin

    2016-09-06

    A superhydrophilic and underwater superoleophobic surface is fabricated by simply coating silica nanospheres onto a glass fiber membrane through a sol-gel process. Such membrane has a complex framework with micro and nano structures covering and presents a high efficiency (more than 98%) of oil-in-water emulsion separation under harsh environments including strong acidic and concentrated salty conditions. This membrane also possesses outstanding stability since no obvious decline in efficiency is observed after different kinds of oil-in-water emulsions separation, which provides it candidate for comprehensive applicability.

  18. Fabrication of Silica Nanospheres Coated Membranes: towards the Effective Separation of Oil-in-Water Emulsion in Extremely Acidic and Concentrated Salty Environments

    Science.gov (United States)

    Chen, Yuning; Liu, Na; Cao, Yingze; Lin, Xin; Xu, Liangxin; Zhang, Weifeng; Wei, Yen; Feng, Lin

    2016-09-01

    A superhydrophilic and underwater superoleophobic surface is fabricated by simply coating silica nanospheres onto a glass fiber membrane through a sol-gel process. Such membrane has a complex framework with micro and nano structures covering and presents a high efficiency (more than 98%) of oil-in-water emulsion separation under harsh environments including strong acidic and concentrated salty conditions. This membrane also possesses outstanding stability since no obvious decline in efficiency is observed after different kinds of oil-in-water emulsions separation, which provides it candidate for comprehensive applicability.

  19. A new chiral derivatizing agent for the HPLC separation of α-amino acids on a standard reverse-phase column.

    Science.gov (United States)

    Kotthaus, A F; Altenbach, H-J

    2011-02-01

    A new chiral derivatizing agent for α-amino acids is described which leads to diastereomers that can be separated by reverse-phase HPLC with direct detection by a diode array detector. The main advantage of the presented procedure is the fact that an excess of the derivatizing reagent can be employed as the product exhibits an absorption maximum at 360 nm, while the reagent has its absorption maximum at 260 nm. Therefore, it is possible to suppress the reagent signal by a detection wavelength of 400 nm leading to an easy and general method for the enantioseparation of a mixture of DL-amino acids and the determination of the enantiomeric purity of α-amino acid as exemplified by 16 different α-amino acids.

  20. Separative recovery with lime of phosphate and fluoride from an acidic effluent containing H3PO4, HF and/or H2SiF6.

    Science.gov (United States)

    Gouider, Mbarka; Feki, Mongi; Sayadi, Sami

    2009-10-30

    Fluoride content and flow-rate of fertilizer plant wastewater from phosphoric acid and/or triple superphosphate (TSP) production lead to the discharge of several thousand tons of fluoride (F(-)) per year and even more for phosphate (PO4(3-)). Since sustainability is an important environmental concern, the removal methods should allow phosphorus and fluoride to be recycled as a sustainable products for use as raw materials either in agricultural or industrial applications. In the present work, separative recovery with lime of these two target species was investigated. A preliminary speciation study, carried out on the crude effluent, showed that two forms of fluoride: HF and H2SiF6 are present in a highly acidic medium (pH approximately 2). Evidence that fluoride is present under both free (HF) and combined (H2SiF6) forms, in the phosphate-containing effluent, was provided by comparing potentiometric titration curves of a crude wastewater sample and synthetic acid mixtures containing H3PO4, HF and H2SiF6. In a second step synthetic effluent containing mixtures of the following acids: HF, H2SiF6 and H3PO4, were treated with lime. The behaviour of these compounds under lime treatment was analysed. The data showed that fluoride has a beneficial effect on phosphate removal. Moreover, by acting on the precipitation pH, a "selective" recovery of fluoride and phosphate ions was possible either from phosphoric acid/hydrofluoric acid or phosphoric acid/hexafluorosilicic acid mixtures. Indeed, the first stage of the separative recovery, led to a fluoride removal efficiency of 97-98% from phosphoric acid/hydrofluoric acid mixture. It was of 93-95% from phosphoric acid/hexafluorosilicic acid mixture. During the second stage, the phosphate precipitation reached 99.8% from both acidic mixtures whereas it did not exceed 82% from a solution containing H3PO4 alone. The XRD and IR analyses showed that during lime treatment, a H2SiF6 hydrolysis occurred, instead of CaSiF6 solid

  1. Method for determination of uranium isotopes in environmental samples by liquid-liquid extraction with triisooctylamine/xylene in hydrochloric media and alpha spectrometry.

    Science.gov (United States)

    Popov, L

    2012-10-01

    Alternative method for determination of uranium isotopes in various environmental samples is presented. The method is based on total decomposition of the solid materials and preconcentration of liquid samples. The separation of uranium from interfering radionuclides and stable matrix elements is attained by liquid-liquid extraction with triisooctylamine/xylene in hydrochloric media. After the additional removal of stable iron by extraction with diisopropyl ether, purified uranium is electrodeposited on stainless steel disks and measured by alpha spectrometry. The analytical method has been successfully applied to the determination of uranium isotopes in water and bottom sediments from the rivers Danube, Ogosta and Tzibritza in Northwestern Bulgaria. The analytical quality was checked by analyzing reference materials with different matrices.

  2. Determination of traces of Pt and Rh in soil and quartz samples contaminated by automobile exhaust after an ion-exchange matrix separation.

    Science.gov (United States)

    Kowalska, Joanna; Kińska, Katarzyna; Pałdyna, Joanna; Czyżewska, Monika; Boder, Kamila; Krasnodębska-Ostręga, Beata

    2014-09-01

    Monitoring of PGEs content in the natural samples is a crucial point in the environment science since catalytic car converters have been introduced. In the presented paper application of a very sensitive voltammetric method for determination of traces of Pt and Rh in the environmental samples contaminated by automobile exhausts is discussed. Voltammetric measurements were carried out in the supporting electrolyte containing formaldehyde and semicarbazide. PGEs were separated from the digested solutions of soils or quartz samples, collected from monitoring plots-by applying an ion-exchange resin Cellex-T. Pt was very effectively separated from the matrix approaching nearly 100% recovery after its elution by hydrochloric acid. Moreover the conditions of soil and quartz samples digestion were discussed. To validate the obtained result an independent analytical method-ICP MS was applied and analysis of certified reference material road dust 723-was completed.

  3. Selective separation of succinic acid from simulated fermentation broth by nanofiltration%纳滤选择性分离丁二酸模拟发酵液

    Institute of Scientific and Technical Information of China (English)

    吴昊; 姜岷; 韦萍; 高超; 杨高; 雷丹

    2011-01-01

    生物法制备的丁二酸发酵液中含有残留的底物(葡萄糖)、甲酸、乙酸及二价无机离子(Mg2+、SO42-)等杂质,不利于分离纯化.采用截留相对分子质量为160的纳滤膜LNG-NF-016对丁二酸模拟发酵液进行分离,考察了pH、操作压力、MgSO4浓度、丁二酸浓度、葡萄糖浓度、料液体积流量、操作温度等因素对纳滤分离性能的影响.纳滤分离的选择性由丁二酸的解离状态决定:模拟发酵液调节至pH3.0,丁二酸未解离,可将其与葡萄糖、MgSO4分离,丁二酸的透过率达98%,葡萄糖、MgSO4的截留率均>85%.随后将透过液调节至pH 6.0,丁二酸形成二价阴离子,可将其与单价的甲酸盐、乙酸盐分离,丁二酸截留率达90%,丁二酸被浓缩至121 g/L,而膜截留液中的甲酸、乙酸浓度均<5 g/L.同一型号纳滤膜可实现模拟发酵液中丁二酸与副产一元有机酸、底物及多价无机离子的选择性分离.%Many impurities existed in succinic acid fermentation broth, such as by-product organic acids (formic acid, acetic acid), residual substrate (glucose) and divalent ion (Mg2+, SO42-) , which was unfavorable to purification. Separation of succinic acid from simulated fermentation broth by nanofiltration membrane LNG-NF-016(MWCO 160) was studied, For this purpose, the effect of operating parameters such as pH in the feed solution, operation pressure, MgSO4 concentration, succinic acid concentration, glucose concentration, cross-flow rate and operation temperature on nanofiltration was investigated using an experimental design technique. The selectivity of nanofiltration depended on the degree of dissociation of succinic acid. At pH about 3. 0, undissociated succinic acid could be separated from glucose, and MgSCX with succinic acid permeation of 98% and glucose and MgSCX with rejection more than 85%. The divalent succinate could be separated from acetate and formate at pH about 6. 0, succinic acid rejection of

  4. 46 CFR 151.50-76 - Hydrochloric acid, spent (NTE 15%).

    Science.gov (United States)

    2010-10-01

    ... two fitted flame screens as described in § 151.03-25. Neither a shut-off valve nor a frangible disk... gaskets. (c) Where special arrangements are approved by the Commandant (CG-522) to permit a pump...

  5. Anticoccidial activity of hydrochloric acid (HCl against Eimeria tenella in broiler chickens

    Directory of Open Access Journals (Sweden)

    Rao Z Abbas

    2011-05-01

    Full Text Available The present study was planned to evaluate the anticoccidial activity of the different concentrations of the HCl against Eimeria tenella infection in broiler chickens in comparison with the amprolium anticoccidial. For this purpose, a total of 198 chicks were placed 11 per pen with three pens per treatment. The different concentrations of HCl (1000ppm, 2000ppm and 3000ppm and amproilum (at the dose rate of 125ppm were given to the experimental groups in drinking water from 10 to 19th days of age. One group was kept as infected non medicated control and one as non infected non medicated control. At the 12th day of age, all the groups were inoculated orally with 75,000 sporulated oocysts except non infected non medicated control. Anticoccidial activity was evaluated on the basis of performance (weight gain, feed conversion ratio and pathogenic (oocyst score, lesion score and mortality %age parameters. Among HCl medicated groups, the maximum anticoccidial effect was seen in the group medicated with 1000ppm HCl followed by 2000ppm and 3000ppm HCl medicated groups. Amprolium and 1000ppm HCl were almost equivalent in suppressing the negative performance and pathogenic effects associated with coccidiosis (Eimeria tenella challenge. In summary, the lower doses of HCl have the potential to be used as alternative to chemotherapeutic drugs for Eimeria tenella control. It is therefore suggested that further studies should be carried out to determine the possible minimum safe levels of HCl with least toxic effects to be used as anticoccidial.

  6. Inhibition of Mild Steel Corrosion in Hydrochloric Acid Solution by New Coumarin

    Directory of Open Access Journals (Sweden)

    Abdul Amir H. Kadhum

    2014-06-01

    Full Text Available A new coumarin derivative, N,N′-((2E,2′E-2,2′-(1,4-phenylenebis (methanylylidenebis(hydrazinecarbonothioylbis(2-oxo-2H-chromene-3-carboxamide PMBH, was synthesized and its chemical structure was elucidated and confirmed using spectroscopic techniques (Infrared spectroscopy IR, Proton nuclear  magnetic resonance, 1H-NMR and carbon-13 nuclear magnetic resonance 13C-NMR. The corrosion inhibition effect of PMBH on mild steel in 1.0 M HCl was investigated using corrosion potential (ECORR, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS, and electrochemical frequency modulation (EFM measurements. The obtained results indicated that PMBH has promising inhibitive effects on the corrosion of mild steel in 1.0 M HCl across all of the conditions examined. Scanning electron microscopy (SEM was used to investigate the morphology of the mild steel before and after immersion in 1.0 M HCl solution containing 0.5 mM of PMBH. Surface analysis revealed improvement of corrosion resistance in presence of PMBH.

  7. Punica granatum leave extract as green corrosion inhibitor for mild steel in Hydrochloric acid

    OpenAIRE

    Abboud Y.; Chagraoui A.; Tanane O.; El Bouari A.; Hannache H.

    2013-01-01

    Leave of Punica granatum extract (LPGE) as green inhibitor for the corrosion of mild steel in 1M HCl solution was studied using weight-loss and potentiodynamic polarization measurements. The results obtained revealed that LPGE has fairly good inhibiting properties for mild steel corrosion in 1M HCl solution, with efficiency of around 94 % at a concentration of 1 g/l. The inhibition was of a mixed anodic–cathodic nature. The film which is formed over the metal surface was analysed by FT-IR spe...

  8. Inhibition of copper corrosion in aerated hydrochloric acid solution by heterocyclic compounds containing a mercapto group

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Daquan; Gao Lixin; Zhou Guoding

    2004-12-01

    Inhibition of copper corrosion by benzotriazole (BTA), 2-mercapto benzoxazole (MBO) and 2-mercapto benzimidazole (MBI) in 0.5 mol L{sup -1} HCl was investigated by weight-loss measurements, potentiodynamic polarization curves and electrochemical impedance spectroscopy. MBI was shown to be the most effective inhibitor among those tested. Potentiodynamic polarization results revealed that the three compounds acted as anodic inhibitors, particularly MBI strongly suppressed anodic current densities. Molecular structure parameters of BTA, MBO and MBI were obtained by using an MM2 forcefield program and PPP-SCF quantum chemical calculation. It was found that MBI has higher levels of HOMO and LUMO energy and the larger {pi}-electron density.

  9. The reduction of l-cystine in hydrochloric acid at mercury drop electrodes

    OpenAIRE

    Ralph, T.R.; Hitchman, M.L.; Millington, J.P.; Walsh, F.C.

    2006-01-01

    The reduction of L-cystine in 0.1 mol dm3 HCl at 298 K has been studied at mercury electrodes. Dropping mercury electrode (DME), static mercury drop electrode (SMDE) and hanging mercury drop electrode (HMDE) modes were used with normal, sampled d.c. and differential pulse polarographic detection. The charge transfer kinetics for the irreversible reduction of L-cystine were complicated by reactant and product adsorption, by the formation of cysteinate complexes between mercury and the product ...

  10. Kinetics of Rare Earth Extraction from Baotou Bastnaesite in Hydrochloric Acid and Aluminum Chloride

    Science.gov (United States)

    Zhang, Xiao-Wei; Li, Mei; Liu, Zhao-Gang; Hu, Yan-Hong; Wang, Mi-Tang

    2017-06-01

    In this paper, the leaching kinetics of rare earth from Baotou bastnaesite in a HCl-AlCl3 solution was investigated. In addition, the effects of the HCl and AlCl3 concentrations, liquid to solid ratio, stirring speed, temperature, and time spent on the rare earth extraction were determined. The results indicated that the extraction was nearly independent of the stirring speed when it did not exceed 300 rpm, and the rate of leaching increased with increases in the HCl and AlCl3 concentrations, liquid to solid ratio, temperature, and time. The optimum dissolution conditions were determined under five experimental conditions. After leaching occurred, the progressive dissolution of the bastnaesite phase could be determined. The leaching kinetics was analyzed with a new variant of the shrinking core model in which both the interfacial transfer and diffusion across the product layer affected the rare earth extraction. The apparent activation energy was 35.57 kJ/mol, and the Arrhenius constant was 341.58 min-1. An empirical equation was derived to describe the extraction process of rare earth minerals.

  11. Electrochemical Study on Newly Synthesized Chlorocurcumin as an Inhibitor for Mild Steel Corrosion in Hydrochloric Acid

    Directory of Open Access Journals (Sweden)

    Ahmed A. Al-Amiery

    2013-11-01

    Full Text Available A new curcumin derivative, i.e., (1E,4Z,6E-5-chloro-1,7-bis(4-hydroxy-3-methoxyphenylhepta-1,4,6-trien-3-one (chlorocurcumin, was prepared starting with the natural compound curcumin. The newly synthesized compound was characterized by elemental analysis and spectral studies (IR, 1H-NMR and 13C-NMR. The corrosion inhibition of mild steel in 1 M HCl by chlorocurcumin has been studied using potentiodynamic polarization (PDP measurements and electrochemical impedance spectroscopy (EIS. The inhibition efficiency increases with the concentration of the inhibitor but decreases with increases in temperature. The potentiodynamic polarization reveals that chlorocurcumin is a mixed-type inhibitor. The kinetic parameters for mild steel corrosion were determined and discussed.

  12. A new online exhaust gas monitoring system in hydrochloric acid regeneration of cold rolling mills.

    Science.gov (United States)

    Tuo, Long; Zheng, Xiang; Chen, Xiong

    2015-07-07

    Measuring the content of hydrogen chloride (HCl) in exhaust gas used to take time and energy. In this paper, we introduce a new online monitoring system which can output real-time data to the monitoring center. The system samples and cools exhaust gas, and after a series of processing, it will be analyzed by a specific instrument. The core part of this system is remote terminal unit (RTU) which is designed on Cortex-A8 embedded architecture. RTU runs a scaled-down version of Linux which is a good choice of OS for embedded applications. It controls the whole processes, does data acquisition and data analysis, and communicates with monitoring center through Ethernet. In addition, through a software developed for windows, the monitoring process can be remotely controlled. The new system is quite beneficial for steel industry to do environment monitoring.

  13. Corrosion Behavior of Ni3(Si,Ti in Hydrochloric Acid Solution

    Directory of Open Access Journals (Sweden)

    Gadang Priyotomo

    2013-06-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} The corrosion behaviour of the intermetallic compounds Ni3(Si,Ti (L12: single phase, has been investigated using an immersion test, electrochemical method, scanning electron microscope in 0.5 kmol/m3 HCl at 303 K. In addition, the corrosion behaviour of austenitic stainless steel type 304 and C276 was studied under the same experimental conditions as references. It was found that the intergranular attack was observed for Ni3(Si,Ti in the immersion test. From the immersion test and polarization curves, Ni3(Si,Ti had the moderate corrosion resistance, while the corrosion resistances of C 276 and type 304 were the highest and the lowest. Ni3(Si,Ti and type 304 were difficult to form a stable passive film, but not for C276. A further experiment must be conducted to clarify the stability of film for Ni3(Si,Ti in detail.

  14. Corrosion inhibition of mild steel in hydrochloric acid solution by some double Schiff bases

    Energy Technology Data Exchange (ETDEWEB)

    Soltani, N. [Payame Noor University (PNU), Shahin Shahr Branch, Isfahan (Iran, Islamic Republic of)], E-mail: N.Soltani@kashanu.ac.ir; Behpour, M.; Ghoreishi, S.M.; Naeimi, H. [Department of Chemistry, Faculty of Science, University of Kashan, Kashan (Iran, Islamic Republic of)

    2010-04-15

    The inhibition effect of four double Schiff bases on the corrosion of mild steel in 2 M HCl has been studied by polarization, electrochemical impedance spectroscopy (EIS) and weight loss measurements. The inhibitors were adsorbed on the steel surface according to the Langmuir adsorption isotherm model. From the adsorption isotherm, some thermodynamic data for the adsorption process were calculated and discussed. Kinetic parameters activation such as E{sub a}, {delta}H*, {delta}S* were evaluated from the effect of temperature on corrosion and inhibition processes. Quantum chemical calculations have been performed and several quantum chemical indices were calculated and correlated with the corresponding inhibition efficiencies.

  15. Interactions of some Schiff base compounds with mild steel surface in hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Bayol, Emel [Department of Chemistry, Faculty of Science and Art, Nigde University, Nigde 51200 (Turkey); Guerten, Tijen [Department of Chemistry, Faculty of Science and Art, Cukurova University, Adana 01330 (Turkey); Guerten, A. Ali [Department of Chemistry, Faculty of Science and Art, Nigde University, Nigde 51200 (Turkey)], E-mail: agurten@nigde.edu.tr; Erbil, Mehmet [Department of Chemistry, Faculty of Science and Art, Cukurova University, Adana 01330 (Turkey)

    2008-12-01

    The inhibition effect of the Schiff bases N,N'-bis(salicylidene)-1,2-ethylenediamine (Salen), N,N'-bis(5-methoxysalicylidene)-1,2-ethylenediamine (MeO-Salen) and N,N'-bis(5-nitrosalicylidene)-1,2-ethylenediamine (NO{sub 2}-Salen) on the corrosion of the mild steel in 1.0 M HCl has been studied by electrochemical impedance spectroscopy (EIS), linear polarisation resistance (LPR) and Tafel polarisation measurements. Maximum inhibition for MeO-Salen was obtained. Results showed that the inhibition efficiency have increased when the concentration of the Schiff bases have increased. Polarisation curves revealed that the Schiff bases acted as anodic inhibitors. The surface adsorption of the Schiff bases has lead to a decrease in the double layer capacitance and to an increase in polarisation resistance. The inhibitor performance depended strongly on the type of functional groups on benzene ring. The adsorption process is spontaneous one and follows Langmuir adsorption isotherm model. Scanning electron microscopy (SEM) has been applied to identify the surface morphology of the mild steel both in the absence and presence of the Schiff base molecules.

  16. Dynamics of the separation of amino acid and mineral salt in the stationary dialysis of solutions with an MK-40 profiled sulfo group cation exchange membrane

    Science.gov (United States)

    Vasil'eva, V. I.; Vorob'eva, E. A.

    2012-11-01

    The conjugated diffusion transport of amino acid and mineral salt through a profiled sulfo group cation exchange membrane that simulates the extraction of amino acid from wash waters of microbiological production containing mineral components not used in synthesis is studied. The competitive nature of the conjugation of flows resulting in a decrease in the rate of the mass transfer of components and their separation factor is established from a comparative analysis of experimental data on the diffusion transfer of phenylalanine and sodium chloride in the form of hydrogen from individual and mixed solutions through a profiled sulfo group cation exchange membrane. The range of concentrations and the ratio of components in solution corresponding to the effective separation of phenylalanine and sodium chloride are determined.

  17. Electrodialytic separation of Cu(II) and As(V) in acidic electrolytes; Separacion electrodialitica de Cu(II) y As(V) en electrolitos acidos

    Energy Technology Data Exchange (ETDEWEB)

    Ibanez, J. P.; Ipinza, J.; Cifuentes, L.

    2007-07-01

    The separation of copper and arsenic from acidic electrolytes by electrodialysis was investigated at room temperature. the effect of current density and pH was studied in a batch cell during 3 hours. The kinetic parameters showed that Cu(II) transport rate was 0.75 mol/m''2/h and the As(V) transport rate was 0.002 mol/m''2/h. An efficient separation between Cu(II) and As(V) was achieved; Generating a concentrated solution of copper with no arsenic, which was obtained independently of the electrolyte acidity and current density used. The effect of the arsenic speciation with pH is discussed as well. (Author) 23 refs.

  18. Fabrication of Silica Nanospheres Coated Membranes: towards the Effective Separation of Oil-in-Water Emulsion in Extremely Acidic and Concentrated Salty Environments

    OpenAIRE

    Yuning Chen; Na Liu; Yingze Cao; Xin Lin; Liangxin Xu; Weifeng Zhang; Yen Wei; Lin Feng

    2016-01-01

    A superhydrophilic and underwater superoleophobic surface is fabricated by simply coating silica nanospheres onto a glass fiber membrane through a sol-gel process. Such membrane has a complex framework with micro and nano structures covering and presents a high efficiency (more than 98%) of oil-in-water emulsion separation under harsh environments including strong acidic and concentrated salty conditions. This membrane also possesses outstanding stability since no obvious decline in efficienc...

  19. Performance and techno-economic assessment of several solid-liquid separation technologies for processing dilute-acid pretreated corn stover.

    Science.gov (United States)

    Sievers, David A; Tao, Ling; Schell, Daniel J

    2014-09-01

    Solid-liquid separation of pretreated lignocellulosic biomass slurries is a critical unit operation employed in several different processes for production of fuels and chemicals. An effective separation process achieves good recovery of solute (sugars) and efficient dewatering of the biomass slurry. Dilute acid pretreated corn stover slurries were subjected to pressure and vacuum filtration and basket centrifugation to evaluate the technical and economic merits of these technologies. Experimental performance results were used to perform detailed process simulations and economic analysis using a 2000 tonne/day biorefinery model to determine differences between the various filtration methods and their process settings. The filtration processes were able to successfully separate pretreated slurries into liquor and solid fractions with estimated sugar recoveries of at least 95% using a cake washing process. A continuous vacuum belt filter produced the most favorable process economics.

  20. Concentration Dependent Influence of Lipopolysaccharides on Separation of Hoof Explants and Supernatant Lactic Acid Concentration in an Ex Vivo/In Vitro Laminitis Model.

    Science.gov (United States)

    Reisinger, Nicole; Schaumberger, Simone; Nagl, Veronika; Hessenberger, Sabine; Schatzmayr, Gerd

    2015-01-01

    Laminitis is one of the most common diseases in horses. It is not only painful for the animal, but also has a significant financial impact on the equine industry. This multifactorial disease affects the connective tissue of the hoof. However, the pathogenesis of laminitis is still not fully understood. Endotoxins, also known as lipopolysaccharides (LPS), and bacterial exotoxins seem to play an important role during the development of laminitis. The aim of our study was to investigate the effect of increasing LPS concentrations (0, 2.5, 5, 10, and 100 μg/mL) on cell viability of isolated epidermal and dermal hoof cells as well as on the tissue integrity of hoof explants. Furthermore, glucose, acetic acid, lactic acid, and propionic acid concentrations in explant supernatants were measured to evaluate the energy metabolism in the hoof tissue. LPS did not exhibit cytotoxic effects on epidermal or dermal cells. Force required to separate LPS treated hoof explants decreased in a concentration dependent manner. Specifically, explants incubated with 10 and 100 μg/mL needed significantly less force to separate compared to control explants. Lactic acid concentrations were significantly decreased in explants incubated with 5, 10, or 100 μg/mL LPS, while glucose, acetic acid and propionic acid concentrations were unaffected by LPS treatment. Our study indicates that LPS has no cytotoxic effect on epidermal and dermal cells isolated from hoof tissue, but impairs integrity of hoof explants. In addition, LPS led to an alteration of the lactic acid production in the lamellar tissue. Since our data highlight that LPS can affect the integrity of the equine hoof tissue in vitro, endotoxins should be further explored for their contribution to facilitate the development of laminitis.

  1. Concentration Dependent Influence of Lipopolysaccharides on Separation of Hoof Explants and Supernatant Lactic Acid Concentration in an Ex Vivo/In Vitro Laminitis Model.

    Directory of Open Access Journals (Sweden)

    Nicole Reisinger

    Full Text Available Laminitis is one of the most common diseases in horses. It is not only painful for the animal, but also has a significant financial impact on the equine industry. This multifactorial disease affects the connective tissue of the hoof. However, the pathogenesis of laminitis is still not fully understood. Endotoxins, also known as lipopolysaccharides (LPS, and bacterial exotoxins seem to play an important role during the development of laminitis. The aim of our study was to investigate the effect of increasing LPS concentrations (0, 2.5, 5, 10, and 100 μg/mL on cell viability of isolated epidermal and dermal hoof cells as well as on the tissue integrity of hoof explants. Furthermore, glucose, acetic acid, lactic acid, and propionic acid concentrations in explant supernatants were measured to evaluate the energy metabolism in the hoof tissue. LPS did not exhibit cytotoxic effects on epidermal or dermal cells. Force required to separate LPS treated hoof explants decreased in a concentration dependent manner. Specifically, explants incubated with 10 and 100 μg/mL needed significantly less force to separate compared to control explants. Lactic acid concentrations were significantly decreased in explants incubated with 5, 10, or 100 μg/mL LPS, while glucose, acetic acid and propionic acid concentrations were unaffected by LPS treatment. Our study indicates that LPS has no cytotoxic effect on epidermal and dermal cells isolated from hoof tissue, but impairs integrity of hoof explants. In addition, LPS led to an alteration of the lactic acid production in the lamellar tissue. Since our data highlight that LPS can affect the integrity of the equine hoof tissue in vitro, endotoxins should be further explored for their contribution to facilitate the development of laminitis.

  2. The roles of xylan and lignin in oxalic acid pretreated corncob during separate enzymatic hydrolysis and ethanol fermentation

    Science.gov (United States)

    Jae-Won Lee; Rita C.L.B. Rodrigues; Hyun Joo Kim; In-Gyu Choi; Thomas W. Jeffries

    2010-01-01

    High yields of hemicellulosic and cellulosic sugars are critical in obtaining economical conversion of agricultural residues to ethanol. To optimize pretreatment conditions, we evaluated oxalic acid loading rates, treatment temperatures and times in a 23 full factorial design. Response-surface analysis revealed an optimal oxalic acid pretreatment...

  3. The separation of niobium from tantalum by extraction with tributyl phosphate and determination of niobium as the thiocyanate complex.

    Science.gov (United States)

    De, A K; Sen, A K

    1966-06-01

    A method is proposed for the rapid extraction and separation of microgram amounts of niobium(V). The niobium is extracted quantitatively by 100 % TBP from 7.7-9.4 M (initial) hydrochloric acid and determined spectrophotometrically as the thiocyanate in TBP-acetophenone solution. Beer's Law is obeyed at 430 mmu over the range 0.8-9.0 mug ml . The system is stable for 72 hr. Caesium, calcium, strontium, barium, aluminium, titanium(IV), zirconium(IV), cerium(TV), fluoride, thiocyanate and oxalate do not interfere (1 mg). Niobium(V) can be determined in a niobium(V)-tantalum(V) mixture. The method is accurate and reproducible to within +/-2%.

  4. Hydrolysis-acidogenesis of food waste in solid-liquid-separating continuous stirred tank reactor (SLS-CSTR) for volatile organic acid production.

    Science.gov (United States)

    Karthikeyan, Obulisamy Parthiba; Selvam, Ammaiyappan; Wong, Jonathan W C

    2016-01-01

    The use of conventional continuous stirred tank reactor (CSTR) can affect the methane (CH4) recovery in a two-stage anaerobic digestion of food waste (FW) due to carbon short circuiting in the hydrolysis-acidogenesis (Hy-Aci) stage. In this research, we have designed and tested a solid-liquid-separating CSTR (SLS-CSTR) for effective Hy-Aci of FW. The working conditions were pH 6 and 9 (SLS-CSTR-1 and -2, respectively); temperature-37°C; agitation-300rpm; and organic loading rate (OLR)-2gVSL(-1)day(-1). The volatile fatty acids (VFA), enzyme activities and bacterial population (by qPCR) were determined as test parameters. Results showed that the Hy-Aci of FW at pH 9 produced ∼35% excess VFA as compared to that at pH 6, with acetic and butyric acids as major precursors, which correlated with the high enzyme activities and low lactic acid bacteria. The design provided efficient solid-liquid separation there by improved the organic acid yields from FW.

  5. Rapid chiral separation of atenolol, metoprolol, propranolol and the zwitterionic metoprolol acid using supercritical fluid chromatography-tandem mass spectrometry - Application to wetland microcosms.

    Science.gov (United States)

    Svan, Alfred; Hedeland, Mikael; Arvidsson, Torbjörn; Jasper, Justin T; Sedlak, David L; Pettersson, Curt E

    2015-08-28

    A method for enantiomeric separation of the three β-blocking agents atenolol, metoprolol, propranolol and the zwitterionic metoprolol acid, a major metabolite of both metoprolol and in environmental matrices also atenolol, has been developed. By use of supercritical fluid chromatography and the polysaccharide-based Chiralpak(®) IB-3, all four compounds were simultaneously enantiomerically separated (Rs>1.5) within 8min. Detection was performed using tandem mass spectrometry, and to avoid isobaric interference between the co-eluting metoprolol and metoprolol acid, the achiral column Acquity(®) UPC(2) BEH 2-EP was attached ahead of to the chiral column. Carbon dioxide with 18% methanol containing 0.5% (v/v) of the additives trifluoroacetic acid and ammonia in a 2:1 molar ratio were used as mobile phase. A post column make-up flow (0.3mL/min) of methanol containing 0.1% (v/v) formic acid was used to enhance the positive electrospray ionization. Detection was carried out using a triple quadrupole mass spectrometer operating in the selected reaction monitoring mode, using one transition per analyte and internal standard. The method was successfully applied for monitoring the enantiomeric fraction change over time in a laboratory scale wetland degradation study. It showed good precision, recovery, sensitivity and low effect of the sample matrix.

  6. Methods development for separation of inorganic anions, organic acids and bases, and neutral organic compounds by ion chromatography and capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jie [Iowa State Univ., Ames, IA (United States)

    1999-04-01

    A novel anion-exchange resin containing three amine groups was prepared by reaction of a chloromethylated polystyrene-divinylbenzene (PS-DVB) resin with diethylenetriamine. After being protonated by contact with an aqueous acid, this resin can be used for ion chromatographic separation of anions. The charge on the resins can be varied from +1 to +3 by changing the mobile phase pH. The selectivity of the new ion exchangers for various inorganic anions was quite different from that of conventional anion exchangers. The performance of this new anion exchanger was studied by changing the pH and the concentration of the eluent, and several different eluents were used with some common anions as testing analytes. Conductivity detection and UV-visible detection were applied to detect the anions after separation. The new resin can also be used for HPLC separation of neutral organic compounds. Alkylphenols and alkylbenzenes were separated with this new polymeric resin, and excellent separations were obtained under simple conditions. This report contains Chapter 1: General introduction and Chapter 6: General conclusions.

  7. Performance of Different Acids on Sandstone Formations

    Directory of Open Access Journals (Sweden)

    M. A. Zaman

    2013-12-01

    Full Text Available Stimulation of sandstone formations is a challenging task, which involves several chemicals and physical interactions of the acid with the formation. Some of these reactions may result in formation damage. Mud acid has been successfully used to stimulate sandstone reservoirs for a number of years. It is a mixture of hydrofluoric (HF and hydrochloric (HCl acids designed to dissolve clays and siliceous fines accumulated in the near-wellbore region. Matrix acidizing may also be used to increase formation permeability in undamaged wells. The change may be up to 50% to 100% with the mud acid. For any acidizing process, the selection of acid (Formulation and Concentration and the design (Pre-flush, Main Acid, After-flush is very important. Different researchers are using different combinations of acids with different concentrations to get the best results for acidization. Mainly the common practice is combination of Hydrochloric Acid – Hydrofluoric with Concentration (3% HF – 12% HCl. This paper presents the results of a laboratory investigation of Orthophosphoric acid instead of hydrochloric acid in one combination and the second combination is Fluoboric and formic acid and the third one is formic and hydrofluoric acid. The results are compared with the mud acid and the results calculated are porosity, permeability, and FESEM Analysis and Strength tests. All of these new combinations shows that these have the potential to be used as acidizing acids on sandstone formations.

  8. High School Forum: "Invitations to Enquiry": The Calcite/Acid Reaction.

    Science.gov (United States)

    Herron, J. Dudley, Ed.; Driscoll, D. R.

    1979-01-01

    Describes a high school chemistry experiment which involves the reaction between calcite and hydrochloric and sulfuric acids. This reaction can be carried out as a projected demonstration and on an individual basis. (HM)

  9. Improvement of l-lactic acid productivity from sweet sorghum juice by repeated batch fermentation coupled with membrane separation.

    Science.gov (United States)

    Wang, Yong; Meng, Hongyu; Cai, Di; Wang, Bin; Qin, Peiyong; Wang, Zheng; Tan, Tianwei

    2016-07-01

    In order to efficiently produce l-lactic acid from non-food feedstocks, sweet sorghum juice (SSJ), which is rich of fermentable sugars, was directly used for l-lactic acid fermentation by Lactobacillus rhamnosus LA-04-1. A membrane integrated repeated batch fermentation (MIRB) was developed for productivity improvement. High-cell-density fermentation was achieved with a final cell density (OD620) of 42.3, and the CCR effect was overcomed. When SSJ (6.77gL(-1) glucose, 4.51gL(-1) fructose and 50.46gL(-1) sucrose) was used as carbon source in MIRB process, l-lactic acid productivity was increased significantly from 1.45gL(-1)h(-1) (batch 1) to 17.55gL(-1)h(-1) (batch 6). This process introduces an effective way to produce l-lactic acid from SSJ.

  10. New Acid Combination for a Successful Sandstone Acidizing

    Science.gov (United States)

    Shafiq, M. U.; Mahmud, H. K. B.; Rezaee, R.

    2017-05-01

    With the development of new enhanced oil recovery techniques, sandstone acidizing has been introduced and played a pivotal role in the petroleum industry. Different acid combinations have been applied, which react with the formation, dissolve the soluble particles; thus increase the production of hydrocarbons. To solve the problems which occurred using current preflush sandstone acidizing technology (hydrochloric acid); a new acid combination has been developed. Core flooding experiments on sandstone core samples with dimensions 1.5 in. × 3 in. were conducted at a flow rate of 2 cm3/min. A series of hydrochloric-acetic acid mixtures with different ratios were tested under 150°F temperature. The core flooding experiments performed are aimed to dissolve carbonate, sodium, potassium and calcium particles from the core samples. These experiments are followed by few important tests which include, porosity-permeability, pH value, Inductively Coupled Plasma (ICP) analysis and Nuclear Magnetic Resonance (NMR measurements). All the results are compared with the results of conventional hydrochloric acid technology. NMR and porosity analysis concluded that the new acid combination is more effective in creating fresh pore spaces and thus increasing the reservoir permeability. It can be seen from the pore distribution before and after the acidizing. Prior applying acid; the large size of pores appears most frequently in the pore distribution while with the applied acid, it was found that the small pore size is most the predominant of the pore distribution. These results are validated using ICP analysis which shows the effective removal of calcium and other positive ions from the core sample. This study concludes that the combination of acetic-hydrochloric acid can be a potential candidate for the preflush stage of sandstone acidizing at high temperature reservoirs.

  11. Preparation and evaluation of poly(alkyl methacrylate-co-methacrylic acid-co-ethylene dimethacrylate) monolithic columns for separating polar small molecules by capillary liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Shu-Ling; Wu, Yu-Ru; Lin, Tzuen-Yeuan; Fuh, Ming-Ren, E-mail: msfuh@scu.edu.tw

    2015-04-29

    Highlights: • Methacrylic acid (MAA) was used to increase hydrophilicity of polymeric monoliths. • Fast separation of phenol derivatives was achieved in 5 min using MAA-incorporated column. • Separations of aflatoxins and phenicol antibiotics were achieved using MAA-incorporated column. - Abstract: In this study, methacrylic acid (MAA) was incorporated with alkyl methacrylates to increase the hydrophilicity of the synthesized ethylene dimethacrylate-based (EDMA-based) monoliths for separating polar small molecules by capillary LC analysis. Different alkyl methacrylate–MAA ratios were investigated to prepare a series of 30% alkyl methacrylate–MAA–EDMA monoliths in fused-silica capillaries (250-μm i.d.). The porosity, permeability, and column efficiency of the synthesized MAA-incorporated monolithic columns were characterized. A mixture of phenol derivatives is employed to evaluate the applicability of using the prepared monolithic columns for separating small molecules. Fast separation of six phenol derivatives was achieved in 5 min with gradient elution using the selected poly(lauryl methacrylate-co-MAA-co-EDMA) monolithic column. In addition, the effect of acetonitrile content in mobile phase on retention factor and plate height as well as the plate height-flow velocity curves were also investigated to further examine the performance of the selected poly(lauryl methacrylate-co-MAA-co-EDMA) monolithic column. Moreover, the applicability of prepared polymer-based monolithic column for potential food safety applications was also demonstrated by analyzing five aflatoxins and three phenicol antibiotics using the selected poly(lauryl methacrylate-co-MAA-co-EDMA) monolithic column.

  12. Separation of clavulanic acid from fermented broth of amino acids by an aqueous two-phase system and ion-exchange adsorption.

    Science.gov (United States)

    da Silva, Clovis Sacardo; Cuel, Maressa Fabiano; Barreto, Verônica Orlandin; Kwong, Wu Hong; Hokka, Carlos O; Barboza, M

    2012-02-15

    The clavulanic acid is a substance which inhibits the β-lactamases used with penicillins for therapeutic treatment. After the fermentation, by-products of low molecular weight such as amino acids lysine, histidine, proline and tyrosine are present in the fermented broth. To remove these impurities the techniques of extraction by an aqueous two-phase system of 17% polyethylene glycol molecular weight 600 and 15% potassium phosphate were used for a partial purification. A subsequent ion-exchange adsorption was used for the recuperation of the clavulanic acid of the top phase and purification getting a concentration factor of 2 and purification of 100% in relation to the amino acids lysine, histidine, proline and tyrosine.

  13. Solvent extraction-separation of La(III), Eu(III) and Er(III) ions from aqueous chloride medium using carbamoyl-carboxylic acid extractants

    Institute of Scientific and Technical Information of China (English)

    Reyhaneh Safarbali; Mohammad Reza Yaftian; Abbasali Zamani

    2016-01-01

    N,N-dibutyldiglycol amic acid (HLI) and N,N-dioctyldiglycol amic acid (HLI) were synthesized and characterized by con-ventional spectroscopic methods. These molecules were examined as extractants for extraction-separation of La(III), Eu(III) and Er(III), as representative ions of light, middle and heavy rare earths, from aqueous chloride solutions. The analysis of the extraction equilibria revealed that the extracted species of lanthanum and europium ions by both of the extractants had a 1:3 metal to ligand ratio. It was suggested that erbium ions were extracted into the organic phase via the formation of Er(LI or I)2Cl complexes. The effect of the organic diluents on the extraction-separation efficiency of the studied rare earths by HLI and HLI was investigated by comparing the results obtained in dichloromethane and carbon tetrachloride. Regardless to the diluent used, the order of selectivity presented by the investigated extractants was Er(III)>Eu(III)>La(III). It is noteworthy that, a significant enhancement in separation of the studied rare earths by the extractants was achieved in their competitive extraction experiments with respect to that obtained in single component extraction experiments. Applicability of the extractants for the removal of rare earth ions from spent Ni-MH batteries was tested by removal of La(III), Eu(III) and Er(III) ions from simulated leach solution of such batteries.

  14. Two-Stage Separation of V(IV) and Al(III) by Crystallization and Solvent Extraction from Aluminum-Rich Sulfuric Acid Leaching Solution of Stone Coal

    Science.gov (United States)

    Shi, Qihua; Zhang, Yimin; Liu, Tao; Huang, Jing; Liu, Hong

    2016-12-01

    To improve separation of V(IV) and Al(III) from aluminum-rich sulfuric acid leaching solution of stone coal, the two-stage separation by crystallization and solvent extraction methods have been developed. A co-extraction coefficient (k) was put forward to evaluate comprehensively co-extraction extent in different solutions. In the crystallization stage, 68.2% of aluminum can be removed from the solution. In the solvent extraction stage, vanadium was selectively extracted using di-2-ethylhexyl phosphoric acid/tri-n-butyl phosphate from the crystalline mother solution, followed by H2SO4 stripped efficiently. A V2O5 product with purity of 98.39% and only 0.10% Al was obtained after oxidation, precipitation, and calcination. Compared with vanadium extraction from solution without crystallization, the counter-current extraction stage of vanadium can be decreased from 6 to 3 and co-extraction coefficient (k) decreased from 2.51 to 0.58 with two-stage separation. It is suggested that the aluminum removal by crystallization can evidently weaken the influence of aluminum co-extraction on vanadium extraction and improve the selectivity of solvent extraction for vanadium.

  15. Acid-base strengths in pyridine

    NARCIS (Netherlands)

    Bos, M.; Dahmen, E.A.M.F.

    1971-01-01

    Although pyridine is a solvent with a low dielectric constant, spectrophotometric determinations show simple dissociation without ion pairs as intermediates for some sulfonphthaleins and polynitrophenols in pyridine. The salts of a number of amines and hydrochloric acid, perchloric acid and picric

  16. Separation of phenolic acids from monosaccharides by low-pressure nanofiltration integrated with laccase pre-treatments

    DEFF Research Database (Denmark)

    Luo, Jianquan; Zeuner, Birgitte; Morthensen, Sofie Thage

    2015-01-01

    monosaccharides (xylose, arabinose, glucose). Four commercial NF membranes (NF270, NP030, NTR7450 and NP010) were evaluated at different pH values and with various laccase pre-treatments (for polymerization of phenolic acids). The results showed that with increasing pH, the retentions of phenolic acids by NF...... increased, reaching 86–88% for NTR7450 and 90–94% for NF270 at pH 9.55. The retentions of monosaccharides kept almost constant (pH but significantly increased at pH 9.55 for the NF270 membrane due to enhancement of solute interactions. Phenolic acids...... could be polymerized by laccase and then completely retained by the NF membranes via size exclusion at pH 5.15. The formation of large polymeric products by laccase could alleviate the irreversible fouling in/on a NF membrane and decrease the monosaccharide retention, while the small polymeric products...

  17. Evaluation of the Fermentation Potential of Pulp Mill Residue to Produce D(-)-Lactic Acid by Separate Hydrolysis and Fermentation Using Lactobacillus coryniformis subsp. torquens.

    Science.gov (United States)

    de Oliveira Moraes, Anelize; Ramirez, Ninoska Isabel Bojorge; Pereira, Nei

    2016-12-01

    Lactic acid is widely used in chemical, pharmaceutical, cosmetic, and food industries, besides it is the building block to produce polylactic acid, which is a sustainable alternative biopolymer to synthetic plastic due to its biodegradability. Aiming at producing an optically pure isomer, the present work evaluated the potential of pulp mill residue as feedstock to produce D(-)-lactic acid by a strain of the bacterium Lactobacillus coryniformis subsp. torquens using separate hydrolysis and fermentation process. Enzymatic hydrolysis, optimized through response surface methodology for 1 g:4 mL solid/liquid ratio and 24.8 FPU/gcellulose enzyme loading, resulted in 140 g L(-1) total reducing sugar and 110 g L(-1) glucose after 48 h, leading to 61 % of efficiency. In instrumented bioreactor, 57 g L(-1) of D(-)-lactic acid was achieved in 20 h of fermentation, while only 0.5 g L(-1) of L(+)-lactic acid was generated. Furthermore, product yield of 0.97 g/g and volumetric productivity of 2.8 g L(-1) h(-1) were obtained.

  18. The Optimal Conditions of Fatty Acids Hydrophilization Separation%脂肪酸乳化结晶分离的适宜条件

    Institute of Scientific and Technical Information of China (English)

    古忠云; 黄通国

    2001-01-01

    采用乳化结晶分离法对不同组成的脂肪酸的分离进行了研究。主要考察了结晶阶段乳化剂用量R、电解质用量W及稀释水用量RW对分离结果的影响,以及适宜的R、W、RW及其与组成的关系。研究结果表明:R、W、RW具有一适宜值,且它们随原料酸中饱和酸质量组成X不同而异。其中R、W分别与X成线性关系;RW与X的关系亦有规律可寻。在适宜条件下进行脂肪酸分离,分离效果最好(液酸产量最高,w(液酸)>90%),可满足各行业需要。%Using the improved hydrophilization process,fatty acid mixtures can be separated into one fraction rich in saturated fatty acid and the other rich in unsaturated fatty acids.The effects of surfactant ratio in crystallization step and quantities of magnesium sulfate and water of dilution on the result of separation were studied.The result showed that these factors had optimal values,which varied with mass fraction of saturated fatty acid.Relation between these factors and the mass fraction of saturated fatty acid was determined.