Sample records for phenolphthalein

  1. Synthesis of optically clear polymeric materials for high temperature windows. [preparation of phenolphthalein polycarbonate resin

    NASA Technical Reports Server (NTRS)

    Pannell, C. E.; Magner, J. E.


    A polymer has been developed that has excellent potential for use as windows in spacecraft as well as conventional aircraft. This polymer, phenolphthalein polycarbonate, has outstanding thermal properties, e.g., in place of melting or burning, it produces an insulating charred foam that closes off transmission of radiant heat through the window. This fact, coupled with an oxygen index of 0.43 and a 177 C tensile strength of 58 mega Newtons/sq m, makes this polymer a prime candidate for further development. Pilot plant preparation in a 20 gallon Pfaudler kettle was accomplished and large test specimens were prepared for evaluations.

  2. Detection and quantitation of trace phenolphthalein (in pharmaceutical preparations and in forensic exhibits) by liquid chromatography-tandem mass spectrometry, a sensitive and accurate method.


    Sharma, Kakali; Sharma, Shiba P; Lahiri, Sujit C


    Phenolphthalein, an acid-base indicator and laxative, is important as a constituent of widely used weight-reducing multicomponent food formulations. Phenolphthalein is an useful reagent in forensic science for the identification of blood stains of suspected victims and for apprehending erring officials accepting bribes in graft or trap cases. The pink-colored alkaline hand washes originating from the phenolphthalein-smeared notes can easily be determined spectrophotometrically. But in many cases, colored solution turns colorless with time, which renders the genuineness of bribe cases doubtful to the judiciary. No method is known till now for the detection and identification of phenolphthalein in colorless forensic exhibits with positive proof. Liquid chromatography-tandem mass spectrometry had been found to be most sensitive, accurate method capable of detection and quantitation of trace phenolphthalein in commercial formulations and colorless forensic exhibits with positive proof. The detection limit of phenolphthalein was found to be 1.66 pg/L or ng/mL, and the calibration curve shows good linearity (r(2) = 0.9974).

  3. Critical anomalies of alkaline fading of phenolphthalein in the critical solution of 2-butoxyethanol + water

    NASA Astrophysics Data System (ADS)

    Du, Zhongyu; Yin, Handi; Hao, Zhiguo; Zheng, Peizhu; Shen, Weiguo


    We have used three-wavelength UV-spectrophotometry to study the reaction of the alkaline fading of phenolphthalein in the critical solution of 2-butoxyethanol + water. It was found that when the temperature was far away from the critical point, the values of the natural logarithm of the rate constant k and the natural logarithm of the chemical equilibrium K determined in our experiments had good linear relationships with the reciprocal of temperature, which served as the backgrounds and were used for correcting k and K in the critical region. The critical slowing down of the reaction and the critical anomaly of the chemical equilibrium were detected near the critical point. The value of the critical exponent characterizing the slowing down effect of the reaction rate was obtained to be 0.156, which was close to the value 0.11 associated with the heat capacity divergence and agreed with the theoretical prediction. The experimental result also confirmed the theoretical prediction of 0.11 for the critical exponent characterizing the weak divergence of the singularity of the chemical equilibrium.

  4. Spectrometric study of AOT-hydrolysis reaction in water/AOT/isooctane microemulsions using phenolphthalein as a chemical probe.


    Mao, Shiyan; Chen, Zhiyun; Fan, Dashuang; An, Xueqin; Shen, Weiguo


    The kinetics of the alkaline hydrolysis of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) in water/AOT/isooctane microemulsions has been studied by monitoring the absorbance change of the phenolphthalein in the system with time. The apparent first-order rate constant k(obs) has been obtained and found to be dependent on both the molar ratio of water to AOT ω and the temperature. The dependences of k(obs) on ω have been analyzed by a pseudophase model which gives the true rate constants k(i) of the AOT-hydrolysis reaction on the interface and the partition coefficients K(wi) for the distribution of OH(-) between aqueous and interface pseudophases at various temperatures; the latter is almost independent of the temperature and ω. The temperature dependences of the reaction rate constants k(obs) and k(i) have been analyzed to obtain enthalpy ΔH(≠), entropy ΔS(≠), and energy E(a) of activation, which indicate that the distribution of OH(-) between aqueous and interface pseudophases increases ΔS(≠) but makes no contribution to E(a) and ΔH(≠). The influence of the overall concentration of AOT in the system on the rate constant has been examined and found to be negligible. It contradicts with what was reported by García-Río et al. (1) but confirms that the first-order reaction of the AOT-hydrolysis takes place on the surfactant interface. The study of the influence of AOT-hydrolysis on the kinetics of the alkaline fading of crystal violet or phenolphthalein in the water/AOT/isooctane microemulsions suggests that corrections for the AOT-hydrolysis in these reactions are required.

  5. Technical note: The effects of Bluestar(®) and luminol when used in conjunction with tetramethylbenzidine or phenolphthalein.


    Luedeke, Makayla; Miller, Emily; Sprague, Jon E


    There are numerous presumptive tests available in the forensic science field to help identify the presence of blood. While many articles are available on the effects of Bluestar(®) and luminol and potential interactions with subsequent DNA identification, the research field falls short in identifying the effects these two presumptive tests may have on subsequent presumptive tests used to help identify blood. To rectify this ongoing issue in the forensic science field, the chemiluminescence methods of Bluestar(®) and luminol for the detection of blood at a crime scene were tested for their effects when used in conjunction with tetramethylbenzidine (TMB) or phenolphthalein (PT) at the forensic science laboratory. Six different substrates (untreated wood, pressure treated wood, ceramic tile, shag carpet, cement block, and cotton clothing) were stained with varying dilutions (range 1:1 to 1:100,000) of blood. Neither luminol nor Bluestar(®) affect the results of PT or TMB tests at blood dilutions equal to or less than 1:100. However, interactions did occur between agents and substrates with blood dilutions 1:1000 or greater. Bluestar(®) was the only presumptive test that can detect blood dilutions of 1:100,000 on some substrates and luminol was inclusive on pressure treated wood. These findings suggests that forensic science laboratory personal need to know and understand the details of how the blood was detected by the crime scene investigator and the substrate on which the blood was obtained from for their preparation of presumptive blood testing with PT or TMB.

  6. Color indicator for supramolecular polymer chemistry: phenolphthalein-containing thermo- and pH-sensitive N-(Isopropyl)acrylamide copolymers and β-cyclodextrin complexation.


    Fleischmann, Carolin; Ritter, Helmut


    The copolymerization parameters of N-(isopropyl)acrylamide (1) and N-(2-hydroxy-5-(1-(4-hydroxyphenyl)-3-oxo-1,3-dihydroisobenzofuran-1-yl)benzyl)acrylamide (2) are determined. For both monomers, the homoaddition proceeds slightly faster than the heteroaddition step; however, the polymer formation occurs in a statistic fashion. Copolymers of different compositions are prepared and the cloud points are determined. Thereby, a significant influence of the concentration of monomer 2 and the pH value is found. For the first time, the complexation of polymer attached phenolphthalein by β-cyclodextrins is shown. Furthermore, it is possible to achieve a decomplexation by the addition of suitable guest molecules. Both procedures can be followed with the naked eye.

  7. Phenolphthalein-Pink Tornado Demonstration

    ERIC Educational Resources Information Center

    Prall, Bruce R.


    The titration of HCl with NaOH has traditionally been used to introduce beginning chemistry students to the concepts of acid-base chemistry and stoichiometry. The demonstration described in this article utilizes this reaction as a means of providing students an opportunity to observe the dynamic motion associated with a swirling vortex and its…

  8. Preparation of thermoresponsive Fe3O4/P(acrylic acid-methyl methacrylate-N-isopropylacrylamide) magnetic composite microspheres with controlled shell thickness and its releasing property for phenolphthalein.


    Zhang, Baoliang; Zhang, Hepeng; Fan, Xinlong; Li, Xiangjie; Yin, Dezhong; Zhang, Qiuyu


    In this work, Fe3O4/P(acrylic acid-methyl methacrylate-N-isopropylacrylamide) (Fe3O4/P(AA-MMA-NIPAm)) thermoresponsive magnetic composite microspheres have been prepared by controlled radical polymerization in the presence of 1,1-diphenylethene (DPE). The shell thickness of thermosensitive polymer (PNIPAm), which was on the surface of the microspheres, can be controlled by using DPE method. The morphology and thermosensitive properties of the composite microspheres, polymerization mechanism of the shell were characterized by TEM, FTIR, VSM, Laser Particle Sizer, TGA, NMR, and GPC. The microspheres with narrow particle size distribution show high saturation magnetization and superparamagnetism. The thermosensitive properties of the composite microspheres can be adjusted indirectly via controlling the addition amount of monomer (NIPAm) in the second step during controlled radical polymerization. Phenolphthalein was chosen as a model drug to investigate drug release behavior of the thermoresponsive magnetic composite microspheres with different shell thickness. Controlled drug release testing reveals that the release behavior depends on the thickness of polymer on the surface of the microspheres.

  9. 27 CFR 21.131 - Sucrose octaacetate.

    Code of Federal Regulations, 2010 CFR


    ... using phenolphthalein indicator. Percent acid as acetic acid=ml NaOH used×0.6/ weight of sample (c... phenolphthalein indicator. Percent sucrose octaacetate=(ml NaOH−ml H2SO4)×4.2412/weight of sample...

  10. Transparent polymeric laminates

    NASA Technical Reports Server (NTRS)

    Parker, J. A.; Fohlen, G. M.; Sawko, P. M.


    Laminate prepared from epoxy-boroxine and phenolphthalein polycarbonate has high mechanical strength at elevated temperature and is resistant to impact, fire, and high-energy thermal radiation. Polycarbonate is prepared by reaction of phenolphthalein with phosgene in presence of amine catalyst and immiscible organic solvent phase.

  11. Molecular Recognition: Detection of Colorless Compounds Based on Color Change

    ERIC Educational Resources Information Center

    Khalafi, Lida; Kashani, Samira; Karimi, Javad


    A laboratory experiment is described in which students measure the amount of cetirizine in allergy-treatment tablets based on molecular recognition. The basis of recognition is competition of cetirizine with phenolphthalein to form an inclusion complex with ß-cyclodextrin. Phenolphthalein is pinkish under basic condition, whereas it's complex form…

  12. The Best Enzyme Investigation Ever? Probably.

    ERIC Educational Resources Information Center

    Cooper, Phil


    Uses alkaline phosphate to remove the phosphate group from phenolphthalein diphosphate. Discusses problems which include the interference of ambient light and temperature variation. Provides detailed information about the apparatus and the experimental procedure. (ASK)

  13. "Mud" + "Blood"--A Very Colorful Demonstration.

    ERIC Educational Resources Information Center

    Hambly, Gordon


    Describes a demonstration in which a bloodred-colored solution of hydrogen peroxide, sodium hydroxide, and phenolphthalein indicator is added to a mud-colored solution of potassium permanganate, hydrated manganous chloride, and sulfuric acid. The mixture turns clear when added together. Draws parallels between the demonstration and the Old…

  14. 27 CFR 21.131 - Sucrose octaacetate.

    Code of Federal Regulations, 2014 CFR


    ... white or cream-colored powder having an intensely bitter taste. (b) Free acid (as acetic acid). Maximum... using phenolphthalein indicator. Percent acid as acetic acid=ml NaOH used×0.6/ weight of sample (c... a steam bath, cool and titrate the excess sodium hydroxide with 0.5 N sulfuric acid...

  15. 27 CFR 21.131 - Sucrose octaacetate.

    Code of Federal Regulations, 2012 CFR


    ... white or cream-colored powder having an intensely bitter taste. (b) Free acid (as acetic acid). Maximum... using phenolphthalein indicator. Percent acid as acetic acid=ml NaOH used×0.6/ weight of sample (c... a steam bath, cool and titrate the excess sodium hydroxide with 0.5 N sulfuric acid...

  16. 27 CFR 21.131 - Sucrose octaacetate.

    Code of Federal Regulations, 2011 CFR


    ... white or cream-colored powder having an intensely bitter taste. (b) Free acid (as acetic acid). Maximum... using phenolphthalein indicator. Percent acid as acetic acid=ml NaOH used×0.6/ weight of sample (c... a steam bath, cool and titrate the excess sodium hydroxide with 0.5 N sulfuric acid...

  17. 27 CFR 21.131 - Sucrose octaacetate.

    Code of Federal Regulations, 2013 CFR


    ... white or cream-colored powder having an intensely bitter taste. (b) Free acid (as acetic acid). Maximum... using phenolphthalein indicator. Percent acid as acetic acid=ml NaOH used×0.6/ weight of sample (c... a steam bath, cool and titrate the excess sodium hydroxide with 0.5 N sulfuric acid...

  18. Colorblindness and Titrations with Visual Indicators.

    ERIC Educational Resources Information Center

    Diehl, Harvey; And Others


    Discusses various issues related to colorblind students performing titrations with visual indicators. Includes tables showing precisions in the titration of a weak acid by colorblind students using phenolphthalein and thymolphthalein and in the titration of a weak base by colorblind persons using methyl red and bromcresol green. (JN)

  19. The Plague Generation.

    ERIC Educational Resources Information Center

    Jones, Richard C.


    Describes an activity to simulate the geometries of a spreading pathogen such as HIV throughout a generation. Students exchange "bodily fluids" three times and are then tested for the presence of "infection." Materials used include base solutions (NaOH or KOH), phenolphthalein (pH indicator), clear plastic cups, and an eye dropper. (PR)

  20. Overhead Projector Demonstrations.

    ERIC Educational Resources Information Center

    Kolb, Doris, Ed.


    Described are three chemistry demonstrations: (1) a simple qualitative technique for taste pattern recognition in structure-activity relationships; (2) a microscale study of gaseous diffusion using bleach, HCl, ammonia, and phenolphthalein; and (3) the rotation of polarized light by stereoisomers of limonene. (MVL)

  1. Initial evaluation tests of General Electric Company 12.0 ampere hour nickel cadmium spacecraft cells with design variables

    NASA Technical Reports Server (NTRS)

    Harkness, J. D.


    All evaluation tests were performed at room ambient pressure and temperature, with discharges at a 2 hour rate. Tests consisted of phenolphthalein leak tests, three capacity tests, an auxiliary electrode test, a charge retention test, an internal short test, a charge efficiency test, overcharge tests, and a pressure versus capacity test. Results of the tests and recommendations for improvements in manufacturing are presented.

  2. Demonstrating Diffusion

    ERIC Educational Resources Information Center

    Foy, Barry G.


    Two demonstrations are described. Materials and instructions for demonstrating movement of molecules into cytoplasm using agar blocks, phenolphthalein, and sodium hydroxide are given. A simple method for demonstrating that the rate of diffusion of a gas is inversely proportional to its molecular weight is also presented. (AJ)

  3. Thermoplastic polymers for improved fire safety

    NASA Technical Reports Server (NTRS)

    Kourtides, D. A.; Parker, J. A.; Hilado, C. J.


    The thermochemical and flammability characteristics of some typical thermoplastic materials currently in use and others being considered for use in aircraft interiors are described. The properties studied included (1) thermomechanical properties such as glass transition and melt temperature, (2) changes in polymer enthalpy by differential scanning calorimetry, (3) thermogravimetric analysis in anaerobic and oxidative environments, (4) oxygen index, (5) smoke evolution, (6) relative toxicity of the volatile products of pyrolysis, and (7) selected physical properties. The generic polymers that were evaluated included: acrylonitrile butadiene styrene, bisphenol A polycarbonate, 9,9 bis (4-hydroxyphenyl) fluorene polycarbonatepoly (dimethyl siloxane) block polymer, phenolphthalein bisphenol A polycarbonate, phenolphthalein polycarbonate, polyether sulfone, polyphenylene oxide, polyphenylene sulfide, polyaryl sulfone, chlorinated polyvinyl chloride homopolymer, polyvinyl fluoride, and polyvinylidene fluoride. Processing parameters, including molding characteristics of some of the advanced polymers, are described. Test results and relative ranking of some of the flammability, smoke, and toxicity properties are presented.

  4. Assessment of relative flammability and thermochemical properties of some thermoplastic materials

    NASA Technical Reports Server (NTRS)

    Kourtides, D. A.; Parker, J. A.


    The thermochemical and flammability characteristics of some typical thermoplastic materials currently in use and others being considered for use in aircraft interiors are described. The properties studied included (1) thermal mechanical properties such as glass transition and melt temperature, (2) changes in polymer enthalpy by differential scanning calorimetry, (3) thermogravimetric analysis in an anaerobic and oxidative environment, (4) oxygen index, (5) smoke evolution, (6) relative toxicity of the volatile products of pyrolysis, and (7) selected physical properties. The generic polymers which were evaluated included: acrylonitrile-butadiene-styrene, bisphenol A polycarbonate, bisphenol fluorenone carbonatedimethylsiloxane block polymer, phenolphthalein-bisphenol A polycarbonate, phenolphthalein polycarbonate, polyether sulfone, polyphenylene oxide, polyphenylene sulfide, polyaryl sulfone, chlorinated polyvinyl chloride homopolymer, polyvinyl fluoride, and polyvinylidene fluoride. Processing parameters including molding characteristics of some of the advanced polymers are described. Test results and relative rankings of some of the flammability, smoke and toxicity properties are presented.

  5. Cyclic AMP-dependent phosphorylation in the control of biotransformation in the liver.


    Bánhegyi, G; Garzó, T; Mészáros, G; Faragó, A; Antoni, F; Mandl, J


    The possibility of a short-term cAMP-dependent regulation of mixed-function oxidation and of glucuronide formation was investigated in isolated mouse hepatocytes and in mouse liver microsomal membranes. N6, O2-dibutyryl cAMP (in accordance with its increasing effect on gluconeogenesis) decreased aminopyrine oxidation and p-nitrophenol conjugation in isolated hepatocytes, while the phenolphthalein conjugation remained unaltered. Similar to dibutyryl cAMP the Ca2+ ionophore A 23187 also decreased aminopyrine oxidation. In cell-free systems the phosphorylation of isolated microsomal membranes by the exogenous cAMP-dependent protein kinase was inhibitory on aminopyrine oxidation and p-nitrophenol glucuronide formation but aniline oxidation and phenolphthalein glucuronidation were not affected. The correlation between the negative cAMP-dependent control of certain processes of biotransformation and the positive cAMP-dependent regulation of gluconeogenesis is discussed.

  6. The relative fire resistance of select thermoplastic materials. [for aircraft interiors

    NASA Technical Reports Server (NTRS)

    Kourtides, D. A.; Parker, J. A.


    The relative thermal stability, flammability, and related thermochemical properties of some thermoplastic materials currently used in aircraft interiors as well as of some candidate thermoplastics were investigated. Currently used materials that were evaluated include acrylonitrile butadiene styrene, bisphenol A polycarbonate, polyphenylene oxide, and polyvinyl fluoride. Candidate thermoplastic materials evaluated include: 9,9-bis(4-hydroxyphenyl)fluorene polycarbonate-poly(dimethylsiloxane) block polymer, chlorinated polyvinylchloride homopolymer, phenolphthalein polycarbonate, polyethersulfone, polyphenylene sulfide, polyarylsulfone, and polyvinylidene fluoride.

  7. Proton NMR for detection, identification and quantification of adulterants in 160 herbal food supplements marketed for weight loss.


    Hachem, Rabab; Assemat, Gaëtan; Martins, Nathalie; Balayssac, Stéphane; Gilard, Véronique; Martino, Robert; Malet-Martino, Myriam


    One hundred and sixty food supplements (FS) marketed for weight loss and mainly purchased on the Internet were analyzed. All the FS were claimed as 100% natural containing only natural compounds, plant extracts and/or vitamins and the presence of an active pharmaceutical ingredient (API) was never mentioned. (1)H NMR spectroscopy was used for detecting the presence of adulterants and for their identification and quantification. Mass spectrometry was used as a complementary method for supporting their identification. Among the 164 samples considered because capsules from 5 different blisters of the same FS were analyzed, 56% were tainted with six API. Forty three contained sibutramine as single adulterant (26%), 9 phenolphthalein (6%) and 23 a mixture of these API (14%) that were both withdrawn from the market several years ago because of toxicity concerns. Sildenafil was found in 12 samples, either as a single adulterant (n=5) or in combination with sibutramine (n=3), phenolphthalein (n=3) and both sibutramine and phenolphthalein (n=1). Fluoxetine was present in 4 formulations, alone (n=3) or in combination with sibutramine and orlistat (n=1). At last, lorcaserine was detected in one FS. The content of sibutramine per dosage unit was comprised between 0.1 and 22 mg and that of phenolphthalein between 0.05 and 56 mg. The study also highlights poor manufacturing practices as evidenced for instance by the variability of API in capsules from different blisters of the same box. This paper demonstrates the need for more effective quality control of weight loss FS and the efficiency of (1)H NMR spectroscopy for the detection of tainted FS.

  8. Active pharmaceutical ingredients detected in herbal food supplements for weight loss sampled on the Dutch market.


    Reeuwijk, Noortje M; Venhuis, Bastiaan J; de Kaste, Dries; Hoogenboom, Ron L A P; Rietjens, Ivonne M C M; Martena, Martijn J


    Herbal food supplements claiming to reduce weight may contain active pharmacological ingredients (APIs) that can be used for the treatment of overweight and obesity. The aim of this study was to determine whether herbal food supplements for weight loss on the Dutch market contain APIs with weight loss properties. Herbal food supplements intended for weight loss (n = 50) were sampled from August 2004 to May 2013. An HPLC-DAD-MS/MS method was used to screen for the presence of the APIs in herbal supplements. In 24 samples the APIs sibutramine, desmethylsibutramine (DMS), didesmethylsibutramine (DDMS), rimonabant, sildenafil and/or the laxative phenolphthalein were identified 41 times. The presence of these APIs was, however, not stated on the label. The potential pharmacological effects of the detected APIs were estimated using data from reported effective doses of approved drugs. Use of 20 of the 24 herbal food supplements may result in potential pharmacological effects. Furthermore, risk assessment of phenolphthalein, a suspected carcinogen and found to be present in 10 supplements, based on the margin of exposure (MOE) approach, resulted in MOE values of 96-30,000. MOE values lower than 10,000 (96-220) were calculated for the daily intake levels of four out of these 10 supplements in which phenolphthalein was found. However, taking into account that weight loss preparations may be used for only a few weeks or months rather than during a lifetime, MOE values may be two to three orders of magnitude higher. The current study shows that the use of food supplements with sibutramine, DMS, DDMS and/or phenolphthalein could result in pharmacological effects.

  9. On the mechanism of floating and sliding of liquid marbles.


    Bormashenko, Edward; Bormashenko, Yelena; Musin, Albina; Barkay, Zahava


    The mechanisms of floating and sliding of liquid marbles are studied. Liquid marbles containing CaCl(2) and marbles containing NaOH water solutions float on water containing Na(2)CO(3) and an alcoholic solution of phenolphthalein with no chemical reaction. Sliding of liquid marbles, consisting of NaOH water solutions, on polymer substrates coated with phenolphthalein is studied as well. No chemical reaction is observed. These observations supply direct experimental evidence for the suggestion that interfaces are separated by an air layer when marbles roll on solid substrates. It is concluded that a liquid marble rests on hydrophobic particles coating the liquid. In contrast, drops containing an NaOH water solution sliding on superhydrophobic surfaces coated with phenolphthalein leave a colored trace. The mechanism of low-friction sliding of drops deposited on superhydrophobic surfaces and liquid marbles turns out to be quite different: there is no direct contact between liquid and solid in the case of marbles' motion.

  10. Effects of presumptive test reagents on the ability to obtain restriction fragment length polymorphism (RFLP) patterns from human blood and semen stains.


    Hochmeister, M N; Budowle, B; Baechtel, F S


    Some of the commonly used presumptive test reagents for identification of blood and semen could potentially affect the recovery of intact high-molecular-weight deoxyribonucleic acid (DNA) from evidentiary samples. Thus, the capability of performing restriction fragment length polymorphism (RFLP) analysis on evidentiary samples could be compromised. In order to investigate the potential effects of presumptive test reagents on the DNA present in these samples, bloodstains on cotton and glass were exposed directly to luminol, benzidine, phenolphthalein, o-tolidine, and leucomalachite green, while semen stains and vaginal swabs containing semen were exposed directly to bromochloroindolyl phosphate (BCIP) and sodium thymolphthalein monophosphate (STMP) reagents. The yield gels for DNA quality and quantity and RFLP results indicated that bloodstains exposed to luminol, benzidine dissolved in ethanol, and phenolphthalein, as well as semen stains and vaginal swabs exposed to BCIP and STMP yield RFLP patterns consistent with that of the uncontaminated control. Except for the phenolphthalein treatment, the quantity of extractable, high-molecular-weight DNA obtained was comparable with that of untreated stains. Therefore, evidentiary material purposely or inadvertently contaminated with these reagents can be successfully typed. However, stains exposed to benzidine dissolved in glacial acetic acid, leucomalachite green, and o-tolidine failed to yield high-molecular-weight DNA or to produce any RFLP patterns.

  11. Chemical test for mammalian feces in grain products: collaborative study.


    Gerber, H R


    A collaborative study was conducted to validate the use of the AOAC alkaline phosphatase method for mammalian feces in corn meal, 44.B01-44.B06, for 7 additional products: brown rice cream, oat bran, grits, semolina, pasta flour, farina, and barley plus (a mixture of barley, oat bran, and brown rice). The proposed method determines the presence of alkaline phosphatase, an enzyme contained in mammalian feces, by using phenolphthalein diphosphate as the enzyme substrate in a test agar medium. Fecal matter is separated from the grain products by specific gravity differences in 1% test agar. As the product is distributed on liquid test agar, fecal fragments float while the grain products sink. The alkaline phosphatase cleaves phosphate radicals from phenolphthalein diphosphate, generating free phenolphthalein, which produces a pink to red-purple color around the fecal particles in the previously colorless medium. Collaborators' recovery averages ranged from 21.7 particles (72.3%) for oat bran to 25.3 particles (84.3%) for semolina at the 30 particle spike level. Overall average background was 0.4 positive reactions per food type. The collaborators reported that the method was quick, simple, and easy to use. The method has been approved interim official first action for all 7 grain products.

  12. Phenolphthalein—Pink Tornado Demonstration

    NASA Astrophysics Data System (ADS)

    Prall, Bruce R.


    The phenolphthalein-pink tornado demonstration utilizes the vortex generated by a spinning magnetic stirring bar in a 1 L graduated cylinder containing 0.01 M HCl to demonstrate Le Châtelier's principle as it applies to the phenolphthalein equilibrium in water H 2 In + 2H 2 O 2H 2 O + + In 2 - where H 2 In is phenophthalein. The addition of 3-4 drops of phenolphthalein indicator solution followed immediately by 3-4 drops of 50% (w/w) NaOH to the vortex of the HCl solution results in a shift to the right in the equilibrium owing to the reaction of OH - + H 3 O + to form water. This shift is accompanied by the vortex becoming visible by the appearance of a pinkish-red color caused by an increase in In 2- concentration within the localized region of the vortex. The demonstration also provides one an excellent opportunity to discuss the topics of limiting reagent and reagent in excess. Some insight regarding the extent to which uniform mixing is achieved when using a magnetic stirrer is also provided. Included is a note from the Feature Editor, Ed Vitz.

  13. Determination of diuretics and laxatives as adulterants in herbal formulations for weight loss.


    Moreira, Ana Paula Lançanova; Motta, Monique Jung; Dal Molin, Thaís Ramos; Viana, Carine; de Carvalho, Leandro Machado


    A new method is described for the determination of the most common diuretic and laxative adulterants found in formulations of anorexics and antidepressants. The method is based on the separation of furosemide, hydrochlorothiazide, chlorthalidone and amiloride (diuretics), phenolphthalein (laxative), amfepramone (anorexic) and fluoxetine and paroxetine (antidepressants) by capillary zone electrophoresis with capacitively coupled contactless conductivity detection. The method showed a precision ranging from 1.9% to 6.9% for a concentration of 25 mg/L, 0.6% to 5.3% for a concentration of 50 mg/L and 1.6% to 6.0% for a concentration of 100 mg/L for all analytes. The accuracy was 99% for amiloride, 102% for chlorthalidone, 101% for hydrochlorothiazide, 101% for furosemide, 94% for phenolphthalein, 105% for fluoxetine, 114% for paroxetine and 117% for amfepramone. The method allowed the drugs to be determined in the formulations at concentrations higher than 5.1 mg/kg for amiloride, 7.7 mg/kg for chlorthalidone, 6.8 mg/kg for hydrochlorothiazide, 10.7 mg/kg for furosemide, 8.4 mg/kg for phenolphthalein, 11.0 mg/kg for fluoxetine, 9.4 mg/kg for paroxetine and 11.0 mg/kg for amfepramone. Three of the 26 analysed herbal formulations were found to be adulterated (not declared on the label) with the diuretic hydrochlorothiazide. Five other samples contained diuretics declared on the label on the formulation. Thus, a total of eight samples, which were marketed as natural products, contained diuretics (declared or not) on the formulation.

  14. Acid-base titrations using microfluidic paper-based analytical devices.


    Karita, Shingo; Kaneta, Takashi


    Rapid and simple acid-base titration was accomplished using a novel microfluidic paper-based analytical device (μPAD). The μPAD was fabricated by wax printing and consisted of ten reservoirs for reaction and detection. The reaction reservoirs contained various amounts of a primary standard substance, potassium hydrogen phthalate (KHPth), whereas a constant amount of phenolphthalein was added to all the detection reservoirs. A sample solution containing NaOH was dropped onto the center of the μPAD and was allowed to spread to the reaction reservoirs where the KHPth neutralized it. When the amount of NaOH exceeded that of the KHPth in the reaction reservoirs, unneutralized hydroxide ion penetrated the detection reservoirs, resulting in a color reaction from the phenolphthalein. Therefore, the number of the detection reservoirs with no color change determined the concentration of the NaOH in the sample solution. The titration was completed within 1 min by visually determining the end point, which required neither instrumentation nor software. The volumes of the KHPth and phenolphthalein solutions added to the corresponding reservoirs were optimized to obtain reproducible and accurate results for the concentration of NaOH. The μPADs determined the concentration of NaOH at orders of magnitude ranging from 0.01 to 1 M. An acid sample, HCl, was also determined using Na2CO3 as a primary standard substance instead of KHPth. Furthermore, the μPAD was applicable to the titrations of nitric acid, sulfuric acid, acetic acid, and ammonia solutions. The μPADs were stable for more than 1 month when stored in darkness at room temperature, although this was reduced to only 5 days under daylight conditions. The analysis of acidic hot spring water was also demonstrated in the field using the μPAD, and the results agreed well with those obtained by classic acid-base titration.

  15. Tenside-free preparation of nanogels with high functional β-cyclodextrin content.


    Kettel, Markus J; Hildebrandt, Haika; Schaefer, Karola; Moeller, Martin; Groll, Juergen


    We present the preparation of ultrafine (R(h), 50 -150 nm) nanogels through tenside-free condensation of reactive prepolymers with β-cyclodextrin (β-CD) in water. These nanogels possess a maximum content of 60 wt % functional β-CD that can form inclusion complexes as demonstrated by dye sorption with phenolphthalein. Aside of this extremely high uptake capacity to hydrophobic molecules, the nanogels also show good adhesion to surfaces in homogeneous distribution with size of R(h) of 25 nm under dry conditions.

  16. Pancreatic vasoactive intestinal polypeptide-oma as a cause of secretory diarrhoea.


    Masel, S L; Brennan, B A; Turner, J H; Cullingford, G L; Cullen, D J


    A 42-year-old woman presented with a 4-year history of worsening diarrhoea that was watery, profuse and confirmed to be secretory in nature. She had tested positive for phenolphthalein on urinary laxative screening but continued to deny laxative usage. Her vasoactive intestinal polypeptide (VIP) level was subsequently found to be markedly elevated. Despite a normal abdominal ultrasound, a computed tomography scan revealed a 5-cm pancreatic tail mass. Octreotide scanning was used to exclude metastatic disease and she went on to have surgical removal of a localized pancreatic vasoactive intestinal polypeptide-oma which resulted in the complete resolution of her diarrhoea.

  17. An improved method for analysis of hydroxide and carbonate in alkaline electrolytes containing zinc

    NASA Technical Reports Server (NTRS)

    Reid, M. A.


    A simplified method for titration of carbonate and hydroxide in alkaline battery electrolyte is presented involving a saturated KSCN solution as a complexing agent for zinc. Both hydroxide and carbonate can be determined in one titration, and the complexing reagent is readily prepared. Since the pH at the end point is shifted from 8.3 to 7.9 - 8.0, m-cresol purple or phenol red are used as indicators rather than phenolphthalein. Bromcresol green is recommended for determination of the second end point of a pH of 4.3 to 4.4.

  18. An improved method for analysis of hydroxide and carbonate in alkaline electrolytes containing zinc

    NASA Technical Reports Server (NTRS)

    Reid, M. A.


    A simplified method for titration of carbonate and hydroxide in alkaline battery electrolyte is presented involving a saturated KSCN solution as a complexing agent for zinc. Both hydroxide and carbonate can be determined in one titration, and the complexing reagent is readily prepared. Since the pH at the end point is shifted from 8.3 to 7.9-8.0, m-cresol purple or phenol red are used as indicators rather than phenolphthalein. Bromcresol green is recommended for determination of the second end point of a pH of 4.3 to 4.4.

  19. Thermochemical characterization of some thermoplastic materials. [flammability and toxicity properties for aircraft interiors

    NASA Technical Reports Server (NTRS)

    Kourtides, D. A.; Parker, J. A.; Hilado, C. J.


    The thermochemical and flammability characteristics of some typical thermoplastic materials currently in use or being considered for use in aircraft interiors are described. The properties studied included thermomechanical properties such as glass-transition and melt temperature, changes in polymer enthalpy, thermogravimetric analysis in anerobic and oxidative environments, oxygen index, smoke evolution, relative toxicity of the volatile products of pyrolysis, and selected physical properties. The generic polymers evaluated included acrylonitrile butadiene styrene, bisphenol A polycarbonate, 9,9 bis (4-hydroxyphenyl) fluorene polycarbonate-poly (dimethylsiloxane) block polymer, phenolphthalein-bisphenol A polycarbonate, phenolphthalein polycarbonate, polyether sulfone, polyphenylene oxide, polyphenylene sulfide, polyaryl sulfone, chlorinated polyvinyl chloride homopolymer, polyvinyl fluoride, and polyvinylidene fluoride. Processing parameters, including molding characteristics of some of the advanced polymers, are described. Test results and relative rankings of some of the flammability, smoke, and toxicity properties are presented. Under these test conditions, some of the advanced polymers evaluated were significantly less flammable and toxic than or equivalent to polymers in current use.

  20. Active oxygen doctors the evidence.


    Castelló, Ana; Francès, Francesc; Corella, Dolores; Verdú, Fernando


    Investigation at the scene of a crime begins with the search for clues. In the case of bloodstains, the most frequently used reagents are luminol and reduced phenolphthalein (or phenolphthalin that is also known as the Kastle-Meyer colour test). The limitations of these reagents have been studied and are well known. Household cleaning products have evolved with the times, and new products with active oxygen are currently widely used, as they are considered to be highly efficient at removing all kinds of stains on a wide range of surfaces. In this study, we investigated the possible effects of these new cleaning products on latent bloodstains that may be left at a scene of a crime. To do so, various fabrics were stained with blood and then washed using cleaning agents containing active oxygen. The results of reduced phenolphthalein, luminol and human haemoglobin tests on the washed fabrics were negative. The conclusion is that these new products alter blood to such an extent that it can no longer be detected by currently accepted methods employed in criminal investigations. This inability to locate bloodstains means that highly important evidence (e.g. a DNA profile) may be lost. Consequently, it is important that investigators are aware of this problem so as to compensate for it.

  1. Determination of Chlorinity of Water without the Use of Chromate Indicator

    PubMed Central

    Hong, Tae-Kee; Kim, Myung-Hoon; Czae, Myung-Zoon


    A new method for determining chlorinity of water was developed in order to improve the old method by alleviating the environmental problems associated with the toxic chromate. The method utilizes a mediator, a weak acid that can form an insoluble salt with the titrant. The mediator triggers a sudden change in pH at an equivalence point in a titration. Thus, the equivalence point can be determined either potentiometrically (using a pH meter) or simply with an acid-base indicator. Three nontoxic mediators (phosphate, EDTA, and sulfite) were tested, and optimal conditions for the sharpest pH changes were sought. A combination of phosphate (a mediator) and phenolphthalein (an indicator) was found to be the most successful. The choices of the initial pH and the concentration of the mediator are critical in this approach. The optimum concentration of the mediator is ca. 1~2 mM, and the optimum value of the initial pH is ca. 9 for phosphate/phenolphthalein system. The method was applied to a sample of sea water, and the results are compared with those from the conventional Mohr-Knudsen method. The new method yielded chlorinity of a sample of sea water of (17.58 ± 0.22) g/kg, which is about 2.5% higher than the value (17.12 ± 0.22) g/kg from the old method. PMID:21461358

  2. Evidence for an UDP-glucuronic acid/phenol glucuronide antiport in rat liver microsomal vesicles.


    Bánhegyi, G; Braun, L; Marcolongo, P; Csala, M; Fulceri, R; Mandl, J; Benedetti, A


    The transport of glucuronides synthesized in the luminal compartment of the endoplasmic reticulum by UDP-glucuronosyltransferase isoenzymes was studied in rat liver microsomal vesicles. Microsomal vesicles were loaded with p-nitrophenol glucuronide (5 mM), phenolphthalein glucuronide or UDP-glucuronic acid, by a freeze-thawing method. In was shown that: (i) the loading procedure resulted in millimolar intravesicular concentrations of the different loading compounds; (ii) addition of UDP-glucuronic acid (5 mM) to the vesicles released both intravesicular glucuronides within 1 min; (iii) glucuronides stimulated the release of UDP-glucuronic acid from UDP acid-loaded microsomal vesicles; (iv) trans-stimulation of UDP-glucuronic acid entry by loading of microsomal vesicles with p-nitrophenol glucuronide, phenolphthalein glucuronide, UDP-glucuronic acid and UDP-N-acetyl-glucosamine almost completely abolished the latency of UDP-glucuronosyltransferase, although mannose 6-phosphatase latency remained unaltered; (v) the loading compounds by themselves did not stimulate UDP-glucuronosyltransferase activity. This study indicates that glucuronides synthesized in the lumen of endoplasmic reticulum can leave by an antiport, which concurrently transports USP-glucuronic acid into the lumen of the endoplasmic reticulum.

  3. Enhanced performance of anion exchange membranes via crosslinking of ion cluster regions for fuel cells

    NASA Astrophysics Data System (ADS)

    Lai, Ao Nan; Guo, Dong; Lin, Chen Xiao; Zhang, Qiu Gen; Zhu, Ai Mei; Ye, Mei Ling; Liu, Qing Lin


    Development of anion exchange membranes (AEMs) with high hydroxide conductivity, good dimensional and alkaline stabilities is still a challenge for the practical application of AEM fuel cells. In this study, we report a new strategy to prepare high-performance AEMs with crosslinked ionic regions. A series of phenolphthalein-containing poly(arylene ether sulfone)s crosslinked AEMs was synthesized by grafting ion groups selectively and densely on the phenolphthalein units to form ion clusters that are further crosslinked to generate the hydrophilic ionic regions. The crosslinking reaction not only improved the dimensional stability of the AEMs, but also increased the aggregation of the ion clusters leading to the formation of hydrophilic/hydrophobic phase-separated morphology and ion-conducting channels. As a result, enhancements in both ion conductivity and dimensional stability can be achieved. The crosslinked AEMs showed high hydroxide conductivities in the range of 52.2-143.4 mS cm-1 from 30 to 80 °C and a superb ratio of relative conductivity to relative swelling at 80 °C. Furthermore, the crosslinked AEMs also exhibited good mechanical properties, thermal and alkaline stabilities and desirable single cell performance. This work presents a promising strategy for the synthesis of high-performance AEMs for fuel cells.

  4. Synthesis and characterization of an amphiphilic cyclodextrin, a micelle with two recognition sites.


    Silva, O Fernando; Fernández, Mariana A; Pennie, Sarah L; Gil, Roberto R; de Rossi, Rita H


    A cyclodextrin derivative (Mod-CD) was synthesized through the monoesterification of beta-cyclodextrin (beta-CD) with 3-((E)-dec-2-enyl)-dihydrofuran-2,5-dione. The compound is an interesting surfactant that can form large aggregates not only through the interaction of the hydrophobic tails as in common amphiphilic compounds but also through the inclusion of the alkenyl chain into the cavity of another Mod-CD molecule. The self-inclusion of the chain in the cavity of cyclodextrin as well as the intermolecular inclusion was demonstrated by 1H NMR measurements that were able to detect methyl groups in three different environments. Besides, in the aggregates of Mod-CD, the cavity is available to interact with external guests such as phenolphthalein, 1-amino adamantane, and Prodan. Phenolphthalein has the same binding constant with Mod-CD and beta-CD, but the equilibrium constant for the interaction with Prodan is about 2 times larger for Mod-CD than for beta-CD. The latter result is attributed to the fact that this probe interacts with the micelle in two binding sites: the cavity of the cyclodextrin and the apolar heart of the micelle as evidenced by the spectrofluorimetric behavior of Prodan in solutions containing different concentrations of Mod-CD.

  5. A graphene tip coupled with liquid chromatography tandem mass spectrometry for the determination of four synthetic adulterants in slimming supplements.


    Jin, Renyao; Li, Linqiu; Guo, Lianxian; Li, Weiqiao; Shen, Qing


    Slimming supplements were popularly sold online driven by the increasement of obesity and the development of social networking platform. However, events of drug abuse in slimming supplements were also frequently reported. In this study, a graphene tip solid-phase extraction (Gtip SPE) and ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was established for determining fenfluramine, phenolphthalein, bumetanide, and sibutramine in slimming supplements. It was validated in terms of linearity (0.9985-0.9995), LOD (1.8ngmL(-1)), LOQ (5.6ngmL(-1)), intra-day precision (<5.1%), inter-day precision (<7.3%), and recovery (82.9-95.2%). Sibutramine is the most commonly used drug, which was detected in Bihais, Galong, and Aolist, with content 12.4, 3.6, 20.3mgg(-1), respectively. Phenolphthalein was also found with content lower than 5.2mgg(-1). The successful application of Gtip SPE and UPLC-MS/MS method indicated its advantage in analyzing low level of contaminates resulted from violation of regulation.

  6. Structure-Based Discovery of Inhibitors of Thymidylate Synthase

    NASA Astrophysics Data System (ADS)

    Shoichet, Brian K.; Stroud, Robert M.; Santi, Daniel V.; Kuntz, Irwin D.; Perry, Kathy M.


    A molecular docking computer program (DOCK) was used to screen the Fine Chemical Directory, a database of commercially available compounds, for molecules that are complementary to thymidylate synthase (TS), a chemotherapeutic target. Besides retrieving the substrate and several known inhibitors, DOCK proposed putative inhibitors previously unknown to bind to the enzyme. Three of these compounds inhibited Lactobacillus caser TS at submillimolar concentrations. One of these inhibitors, sulisobenzone, crystallized with TS in two configurations that differed from the DOCK-favored geometry: a counterion was bound in the substrate site, which resulted in a 6 to 9 angstrom displacement of the inhibitor. The structure of the complexes suggested another binding region in the active site that could be exploited. This region was probed with molecules sterically similar to sulisobenzone, which led to the identification of a family of phenolphthalein analogs that inhibit TS in the 1 to 30 micromolar range. These inhibitors do not resemble the substrates of the enzyme. A crystal structure of phenolphthalein with TS shows that it binds in the target site in a configuration that resembles the one suggested by DOCK.

  7. Thermal mixing in a stratified environment

    NASA Astrophysics Data System (ADS)

    Kraemer, Damian; Cotel, Aline


    Laboratory experiments of a thermal impinging on a stratified interface have been performed. The thermal was released from a cylindrical reservoir located at the bottom of a Lucite tank. The stratified interface was created by filling the tank with two different saline solutions. The density of the lower layer is greater than that of the upper layer and the thermal fluid, thereby creating a stable stratification. A pH indicator, phenolphthalein, is used to visualize and quantify the amount of mixing produced by the impingement of the thermal at the interface. The upper layer contains a mixture of water, salt and sodium hydroxide. The thermal fluid is composed of water, sulfuric acid and phenolphthalein. When the thermal entrains and mixes fluid from the upper layer, a chemical reaction takes place, and the resulting mixed fluid is now visible. The ratio of base to acid, called the equivalence ratio, was varied throughout the experiments, as well as the Richardson number. The Richardson number is the ratio of potential to kinetic energy, and is based on the thermal quantities at the interface. Results indicate that the amount of mixing produced is proportional to the Richardson number raised to the -3/2 power. Previous experiments (Zhang and Cotel 1999) revealed that the entrainment rate of a thermal in a stratified environment follows the same power law.

  8. Structural Relaxations and Thermodynamic Properties of Molecular Amorphous Solids by Mechanical Milling

    NASA Astrophysics Data System (ADS)

    Tsukushi, I.; Yamamuro, O.; Matsuo, T.

    The organic crystals of tri-O-methyl-β-cyclodextrin (TMCD) and its three clathrate compounds containing benzoic acid (BA), p-nitrobenzoic acid (NBA) and p-hydroxybenzoic acid (HBA), sucrose (SUC), salicin (SAL), phenolphthalein (PP), 1,3,5-tri-α-naphthylbenzene (TNB) were amorphized by milling with a vibrating mill for 2 ˜ 16 hours at room temperature. The amorphization was checked by differential scanning calorimetry (DSC) and X-ray powder diffraction. The heat capacities of crystals, liquid quenched glasses (LQG), and mechanically-milled amorphous solid (MMAS) of TMCD and TNB were measured with an adiabatic calorimeter in the temperature range between 12 and 375 K. For both compounds, the enthalpy relaxation of MMAS appeared in the wide temperature range below Tg and the released configurational enthalpy was much larger than that of LQG, indicating that MMAS is more disordered and strained than LQG.

  9. Solid state amorphization of organic molecular crystals using a vibrating mill

    NASA Astrophysics Data System (ADS)

    Tsukushi, Itaru; Yamamuro, Osamu; Matsuo, Takasuke


    The solid-state amorphization of organic molecular crystals was studied by differential scanning calorimetry (DSC) and X-ray powder diffraction. Two clathrate compounds of tri- O-methyl-β-cyclodextrin (TMCD) containing p-nitrobenzoic acid (NBA) and p-hydroxybenzoic acid (HBA), and seven other organic compounds, sucrose (SUC), salicin (SAL), phenolphthalein (PP), 1,3,5-tri-α-naphthylbenzene (TNB), p-quaterphenyl ( p-QP), p-terphenyl ( p-TP) and 1,3,5-triphenylbenzene (TPB) were ground for 2-16 h with a vibrating mill at room temperature. A halo diffraction pattern and exothermic effect due to the crystallization were observed in TMCD-NBA, TMCD-HBA, SUC, SAL, PP and TNB, indicating amorphization of these crystals. The ability of solid-state amorphization in organic molecular crystals was discussed from a thermodynamic point of view.

  10. A comparison of the presumptive luminol test for blood with four non-chemiluminescent forensic techniques.


    Webb, Joanne L; Creamer, Jonathan I; Quickenden, Terence I


    Presumptive blood detection tests are used by forensic investigators to detect trace amounts of blood or to investigate suspicious stains. Through the years, a number of articles have been published on the popular techniques of the day. However, there is no single paper that critiques and compares the five most common presumptive blood detection tests currently in use: luminol, phenolphthalein (Kastle-Meyer), leucomalachite green, Hemastix and the forensic light source. The present authors aimed to compare the above techniques with regard to their sensitivity, ease of use and safety. The luminol test was determined to be the most sensitive of the techniques, while Hemastix is a suitable alternative when the luminol test is not appropriate.

  11. Approaches to flame resistant polymeric materials

    NASA Technical Reports Server (NTRS)

    Liepins, R.


    Four research and development areas are considered for further exploration in the quest of more flame-resistant polymeric materials. It is suggested that improvements in phenolphthalein polycarbonate processability may be gained through linear free energy relationship correlations. Looped functionality in the backbone of a polymer leads to both improved thermal resistance and increased solubility. The guidelines used in the pyrolytic carbon production constitute a good starting point for the development of improved flame-resistant materials. Numerous organic reactions requiring high temperatures and the techniques of protected functionality and latent functionality constitute the third area for exploration. Finally, some well-known organic reactions are suggested for the formation of polymers that were not made before.

  12. Carbonaceous nanofiber membrane functionalized by beta-cyclodextrins for molecular filtration.


    Chen, Ping; Liang, Hai-Wei; Lv, Xiao-Han; Zhu, Hai-Zhou; Yao, Hong-Bin; Yu, Shu-Hong


    In this paper, we report the fabrication of carbonaceous nanofiber (CNF) membranes functionalized by beta-cyclodextrins (CNF-β-CD membrane) and their application for molecular filtration. The chemically synthesized carbonaceous nanofibers were first functionalized by β-CD, and the free-standing CNF membrane can be prepared by a simple filtration process. The membrane shows a remarkable capability to function as an ideal molecular filter through complexation of phenolphthalein molecules with the cyclodextrin molecules grafted on the CNFs. As a typical dye pollutant, fuchsin acid can also be effectively removed from the solution through such a membrane. Engineering the surface of this carbonaceous nanofiber membrane may allow it to be used for other applications such as chiral separation and drug delivery.

  13. Sequestration of CO2 by concrete carbonation.


    Galan, Isabel; Andrade, Carmen; Mora, Pedro; Sanjuan, Miguel A


    Carbonation of reinforced concrete is one of the causes of corrosion, but it is also a way to sequester CO2. The characteristics of the concrete cover should ensure alkaline protection for the steel bars but should also be able to combine CO2 to a certain depth. This work attempts to advance the knowledge of the carbon footprint of cement. As it is one of the most commonly used materials worldwide, it is very important to assess its impact on the environment. In order to quantify the capacity of cement based materials to combine CO2 by means of the reaction with hydrated phases to produce calcium carbonate, Thermogravimetry and the phenolphthalein indicator have been used to characterize several cement pastes and concretes exposed to different environments. The combined effect of the main variables involved in this process is discussed. The moisture content of the concrete seems to be the most influential parameter.

  14. Detection of bacterial phosphatase activity by means of an original and simple test.

    PubMed Central

    Satta, G; Grazi, G; Varaldo, P E; Fontana, R


    A new test for the detection of bacterial phosphatase activity has been devised. The test is performed using agar media containing both methyl green (MG) and phenolphthalein diphosphate (PDP); in these media phosphatase-producing strains grow deep-green-stained colonies whereas non-producing strains do not. A total of 739 different strains were tested, including 593 staphylococci, 95 micrococci, 11 streptococci, 10 corynebacteria, 14 enterobacteria, and 16 candidae. All strains found phosphatase-positive according to the conventional phosphatase test displayed deep-green-stained colonies on MG-PDP media, whereas all phosphatase-negative strains showed unstained colonies on the same media. The main advantages of the present phosphatase test as compared with other conventional ones are that it is more simple to perform, it can reveal the phosphatase activity of colonies grown in deep agar, and can be incorporated into commercial multitest kits. PMID:87403

  15. Simultaneous determination of mycophenolic acid and its glucuronide and glycoside derivatives in canine and feline plasma by UHPLC-UV.


    Rivera, Sol Maiam; Hwang, Julianne K; Slovak, Jeniffer E; Court, Michael H; Villarino, Nicolas F


    Cats and dogs can suffer from multiple autoimmune diseases. Mycophenolic acid (MPA) is a potentially useful immunosuppressant drug in cats and dogs, because of its well-documented efficacy in controlling autoimmune disease in humans. However, the pharmacokinetics and pharmacodynamics in these species remain to be determined. We have developed and validated a sensitive, precise, accurate and reproducible method that provides consistent quantification of MPA and its major derivatives, MPA phenol glucoside and MPA phenol glucuronide, in canine and feline plasma using ultra-high-pressure liquid chromatography coupled to an ultraviolet detector. The main advantages of this novel method include a small sample volume, easy sample preparation, a short chromatographic analysis time and the option to select either phenolphthalein β-d-glucuronide or mycophenolic acid carboxybutoxy ether as internal standard. Results of validation indicate that this analytical method is suitable to study the plasma disposition of MPA and its derivatives in dogs and cats.

  16. An automatic system for acidity determination based on sequential injection titration and the monosegmented flow approach.


    Kozak, Joanna; Wójtowicz, Marzena; Gawenda, Nadzieja; Kościelniak, Paweł


    An automatic sequential injection system, combining monosegmented flow analysis, sequential injection analysis and sequential injection titration is proposed for acidity determination. The system enables controllable sample dilution and generation of standards of required concentration in a monosegmented sequential injection manner, sequential injection titration of the prepared solutions, data collecting, and handling. It has been tested on spectrophotometric determination of acetic, citric and phosphoric acids with sodium hydroxide used as a titrant and phenolphthalein or thymolphthalein (in the case of phosphoric acid determination) as indicators. Accuracy better than |4.4|% (RE) and repeatability better than 2.9% (RSD) have been obtained. It has been applied to the determination of total acidity in vinegars and various soft drinks. The system provides low sample (less than 0.3 mL) consumption. On average, analysis of a sample takes several minutes.

  17. Flammability and Photo-Stability of Selected Polymer Systems

    NASA Technical Reports Server (NTRS)

    Lo, Jeelin


    A systematic approach to the improvement of the flammability of epoxy resins, bisphenol-A polycarbonate poly(butylene terephthalate), and Nylon 6.6 by introducing halogens and loop functionality into the flame retardants is described. The phthalides (the loop functionality containing molecules) include 3,3-bis(4-bromophenyl)-phthalide, 3,3-bis(4-chlorophenyl)phthalide, and phenolphthalein. The phthalide containing epoxy resins are synthesized and characterized in comparison with the bisphenol-A epoxy resins in terms of flammability in the copolymer systems. The resins include diglycidyl ethers of phenolphthalein, bisphenol-A. tetrabromobisphenol-A, and tetraoromophenolphthalein. The vaporization of the phthalide additive in the polymers is observed in Thermal Gravimetric Analysis. The flame retardancy is primarily due to the presence of halogens. In the poly(butylene terephthalate) system, the cleavage of the C(sub aromatic) -B bond of the flame retardant additive enhances the crosslinking react ions between the aromatic rings resulting in an increase of char formation. In the epoxy resin systems, loop functionality contributes to char formation to a larger extent. The interaction between the epoxy resin and poly-(butylene terephthalate) follows the mechanism of insertion of the oxirane ring into the ester bond. This mechanism is studied by FT-IR. The investigation of the thermal properties of the char-forming phenol-formaldehyde resins is conducted to provide information for the systematic design of high temperature flame-resistant phenolics. NMR and FT-IR are used to characterize the oligomeric resins and the cured resins. The curing agents used in the study include formaldehyde, s-trioxane and terephthaloyl chloride. The brominated phenolic resins are found to have higher oxygen indices with lower char yields.

  18. Cerenkov specific contrast agents for detection of pH in vivo

    PubMed Central

    Czupryna, Julie; Kachur, Alexander V.; Blankemeyer, Eric; Popov, Anatoliy V.; Karp, Joel S.; Delikatny, E. James


    We report the design, testing and in vivo application of pH sensitive contrast agents designed specifically for Cerenkov imaging. Radioisotopes used for positron emission tomography (PET) emit photons via Cerenkov radiation. The multispectral emission of Cerenkov radiation allows for selective bandwidth quenching, where a band of photons are quenched by absorption by a functional dye. Under acidic conditions, 18F-labeled derivatives emit the full spectrum of Cerenkov light. Under basic conditions, the dyes change color and a wavelength-dependent quenching of Cerenkov emission is observed. METHODS Mono and di-18F-labeled derivatives of phenolsulfonphthalein (phenol red) and meta-cresolsulfonphthalein (cresol purple) were synthesized by electrophilic fluorination. Cerenkov emission was measured at different wavelengths as a function of pH in vitro. Intramolecular response was measured in fluorinated probes; intermolecular quenching by mixing phenolphthalein with 18F FDG. Monofluorocresol purple (MFCP) was tested in mice treated with acetazolamide to cause urinary alkalinization and Cerenkov images compared to PET images. RESULTS Fluorinated pH indicators were produced with radiochemical yields of 4-11% at >90% purity. Selective Cerenkov quenching was observed intramolecularly with difluorophenol red or MFCP, and intermolecularly in phenolphthalein 18F-FDG mixtures. The probes were selectively quenched in the bandwidth closest to the indicator’s absorption maximum (λmax) at pHs above the indicator pKa. Addition of acid or base to the probes resulted in reversible switching from unquenched to quenched emission. In vivo, the bladders of acetazolamide-treated mice exhibited a wavelength-dependent quenching in Cerenkov emission, with the greatest reduction occurring near the λmax. Ratiometric imaging at two wavelengths showed significant decreases in Cerenkov emission at basic pH and allowed the estimation of absolute pH in vivo. CONCLUSIONS We have created contrast

  19. A pH Indicator-linked Immunosorbent assay following direct amplification strategy for colorimetric detection of protein biomarkers.


    Shao, Fengying; Jiao, Lei; Miao, Luyang; Wei, Qin; Li, He


    A new pH indicator-linked immunosorbent assay (PILISA) reached pg/mL sensitivity based on pH indicator molecules loaded carbon nitride nanosheets as signal enhancer has been developed for colorimetric detection of protein biomarkers. As the secondary antibody binds to the carbon nitride nanosheets, the carbon nitride nanosheets and pH indicator complex as the signal amplification platform for colour change by detecting absorbance of pH indicator. The colour change was resulted from the releasing of pH indicator molecules from carbon nitride nanosheets triggered by alkali solution (AS). In this novel PILISA, the intensity absorbance of pH indicator is proportional to the concentration of the disease marker. The outstanding detection performance of the PILISA can be attributed to the following reasons: (1) ultrathin carbon nitride nanosheets with a larger surface area could adsorb abundant phenolphthalein (PP) molecules through hydrophobic interactions as well as the resulted PP anions can be free easily released into aqueous solution, leading to an obvious allochroic response; (2) the signal intensity is precisely determined by the amount of PP molecules loading onto the carbon nitride nanosheets surface, which ensures simple, low-cost and stable colorimetric detection. As expected, this new PILISA method offered an enzyme-free approach followed enzyme-linked immunosorbent assay format, which showed great promising potential as an innovative robust assay method for practical clinical applications.

  20. Carbonation and pH in mortars manufactured with supplementary cementitious materials

    SciTech Connect

    McPolin, D.O.; Basheer, P.A.M.; Long, A.E.


    An investigation of carbonation in mortars and methods of measuring the degree of carbonation and pH change is presented. The mortars were manufactured using ordinary portland cement, pulverized fuel ash, ground granulated blast-furnace slag, metakaolin, and microsilica. The mortars were exposed to a carbon dioxide-rich environment (5% CO{sub 2}) to accelerate carbonation. The resulting carbonation was measured using phenolphthalein indicator and thermogravimetric analysis. The pH of the pore fluid and a powdered sample, extracted from the mortar, was measured to give an accurate indication of the actual pH of the concrete. The pH of the extracted powder mortar sample was found to be similar to the pH of the pore fluid expressed from the mortars. The thermogravimetric analysis suggested two distinct regions of transport of CO{sub 2} within mortar, a surface region where convection was prevalent and a deeper region where diffusion was dominant. The use of microsilica has been shown to decrease the rate of carbonation, while pulverized fuel ash and ground granulated blast-furnace slag have a detrimental effect on carbonation. Metakaolin has little effect on carbonation.

  1. Mixing in colliding, ultrasonically levitated drops.


    Chainani, Edward T; Choi, Woo-Hyuck; Ngo, Khanh T; Scheeline, Alexander


    Lab-in-a-drop, using ultrasonic levitation, has been actively investigated for the last two decades. Benefits include lack of contact between solutions and an apparatus and a lack of sample cross-contamination. Understanding and controlling mixing in the levitated drop is necessary for using an acoustically levitated drop as a microreactor, particularly for studying kinetics. A pulsed electrostatic delivery system enables addition and mixing of a desired-volume droplet with the levitated drop. Measurement of mixing kinetics is obtained by high-speed video monitoring of a titration reaction. Drop heterogeneity is visualized as 370 nl of 0.25 M KOH (pH: 13.4) was added to 3.7 μL of 0.058 M HCl (pH: 1.24). Spontaneous mixing time is about 2 s. Following droplet impact, the mixed drop orbits the levitator axis at about 5 Hz during homogenization. The video's green channel (maximum response near 540 nm) shows the color change due to phenolphthalein absorption. While mixing is at least an order of magnitude faster in the levitated drop compared with three-dimensional diffusion, modulation of the acoustic waveform near the surface acoustic wave resonance frequency of the levitated drop does not substantially reduce mixing time.

  2. Solvothermal synthesis of V{sub 4}O{sub 9} flake-like morphology and its photocatalytic application in the degradation of methylene blue

    SciTech Connect

    Chine, M.K.; Sediri, F.; Gharbi, N.


    Highlights: ► Flake-like nanocrystalline V{sub 4}O{sub 9} was synthesized by a solvothermal route. ► Photocatalytic activity has been evaluated by the degradation of methylene blue under visible light irradiation. ► V{sub 4}O{sub 9} nanoflakes exhibited much higher photocatalytic activity two times higher than the bulk V{sub 2}O{sub 5}. -- Abstract: Flake-like nanocrystalline V{sub 4}O{sub 9} has been successfully synthesized by solvothermal process using V{sub 2}O{sub 5} as vanadium source and phenolphthalein as a reducing agent and a structure-directing template. Techniques X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and ultraviolet–visible (UV–vis) spectroscopy have been used to characterize the structure, the morphology and the composition of the material. The photocatalytic activity of the material has been evaluated by the degradation of methylene blue under visible light irradiation. As a result, after the lapse of 150 min, around 93.54% bleaching was observed, with V{sub 4}O{sub 9} nanoflakes yielding more photodegradation compared to that of bulk V{sub 2}O{sub 5}. This presents a degradation percentage of about 44.67%.

  3. Polymeric redox-responsive delivery systems bearing ammonium salts cross-linked via disulfides

    PubMed Central


    Summary A redox-responsive polycationic system was synthesized via copolymerization of N,N-diethylacrylamide (DEAAm) and 2-(dimethylamino)ethyl methacrylate (DMAEMA). N,N’-bis(4-chlorobutanoyl)cystamine was used as disulfide-containing cross-linker to form networks by the quaternization of tertiary amine groups. The insoluble cationic hydrogels become soluble by reduction of disulfide to mercaptanes by use of dithiothreitol (DTT), tris(2-carboxyethyl)phosphine (TCEP) or cysteamine, respectively. The soluble polymeric system can be cross-linked again by using oxygen or hydrogen peroxide under basic conditions. The redox-responsive polymer networks can be used for molecular inclusion and controlled release. As an example, phenolphthalein, methylene blue and reactive orange 16 were included into the network. After treatment with DTT a release of the dye could be recognized. Physical properties of the cross-linked materials, e.g., glass transition temperature (T g), swelling behavior and cloud points (T c) were investigated. Redox-responsive behavior was further analyzed by rheological measurements. PMID:24062825

  4. DNA evidence uncompromised by active oxygen.


    Castelló, Ana; Francés, Francesc; Verdú, Fernando


    Currently, forensic sciences can make use of the potential of instrumental analysis techniques to obtain information from the smallest, even invisible, samples. However, as laboratory techniques improve, so too should the procedures applied in the search for and initial testing of clues in order to be equally effective. This requires continuous revision so that those procedures may resolve the problems that samples present. As far as bloodstains are concerned, there are methods available that are recognized as being both highly sensitive and effective. Nevertheless, the marketing of new cleaning products, those that contain active oxygen, has raised doubts about the ability of those procedures to detect blood. It has been shown that stains washed with these detergents (and still visible) invalidated both the presumptive test (reduced phenolphthalein, luminol, and Bluestar) and that applied for determining human hemoglobin. These findings have caused considerable concern both within the forensic and scientific community, and among the general public, so obliging us to seek solutions. In this work, the effect of these new cleaning products on DNA analyses is studied. The results, encouraging ones, show that these detergents, despite invalidating all other tests, do not hinder the extraction, or the subsequent analysis, of DNA.

  5. Number of bacteria decomposing organic phosphorus compounds and phosphatase activity in the sand of two marine beaches differing in the level of anthropopressure.


    Mudryk, Z J; Perliński, P; Antonowicz, J; Robak, D


    Number of heterotrophic bacteria ability to decompose organic phosphorus compounds and the level of phosphatase activity in the sand of two marine beaches (southern coast of the Baltic Sea) differing in the level of anthropopressure were studied. The study showed that the number of bacteria and level phosphatase activity were higher in the sand of the beach subjected to stronger anthropopressure. In both studied beaches bacteria hydrolysing DNA were the most numerous (92.7-302.8 CFU·g(-1) d.w.). The least numerous were phytin (26.0·10(3) CFU·g(-1) d.w.) and phenolphthalein diphosphate (11.1·10(3) CFU·g(-1) d.w.) decomposing bacteria. Number of bacteria able to attack tested organic phosphorus compounds were the most numerous in dry zones (10.77-739.92 CFU·g(-1) d.w.) then wet zones (3.34-218.15 CFU·g(-1) d.w.). In both studied beaches bacteria hydrolysing organic phosphorus compounds and phosphatase activity generally were more numerous in surface sand layer. Seasonal variation in the occurrence of bacteria in both studied beaches was observed.

  6. A Low-Cost Device for Automatic Photometric Titrations

    NASA Astrophysics Data System (ADS)

    Rocha, Fábio R. P.; Reis, Boaventura F.


    Electronics is an important topic in chemistry courses. However, the introduction of basic concepts is often difficult and the lab instruments are frequently seen as "black boxes". To address this problem, we propose the construction of a simple, low-cost (about $150 U.S.) automatic photometric titrator employing a light-emitting diode (LED) and a phototransistor. The electronic circuit can be assembled by the students themselves. The device was employed to implement a common procedure in chemical labs, making feasible the introduction of concepts related to electronics in undergraduate chemistry courses. The titrator is able to work automatically, since a feedback system permits stopping the addition of titrant solution when the end-point is achieved. With this demonstration, it can be stressed that automatic procedures can be implemented without expensive instruments. Additionally, a classical procedure becomes more attractive to the students and its importance to chemical analysis can be emphasized. The feasibility of the titrator was demonstrated by acid-base titrations of HCl solutions with NaOH in the presence of phenolphthalein and by iodimetric determination of ascorbic acid in vitamin C tablets and lemon juice. Precise results (0.7% relative standard deviation, n = 10) in agreement at the 95% confidence level with those attained by a conventional procedure were obtained.

  7. Physical-chemical parameters and validation of a colorimetric method for deoxycholic and ursodeoxycholic acids: kit reagent and optical sensor.


    Cadena, Pabyton G; Araújo, Alberto N; Montenegro, Maria C B S M; Pimentel, Maria C B; Filho, José L Lima; Silva, Valdinete L


    The simple and low cost β-cyclodextrin (β-CD)-phenolphthalein (PHP) inclusion complex was used for both the study of physical-chemical parameters and validation of analytical procedures for deoxycholic acid (DCA) and ursodeoxycholic acid (UDCA) determinations in different formulations. The usefulness of this inclusion complex is proposed either in the form of kit reagent and as an original optical sensor for DCA and UDCA. The results showed that temperature had a negative effect on the equilibrium constant resulting in high negative values of enthalpy and positive values of entropy. The half-life values for DCA and UDCA measurements were 68.71 and 294.71 days, respectively. The method was validated showing limits of detection and quantification of 4.92×10(-5) mol L(-1) and 1.64×10(-4) mol L(-1) for DCA, 1.14×10(-5) mol L(-1) and 3.79×10(-5) mol L(-1) for UDCA, respectively. The developed optical sensor also showed response linearity, ease of implementation and potential application in fast screening tasks even out of the laboratory.

  8. Functional heterogeneity of UDP-glucuronosyltransferase as indicated by its differential development and inducibility by glucocorticoids. Demonstration of two groups within the enzyme's activity towards twelve substrates.

    PubMed Central

    Wishart, G J


    1. UDP-glucuronosyltransferase activity towards 12 substrates has been assessed in rat liver during the perinatal period. 2. Between days 16 and 20 of gestation, enzyme activities towards the substrates 2-aminophenol, 2-aminobenzoate, 4-nitrophenol, 1-naphthol, 4-methylumbelliferone and 5-hydroxytryptamine (the 'late foetal' group) surge to reach adult values, while activities towards bilirubin, testosterone, beta-oestradiol, morphine, phenolphthalein, and chloramphenicol (the 'neonatal' group) remain negligible or at less than 10% of adult values. 3. By the second postnatal day, enzyme activities towards the neonatal group have attained, or approached adult values. 4. Dexamethasone precociously stimulates in 17-day foetal liver in utero transferase activities in the late foetal, but not the neonatal group. A similar inductive pattern is found for 15-day foetal liver in organ culture. 5. It is suggested that foetal glucocorticoids, whose synthesis markedly increases between days 16 and 20 of gestation, are responsibile for triggering the simultaneous surge of all the hepatic UDP-glucuronosyltransferase activities in the late foetal group. The neonatal group of activities apparently require a different or additional stimulus for their appearance. 6. The relationship of these two groups of transferase activities to other similar groups observed during induction by xenobiotics and enzyme purification is discussed. PMID:101211

  9. A novel eco-friendly technique for efficient control of lime water softening process.


    Ostovar, Mohamad; Amiri, Mohamad


    Lime softening is an established type of water treatment used for water softening. The performance of this process is highly dependent on lime dosage. Currently, lime dosage is adjusted manually based on chemical tests, aimed at maintaining the phenolphthalein (P) and total (M) alkalinities within a certain range (2 P - M > or = 5). In this paper, a critical study of the softening process has been presented. It has been shown that the current method is frequently incorrect. Furthermore, electrical conductivity (EC) has been introduced as a novel indicator for effectively characterizing the lime softening process.This novel technique has several advantages over the current alkalinities method. Because no chemical reagents are needed for titration, which is a simple test, there is a considerable reduction in test costs. Additionally, there is a reduction in the treated water hardness and generated sludge during the lime softening process. Therefore, it is highly eco-friendly, and is a very cost effective alternative technique for efficient control of the lime softening process.

  10. Design and characterization of a plastic optical fiber pH sensor

    NASA Astrophysics Data System (ADS)

    Ferreira, Licínio; Simões, Pedro; Carvalho, Rui S.; Lopes, Paulo; Ferreira, Mário


    In this paper are present the design and characterization of a pH sensor using plastic optical fiber (POF) technology and a material produced by the sol-gel process with TEOS (tetraethyl orthosilicate) to immobilize universal indicator of pH (comprised of Thymol Blue, Methyl Red, Bromothymol Blue and Phenolphthalein) inside the silica matrix. This matrix is positioned between two extensions of plastic optical fiber tightly positioned at each side with both fibers aligned and sharing a common optical axis. This set will work as a pH sensor since the matrix embedded with indicator and in the presence of a solution (basic or acid solution) will change the optical transmittance properties. The optical source is a superluminescent white LED and the receiver is a photodiode having a good and linear responsivity in the visible spectrum. This pH sensitive matrix has large pores which allow the diffusion of the surrounding fluid molecules into the matrix and thus the close contact of these to the indicator molecules. This contact causes the change of color of the whole matrix allowing proper colorimetric detection by the photodiode. This variation of color associated with the detector wavelength linear response is the base of operation of the proposed device. This pH sensor presents many advantages over the standard and commercial pH meters namely, lightweight, portability and a low cost.

  11. Optimization of nanolime solvent for the consolidation of coarse porous limestone

    NASA Astrophysics Data System (ADS)

    Borsoi, Giovanni; Lubelli, Barbara; van Hees, Rob; Veiga, Rosário; Silva, António Santos


    The potentialities of nanomaterials for application in the field of conservation have been widely investigated in the last two decades. Among nanomaterials, nanolimes, i.e., dispersions of lime nanoparticles in alcohols are promising consolidating products for calcareous materials. Nanolimes are effective in recovering the very superficial loss of cohesion of decayed materials, but they do not always provide sufficient mass consolidation. This limitation is mainly related to the deposition of the nanoparticles nearby the surface of the material. Experimental research has been set up with the aim of improving the in-depth deposition of lime nanoparticles. Previous research by the authors has shown that nanolime deposition within a substrate can be controlled by adapting the nanolimes properties (kinetic stability and evaporation rate) to the moisture transport behavior of the substrate. Nanolime properties can be modified by the use of different solvents. In this research, nanolime dispersions have been further optimized for application on Maastricht limestone, a coarse porous limestone. Firstly, nanolimes were synthesized and dispersed in ethanol and/or water, both pure and mixed in different percentages. Subsequently, based on the kinetic stability of the nanolime dispersions, the most promising solvent mixtures were selected and applied on the limestone. The deposition of lime nanoparticles within the limestone was studied by phenolphthalein test, optical microscopy and scanning electron microscopy. The results confirm that nanolime dispersed in a mixture of ethanol (95 %) and water (5 %) can guarantee a better nanoparticles in-depth deposition within coarse porous substrates, when compared to dispersions in pure ethanol.

  12. Qualitative Analysis of Fourteen White Solids and Two Mixtures Using Household Chemicals

    NASA Astrophysics Data System (ADS)

    Oliver-Hoyo, Maria; Allen, Deedee; Solomon, Sally; Brook, Bryan; Ciraolo, Justine; Daly, Shawn; Jackson, Leia


    This is a revised and expanded version of a previously published qualitative analysis scheme for the identification of 11 white solids using materials readily available in drugstores, supermarkets, or variety stores. Phenolphthalein has been eliminated because the FDA banned its use in over-the-counter laxatives; instead, tests for pH are conducted using red cabbage indicator. Once commonly used by diabetics to test urine, copper reduction tablets are no longer widely available and are replaced by a mixture of ingredients. Three white solids and two types of mixtures, commercial antacid tablets and baking powder, have been added to the scheme. All procedures can be done with the simplest of equipment. Amounts of solids are measured volumetrically and heat is supplied by contact with hot tap water. The use of household chemicals reduces waste disposal problems while making the experiment suitable for a laboratory exercise in a distance-learning course. This experiment can be adapted for many levels of instruction. In middle school only the safer tests should be included; honors general chemistry students can be asked to design an analysis scheme for the 14 household chemicals.

  13. Kinetic Uptake Studies of Powdered Materials in Solution

    PubMed Central

    Mohamed, Mohamed H.; Wilson, Lee D.


    Challenges exist for the study of time dependent sorption processes for heterogeneous systems, especially in the case of dispersed nanomaterials in solvents or solutions because they are not well suited to conventional batch kinetic experiments. In this study, a comparison of batch versus a one-pot setup in two variable configurations was evaluated for the study of uptake kinetics in heterogeneous (solid/solution) systems: (i) conventional batch method; (ii) one-pot system with dispersed adsorbent in solution with a semi-permeable barrier (filter paper or dialysis tubing) for in situ sampling; and (iii) one-pot system with an adsorbent confined in a semi-permeable barrier (dialysis tubing or filter paper barrier) with ex situ sampling. The sorbent systems evaluated herein include several cyclodextrin-based polyurethane materials with two types of phenolic dyes: p-nitrophenol and phenolphthalein. The one-pot kinetics method with in situ (Method ii) or ex situ (Method iii) sampling described herein offers significant advantages for the study of heterogeneous sorption kinetics of highly dispersed sorbent materials with particles sizes across a range of dimensions from the micron to nanometer scale. The method described herein will contribute positively to the development of advanced studies for heterogeneous sorption processes where an assessment of the relative uptake properties is required at different experimental conditions. The results of this study will be advantageous for the study of nanomaterials with significant benefits over batch kinetic studies for a wide range of heterogeneous sorption processes.

  14. Comparison of Salivary Beta Glucuronidase Activity in Chronic Periodontitis Patients with and without Diabetes Mellitus

    PubMed Central

    ND, Jayakumar; Varghese, Sheeja


    Aim of the study: The aim of the study was to estimate the salivary beta glucuronidase (β) activity in patients with chronic periodontitis with and without diabetes mellitus and to evaluate the relationship between Beta Glucuronidase activity and Periodontal clinical parameters. Materials and Methods: The study consisted of 80 patients of both sexes with age ranging from 20-60 years and they were divided into four groups. Clinical parameters such as Gingival index, Probing depth and Clinical attachment loss were measured. Salivary Beta Glucuronidase activity was measured using spectrophotometer with reagents like phenolphthalein glucuronic acid, phosphate and glycine buffer. Results: The mean BG activity of Group IV (1.17 ± 0.27) was significantly higher than mean BGA levels of Group I, II, III. The p-value was < 0.05. The mean BGA levels of Group III (0.78 ± 0.17) was significantly higher than mean BGA levels of Group I, Group II at 5 % level. There was a significant positive linear relationship between salivary β Glucuronidase level and Probing Depth, clinical attachment level in the experimental Groups. Conclusion: The salivary β Glucuronidase level was higher in Diabetic patients with periodontitis than nondiabetic periodontitis patients. PMID:25121058

  15. [Analysis and identification of illegal constituents in health food products implicitly advertizing tonic or slimming effect in the National Institute of Health Sciences in Japan].


    Goda, Yukihiro


    With the prefectural governments' aid of the purchase, the Division of Pharmacognosy, Phytochemistry and Narcotics, National Institute of Health Sciences (NIHS) successively has surveyed illegal constituents in health food products implicitly advertizing tonic or slimming effect since the fiscal year of 2002 (slimming type) or 2003 (tonic type). The average numbers of the analyzed products per year are about 100 (slimming type) and 150 (tonic type), respectively. We also continuously distribute standards of authentic samples of several illegal components such as N-nitrosofenfluramine (NFF) and sildenafil (SIL) to prefectural institutes and the average gross number per year is about 140. In the case of slimming type, the fact that the products containing NFF were widely sold in Japanese markets in 2002 is well known. In addition, phenolphthalein, fenfluramine, sibtramine, desdimethylsibtramine, orlistat, mazindol, Rhubarb, Senna Leaf, etc. have been found as illegal constituents. In the tonic type products, we have identified more than 20 synthetic compounds relating to the erectile dysfunction (ED) treatment drugs, SIL, vardenafil and tadalafil (TDF). Since 2005, their synthetic intermediates and the patented but non-approved PDE5 inhibitors also have been found. It should be noted that TDF was found in the shells of capsule in 2009 and that mutaprodenafil was found as pro-drug type illegal component in 2010. In this report identification method of these illegal constituents is briefly described and then analytical trend in this decade is reviewed.

  16. Use of trehalose-mannitol-phosphatase agar to differentiate Staphylococcus epidermidis and Staphylococcus saprophyticus from other coagulase-negative staphylococci.

    PubMed Central

    Stevens, D L; Jones, C


    Using a plate medium containing trehalose, mannitol, and phenolphthalein diphosphate (TMPA), we differentiated significant clinical isolates of Staphylococcus epidermidis by their lack of acid production in 18 h from other coagulase-negative staphylococci, with our results having a sensitivity (R. S. Galen and S. R. Gambino, Beyond Normality: The Predictive Value and Efficiency of Medical Diagnoses) of 100%, a specificity of 89.9%, and a positive predictive value of 94.8%. With a Taxo A bacitracin disk, which differentiates Staphylococcus species from Micrococcus species, no zone of inhibition was seen for 96% of all staphylococcal strains, with 5 of 26 strains of Staphylococcus saprophyticus exhibiting zone diameters up to 10 mm. By using resistance to a 5-microgram novobiocin disk, we differentiated S. saprophyticus, with our results having a sensitivity of 100%, a specificity of 97.1%, and a positive predictive value of 83.9% on TMPA. These two species represented 77.8% of coagulase-negative staphylococci isolated. Reference strains fo Staphylococcus and Micrococcus species were differentiated by TMPA. The cost of TMPA was compared with that of another method. TMPA was found to offer an inexpensive, sensitive method for rapidly differentiating coagulase-negative Staphylococcus isolates. PMID:6096398

  17. Effects of subacute treatment with cocaine on activities of n-demethylase, UDP-glucuronyltransferase and sulfotransferase in WKY and SHR rat liver - sex and strain differences

    SciTech Connect

    Watanabe, H.K.; Hoskins, B.; Ho, I.K.


    The effects of subacute treatment with cocaine on activities of cocaine N-demethylase, UDP-glucuronyltransferase (GT) toward 4-nitrophenol and phenolphthalein and sulfotransferase (ST) toward androsterone and 4-nitrophenol in livers from Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) were investigated. Hepatic metabolism of cocaine was different between the sexes (with males having higher N-demethylase activity) and the strains (with WKY rats having higher activity). The effects of subacute cocaine administration on the activity of cocaine N-demethylase were also sex- and strain-related. Whereas cocaine administration increased activity of hepatic N-demethylase in both female strains, it decreased activity in male WKY and had no effect on activity in male SHR. Sex and strain-related as well as cocaine-induced differences were also found in activities of hepatic GT toward 4-nitrophenol and phenolphtalein as well as in activity of hepatic ST towards andersterone and 4-nitrophenol. These results suggest that some of the individual variation in the effects of cocaine may be due to sex and genetic differences in the hepatic metabolism of cocaine and/or in sexually and/or genetically-determined differences in how cocaine affects hepatic metabolism of other xenobiotics. 20 references, 4 figures.

  18. Sequential injection titration with spectrophotometric detection for the assay of acidity in fruit juices.


    Jakmunee, Jaroon; Rujiralai, Thitima; Grudpan, Kate


    A simple sequential injection analysis (SIA) with spectrophotometric detection for an assay of acidity in fruit juice was investigated. An alkaline reagent (sodium hydroxide), a sample and an indicator (phenolphthalein) were first aspirated and stacked as adjacent zones in a holding coil. With flow reversal through a reaction coil to the detector, zone penetration occurred, leading to a neutralization reaction that caused a decrease in the color intensity of the indicator being monitored for absorbance at 552 nm. The effects of various parameters were studied. Linear calibration graphs for acidities of 0.2 - 1.0 and 0.5 - 2.5% w/v citric acid as a standard, with a relative standard deviation of 1% (acidity of 0.3 - 0.6% w/v as citric acid, n=11) and a sample throughput of 30 samples h(-1), were achieved. The developed method was validated by a standard titrimetric method for assaying the acidity of fruit juice samples.

  19. Monitoring accelerated carbonation on standard Portland cement mortar by nonlinear resonance acoustic test

    NASA Astrophysics Data System (ADS)

    Eiras, J. N.; Kundu, T.; Popovics, J. S.; Monzó, J.; Borrachero, M. V.; Payá, J.


    Carbonation is an important deleterious process for concrete structures. Carbonation begins when carbon dioxide (CO2) present in the atmosphere reacts with portlandite producing calcium carbonate (CaCO3). In severe carbonation conditions, C-S-H gel is decomposed into silica gel (SiO2.nH2O) and CaCO3. As a result, concrete pore water pH decreases (usually below 10) and eventually steel reinforcing bars become unprotected from corrosion agents. Usually, the carbonation of the cementing matrix reduces the porosity, because CaCO3 crystals (calcite and vaterite) occupy more volume than portlandite. In this study, an accelerated carbonation-ageing process is conducted on Portland cement mortar samples with water to cement ratio of 0.5. The evolution of the carbonation process on mortar is monitored at different levels of ageing until the mortar is almost fully carbonated. A nondestructive technique based on nonlinear acoustic resonance is used to monitor the variation of the constitutive properties upon carbonation. At selected levels of ageing, the compressive strength is obtained. From fractured surfaces the depth of carbonation is determined with phenolphthalein solution. An image analysis of the fractured surfaces is used to quantify the depth of carbonation. The results from resonant acoustic tests revealed a progressive increase of stiffness and a decrease of material nonlinearity.

  20. An improved microfluidics approach for monitoring real-time interaction profiles of ultrafast molecular recognition

    NASA Astrophysics Data System (ADS)

    Batabyal, Subrata; Rakshit, Surajit; Kar, Shantimoy; Pal, Samir Kumar


    Our study illustrates the development of a microfluidics (MF) platform combining fluorescence microscopy and femtosecond/picosecond-resolved spectroscopy to investigate ultrafast chemical processes in liquid-phase diffusion-controlled reactions. By controlling the flow rates of two reactants in a specially designed MF chip, sub-100 ns time resolution for the exploration of chemical intermediates of the reaction in the MF channel has been achieved. Our system clearly rules out the possibility of formation of any intermediate reaction product in a so-called fast ionic reaction between sodium hydroxide and phenolphthalein, and reveals a microsecond time scale associated with the formation of the reaction product. We have also used the developed system for the investigation of intermediate states in the molecular recognition of various macromolecular self-assemblies (micelles) and genomic DNA by small organic ligands (Hoechst 33258 and ethidium bromide). We propose our MF-based system to be an alternative to the existing millisecond-resolved "stopped-flow" technique for a broad range of time-resolved (sub-100 ns to minutes) experiments on complex chemical/biological systems.

  1. A Full Automatic Device for Sampling Small Solution Volumes in Photometric Titration Procedure Based on Multicommuted Flow System

    PubMed Central

    Borges, Sivanildo S.; Vieira, Gláucia P.; Reis, Boaventura F.


    In this work, an automatic device to deliver titrant solution into a titration chamber with the ability to determine the dispensed volume of solution, with good precision independent of both elapsed time and flow rate, is proposed. A glass tube maintained at the vertical position was employed as a container for the titrant solution. Electronic devices were coupled to the glass tube in order to control its filling with titrant solution, as well as the stepwise solution delivering into the titration chamber. The detection of the titration end point was performed employing a photometer designed using a green LED (λ=545 nm) and a phototransistor. The titration flow system comprised three-way solenoid valves, which were assembled to allow that the steps comprising the solution container loading and the titration run were carried out automatically. The device for the solution volume determination was designed employing an infrared LED (λ=930 nm) and a photodiode. When solution volume delivered from proposed device was within the range of 5 to 105 μl, a linear relationship (R = 0.999) between the delivered volumes and the generated potential difference was achieved. The usefulness of the proposed device was proved performing photometric titration of hydrochloric acid solution with a standardized sodium hydroxide solution and using phenolphthalein as an external indicator. The achieved results presented relative standard deviation of 1.5%. PMID:18317510

  2. Structure and properties of PVDF membrane with PES-C addition via thermally induced phase separation process

    NASA Astrophysics Data System (ADS)

    Wu, Lishun; Sun, Junfen


    Polyvinylidene fluoride (PVDF) membrane and PVDF membrane with phenolphthalein polyethersulfone (PES-C) addition were prepared via thermally induced phase separation (TIPS) method by using diphenyl carbonate (DPC) and dimethyl acetamide (DMAc) as mixed diluents. The effects of coagulation temperature and pre-evaporation time on structure and properties of membranes were studied. The changes of sewage flux in MBR and the attenuation coefficient of sewage flux were investigated. The resistance distributions of PVDF and PVDF/PES-C membranes were compared by resistance analysis. Membrane composition and structure were characterized by ATR-FTIR, TGA, SEM and AFM. The foulant on membranes was analyzed by FTIR. The contact angle of PVDF/PES-C membrane was lower than that of PVDF membrane. A thinner skin layer and a porous cellular support layer formed in PVDF/PES-C membrane and resulted in a higher porosity and pure water flux. The pure water flux and porosity of PVDF/PES-C membrane increased with rising coagulation temperature and decreased with extending pre-evaporation time. The flux attenuation coefficient, the cake layer resistance and internal fouling resistance of PVDF/PES-C membrane in MBR were smaller than those of PVDF membrane in MBR. The FTIR spectrum of foulant on membrane indicated that the foulant on PVDF/PES-C membrane was mostly composed of protein and polysaccharide, while the foulant on pure PVDF membrane included biopolymer clusters besides protein and polysaccharide.

  3. Effect of mineral additives (natural pozzolana and sand of dunes) by substitution of cement on the performance and durability of mortars

    NASA Astrophysics Data System (ADS)

    Saidi, M.; Safi, B.


    The objective of our work consists of the study of the substitution effects of clinker by mineral additions such as: natural pozzolana (PZ) and the sand of dunes (SD) finely crushed on the mechanical properties and the durability of the mortars worked out according to various combinations containing these additions. The results from this research confirm that the substitution of 20% to 30% of cement APC (Artificial Portland Cement) by additions in binary cement (APC + PZ) or ternary (APC + PZ + SD) contributes positively to the mechanical strength of mortars and resistance to the chemical attacks in various corrosive conditions such as: hydrochloric acid, sulfuric acid and nitric acid. The mechanical strength of the different variants is comparable to those of the APC. The test results of the weight loss and phenolphthalein shows that the chemical resistance of variants (PZ20) and (PZ20 with SD5) are larger compared to the reference mortar APC and other variants. This study shows that adding value by substituting a part of clinker. This substitution can save 20% to 30% of clinker used for the manufacture of cement; this will have a beneficial effect for cement and economically (less energy spent for the clinker burning). This study contributes to the protection of the environment as to produce one ton of clinker generates about one ton of CO2 is harmful to the atmosphere. Based on our results we will reduce from 20% to 30% CO2 gas responsible for the greenhouse effect.

  4. Golgi-resident PAP-specific 3'-phosphatase-coupled sulfotransferase assays.


    Prather, Brittany; Ethen, Cheryl M; Machacek, Miranda; Wu, Zhengliang L


    Sulfotransferases are a large group of enzymes that transfer a sulfonate group from the donor substrate, 3'-phosphoadenosine-5'-phosphosulfate (PAPS)(1), to various acceptor substrates, generating 3'-phosphoadenosine-5'-phosphate (PAP) as a by-product. A universal phosphatase-coupled sulfotransferase assay is described here. In this method, Golgi-resident PAP-specific 3'-phosphatase (gPAPP) is used to couple to a sulfotransferase reaction by releasing the 3'-phosphate from PAP. The released phosphate is then detected using malachite green reagents. The enzyme kinetics of gPAPP have been determined, which allows calculation of the coupling rate, the ratio of product-to-signal conversion, of the coupled reaction. This assay is convenient, as it eliminates the need for radioisotope labeling and substrate-product separation, and is more accurate through removal of product inhibition and correction of the results with the coupling rate. This assay is also highly reproducible, as a linear correlation factor above 0.98 is routinely achievable. Using this method, we measured the Michaelis-Menten constants for recombinant human CHST10 and SULT1C4 with the substrates phenolphthalein glucuronic acid and α-naphthol, respectively. The activities obtained with the method were also validated by performing simultaneous radioisotope assays. Finally, the removal of PAP product inhibition by gPAPP was clearly demonstrated in radioisotope assays.

  5. Carbon analysis for inspecting carbonation of concrete using a TEA CO2 laser-induced plasma.


    Kagawa, Kiichiro; Idris, Nasrullah; Wada, Munehide; Kurniawan, Hendrik; Tsuyuki, Kenichiro; Miura, Satoru


    It has been demonstrated that a spectrochemical analysis of carbon using the laser plasma method can be successfully applied to inspect the carbonation of concrete by detecting carbon produced in aged concrete by a chemical reaction of Ca(OH)2 with CO2 gas in environmental air, turning into CaCO3, which induces degradation of the quality of building concrete. A comparative study has been made using a TEA CO2 laser (500-1000 mJ) and a Q-switched Nd-YAG laser (50-200 mJ) to search for the optimum conditions for carbon analysis, proving the advantage of the TEA CO2 laser for this purpose. Also, it was clarified that laser irradiation with suitable defocusing conditions is a crucial point for obtaining high sensitivity in the detection of carbon. Practical experiments on the inspection of carbonation were carried out using both a concrete sample that had been intentionally carbonated by exposure to high concentrations of CO2 gas and a naturally carbonated concrete sample. As a result, good coincidence was observed between the laser method and the ordinary method, which uses the chemical indicator phenolphthalein, implying that this laser technique is applicable as an in situ quantitative method of inspection for carbonation of concrete.

  6. Sequential injection redox or acid-base titration for determination of ascorbic acid or acetic acid.


    Lenghor, Narong; Jakmunee, Jaroon; Vilen, Michael; Sara, Rolf; Christian, Gary D; Grudpan, Kate


    Two sequential injection titration systems with spectrophotometric detection have been developed. The first system for determination of ascorbic acid was based on redox reaction between ascorbic acid and permanganate in an acidic medium and lead to a decrease in color intensity of permanganate, monitored at 525 nm. A linear dependence of peak area obtained with ascorbic acid concentration up to 1200 mg l(-1) was achieved. The relative standard deviation for 11 replicate determinations of 400 mg l(-1) ascorbic acid was 2.9%. The second system, for acetic acid determination, was based on acid-base titration of acetic acid with sodium hydroxide using phenolphthalein as an indicator. The decrease in color intensity of the indicator was proportional to the acid content. A linear calibration graph in the range of 2-8% w v(-1) of acetic acid with a relative standard deviation of 4.8% (5.0% w v(-1) acetic acid, n=11) was obtained. Sample throughputs of 60 h(-1) were achieved for both systems. The systems were successfully applied for the assays of ascorbic acid in vitamin C tablets and acetic acid content in vinegars, respectively.

  7. A preliminary nationwide survey of the presence of emerging contaminants in drinking and source waters in Brazil.


    Machado, Kelly C; Grassi, Marco Tadeu; Vidal, Cristiane; Pescara, Igor C; Jardim, Wilson F; Fernandes, Andreia N; Sodré, Fernando F; Almeida, Fernanda V; Santana, Joyce S; Canela, Maria Cristina; Nunes, Camila R O; Bichinho, Kátia M; Severo, Flaviana J R


    This is the first nationwide survey of emerging contaminants in Brazilian waters. One hundred drinking water samples were investigated in 22 Brazilian state capitals. In addition, seven source water samples from two of the most populous regions of the country were evaluated. Samples were collected from June to September of 2011 and again during the same period in 2012. The study covered emerging contaminants of different classes, including hormones, plasticizers, herbicides, triclosan and caffeine. The analytical method for the determination of the compounds was based on solid-phase extraction followed by analysis via liquid chromatography electrospray triple-quadrupole mass spectrometry (LC-MS/MS). Caffeine, triclosan, atrazine, phenolphthalein and bisphenol A were found in at least one of the samples collected in the two sampling campaigns. Caffeine and atrazine were the most frequently detected substances in both drinking and source water. Caffeine concentrations in drinking water ranged from 1.8ngL(-1) to values above 2.0μgL(-1) while source-water concentrations varied from 40ngL(-1) to about 19μgL(-1). For atrazine, concentrations were found in the range from 2.0 to 6.0ngL(-1) in drinking water and at concentrations of up to 15ngL(-1) in source water. The widespread presence of caffeine in samples of treated water is an indication of the presence of domestic sewage in the source water, considering that caffeine is a compound of anthropogenic origin.

  8. COMPACT and molecular structure in toxicity assessment: a prospective evaluation of 30 chemicals currently being tested for rodent carcinogenicity by the NCI/NTP.

    PubMed Central

    Lewis, D F; Ioannides, C; Parke, D V


    A new series of 30 miscellaneous National Toxicology Program chemicals has been evaluated prospectively for carcinogenicity and overt toxicity by COMPACT (Computer Optimised Molecular Parametric Analysis for Chemical Toxicity. CYP1A and CYP2E1). Evaluations were also made by Hazardexpert, and for metal ion redox potentials; and these, together with COMPACT, were compared with results from the Ames test for mutagenicity in Salmonella, the micronucleus test, and 90-day subchronic rodent pathology. Seven of the 30 chemicals (nitromethane, chloroprene, xylenesulphonic acid, furfuryl alcohol, anthraquinone, emodin, cinnamaldehyde) were positive for potential carcinogenicity in the COMPACT evaluation; xylenesulphonic acid and furfuryl alcohol were only equivocally positive. Four of the 30 chemicals-scopolamine, D&C Yellow No. 11, citral, cinnamaldehyde-were positive by Hazardexpert; 6 of 30-D&C Yellow No. 11, 1-chloro-2-propanol, anthraquinone, emodin, sodium nitrite, cinnamaldehyde-were positive in the Ames test; 2 of 30-phenolphthalein and emodin-were positive in the in vivo cytogenetics test; and 3 of 30-molybdenum trioxide, gallium arsenide, vanadium pentoxide-were metal compounds with redox potentials of the metal/metal ion indicative of possible carcinogenicity. The overall prediction for carcinogenicity was positive for 12 of 30 chemicals: nitromethane, chloroprene, D&C Yellow No. 11, molybdenum trioxide, 1-chloro-2-propanol, furfuryl alcohol, gallium arsenide, anthraquinone, emodin, sodium nitrite, cinnamaldehyde, vanadium pentoxide). This overall prediction has been made on the basis of the results of the computer tests and from consideration of the information from bacterial mutagenicity, together with likely lipid solubility and pathways of metabolism and elimination. PMID:8933049

  9. The Inhibitory Effect of Ciprofloxacin on the β-Glucuronidase-mediated Deconjugation of the Irinotecan Metabolite SN-38-G.


    Kodawara, Takaaki; Higashi, Takashi; Negoro, Yutaka; Kamitani, Yukio; Igarashi, Toshiaki; Watanabe, Kyohei; Tsukamoto, Hitoshi; Yano, Ryoichi; Masada, Mikio; Iwasaki, Hiromichi; Nakamura, Toshiaki


    The enterohepatic recycling of a drug consists of its biliary excretion and intestinal reabsorption, which is sometimes accompanied by hepatic conjugation and intestinal deconjugation reactions. β-Glucuronidase, an intestinal bacteria-produced enzyme, can break the bond between a biliary excreted drug and glucuronic acid. Antibiotics such as ciprofloxacin can reduce the enterohepatic recycling of glucuronide-conjugated drugs. In this study, we established an in vitro system to evaluate the β-glucuronidase-mediated deconjugation of the irinotecan metabolite SN-38-G to its active SN-38 form and the effect of ciprofloxacin thereon. SN-38 formation increased in a time-dependent manner from 5 to 30 min. in the presence of β-glucuronidase. Ciprofloxacin and phenolphthalein-β-D-glucuronide (PhePG), a typical β-glucuronidase substrate, significantly decreased SN-38-G deconjugation and, hence SN-38 formation. Similarly, the antibiotics enoxacin and gatifloxacin significantly inhibited the conversion of SN-38-G to SN-38, which was not observed for levofloxacin, streptomycin, ampicillin and amoxicillin/clavulanate. Ciprofloxacin showed a dose-dependent inhibitory effect on the β-glucuronidase-mediated conversion of SN-38-G to SN-38 with a half-maximal inhibitory concentration (IC50 ) value of 83.8 μM. PhePG and ciprofloxacin afforded the inhibition in a competitive and non-competitive manner, respectively. These findings suggest that the reduction in the serum SN-38 concentration following co-administration of ciprofloxacin during irinotecan treatment is due, at least partly, to the decreased enterohepatic circulation of SN-38 through the non-competitive inhibition of intestinal β-glucuronidase-mediated SN-38-G deconjugation.

  10. Inhibitory effect of ciprofloxacin on β-glucuronidase-mediated deconjugation of mycophenolic acid glucuronide.


    Kodawara, Takaaki; Masuda, Satohiro; Yano, Yoshitaka; Matsubara, Kazuo; Nakamura, Toshiaki; Masada, Mikio


    The interaction between mycophenolate (MPA) and quinolone antibiotics such as ciprofloxacin is considered to reduce the enterohepatic recycling of MPA, which is biotransformed in the intestine from MPA glucuronide (MPAG) conjugate excreted via the biliary system; however, the molecular mechanism underlying this biotransformation of MPA is still unclear. In this study, an in vitro system was established to evaluate β-glucuronidase-mediated deconjugation and to examine the influence of ciprofloxacin on the enzymatic deconjugation of MPAG and MPA resynthesis. Resynthesis of MPA via deconjugation of MPAG increased in a time-dependent manner from 5 to 60 min in the presence of β-glucuronidase. Ciprofloxacin and phenolphthalein-β-d-glucuronide (PhePG), a typical β-glucuronidase substrate, significantly decreased the production of MPA from MPAG in the β-glucuronidase-mediated deconjugation system. In addition, enoxacin significantly inhibited the production of MPA from MPAG, while levofloxacin and ofloxacin had no inhibitory effect on MPA synthesis. Pharmacokinetic analysis revealed that ciprofloxacin showed a dose-dependent inhibitory effect on MPA production from MPAG via β-glucuronidase with a half-maximal inhibitory concentration (IC50 ) value of 30.4 µm. While PhePG inhibited the β-glucuronidase-mediated production of MPA from MPAG in a competitive manner, ciprofloxacin inhibited MPA synthesis via noncompetitive inhibition. These findings suggest that the reduction in the serum MPA concentration during the co-administration of ciprofloxacin is at least in part due to the decreased enterohepatic circulation of MPA because of noncompetitive inhibition of deconjugation of MPAG by intestinal β-glucuronidase.

  11. Measurements of Molecular Mixing in a High Schmidt Number Rayleigh-Taylor Mixing Layer

    SciTech Connect

    Mueschke, N J; Schilling, O; Youngs, D L; Andrews, M


    Molecular mixing measurements are performed for a high Schmidt number (Sc {approx} 10{sup 3}), small Atwood number (A {approx} 7.5 x 10{sup -4}) buoyancy-driven turbulent Rayleigh-Taylor mixing layer in a water channel facility. Salt was added to the top stream to create the desired density difference. The degree of molecular mixing was measured as a function of time by monitoring a diffusion-limited chemical reaction between the two fluid streams. The pH of each stream was modified by the addition of acid or alkali such that a local neutralization reaction occurred as the two fluids molecularly mixed. The progress of this neutralization reaction was tracked by the addition of phenolphthalein - a pH-sensitive chemical indicator - to the acidic stream. Accurately calibrated backlit optical techniques were used to measure the average concentration of the colored chemical indicator. Comparisons of chemical product formation for pre-transitional buoyancy- and shear-driven mixing layers are given. It is also shown that experiments performed at different equivalence ratios (acid/alkali concentration) can be combined to obtain a mathematical relationship between the colored product formed and the density variance. This relationship was used to obtain high-fidelity, quantitative measures of the degree of molecular mixing which are independent of probe resolution constraints. The dependence of such mixing parameters on the Schmidt and Reynolds numbers is examined by comparing the current Sc {approx} 10{sup 3} measurements with Sc = 0.7 gas-phase and Pr = 7 liquid-phase measurements. This comparison indicates that the Schmidt number has a large effect on the bulk quantity of mixed fluid at small Reynolds numbers Re{sub h} < 10{sup 3}. At late times, all mixing parameters indicated a greater degree of molecular mixing and a decreased Schmidt number dependence. Implications for the development and quantitative assessment of turbulent transport and mixing models appropriate for

  12. Determination of direct and fugitive PM emissions in a Mediterranean harbour by means of classic and novel tracer methods.


    Moreno, Natalia; Viana, Mar; Pandolfi, Marco; Alastuey, Andrés; Querol, Xavier; Chinchón, Servando; Pinto, Juan Francisco; Torres, Federico; Díez, Juan Manuel; Saéz, José


    Remodelling works are frequent in harbour areas, given that they must adapt to rapidly changing market requirements. Depending on their nature (construction, demolition, etc.), these works may be carried out during long periods of time and thus exert a significant impact on the air quality at the harbours and their surroundings. The air quality at the Valencia harbour was studied during an enlargement project. Four sampling stations aimed to cover the major dust-emitting activities in the harbour. In addition, a sampling campaign was carried out to collect dust materials at their emission sources (e.g., loading and unloading of clinker and petroleum coke, as well as the enlargement works). Differences obtained between PM levels at the monitoring sites were correlated with the distance between sampling stations and enlargement works and/or harbour operations, as well as with the preferential wind direction. In all cases, the days with the highest PM_10 levels were linked to wind directions coinciding with the location of the enlargement works or the clinker and petroleum coke stocks. Classic source apportionment methodologies (PCA and CMB) were applied to the data, but their interpretation was complex due to the similar chemical signatures of PM originating from direct and fugitive emissions from stocked materials (e.g., clinker), and the enlargement works. To overcome this difficulty, a novel non-statistical approach was used to obtain quantitative estimations of the contributions from sources (petroleum coke and clinker), based on the correlation between specific PM components (e.g., carbonaceous species) and source tracers (e.g., V). Finally, a qualitative test using phenolphthalein was devised to identify the presence of clinker on the filters, which provided positive results. This novel tracer approach is thus recommended for harbour authorities.

  13. Study of dynamics and crystallization kinetics of 5-methyl-2-[(2-nitrophenyl)amino]-3-thiophenecarbonitrile at ambient and elevated pressure

    NASA Astrophysics Data System (ADS)

    Adrjanowicz, K.; Kaminski, K.; Paluch, M.; Ngai, K. L.; Yu, Lian


    The organic liquid ROY, i.e., 5-methyl-2-[(2-nitrophenyl)amino]-3-thiophenecarbonitrile, has been a subject of detailed study in the last few years. One interest in ROY lies in its polymorph-dependent fast crystal growth mode below and above the glass transition temperature. This growth mode is not diffusion controlled, and the possibility that it is enabled by secondary relaxation had been suggested. However, a previous study by dielectric relaxation spectroscopy had not been able to find any resolved secondary relaxation. The present paper reports new dielectric measurements of ROY in the liquid and glassy states at ambient pressure and elevated pressure, which were performed to provide more insight into the molecular dynamics as well as the crystallization tendency of ROY. In the search of secondary relaxation, a special glassy state of ROY was prepared by applying high pressure to the liquid state, from which secondary relaxation was possibly resolved. Thus, the role of secondary relaxation in crystallization of ROY remains to be clarified. Notwithstanding, the secondary relaxation present is not necessarily the sole enabler of crystallization. In an effort to search for possible cause of crystallization other than secondary relaxation, we also performed crystallization kinetics studies of ROY at different T and P combinations while keeping the structural relaxation time constant. The results show that crystallization of ROY speeds up with pressure, opposite to the trend found in the crystallization of ibuprofen studied up to 1 GPa. The dielectric relaxation and thermodynamic properties of ROY with phenolphthalein dimethylether (PDE) are similar in many respects, but PDE does not crystallize. Taking all the above into account, besides the secondary relaxation, the specific chemical structure, molecular interactions and packing of the molecules are additional factors that could affect the kinetics of crystallization found in ROY.

  14. Comparative Evaluation of Four Presumptive Tests for Blood to Detect Epithelial Injury on Fish

    SciTech Connect

    Colotelo, Alison HA; Smokorowski, Karen; Haxton, Tim; Cooke, Steven J.


    Current methods of fish epithelial injury detection are limited to gross macroscopic examination that has a subjective bias as well as an inability to reliably quantify the degree of injury. Fluorescein, a presumptive test for blood, has been shown to have the capability to detect and quantify fish epithelial injury. However, there are several other presumptive tests for blood (Bluestar*, phenolphthalein, and HemastixH) that may have benefits over the use of fluorescein, particularly for field research on wild fish. This study investigated the capabilities of these four tests to detect and quantify a variety of injuries commonly encountered by fish (abrasion, cuts, fin frays, and punctures) using the freshwater bluegill Lepomis macrochirus as a model. Fluorescein was consistently found to be the most reliable (i.e., detected the highest proportion of true positive results and rarely detected false positive reactions) of the four presumptive tests for blood compared. Further testing was conducted to examine the reliability of fluorescein. By 24 h after an injury was inflicted, the injury was no longer detectable by fluorescein, and when fluorescein was applied to an injured fish, the fluorescein was no longer detectable 3 h after application. In a comparison of two common anaesthetics used in fisheries research, there was no significant difference in the proportion of injury detected when 3- aminobenzoic acid ethyl ester methanesulfate (tricaine) was used compared with a clove oil and ethanol (1:9) solution. In summary, fluorescein was the most reliable presumptive test for blood examined in this study for the detection and quantification of recent (hours) fish epithelial injury.

  15. Clustering and diagnostic modelling of slimming aids based on chromatographic and mass spectrometric fingerprints.


    Custers, D; Van Hoeck, E; Courselle, P; Apers, S; Deconinck, E


    Herbal medicines and food supplements intended as slimming aids are increasingly gaining popularity worldwide, especially for treating obesity. In this study, an ultra-performance liquid chromatography coupled to photodiode array detection (UPLC-PDA) and an ultra-performance liquid chromatography mass spectrometry (UPLC-MS) method were developed to analyze 92 slimming aids (confiscated by customs), aimed at acquiring highly informative fingerprints. Three types of fingerprints were acquired (PDA, Total Ion Chromatograms (TIC), and MS fingerprints) which were used in the chemometric data analysis. Both unsupervised (i.e., Hierarchical Cluster Analysis (HCA)) and supervised techniques (i.e., Classification and Regression Tree (CART) and Partial Least Squares - Discriminant Analysis (PLS-DA)) were applied. The aim was to perform an in-depth study of the samples, thereby exploring potential patterns present in the data. HCA was able to generate a clustering which was mainly defined by chemical compounds detected in the samples, i.e., sibutramine, phenolphthalein and amfepramone. PLS-DA generated the best diagnostic models for both PDA and TIC fingerprints, characterized by correct classification rates of external validation of 85% and 80%, respectively. For the MS fingerprints, the best model was obtained by CART (65% correct classification rate of external validation). Despite a lower correct classification rate, exploration of the concerned misclassifications revealed that the MS fingerprints proved to be superior since even very low concentrations of sibutramine could be detected. This study shows that reliable chemometric models can be obtained, based on the presence of prohibited chemical substances, which allow high-throughput data analysis of such samples. Moreover, they generate a prime notion of potential threat to a patient's health posed by these kinds of slimming aids. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Poly(ε-caprolactone) nanowebs functionalized with α- and γ-cyclodextrins.


    Narayanan, Ganesh; Gupta, Bhupender S; Tonelli, Alan E


    The effects of alpha- and gamma-cyclodextrins (α- and γ-CDs) on the thermal and crystal nucleation behavior of electrospun poly(ε-caprolactone) (PCL) nanofibers have been investigated. PCL/CD composite nanofibers were obtained for the first time by electrospinning the mixture from chloroform/N,N-dimethylformamide (60:40). Scanning electron microscopy analyses indicated that neat PCL nanofibers have an average diameter of 400 nm, which increases with the addition of CDs. The presence of CDs on or in the electrospun PCL fibers in the electrospun mats was investigated using Fourier transform infrared spectroscopy, thermogravimetric analysis, and wide-angle X-ray diffraction analysis. Differential scanning calorimetry showed that the PCL/CD composite fibers exhibit higher crystallization temperatures and sharper crystallization exotherms with increased CD loading, indicating the ability of CDs to nucleate PCL crystallization. Water contact angle (WCA) measurements indicate an inverse relationship between WCA and α- or γ-CD concentration up to 30% loading. Phenolphthalein absorption tests were performed to study the kinetics of their inclusion complex (IC) formation with CDs. Unexpectedly, γ-CD-functionalized nanowebs performed better than α-CD. This might be because at elevated loadings some α-CDs may have threaded over PCL chains and formed ICs, whereas γ-CD did not. With their encapsulation capabilities and their lowered hydrophobicity, PCL/CD composite fibers might have potential uses in medical applications, in particular as wound odor absorbants in dressings, because it is well known that CDs can form ICs with these odorants, thereby effectively removing them.

  17. p53 induction as a genotoxic test for twenty-five chemicals undergoing in vivo carcinogenicity testing.

    PubMed Central

    Duerksen-Hughes, P J; Yang, J; Ozcan, O


    In vivo carcinogenicity testing is an expensive and time-consuming process, and as a result, only a relatively small fraction of new and existing chemicals has been tested in this manner. Therefore, the development and validation of alternative approaches is desirable. We previously developed a mammalian in vitro assay for genotoxicity based on the ability of cells to increase their level of the tumor-suppressor protein p53 in response to DNA damage. Cultured cells are treated with various amounts of the test substances, and at defined times following treatment, they are harvested and lysed. The lysates are analyzed for p53 by Western blot and/or enzyme-linked immunosorbent assay analysis. An increase in cellular p53 following treatment is interpreted as evidence for DNA damage. To determine the ability of this p53-induction assay to predict carcinogenicity in rodents and to compare such results with those obtained using alternate approaches, we subjected 25 chemicals from the predictive toxicology evaluation 2 list to analysis with this method. Five substances (citral, cobalt sulfate heptahydrate, D&C Yellow No. 11, oxymetholone, and t-butylhydroquinone) tested positive in this assay, and three substances (emodin, phenolphthalein, and sodium xylenesulfonate) tested as possibly positive. Comparisons between the results obtained with this assay and those obtained with the in vivo protocol, the Salmonella assay, and the Syrian hamster embryo (SHE) cell assay indicate that the p53-induction assay is an excellent predictor of the limited number of genotoxic carcinogens in this set, and that its accuracy is roughly equivalent to or better than the Salmonella and SHE assays for the complete set of chemicals. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:10504146

  18. Reductive metabolism of nabumetone by human liver microsomal and cytosolic fractions: exploratory prediction using inhibitors and substrates as marker probes.


    Matsumoto, Kaori; Hasegawa, Tetsuya; Koyanagi, Junichi; Takahashi, Tamiko; Akimoto, Masayuki; Sugibayashi, Kenji


    The metabolic reduction of nabumetone was examined by inhibition and correlation studies using human liver microsomes and cytosol. This reduction was observed in both fractions, with the V(max) values for reduction activity being approximately fourfold higher, and the V(max)/K(m) values approximately three-fold higher, in the microsomes than in the cytosol. The reduction of nabumetone was inhibited by 18β-glycyrrhetinic acid, an 11β-hydroxysteroid dehydrogenase (11β-HSD) inhibitor, in the microsomal fraction. The reduction activity was also inhibited by quercetin and menadione [carbonyl reductase (CBR) inhibitors], and by phenolphthalein and medroxyprogesterone acetate [potent inhibitors of aldo-keto reductase (AKR) 1C1, 1C2 and 1C4] in the cytosol. A good correlation (r² = 0.93) was observed between the reduction of nabumetone and of cortisone, as a marker of 11β-HSD activity, in the microsomal fractions. There was also an excellent relationship between reduction of nabumetone and of the AKR1C substrates, acetohexamide, and ethacrynic acid (r 2 = 0.92 and 0.93, respectively), in the cytosol fractions. However, a poor correlation was observed between the formation of 4-(6-methoxy-2-naphthyl)-butan-2-ol (MNBO) from nabumetone and CBR activity (with 4-benzoyl pyridine reduction as a CBR substrate) in the cytosol fractions (r² = 0.24). These findings indicate that nabumetone may be metabolized by 11β-HSD in human liver microsomes, and primarily by AKR1C4 in human liver cytosol, although multiple enzymes in the AKR1C subfamily may be involved. It cannot be completely denied that CBR is involved to some extent in the formation of MNBO from nabumetone in the cytosol fraction.

  19. Novel approaches to analysis by flow injection gradient titration.


    Wójtowicz, Marzena; Kozak, Joanna; Kościelniak, Paweł


    Two novel procedures for flow injection gradient titration with the use of a single stock standard solution are proposed. In the multi-point single-line (MP-SL) method the calibration graph is constructed on the basis of a set of standard solutions, which are generated in a standard reservoir and subsequently injected into the titrant. According to the single-point multi-line (SP-ML) procedure the standard solution and a sample are injected into the titrant stream from four loops of different capacities, hence four calibration graphs are able to be constructed and the analytical result is calculated on the basis of a generalized slope of these graphs. Both approaches have been tested on the example of spectrophotometric acid-base titration of hydrochloric and acetic acids with using bromothymol blue and phenolphthalein as indicators, respectively, and sodium hydroxide as a titrant. Under optimized experimental conditions the analytical results of precision less than 1.8 and 2.5% (RSD) and of accuracy less than 3.0 and 5.4% (relative error (RE)) were obtained for MP-SL and SP-ML procedures, respectively, in ranges of 0.0031-0.0631 mol L(-1) for samples of hydrochloric acid and of 0.1680-1.7600 mol L(-1) for samples of acetic acid. The feasibility of both methods was illustrated by applying them to the total acidity determination in vinegar samples with precision lower than 0.5 and 2.9% (RSD) for MP-SL and SP-ML procedures, respectively.

  20. Physical Selectivity of Molecularly Imprinted polymers evaluated through free volume size distributions derived from Positron Lifetime Spectroscopy

    NASA Astrophysics Data System (ADS)

    Pasang, T.; Ranganathaiah, C.


    The technique of imprinting molecules of various sizes in a stable structure of polymer matrix has derived multitudes of applications. Once the template molecule is extracted from the polymer matrix, it leaves behind a cavity which is physically (size and shape) and chemically (functional binding site) compatible to the particular template molecule. Positron Annihilation Lifetime Spectroscopy (PALS) is a well known technique to measure cavity sizes precisely in the nanoscale and is not being used in the field of MIPs effectively. This method is capable of measuring nanopores and hence suitable to understand the physical selectivity of the MIPs better. With this idea in mind, we have prepared molecular imprinted polymers (MIPs) with methacrylicacid (MAA) as monomer and EGDMA as cross linker in different molar ratio for three different size template molecules, viz. 4-Chlorophenol (4CP)(2.29 Å), 2-Nephthol (2NP) (3.36 Å) and Phenolphthalein (PP) (4.47Å). FTIR and the dye chemical reactions are used to confirm the complete extraction of the template molecules from the polymer matrix. The free volume size and its distribution have been derived from the measured o-Ps lifetime spectra. Based on the free volume distribution analysis, the percentage of functional cavities for the three template molecules are determined. Percentage of functional binding cavities for 4-CP molecules has been found out to be 70.2% and the rest are native cavities. Similarly for 2NP it is 81.5% and nearly 100% for PP. Therefore, PALS method proves to be very precise and accurate for determining the physical selectivity of MIPs.

  1. Net alkalinity and net acidity 1: Theoretical considerations

    USGS Publications Warehouse

    Kirby, C.S.; Cravotta, C.A.


    Net acidity and net alkalinity are widely used, poorly defined, and commonly misunderstood parameters for the characterization of mine drainage. The authors explain theoretical expressions of 3 types of alkalinity (caustic, phenolphthalein, and total) and acidity (mineral, CO2, and total). Except for rarely-invoked negative alkalinity, theoretically defined total alkalinity is closely analogous to measured alkalinity and presents few practical interpretation problems. Theoretically defined "CO 2-acidity" is closely related to most standard titration methods with an endpoint pH of 8.3 used for determining acidity in mine drainage, but it is unfortunately named because CO2 is intentionally driven off during titration of mine-drainage samples. Using the proton condition/mass- action approach and employing graphs to illustrate speciation with changes in pH, the authors explore the concept of principal components and how to assign acidity contributions to aqueous species commonly present in mine drainage. Acidity is defined in mine drainage based on aqueous speciation at the sample pH and on the capacity of these species to undergo hydrolysis to pH 8.3. Application of this definition shows that the computed acidity in mg L -1 as CaCO3 (based on pH and analytical concentrations of dissolved FeII, FeIII, Mn, and Al in mg L -1):aciditycalculated=50{1000(10-pH)+[2(FeII)+3(FeIII)]/56+2(Mn)/ 55+3(Al)/27}underestimates contributions from HSO4- and H+, but overestimates the acidity due to Fe3+ and Al3+. However, these errors tend to approximately cancel each other. It is demonstrated that "net alkalinity" is a valid mathematical construction based on theoretical definitions of alkalinity and acidity. Further, it is shown that, for most mine-drainage solutions, a useful net alkalinity value can be derived from: (1) alkalinity and acidity values based on aqueous speciation, (2) measured alkalinity minus calculated acidity, or (3) taking the negative of the value obtained in a

  2. Effects of the use of ultrasonic waves on biodiesel production in alkaline transesterification of bleached tallow and vegetable oils: Cavitation model

    NASA Astrophysics Data System (ADS)

    Alape Benitez, Fabio

    Experiments of biodiesel production via methanolysis were performed at methanol/triglyceride molar ratios of 3, 4.5, and 6 and temperatures of 25°C, 40°C and 60°C; the reaction was monitored by HPLC, X-Ray, and GC-MS until equilibrium. A mathematical model called CAVITATION MODEL was developed to deal with mass transfer aspects of the alkaline transesterification reaction of vegetable oils; a comparison between the cavitation model and diffusion through spherical pores was made. Gas-vapor bubble dynamics for the methanol-soybean oil and methanol-tallow system were examined at 40°C and 42°C, respectively. The Rayleight-Plesset equations were used to describe the isothermal growth and adiabatic collapse of the bubble formed when a field of ultrasound at 20 KHz is applied. Temperatures of 2265 K and 426 K were estimated for a bubble in soybean oil-methanol and tallow-methanol systems, respectively. These "Hot Spots" could be responsible for the increment of the temperature occurred and the acoustic streaming observed during the alkaline transesterification reaction. Also, a diffusion analysis with the pore model was made to predict the concentration profile of the triglycerides within the liquid drops of alcohol created after the collapse of the gas-vapor bubbles; spherical shapes were studied. A computational model was made in MathCad to evaluate the effectiveness at different Thiele modulus values in order to estimate mass transfer coefficients for the most critical conditions of pure diffusion and these coefficients were compared with those found by the cavitation model estimation. Pictures of the reactant system soybean oil-methanol-potassium hydroxide, with the red dyed methanol using phenolphthalein, showed that the alkalinity of the system represented by potassium hydroxide remains in the interface alcohol-oil and then is displaced into the glycerol or down layer. The present study serves as a basis for the analysis of heterogeneous reactions with

  3. Chemical enhancement techniques of bloodstain patterns and DNA recovery after fire exposure.


    Tontarski, Karolyn L; Hoskins, Kyle A; Watkins, Tani G; Brun-Conti, Leanora; Michaud, Amy L


    It is common in forensic casework to encounter situations where the suspect has set a fire to cover up or destroy possible evidence. While bloodstain pattern interpretation, chemical enhancement of blood, and recovery of deoxyribonucleic acid (DNA) from bloodstains is well documented in the literature, very little information is known about the effects of heat or fire on these types of examinations. In this study, a variety of known types of bloodstain patterns were created in a four-room structure containing typical household objects and furnishings. The structure was allowed to burn to flashover and then it was extinguished by firefighters using water. Once the structure cooled over night, the interior was examined using a bright light. The bloodstains were evaluated to see if the heat or fire had caused any changes to the patterns that would inhibit interpretation. Bloodstain patterns remained visible and intact inside the structure and on furnishings unless the surface that held the blood was totally burned away. Additionally, a variety of chemical techniques were utilized to better visualize the patterns and determine the possible presence of blood after the fire. The soot from the fire formed a physical barrier that initially interfered with chemical enhancement of blood. However, when the soot was removed using water or alcohol, the chemicals used, fluorescein, luminol, Bluestar, and Hemastix, performed adequately in most of the tests. Prior to DNA testing, the combined phenolphthalein/tetramethyl benzidine presumptive test for the presence of blood was conducted in the laboratory on samples recovered from the structure in an effort to assess the effectiveness of using this type of testing as a screening tool. Test results demonstrated that reliance on obtaining a positive presumptive result for blood before proceeding with DNA testing could result in the failure to obtain useful typing results. Finally, two DNA recovery methods (swabbing the stain plus

  4. Adsorption properties of cross-linked cellulose-epichlorohydrin polymers in aqueous solution.


    Udoetok, Inimfon A; Dimmick, Raquel M; Wilson, Lee D; Headley, John V


    Cellulose was cross-linked with epichlorohydrin (EP) at variable levels (CLE-0.5, CLE-2 and CLE-4), where CLE-i denotes the cellulose to EP mole ratios. The cross-linked products were characterized by TGA and FT-IR spectroscopy, pH at the point of zero charge (pHpzc), water swelling, and dye-adsorption methods employing two types of dyes [phenolphthalein (phth) and p-nitrophenol (PNP)]. The characterization methods provide evidence of cross-linking of cellulose in accordance with variations in surface area, PZC, available surface hydroxyl groups, and thermal stability when compared against pristine cellulose. The pHpzc of the sorbent materials was ∼ 6.5 indicating a negative surface charge occurs above pHpzc. The cross-linked polymers possess greater swelling properties relative to pristine cellulose. Detailed adsorption studies were carried out at pH 9 for cellulose and CLE-i with five types single component carboxylate anions [2-hexyldecanoic acid (S1), trans-4-pentylcyclohexanecarboxylic acid (S2), 2-dicyclohexylacetic acid (S3), adamantane carboxylic acid (S4), and cyclohexane carboxylic acid (S5)] at 295 K. The uptake properties of PNP with cellulose and CLE-i were also compared at pH 5 and 9, respectively. CLE-2 had the highest uptake of PNP (Qm=1.22 × 10(-1)mmol/g, pH 9) and S1 (Qm=4.27 mg/g) while cellulose and CLE-4 had the strongest binding affinity (1.43 L/mmol and 5.90 × 10(-2)L/mg), respectively. Uptake of PNP by CLE-0.5 at pH 5 (Q m=5.30 × 10(-2)mmol/g) was higher than uptake at pH 9 (Qm=3.11 × 10(-2)mmol/g). Sorption of CLE-4 with S1, S2 and S3 showed that relative uptake of the surrogates had the following order: S3>S2>S1, where S2 had the strongest binding affinity to CLE-i. CLE-2 had the highest sorption capacity towards Si in an equimolar mixture with evidence of molecular selective uptake. At pH 9, low uptake was mainly related to electrostatic repulsion between the negatively charged sorbent surface and the carboxylate head groups of Si.

  5. Application of experimental and numerical simulation techniques to microscale devices

    NASA Astrophysics Data System (ADS)

    Somashekar, Vishwanath

    Two of the areas that have become relevant recently are the areas of mixing in micro-scale devices, and manufacturing of functional nanoparticles. MicroPIV experiments were performed on two different mixers, one a wide microchannel with the surface grooves, in the laminar regime, and the other, a confined impinging jets reactor, in the laminar and turbulent regimes. In the wide microchannel with surface grooves, microPIV data were collected at the interface and the midplane at the Reynolds numbers of 0.08, 0.8, and 8. The experiments were performed on three internal angles of the chevrons, namely 135°, 90°, and 45°. The normalized transverse velocity generated in the midplane due to the presence of the grooves, is the strongest for the internal angle of 135°, and in that, the normalized transverse velocity is maximum at the Reynolds numbers of 0.08 and 0.8. MicroPIV experiments were performed in a confined impinging jets reactors at Reynolds numbers of 200, 1000, and 1500. The data was collected in the midplane, and turbulent statistics were further computed. The high velocity jets impinge along the centerline of the reactor. Upon impinging, part of the fluid turns towards the top wall and the majority of it turn towards the outlet. This high velocity impingement causes and unstable zone called the impingement zone, which moves about the centerline line, causing the jets to flap back and forth. Spatial correlations were computed to get an estimate of the size of the coherent structures. Large eddy simulation was performed on the CIJR for the Reynolds numbers of 1000 and 1500, using OpenFOAM. The Reynolds number is based on the inlet jet hydraulic diameter. Excellent agreement was found with the experimental and simulation data. Turbulent reactive mixing in a rectangular microscale confined impinging-jets reactor (CIJR) was investigated using the pH indicator phenolphthalein in this study for three different jet Reynolds numbers of 25, 1000 and 1500. Laminar

  6. Self-Assembled and Cross-Linked Animal and Plant-Based Polysaccharides: Chitosan-Cellulose Composites and Their Anion Uptake Properties.


    Udoetok, Inimfon A; Wilson, Lee D; Headley, John V


    Self-assembled and cross-linked chitosan/cellulose glutaraldehyde composite materials (CGC) were prepared with enhanced surface area and variable morphology. FTIR, CHN, and (13)C solid state NMR studies provided support for the cross-linking reaction between the amine groups of chitosan and glutaraldehyde; whereas, XRD and TGA studies provided evidence of cellulose-chitosan interactions for the composites. SEM, equilibrium swelling, and nitrogen adsorption studies corroborate the enhanced surface area and variable morphology of the cross-linked biopolymers. Equilibrium sorption studies at alkaline conditions with phenolic dyes, along with single component and mixed naphthenates in aqueous solution revealed variable uptake properties with the composites. The Freundlich isotherm model revealed that the composite at the highest levels of cross-linker, CGC3, had the highest sorption affinity (KF; L mmol/g) for phenolphthalein (phth) followed by ortho-nitrophenyl acetic acid (ONPAA) and para-nitrophenol (PNP), as follows: Phth (5.03 × 10(-1)) > ONPAA (2.28 × 10(-1)) > PNP (8.49 × 10(-2)). The Sips isotherm model provided a good description of the sorption profile of single component and naphthenate mixtures. The monolayer uptake capacity (Qm; mg g(-1)) is given in parentheses: 2-hexyldecanoic acid (S1; 115 mg/g) > 2-naphthoxyacetic acid (S3; 40.5 mg/g) > trans-4-pentylcyclohexylcarboxylic acid (S2; 13.7 mg/g). By comparison, the Qm values for CGC3 with naphthenate mixtures (24.1 and 27.4 mg/g) according to UV spectroscopy and electrospray ionization mass spectrometry (ESI-HRMS). The sorbent materials generally show greater uptake with naphthenates that possess lower vs higher double bond equivalence (DBE) values. Kinetic studies revealed that the sorption of phth adopted behavior described by the pseudo-second order model, while uptake for S3 and naphthenate mixtures adopted pseudo-first order behavior. This study contributes to a greater understanding of the

  7. Self-Irradiation Effects on 99Mo Reagents and Products

    SciTech Connect

    Carson, S.D.; Garcia, M.J.; McDonald, M.J.; Simpson, R.L.; Tallant, D.R.


    produced in 1996 and shipped to pharmaceutical houses for evaluation of compatibility with oxime solution used to precipitate `?vfo as the oxime complex is both air and light-sensitive, and containing a black precipitate that forms during shipment, presumably as a result of self- irradiation. Addition of sodium hypochlorite to the product solution prior to shipment prevents precipitate formation, indicating the precipitate is a reduced form of `%lo. to remove any precipitate. Duplicate aliquots of the filtered samples were titrated to a phenolphthalein irradiation and afler standing at room temperature for 86.4 hours. Precipitates were washed to a FTIR analysis of the white precipitate showed it to be alpha benzoin oxime. Since the basic After 86.4 hours, no precipitate had formed in bottles containing sodium hypochlorite. Black precipitate had formed in all bottles that did not contain sodium hypochlorite after 14.4 hours. The precipitate appeared to initially form on the surface of the HDPE sample bottles and Black precipitate was first noticed in sample set 1 after 28.8 hrs' irradiation. No visible sample containing precipitate was kept at room temperature in the original bottle. Precipitate in sample sets 2 and 3. Since no precipitate formed in these bottles, this was equivalent to duplicate samples. Once the precipitate in the 20-mL aliquots that had been set aside had returned to sample sets 1 through 3 and the samples with redissolved precipitate all experienced an average decrease in base strength of 0.013 meq mL-l. Sample 1-C had a decrease of 0.004 meq mL-l and sample 1-D had returned to the initial value of 0.198 meq mL-l. Raman spectra for the black precipitate from samples l-C, 1-D and supplemental sample set 1 Fig. 2. Raman spectra of the black precipitate formed in 9%40 product solutions after 28.8,43.2, 72 and 86.4 hours of `oCo irradiation in Sandia's Gamma Irradiation Facility. increase with time, as seen in the titration of 1-C and 1-D samples

  8. Photocatalytic oxidation of organic compounds via waveguide-supported titanium dioxide films

    NASA Astrophysics Data System (ADS)

    Miller, Lawrence W.

    A photochemical reactor based on titanium dioxide (TiO2)-coated silica optical fibers was constructed to explore the use of waveguide-supported TiO2 films for photocatalytic oxidation of organic compounds. The reactor was used for the photocatalytic oxidation of 4-chlorophenol in water. It was confirmed that TiO2 films could be securely attached to silica optical fibers. The 4-chlorophenol (100 mumol/L in water) was successfully oxidized on the TiO2 surface when UV light (310 nm--380 nm) was propagated through the fibers to the films. Rates of 4-chlorophenol oxidation and UV light flux to the fibers were measured. The quantum efficiency of 4-chlorophenol oxidation [defined as the change in 4-chlorophenol concentration divided by the UV light absorbed by the catalyst] was determined as a function of TiO2 catalyst film thickness and internal incident angle of propagating UV light. A maximum quantum efficiency of 2.8% was measured when TiO2 film thickness was ca. 80 nm and the maximum internal incident angle of propagating light was 84°. Quantum efficiency increased with increasing internal angle of incidence of propagating light and decreased with TiO2 film thickness. UV-Visible internal reflection spectroscopy was used to determine whether UV light propagated through TiO2-coated silica waveguides in an ATR mode. Propagation of UV light in an ATR mode was confirmed by the similarities between internal reflection spectra of phenolphthalein obtained with uncoated and TiO2-coated silica crystals. Planar silica waveguides coated with TiO2 were employed in a photocatalytic reactor for the oxidation of formic acid (833 mumol/L in water). It was shown that the quantum yield of formic acid oxidation [defined as the moles of formic acid oxidized divided by the moles of UV photons absorbed by the catalyst] on the waveguide-supported TiO2 surface is enhanced when UV light propagates through the waveguides in an ATR mode. A maximum quantum yield of 3.9% was found for formic