Showing papers on "Buffer solution published in 1983"

Chemical stability of carbonate- and fluoride-containing apatites.

Abstract: Apatites containing CO3 and/or F were synthesized and exposed to acid buffer. The extent of dissolution was determined (as m M Ca/ml buffer solution) and the apatites chara

Effect of pH on Disintegration and Dissolution of Ketoconazole Tablets

Abstract: The effect of pH on the in vitro disintegration, dissolution, and solubility of ketoconazole tablets was studied. One 200-mg ketoconazole tablet was added to each of five different buffer solutions having pH values of 2 to 6;900 ml of each solution containing the ketoconazole was placed in a stationary basket dissolution device and stirred at 500 rpm at 37 degrees C for 60 minutes. Single 1-ml samples of each solution were obtained at 1,3, and 5 minutes after addition of the drug, and then every 5 minutes for the duration of the sampling period. This same procedure was repeated using two 200-mg tablets in the buffer solution at pH 3. The effect of pH on ketoconazole solubility was studied by gradually increasing the pH of a ketoconazole solution at pH 3 to pH 10. Samples of this solution were analyzed periodically after allowing a short period for equilibration of pH. All samples were assayed spectrophotometrically against blanks, and concentrations were determined by comparison with a standard curve. Disintegration of ketoconazole tablets occurred within 5 minutes in each buffer solution and was unaffected by pH. At pH 2 and 3, dissolution of ketoconazole was greater than 85% complete after five minutes, and all ketoconazole had dissolved after 30 minutes. As pH increased, the rate and extent of dissolution slowed; only 10% of ketoconazole was dissolved after 60 minutes at pH 6. Ketoconazole precipitated rapidly from solution as the pH of the dissolution medium exceeded 5.5. There was no difference in the rate or extent of dissolution of ketoconazole for the two doses studied at pH 3. In the buffer solutions tested, dissolution but not disintegration of ketoconazole tablets is pH-dependent. Dissolution characteristics of 200- and 400-mg doses of ketoconazole are similar at pH 3.

LIME REQUIREMENT DETERMINATION OF ACID ORGANIC SOILS USING BUFFER-pH METHODS

Abstract: The aims of this study were to calibrate and assess the accuracy of seven buffer solutions for determining the lime requirement (LR) of organic soils using buffer-pH methodology. The various buffers were evaluated by comparing the precision of regression equations adjusted to the relationships between the LR rates required to achieve pH 5.0 (0.01 M CaCl2; ≈ 5.4 (H2O)), as determined by incubation, and soil-buffer pH values. The buffers tested and their initial pH values were as follows: Shoemaker, McLean and Pratt (SMP), pH 7.5; Woodruff, pH 7.0; Yuan, pH 7.0 and 6.0; Mehlich, pH 6.6; 0.1 N Ca(OAc)2, pH 5.5; 0.1 N Ba(OAc)2, pH 5.5; and 0.1 N NH4OAc, pH 5.5.Results indicate that the liming material had reacted with the CaCO3 neutralizable acidity of these soils within 2 mo as the pH values of the incubated samples did not change materially from the 2nd to the 8th month of incubation. Furthermore, the pH values of the soils utilized in this study increased linearly with increasing rates of applied CaCO3. In...

Hepatocyte growth factor

Abstract: PURPOSE: The titled factor, protein derived from mammalian serum, having specific physical and chemical properties, and physiological activity. CONSTITUTION: A hepatocyte growth factor, protein [estimated molecular weight by gel filtration: 150,000; adsorbed on DEAE-cellulose equilibrated with 10mM phosphoric acid buffer solution (pH=7.0), eluted with the buffer solution containing 0.2M NaCl; not adsorbed on CM-cellulose equilibrated with 10mM phosphoric acid buffer solution (pH=7.0); adsorbed on heparin-Sepharose CL-6B equilibrated with 10mM phosphoric acid buffer solution (pH=7.0), not eluted with the buffer solution containing 0.5M NaCl, eluted with the buffer solution containing 1.5M NaCl; having activity to multiply hepatocyte growth factor in vitro] obtained from mammalian (e.g., human, horse, bovine, etc.) serum by combining treatment with protein-precipitating medium with ultrafiltration, molecular sieve chromatography, centrifugation, etc. COPYRIGHT: (C)1985,JPO&Japio

A solid‐phase buffer technique to maintain low concentrations of phosphate in nutrient solutions

Abstract: An inexpensive and mechanically simple technique has been developed to maintain realistically low P concentrations in nutrient solutions using a solid‐phase buffer. Phosphate is adsorbed on alumina in a PVC column, and the resulting alumina‐F is desorbed against nutrient solution circulated through the column. Kinetics of P adsorption and desorption indicate that the solid‐phase‐P has rapidly and slowly desorbing components and that buffering capacity is limited by desorption from the solid phase. The technique has been used to maintain F concentrations as low as 0.4 minol m‐3 for 26 days in experiments with maize (Zea mays L.), and in solution cultures with prune (Prunus domestica L.) trees. Effects of P supply on P accumulation and P transport are discussed.

Low-molecular weight peptide mixture and method of producing same

Abstract: A method of producing a low-molecular weight peptide mixture, comprising the steps of dissolving a first protease in a buffer solution adjusted to an optimum pH for the protease ranging from pH 3 to 10, adding at least one first protein in a buffer solution having a pH of from 3 to 10 and a concentration of 10 to 60% by weight of the protein material and thoroughly mixing the solution, adding a solution of an ester of at least one amino acid pre-formed by esterification of the amino acid with an alcohol, the pH of said buffer solution being optimum for the incorporation of said amino acid in said starting protein in the presence of said first protease in a plastein reaction, reacting said ester of at least one amino acid with said starting protein in a plastein reaction in the mixed solution whereby said at least one amino acid is covalently incorporated into said starting protein to produce a plastein reaction solution containing a modified protein, hydrolyzing said modified protein using at least one second protease having a different specificity from said at least one first protease to produce a low-molecular weight peptide mixture having an amino acid content which has different proportions of amino acids than does said starting protein, and separating from the solution said low-molecular weight peptide mixture which comprises a major proportion of dipeptides and tripeptides and containing not more than 15% by weight of free amino acids and not more than 20% by weight of a high-molecular weight fraction of compounds having a molecular weight of not lower than 700 and removable by gel filtration. The said low-molecular weight peptide mixture is readily absorbable and a useful nutrient.

Reagent for measuring direct bilirubin by enzymatic method and method for measurement thereof

Abstract: Reagent for the measurement of direct bilirubin comprising a buffer solution having a pH range of 3.5 to 4.5 which contains bilirubin oxidase, preferably in the form of a test kit consisting essentially of (i) a buffer solution having a pH range of 3.5 to 4.5, (ii-a) a lyophilized bilirubin oxidase, (ii-b) a buffer solution for dissolving the lyophilized bilirubin oxidase, and (iii) a standard serum containing a prescribed amount of bilirubin, and a method for measurement of direct bilirubin by using the reagent. The reagent and method are useful for diagnosis of various diseases, for example, various hepatic diseases (e.g. jaundice) and cholepathia.

Determination of sulfurous acid in liquids and an apparatus therefor

Abstract: A method and an apparatus providing a simple and speedy determination of a slight amount of sulfurous acid contained in liquids by means of pH meters, based on the Modified Rankine's method in principle, and wherein the pH of a first sample of liquid is determined before and after adding an amount of hydrogen peroxide thereto, the pH of a second sample of liquid is determined before and after adding an amount of an acid or lower pH buffer solution thereto, and the concentration of sulfurous acid in the liquid is calculated from the measured pH values and an equation derived from the functional relationship: c=f(ΔpH.sub.A, ΔpH.sub.B) wherein c is the concentration of sulfurous acid.

Simple measuring method for hemoglobin a1 in blood

Abstract: PURPOSE:To obtain a simple measuring method having high practical value without being interferred with temperature completely in normal operation temperature, by basing on a HbA1a, b, c batch elution using a micro column and passing a development liquid having lower salt concentration or pH than a buffer solution filled in the column preliminarily and then, forming a continuous concentration gradient in the column. CONSTITUTION:A column 1 packed with a weak acidic cation exchange resin 2 equillibrated by a phosphate buffer solution consisting of acidic phosphate and basic phosphate, is used. At first, caps 7 and 8 of the column 1 shown by figure (a) are taken off and the buffer solution in the column 1 is flowed out. Next, hemolytic blood 3 is dropped to the center of 50mul resin as shown by figure (b). After the blood 3 soaked into the resin, 750mul development solution 9 belonging to the same group as the buffer solution used for conditioning of the ion exchange resin and having lower hemoglobin elution than said buffer solution, is added to the blood 3 and the hemoglobin in the blood 3 is developed in the column 1 as shown by figure (c). HbA1a, b, c are eluted passing through 8ml eluting solution 10 having a higher hemoglobin elution effect than the solution 9 after throwing away the whole outflow from the lower end of the column 1.

Preparation and Properties of Polymers Anchoring Biphenyl-2-ol

Abstract: The monomer, 2-biphenylyl acrylate (BPA), was prepared and was polymerized and copolymerized with vinyl acetate (VAc), styrene and N-vinylpyrrolidone. The reactivity ratios of BPA (M1) with VAc were evaluated as r1=4.6+0.4 and r2=0.37+0.08. The polymers were hydrolyzed in methanol–phosphate buffer solution(pH 6 and 8), and the release rate of biphenyl-2-ol from the polymer was investigated.

Buffer and Salt Damage to the Filamentous Cyanobacterium Anabaena cylindrica

Abstract: Summary: The commonly used buffer HEPES was found to cause severe disintegration of the cyanobacterium Anabaena cylindrica, as measured by filament breakage, cell disruption, phycocyanin release and nitrogenase inhibition. The effect became increasingly severe as the buffer concentration was increased above 10 mM. The observed cell damage does not appear to be unique to HEPES, similar observations being made with Tris/HCl, sodium phosphate, sodium sulphate and sodium chloride. It appears that the cells are very sensitive to ionic strength.

Intermediate rinse for cold permanent wave setting

Abstract: PURPOSE:A rinse that is made by adding glyoxal and anionic and/or nonionic surfactants to a solution with buffering action and is used in the intermediate step in the two-bath type cold permanent wave setting to inactivate the unreacted thioglycolic acid. CONSTITUTION:The titled rinse is obtained by adding glyoxal and surfactants to a buffer solution of 5-6pH so that their concentrations become 1.5-3 and 0.001-0.1% respectively. As the buffer solution, is cited an aqueous solution containing an organic acid of less than 5 pK1 such as acetic acid or citric acid and its alkali metal salt or alkali metal hydroxide, while sodium laurylsulfate or polyoxyethylene nonylphenyl ether is cited as a surface active agent. The resultant rinse neutralizes the alkali, simultaneously inactivates the remaining thioglycolic acid to prevent the second agent from lowering its effect and the hair from being damaged.

Chemical gilding bath

Abstract: A chemical gilding bath is formulated on the basis of an alkaline, aqueous solution of an alkali gold cyanide complex and has a reducing agent and a stabilizing agent therein. The reducing agent is an organic compound containing at least one enol group within the molecular structure thereof, such as ascorbic acid or salts thereof. The pH value of the bath is adjusted by a buffer solution so as to range between about 7.5 to 12 and preferably is about 8.

Simple and quick microquantitative determination of hemoglobin

Abstract: PURPOSE:To quantitatively determine hemoglobin simply and quickly, by acting an oxidizing agent to the blood to produce Fe and denaturated protein, then reduced to Fe by adding a reducing agent and develops the color of Fe by a specific reagent, then dissolving denatured protein by adding a buffer solution, etc. and determine Fe by colorimetry. CONSTITUTION:A fixed quantity of 100 times diluted blood is sampled to a test tube and a NaClO solution, an aqueous solution of H2O2, and a mixed sulution of aqueous solution of Na2O2 etc., and hydrochloric acid, are added and is left for a prescribed time. Hereafter, an aqueous solution of a reducing agent such as ascorbic acid and thioglycolic acid, etc. to produce Fe . Next, after adding an aqueous solution of bathophenanthrone, 1M acetic acid buffer solution (6.5pH) or alkaline solution is added in order to remove turbidity of colored liquid and denatured protein is dissolved. Then, the colorimetric determination is carried out by 535nm wavelength. On one hand, blank value is found by operating in the same way not adding blood as the comparison and the Fe is measured and then, the quantity of hemoglobin is found by calculating said measured value.

バナジウム(iv)-シクロヘキサンジアミン四酢酸錯体のポーラログラフ接触波による硝酸及び亜硝酸イオンの定量法

Abstract: The polarographic reduction current of 1, 2-cyclohexanediaminetetraacetato-vanadium (IV) complex {V (IV)-CyDTA} in NH4Cl-NH3 buffer solution increased with adding nitrate or nitrite to this solution, that is, a catalytic wave appeared. When the concentration of V(IV)-CyDTA is five times larger than that of nitrate or nitrite ion, the catalytic current is proportional to the concentration of the oxidant. This phenomenon was utilized for the determination of nitrate and nitrite ions. Nitrate or nitrite ion in NH4Cl-NH3 buffer solution was determined at pH 8.6 by this method. Nitrite ion in the mixture of nitrate and nitrite ions could be determined without the influence of nitrate ion by using V(IV)-CyDTA of less than 0.5 mM. However, as the determination of nitrate ion in the mixture was affected by nitrite ion, a calibration curve for nitrate ion in the presence of a known amount of nitrite was obtained by using V(IV)-CyDTA in (110) mM and nitrate ion in the mixture could be determined. This method is useful for the determination of nitrate ion and/or nitrite ion in the mixture of both ions.

Production of immobilized microbial cell or enzyme

Abstract: PURPOSE: To produce immobilized microbial cell or enzyme having high mechanical gel strength, in high efficiency, with extremely little loss of the enzymatic activity, by adding silica sol to carrageenan or agar, etc, and using the mixture as the gel substrate CONSTITUTION: Carrageenan, agar or gelatin is dissolved in water, a buffer solution or a hydrophilic organic solvent under heating, and silica sol is dissolved in said solution under heating to obtain a gel substrate The substrate is mixed with microbial cells, enzyme, insolubilized enzyme, or enzyme adsorbed to an insolubilized carrier, or suspension of the above substances in water, a buffer solution or a hydrophilic organic solvent, to obtain a gel substrate mixture having a pH of 3W10 The mixing is carried out at a temperature to prevent the solidification of the gel substrate and the extermination or inactivation of the microbial cell or enzyme The obtained gel substrate mixture is made to contact with a gelatinizing agent COPYRIGHT: (C)1985,JPO&Japio

Color reagent for determining magnesium

Abstract: PURPOSE:To prepare a color reagent which can accurately determine Mg through a simple operation and has an excellent shelf stability, by heat ageing a carbonate buffer solution containing xylidyl blue, a nonionic surface-active agent, N(C2H5OH)3, and glycol etherdiaminetetraacetic acid. CONSTITUTION:A carbonate buffer solution of pH10.5-12.0 containing 0.008- 0.015% xylidyl blue, 3-8% nonionic surface-active agent such as polyoxyethylene nonylphenyl ether, 0.1-0.2% glycol etherdiamine-N,N,N',N'-tetraacetic acid, and 0.1-0.3M Na2CO3 is heat aged to prepare a color reagent for determining and analyzing MgO in soil. A specified quantity of the reagent is added to a specified quantity of liquid MgO extract to color the extract for colorimetry. The reagent is well dissolved in distilled water and needs no alcohol. Interfering ion such as Fe, Mn or Ca is masked to allow determination of Mg without any obstacle. The reagent can be preserved stably for at least 2 months.

Recovery of enzyme

Abstract: PURPOSE:To carry out the desorption and recovery of enzyme from an ion exchange material adsorbed with the enzyme, in high efficiency, without causing the deactivation of the enzyme, by using a solution of ammonium sulfate as the desorption liquid. CONSTITUTION:In the desorption of various enzymes such as acyl polyamineamide hydrolase adsorbed to an ion exchange material such as weakly acidic anion exchange material, a solution of ammonium sulfate is used as the desorption liquid. The solution is e.g. aqueous solution, buffer solution, or an aqueous solution containing an organic solvent such as acetone, ethyl alcohol, etc., and the concentration of ammonium sulfate is usually 0.025-0.5mol.

Cellular biocatalysts and the preparation thereof

Abstract: The cellular biocatalysts can be obtained by A) Immobilisation of an enzymatically active cell material from whole, undamaged native or optionally previously permeabilised cells or cell fragments and the subcellular particles thereof and/or mixtures of whole native cells with their cell fragments, subcellular particles and the complete, liberated cell contents and/or whole, individually crosslinked and permeabilised cells by bringing into contact, at -30 to +50 DEG C in an aqueous medium and at a pH of 5.0 to 9.0, with a water-soluble, chemically reactive polymer which is obtained by reaction of a water-soluble substance with at least two primary and/or secondary amino groups in the molecule with one or more dialdehydes at 0 to 60 DEG C in an aqueous medium at a pH of 4.0 to 12.0, B) removal of the resulting cell aggregates from the reaction mixture and washing wih water or a buffer solution and, where appropriate, C) further permeabilisation and/or mechanical stabilisation. The cellular biocatalysts according to the invention which are based on immobilised cells are suitable for industrial biotechnological conversions in batchwise or continuous processes, especially for generating products and intermediates of pharmacological, agricultural or nutritional importance.

Stabilizing device for buffer solution

Abstract: PURPOSE:To raise safety by installing a device that detects the flow of a buffer solution and cutting off the power source to temperature regulating device and so on or sounding an alarm buzzer or other safety means. CONSTITUTION:A buffer solution 16 in a vessel 15 for the buffer solution is supplied by means of a circulation pump 25 through a pipe 17 to a pipe 27 that is wound round a heating drum 26. The buffer solution whose temperature has reached a constant temperature through the heating drum 26 is returned again to the buffer solution vessel 15 by traversing the wall. Here the oxygen dissolved in the buffer solution is balanced by the multiple effect of the negative effect to the buffer solution and pulsating flow effect by the circulation pump 25 and the heating effect by the heating drum 26. While the buffer solution is circulating, the light flux from the light source 19 gets into a light receiving element 21 to turn on a switching circuit and supplies electric power of the power source 24. If the buffer solution is exhausted, total reflection develops by the difference of the reflective indices by passing from a glass tube 20' to the air and incident light to the light receiving element 21 to turn off the switching circuit and overheat is avoided.