Acid Sodium Hydroxide Research Articles

Reactions of 6‐Tricyanovinyldihydroquinolines

AbstractReactions of 6‐tricyanovinyldihydroquinoline with concentrated hydrochloric acid and methanolic sodium hydroxide yield chlorine substitution on the heterocyclic ring and methoxide substitution of the cyano group, respectively. The chlorine substitution via a radical process is initiated from the tricyanovinyl group by the irradiation of visible light.

Determination of cisplatin and cis-diammineaquachloroplatinum(II) ion by liquid chromatography using post-column derivatization with diethyldithiocarbamate

A post-column derivatization method has been developed for the determination of cisplatin and its monohydrated form. Cisplatin was isolated on a strong anion-exchange column, while a strong cation-exchange column was used for the monohydrated complex. Diethyldithiocarbamate was used as reagent and the influence of temperature, pH and methanol content on the yield of derivative was investigated. The reaction was quantitative using a packed-bed reactor with a surrounding temperature of 115°C and a mobile phase consisting of 0.125 M succinic acid—sodium hydroxide buffer pH 5.2 and methanol (2:3, v/v). The resulting complex, Pt(DDTC) 2, was monitored photometrically at 344 nm. The precision of the determination was 11.5% (C.V.) at an injected amount of 20 ng ( n = 12) for monoaqua and 8.0% (C.V.) at 9 ng ( n = 10) for cisplatin. The method was used to evaluate the plasma concentration of cisplatin and its monohydrated form in a patient.

A radioanalytical method for samarium-151 and promethium-147 in environmental samples

A radioanalytical method for low level samarium-151 (151Sm) and promethium-147 (147Pm) in environmental samples has been studied for the environmental assessment around nuclear facilities. In this study, we use the separation method with high performance liquid chromatography (HPLC) to determine 151Sm and 147Pm in environmental samples such as sea sediments and marine organisms. Samarium-151 and 147Pm in environmental samples are coprecipitated with other lanthanoids alter adding neodymium (Nd). These nuclides are purified by anion exchange methods in methanol-mineral acid media. After the purification, 151Sm and 147Pm are separated with HPLC in lactic acid-sodium hydroxide media, and determined with liquid scintillation counting, respectively. The Nd is determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) to correct chemical recoveries of these nuclides. The detection limits for 151Sm and 147Pm in this method are about 0.01 Bq/sample

A comparative study of the influence of surface pretreatment on the failure characteristics of adhesively bonded titanium

AbstractThe durability of adhesive joints fabricated from two titanium alloys, commercially pure titanium (TA6) and Ti–6Al–4V (TA10), has been investigated using the wedge cleavage test. Seven different methods of adherend pretreatment were investigated: writ blasting (GB), chromatic acid anodizing (CAA) and sodium hydroxide anodizing (SHA), used alone and with the addiiton of an epoxy primer prior to adhesive bonding. A silane adhesion promoter was also used in conjunction with the grit‐blasted adherend. As expected, the durability depended critically on the substrate pretreatment, with SHA‐treated joints giving the best durability and GB the worst performance. The application of a primer or adhesion promoter tended to improve the situation somewhat. The failure mode was apparently adhesive (interfacial), but when the interfacial failure surfaces were examined by XPS, polymeric residues were identified on the adherend surfaces of all joints. In the case of those joints that exhibited good durability three was evidence of transfer of titanium to the polymer side of the locus of failure. The locus of failure in these cases may be described in terms of a mixed mode failure on a microscale.

Determination of glyphosate and its metabolite, (aminomethyl)phosphonic acid, in serum using capillary electrophoresis

Capillary electrophoresis has been used to separate and quantitate glyphosate and its major metabolite, (aminomethyl)phosphonic acid (AMPA), in serum. The two compounds, after derivatization with p-toluenesulphonyl chloride, were clearly separated with 0.1 M boric acid—sodium hydroxide buffer (pH 9.6) containing 10% methanol. The separation was completed within 15 min at an applied potential of 30 kV. Calibration curves for the assay were linear over both the lower (0.5–10 μg/ml) and the higher (10–100 μg/ml) concentration ranges. The within-run and day-to-day coefficients of variation of peak area were 1.4–4.4 and 4.4–8.5%, respectively, for glyphosate and 1.8–2.9 and 1.8–2.9%, respectively, for AMPA. The within-run and day-to-day precisions of the migration time for both compounds were less than 1.8% and less than 2.5%, respectively. The detection limit of both derivatives was 0.1 μg/ml in spiked sera, and the recoveries of glyphosate and AMPA were 87.9–88.8 and 78.4–86.9%, respectively. In this study, the reproducibility and the effect of pH changes on the electropherograms were especially examined.

Comparison between enzymatically and chemically extracted pectins from apple cell walls

The pectic material that was not extractable by cyclohexane-diamino-tetracetic acid was extracted from apple cell walls (i) successively by hot buffer, hot acid and cold dilute sodium hydroxide, and (ii) in parallel by buffer, arabinanases and galactanase and pectin-lyase. The pectin extracts were analysed for uronic acid and neutral sugar contents. Their molecular weight distribution was obtained by gel-permeation chromatography. Subfractions from gel-permeation chromatography were also analysed for uronic acid and individual neutral sugars. The pectin-lyase extracted the highest amount of uronic acid (55% of the strongly bound uronides). The dilute sodium hydroxide, solubilizing 34% of the uronic acid, was the most efficient chemical treatment. Hot acid and arabinanases and galactanase led to extraction of limited amounts of pectins. The sodium hydroxide and pectin-lyase extracts showed two subfractions on gel-permeation chromatography, one of them rich in neutral sugars and of high molecular weight.

Boron isotope fractionation accompanying boron mineral formation from aqueous boric acid-sodium hydroxide solutions at 25.DEG.C..

A series of experiments was carried out in which boron minerals were precipitated from pH- and chemical composition-controlled solutions at 25°C and boron isotope fractionation accompanying the mineral deposition was measured. Borax, sassolite and sborgite were synthesized from aqueous boric acid-sodium hydroxide solutions. Borax was obtained from solutions with higher pH and sassolite from solutions with lower pH, irrespective of the mole ratio of B and Na in the solution. The fractionation factor, S, defined as S = (11B/10B)mineral/(11B/10B)solution increases with increasing the pH of the solution for both borax and sassolite. A cross-over point at which S = 1 was found at about pH = 9.5 for borax, while S was always larger than unity for sassolite. The present results of boron isotope fractionation are consistent with theoretical prediction of equilibrium isotope effects, although the experimental equilibrium constant of the boron isotope exchange reaction between B(OH)3 and B(OH)4– at 25°C is larger than that theoretically predicted (1.03–1.05 compared to 1.0194).

Atividade moluscicida da mistura de ácidos 6-n-alquil salicílicos (ácido anacárdico) e dos seus complexos com cobre (II) e chumbo (II)

The molluscicide activity of hexanic extract from Anacardium occidentale L. (cashew) nut shell, of copper (II) complex, of lead (II) complex and anacardic acid has been compared in the laboratory in an attempt to obtain better stability than anacardic acid. This was obtained from the hexanic extract of the cashew nut shell by precipitation with lead (II) hydroxide or cupric sulfate plus sodium hydroxide or (II) cupric hydroxide followed by treatment of lead (II) complex with a diluted solution of sulfuric acid. Ten products of the mixture obtained were tested on adults snails of Biomphalaria glabrata at 1 to 10 ppm. The most active products were copper (II) complex, obtained by cupric sulfate plus sodium hydroxide, and anacardic acid (sodium hydroxide) which presented activity at 4 ppm. The anacardic acid's lead content was above the limits accepted by the United States standards.

Effect of Curd Forming of Colostrum on Absorption of Immunoglobulin G in Newborn Calves

Pooled colostrum from the first three milkings postpartum was used in two trials to determine the effect of abomasal curd forming on absorption of IgG in newborn calves. In Experiment 1, two groups of seven Friesland calves each received 1h postpartum 1L of untreated colostrum or colostrum treated with an oxalic acid-sodium hydroxide buffer to prevent coagulation. Calves were not allowed to suckle their dams and received colostrum in teat bottles. The same treatments were applied for Experiment 2, except that eight calves per group were used, and each calf received 2L colostrum. Blood samples were taken from the jugular vein 6h postfeeding, and plasma IgG concentration was determined by a radial immunodiffusion technique.Plasma IgG concentration, estimated IgG absorption, and apparent efficiency of absorption 6h postfeeding for the coagulable and noncoagulable treatments, respectively, were 11.6 and 6.6 mg/ml, 28.1 and 15.8 g/d, and 87.8 and 49.3% for Experiment 1; and 21.2 and 12.9 mg/ml, 48.6 and 34.2 g/d, and 60.8 and 42.8% for Experiment 2. It was concluded that the curd-forming ability of colostrum is an important factor in effective absorption of IgG by calves during the first 6h postfeeding.

Casein Curd-Forming Ability and Abomasal Retention of Milk Replacer Components in Young Calves

Thirty-six Holstein calves, 2 to 4 d of age, were randomly divided into two groups to determine the effect of curd development on abomasal retention times and estimated passage rates of different milk replacer components. One milk replacer based on low heat skim milk powder was formulated to contain 25.8% CP and 21.1% fat. Casein coagulation was prevented in one case by precipitating Ca++ with an oxalic acid-sodium hydroxide buffer solution added to the reconstituted diet. The abomasa of all animals were removed following anesthesia, and the contents were measured and analyzed for fresh matter, DM, CP, and fat. For both the control and treated calves, measurements wee made on two animals before feeding time and on four animals at 1, 2, 4, and 6h postfeeding. Abomasal curd development resulted in significantly higher retention values of DM, CP, and fat at 1,4, and 6h postfeeding than when curd was prevented. At 2h postfeeding, curd development tended to result in higher CP and fat retention but DM retention was lower than in the absence of curd formation. Estimated cumulative flow over 6h postfeeding of DM, CP, and fat, expressed as percentage of intake, was higher for the treated group than for control, which was not the case for fresh matter. The technique developed in the present work may have advantages over usual cannulation techniques because physiologically intact animals are used.

New Polymer Synthesis: Polymers Possessing Diiminosulfoxide Functionality in the Backbone

Abstract Three new monomers with sulfinylimine functionality have been prepared. They react with appropriate aromatic diamines to give a new class of polymers having the diiminosulfoxide (—NH—SO—NH—) functional group in their backbone. the monomers as well as polymers are characterized by spectral data and elemental analysis. Experiments were carried out to find the effect of reaction time and solvent on the polymerization reaction. the polymers are soluble in electron-donating organic solvents, such as DMF, NMP, and DMAC, and insouble in most nonpolar solvents. They are thermostable up to 200°C, but their stability in the presence of sulfuric acid and aqueous sodium hydroxide is low.

Determination of salicylic acid and its metabolites in urine by derivative synchronous spectrofluorimetry

The simultaneous determination of salicylic acid in binary and/or ternary mixtures and its two main urinary metabolites is proposed. Mixtures of salicylic, salicyluric and gentisic acids are resolved by synchronous spectrofluorimetry, in combination with first-derivative measurements. The urine is extracted with diethyl ether in acid medium. Salicylic and salicyluric acids are re-extracted into glycine-sodium hydroxide buffer solution of pH 11.6 and determined at that pH, and salicylic and gentisic acids are re-extracted into boric acid-sodium hydroxide buffer solution of pH 8.5 and determined at pH 6.

Dissolution into multicomponent solutions: Benzoic acid and aqueous sodium hydroxide

Multicomponent diffusion equations have been used to describe dissolution of a solid into a ternary liquid mixture. The example of dissolution of benzoic acid into aqueous sodium hydroxide solutions is treated in order to illustrate the importance of coupled diffusion. In this example, diffusion of dissolved acid from the solid/liquid interface into the bulk solution produces a large counterflow of sodium hydroxide. The resulting buildup of sodium hydroxide near the solid/liquid interface increases the steady-state solubility of benzoic acid in the interfacial solution by about 50% relative to its solubility in the bulk sodium hydroxide solution. Ternary diffusion coefficients for aqueous benzoic acid + sodium hydroxide mixtures at 25°C are reported.

Application of Van Soest Acid Detergent Fiber Method for Analysis of Shellfish Chitin

The Van Soest acid detergent fiber method was compared with the modified Welinder method for chitin analysis of Alaskan crab and shrimp meals to determine whether chitin constituted a significant fibrous component of shellfish meals. In the Welinder method, chitin is determined gravimetrically following decalcification and deproteinization with .1 M ethylenediaminetetraacetic acid and 2N sodium hydroxide, respectively, Chitin is a fibrous component of shellfish meals, and the Van Soest acid detergent fiber method is acceptable for determination of shellfish chitin.

Reversed-phase ion-pair partition chromatography of iron, cobalt and nickel chelates with 4-hydroxy-3-(2-pyridylazo)naphthalene-1-sulphonic acid

The reversed-phase ion-pair partition chromatography of 4-hydroxy-3-(2-pyridylazo0naphthalene-1-sulphonic acid (α-PAN-4S) and its metal chelates was studied. Cobalt(III), iron(I) and nickel(II) chelates and excess of α-PAN-4S were separated on the column and eluted with acetonitrile—water (37–:60–63, v/v) containing 0.025 M tetrabuylammonium bromide, 0.005 M 3-(N-morpholino)propanesulphonic acid—sodium hydroxide buffer (pH 7) and 10 −4 M Na 2(EDTA). Cobalt, iron and nickel were simultaneously determined without interferences from other metals. The effects of the elunt composition and pH on the retention of all species were examined. The method was applied to the determination of cobalt, iron and nickel in a glass sample.

Equivalence-point location in the titration of a weak acid with sodium hydroxide solution: a comparison of photometric and potentiometric methods. Influence of titrant carbonation on the accuracy and precision of end-points

Using standard laboratory equipment a statistical comparison was carried out of several photometric methods (normal and various Higuchi plots) and potentiometric methods (point of inflection and Gran) for equivalence-point location in an acetic acid-sodium hydroxide solution titration. All methods exhibited similar precision but were divided into two groups with respect to accuracy. With increasing carbonate concentration in the titrant there was a decrease in the linear range for Higuchi and Gran plots and a decrease in accuracy for all methods.

PAS-Formaldehyde Polymer as a Polymeric Ligand

Abstract p-Aminosalicylic acid (PAS) was condensed with formaldehyde in the presence of aqueous oxalic acid and aqueous sodium hydroxide. The polymer sample (PAS-F,1) obtained withacid catalyst was characterized by IR spectral study, by its Mn determined by nonaqueous conductometric titration both against standard acid and alkali, by viscometric study in formic acid, and by DTA. The IR spectral and general characteristics of a polymer sample (PAS-F,2) prepared in the presence of aqueous alkali resemble those of a polymer sample (AP-F) prepared similarly from m-aminophenol and formaldehyde, indicating decarboxylation of PAS during the base-catalyzed polymerization of PAS with formaldehyde. Polymeric metal chelates of Fe(III), Cu(II), Zn(II), and Mn(II) ions with the PAS-F,1 polymer sample have been prepared and characterized by elemental analyses, IR spectral study, measurements of magnetic moments, and thermal analyses. Chelation ion-exchanging properties of the PAS-F,1 polymer sample have also been studied employing the batch equilibration method.

Effect of zinc ion on the hemolytic activity of thermostable direct hemolysin from Vibrio parahaemolyticus, streptolysin O, and Triton X-100

The effect of Zn2+ on hemolysis induced by the thermostable direct hemolysin from Vibrio parahaemolyticus (vibriolysin) streptolysin O, and Triton X-100 was studied. We found that in certain buffers, such as tris(hydroxymethyl)-aminomethane-hydrochloride, boric acid-borax, and N-hydroxyethyl piperazine-N'-2-ethanesulfonic acid-sodium hydroxide, hemoglobins released from erythrocytes were easily precipitated by addition of Zn2+, thus resulting in a false inhibition of hemolysin by Zn2+ when hemolysis was assayed by measuring absorbance at 540 nm of released hemoglobins. Under experimental conditions in which hemoglobin was not precipitated, hemolysis induced by streptolysin O was inhibited by Zn2+, whereas that induced by vibriolysin and Triton X-100 was not. Thus, we concluded that the mode of inhibitory action of Zn2+ on hemolysis was not due to a reversible alteration in the state of the lipid bilayer of erythrocytes membranes as proposed by Avigad and Bernheimer (Infect. Immun. 13:1378-1381, 1976).

A simple and rapid thyroxine radioimmunoassay (T 4-ria) in unextracted human serum; a comparison of T 4-ria and T 4 displacement assay, T 4(D), in normal and pathologic sera

A simple, rapid and accurate thyroxine radioimmunoassay (T 4-RIA) in unextracted serum or plasma has been described, and for comparison T 4 determinations have also been made by a T 4(D) procedure using Abbott Tetrasorb kits. T 4-RIA procedure basically involved denaturation of serum to dissociate T 4-protein bond, and T 4 released was allowed to react with [ 125I]T 4-labeled T 4 antiserum elicited by immunizing rabbits against bovine thyroglobulin. The displaced unbound [ 125I] T 4 was rapidly taken up by an anionic resin sponge within 15 min and this sponge [ 125I]T 4 uptake was linearly related to T 4 present in standards or serum. The denaturation of serum effected by trichloroacetic acidsodium hydroxide permitted virtually 100% T 4 extraction recovery in normal, pregnancy, hypo- and hyperthyroid sera whereas 72.9–87.6% T 4 recovery from normal serum (and with large individual differences) was noted with lower alcohols in T 4(D) procedure. Cumbersome and/or tedious steps such as pre-extraction, centrifugation, time consuming bound and unbound hormone separation procedures, etc. are obviated in T 4-RIA and the entire assay can be completed in the same tube in approximately an hour. These attributes along with increased sensitivity and specificity and the need for only microamounts of test sera (25–50 μ1) in T 4-RIA offer distinct advantages over T 4(D) procedures, and in simplicity excel even other T 4-RIAs. T 4-RIA values in physiological and pathological states were highly correlated ( r = 0.97) with T 4(D) measurements and no differences between these two techniques were found. The reported discrepancies between T 4-RIA and T 4(D) measurements in human sera and some

CARBOXYMETHYLATION OF COTTON FABRICS BY GLYCOLIC ACID

Partial carboxylmethylation of cotton fabrics was examined using glycolic acids and sulfuric acid, phosphoric acid. or acetic acid as acidic catalyzers. It was found that the reaction of this procedure gave a partially carboxylmethylated cellulose having the crystalline lattice of cellulose I, whereas the usual method used to date where the reaction was achieved in the chloroacetic acid-sodium hydroxide system gave crystalline lattice of cellulose II.