Presence Of Sodium Sulfate Research Articles

A one-step oxidative synthesis of trimethylantimony(v) diacylates

Trimethylantimony(v) diacylates Me3Sb(OCOR)2 (R = H, Me, Ph) have been obtained in 72–75 % yield by the interaction of trimethylantimony withtert-butylhydroperoxide and carboxylic acids at the ratio of 1 ∶ 1 ∶ 2 in benzene (20 °C, 20 h) in the presence of sodium sulfate.

Removal of Sulfate Interference in the Determination of Bismuth and Thallium by Graphite Furnace Atomic Absorption Spectrometry

A mixture of ammonium-EDTA, nickel and copper nitrates is suitable as a matrix modifier for the removal of sulfate interference in the determination of bismuth by graphite furnace atomic absorption spectrometry. A mixture of ammonium-EDTA and nickel nitrate is suitable as the modifier for a thallium determination. In the presence of sodium sulfate, the tolerable ashing temperatures for bismuth and thallium were decreased. Although an organic compound, such as EDTA, enhances the interference from sulfate, by the addition of nickel and copper nitrates this interference can be removed. Since analyte and other cations are masked by EDTA, the coexisting sulfates are converted to ammonium salt, which is readily decomposed and eliminated from the furnace during the ashing step. In the presence of these matrix modifiers, the tolerable concentrations of coexisting sodium sulfate for bismuth and thallium were ca. 1000-times greater than those in the absence of the modifier.

Salt effect on base hydrolysis of tris(1, 10-phenanthroline) iron(II) at 25°C

The kinetics of base hydrolysis of tris(1,10-phenanthroline) iron(II) has been investigated in the presence of sodium sulfate and sodium benzoate at 25°C. Pre-c.m.c. association constant (km) decreases as the salt concentration increases. The average number of monomer per micelle varies from 4 to 2.

Effect of glycosaminoglycans and PEG on fusion of sendai virus with phosphatidylserine vesicles

The fusion of Sendai virus with phosphatidylserine vesicles was monitored by a pyrene-phosphatidylcholine fluorescence assay. A strong influence of pH and ionic strength on the extent of fusion was observed. The negatively-charged polymers (dextran sulfate, heparin and chondroitin sulfate) inhibited the ability of the viruses to fuse with the liposomes. The extent of inhibition, for a given amount (w/v) of the polymers, was the greatest for dextran sulfate followed by heparine and chondroitin sulfate. The extent of inhibition depended on the pH and ionic strength of the solution; the lower the pH of the solution, the more effective the fusion inhibition by the polymers. The molecular weight of dextran sulfate (DS) influenced the inhibition effecct, i.e., DS with higher molecular weight exhibited a stronger inhibition effect. The presence of sodium sulfate, even in excess concentration, had no inhibitory effect on fusion. On the other hand, PEG had an opposite effect on fusion compared to the negatively-charged polymers, and it decreased their inhibition effect when both were present in the same media. It is concluded that the inhibition of the fusion activity of Sendai virus results from the adherence of negatively-charged polymers to the virus surface preventing close contacts between the virus and liposome surface.

Drop stabilisation by inorganic solids in suspension polymerisation: modification by electrolytes using a wax model

AbstractFinely divided inorganic solids can be used for drop stabilisation in suspension polymerisation. Usually solids are dispersed in water in the presence of electrolytes formed during their preparation. Experiments, using a wax model as described previously,1 have been carried out by using two inorganic solids, magnesium phosphate and calcium phosphate, in either the presence or absence of electrolytes. The experiments showed that the effect of electrolytes depends on both the inorganic solid which is used and on the nature of the electrolyte which is present. Magnesium phosphate was a destabiliser in the absence of electrolytes but could act as a stabiliser in the presence of sodium sulphate. Calcium phosphate acted as a stabiliser both in the presence and in the absence of electrolytes.

Purification and characterization of xylanase from the mid-gut gland of the apple snail (Pomacea canaliculata).

At least fourteen or fifteen kinds of endo-xylanase components (endo-X) were found to participate in the xylan-hydrolysing activity of the mid-gut gland of the apple snail (Pomacea canaliculata). One of these endo-X was purified to electrophoretic homogeneity from the mid-gut glands of the female snails. Its molecular weight and isoelectric point were estimated to be about 42,000 by SDS-PAGE and 7.45, respectively. The optimum pH of the enzyme reaction existed between 6.0–6.3, and the activity was stable from pH 4.5–9.0, and was stable for 15min at 40°C and pH 6.0. The activity of this enzyme rose markedly in the presence of some chlorides or sodium bromide, but not in the presence of sodium sulfate or sodium citrate.

Indole derivatives. 136. 4-, 5-, 6-, and 7-Nitro-3-indolesulfonic chlorides and sulfonamides

The reaction of nitroindoles with chlorosulfonic acid in the presence of sodium sulfate was used to synthesize 4-, 5-, 6-, and 7-nitroindole-3-sulfonyl chlorides. Under the influence of ammonia and several amines these compounds were convened to nitroindole-3-sulfonamides which were reduced with hydrazine hydrate in the presence of Raney nickel to the corresponding amines.

Gas bubble hydration and water removal in foam fractionation and ion flotation of some metals

Water removal on gas bubbles (the presence of various divalent metals did not distinctly influence the removal rate) and the water sheath thickness of the bubbles increase with increasing sodium sulfate concentration in foam fractionation of divalent metal cations using lauryl sulfate. However, the presence of sodium sulfate has a negative effect on the water sheath thickness in ion flotation of metal cations with laurate collector. In ion flotation of metal complex anions with cetyltrimethylammonium collector the water removal decreases with increasing thiocyanate ligand concentration and, in relation to various metals, follows the order Cd < Zn < Cu ⩽ Co < Ni < no metal. The presence of various acids in the flotation of cobalt complexes causes the change in the water removal as follows: HClO 4 < HNO 3 < HCl < H 2SO 4 < H 3PO 4. Moreover, the surface tension of the foam separation (water removal) media was measured. In the discussion, the structure of the adsorption-hydration layer at the gas/solution interface and the interactions of collector and counterions with water molecules were considered.

Glutathione monoethyl ester: High-performance liquid chromatographic analysis and direct preparation of the free base form

Glutathione monoethyl ester ( l-γ-glutamyl- l-cysteinylglycine ethyl ester) was shown by R. N. Puri and A. Meister (1983, Proc. Natl. Acad. Sci. USA 80, 5258–5260) to be taken up by several tissues and intracellularly hydrolyzed to GSH. Since GSH itself is not significantly taken up by tissues, glutathione monoesters provide the most direct and convenient means available for increasing the intracellular GSH concentration of many tissues and cell types. In previous studies glutathione esters were prepared by HCl- or H 2SO 4-catalyzed esterification, and the product esters were precipitated as acidic salts by addition of ether to the reaction mixtures. In the present studies, glutathione monoethyl ester was synthesized by H 2SO 4-catalyzed esterification in the presence of sodium sulfate as the dehydrating agent. When no GSH remained, alcohol-washed Dowex-1 resin (hydroxide form) was added to remove sulfate and neutralize the reaction mixture. After the resin was removed by filtration, glutathione monoethyl ester crystallized in the chilled filtrate. The product was free of sulfate, GSH, and glutathione diester; its solutions in water or saline were neutral. Preparations obtained to date are nontoxic when administered to mice in doses up to at least 10 mmol/kg. Progress of the esterification reaction and purity of the product were determined quantitatively by HPLC after derivatization of the thiols with monobromobimane. Elution times of GSH, glutathione diester, and glutathione monoesters involving either the glutamyl or the glycyl carboxylate groups are reported.

Fluorescence in microemulsions and reversed micelles : A Review and New Results

The use of fluorescence to study physicochemical structures of alcohol/surfactant/water systems, microemulsions and reversed micelles is reviewed, and the application of these media in analytical fluorescence spectroscopy is discussed. The sodium dodecylsulfate/1-pentanol/heptane/ water system is studied by using pseudo-ternary diagrams. Wide areas of existence of thermodynamically stable and optically clear phases (Winsor IV and two liquid crystals) were found both in the absence and presence of sodium sulfate (0.2 M). The influence of the composition of media on the fluorescence characteristics of pyrene, benzo [e]pyrene, 2-naphthol and p-amino-benzoic acid is studied.

Effect of Sodium Sulphate on Tissue Cultures of Brassica napus cv. Westar and Brassica campestris L. cv. Tobin

Summary Callus cultures of Brassica napus cv. Westar and Brassica campestris cv. Tobin were established to assess the effect of sodium sulphate on growth and adventitious shoot formation. Brassica campestris was more sensitive to sodium sulphate than B. napus both in vitro and in vivo , the latter measured in a seed germination test. Selection of tolerant callus after subculture on sodium sulphate containing medium was achieved in B. napus but not B. campestris . These cultures were tolerant to 1.5 to 2 % Na 2 SO 4 (w/v) and were characterized by increased growth, viability and water content in the presence of sodium sulphate. The tolerant callus, but not unselected cultures, displayed a long-term capacity for rhizogenesis. A wide range of growth regulator supplements or culture conditions failed to induce adventitious shoot formation in hypocotyl sections or callus of B. campestris . In B. napus , addition of sodium sulphate inhibited shoot formation from hypocotyl sections. The extent of inhibition by sodium sulphate was lower, and the hormonal requirements for regeneration were less specific, in hypocotyl sections from seeds germinated in the presence of 1 % Na 2 SO 4 than in its absence.

The pitting of mild steel in phosphate-borate solutions in the presence of sodium sulphate

The localized corrosion of mild steel in neutral buffered solutions containing Na 2SO 1 was studied using potentiostatic and potentiodynamic techniques complemented by scanning electron microscopy. The breakdown potential changes linearly with the logarithm of Na 2SO 4 concentration. The logarithm of the induction time for pit initiation decreases linearly with the reciprocal of the applied potential, until the inhibition potential region is reached. Open circuit potential decay measured shows that the apparent thickness of the passive oxide film decreases at potential values more negative than the breakdown potential. The pitting current density is close to the diffusion limiting current of iron dissolution through a FeSO 4 film. Results suggest that two-dimensional FeSO 4 salt islands are formed before pitting, as it has been postulated for iron in halide-containing solutions.

Electron reactions with thiosulphate ions at various ionic strengths

The rate constant for the reaction of the hydrated electron with thiosulphate has been measured in the absence and presence of sodium sulphate. The bimolecular rate constant obtained by dividing the observed pseudo first order rate constant by the concentration of Na 2S 2O 3 did not change significantly when a fraction of the Na 2S 2O 3 was replaced by Na 2SO 4. It is concluded that both salts have the same physical effects on the rate constant. Neither salt is fully dissociated at the concentrations employed so that the solutions contained S 2O 2- 3 and NaS 2O - 3. Rate constants for the reaction of e - aq with each ion could not be calculated, but a value of k(e - aq+S 2O 2- 3) of ca. 5 X 8 dm 3 mol -1 s -1 at zero ionic strength was estimated from a short extrapolation from 1.07 x 10 -2 mol dm -3 Na 2S 2O 3 for which k=(1.82 ± 0.02) x 10 8 dm 3 mol -1 s -1. This value is different from previously published values which vary by a factor of 24. For ca. 0.1 mol dm -3 solutions of S 2O 2- 3 the end-of-pulse yield of e - aq was found to be the same as for 10 -3 mol dm -3 H + aq, indicating that S 2O 2- 3 does not scavenge presolvated electrons at that concentration. Such solutions, therefore, could not inhibit muonium formation in they provide a background against which to test models of muonium formation.

The effect of alginate impressions on the surface of cast gypsum. II. The role of sodium sulphate in incompatibility.

Of the materials tested only two alginates, Palginex (D), and Echo (C), show good surface reproduction when Vel-Mix (1), Ainsworth Greenstone (4), and Investo Greenstone (5) are cast against them. The above two alginates were shown to have a potassium and sulphate rich exudate. The reasonable surface produced by CA-37 (A) can be attributed to a proportional decrease in the ratio of potassium to sulphate present in the exudate, compared with Echo (C) and Palginex (D). S.S. White (B), Kromopan (E), and Tissutex (G) produce poor cast surfaces when high strength gypsum products are set against them. The exudates from these alginates were found to consist almost entirely of sodium sulphate. This study suggests that one way to improve the surface compatibility of alginates with gypsum products would be to modify the chemistry of the impression material so that a reactor other than calcium sulphate is used, to eliminate the appearance of sulphate ions in the exudate. Moreover, sources of sodium ions should also be eliminated. Therefore soluble alginates other than sodium alginate should be preferred, and a retarder other than one or other of the forms of sodium phosphate should be used. These changes would ensure that sulphate, particularly sodium sulphate, would not be produced as a by-product of the setting reaction. This in turn would eliminate the effects of incompatibility at present encountered to a greater or lesser extent with most combinations of alginate impression materials and gypsum cast materials.

Isoelectric focusing of human antibodies directed against a high molecular weight antigen

A simple technique has been developed to assess the spectrotypes of antigen-specific human autoantibodies. Following isoelectric focusing in 3 M urea at 1200 V for 2 h, immunoglobulins were fixed in polyacrylamide gels by precipitation with sheep anti-human immunoglobulin in the presence of sodium sulphate. Specific anti-thyroglobulin antibody bands were labelled by reaction with [ 125I]thyroglobulin, an antigen with a molecular weight of 660,000 daltons which is too large to enter the gel. The advantages of this method include increased sensitivity and reproducibility, and the ability to produce sharper bands and less non-specific binding than other methods.

4—THE EFFECTS OF SOLUBILIZATION IN THE SCOURING OF WOOL WITH NON-IONIC DETERGENTS

An investigation is described in which it was found that solubilized wool grease raised or eliminated the cloud point of a non-ionic detergent or produced a ‘double cloud point’. The effect was reversed by the addition of sodium sulphate. The grease-solubilizing capacities of non-ionic detergents were increased by the presence of sodium sulphate or suint. Of the detergents investigated, the highest capacity for solubilizing wool grease was shown by 8.5 ethoxy-nonylphenol.

Improved hydrolysis of urinary 17-hydroxycorticosteroid glucuronides with beta-glucuronidase from Helix pomatia, on adding sodium sulfate.

Sodium sulfate increases the hydrolysis of urinary 17-hydroxycorticosteroid glucuronides with beta-glucuronidase preparations derived from Helix pomatia because it removes the inhibitory activity of urinary high-molecular-weight substances. For maximum hydrolysis of urinary 17-hydroxycorticosteroid glucuronides, the hydrolysis [5 ml of urine, 0.5 ml of 2 mol/liter acetate buffer (pH 5.0)] should be conducted in the presence of sodium sulfate (final concentration: 80 g/liter) with (a) 600 Fishman units of the enzyme per milliliter of urine (18 h at 52 degrees C) or (b) with 1500 units of the enzyme per milliliter of urine (3 h at 57 degrees C). Under conditions a, analytical recovery of steroid glucuronides added to 12 urine samples was 99 +/- 2.1% (96-102%). Values obtained for 20 urine samples with this method were 99 +/- 2.7% (93-104%) as great as those yielded by a method in which 600 units of the enzyme from bovine liver are used together with sodium sulfate (18 h at 48 degrees C).

Investigations of reactions involved in flameless atomic absorption procedures: Part VI. A Study of some factors influencing the determination of lead in sulphate matrices

The degree of interference from various sulphates in the determination of lead by flameless a.a.s. is high (e.g. the decrease in the signal from lead is 10% for 2 nanomol of sodium sulphate) and decreases in the order sodium ⩾ potassium ⩾ calcium ⩾ magnesium. The interference from magnesium sulphate can be eliminated by ashing the sample at 870 ± 10°C. Results obtained from high-temperature equilibrium calculations show that gaseous lead sulphide is responsible for the interferences in the presence of sodium sulphate. Theoretical conditions for the formation of gaseous lead sulphide are outlined. The influence of carbon on the reactions involved was investigated by use of standard graphite as well as glassy carbon tubes; the results are compared with those found theoretically. In the presence of a tenfold excess of lanthanum(III), the recovery of lead is higher than 90% for all the sulphates investigated, at least up to an amount of 0.2 μ mol. The addition of oxygen as well as hydrogen to the inert gas decreases the interference from sodium sulphate, in accordance with the theoretical predictions.

Renal test dyes III. Effect of dyes suitable for renal passage time measurements on renal function.

The effects of the triaryl-methane dyes Lissamine Green SF (LF SF). Lissamine Green BN (LG BN), Lissamine Green V (LG V) and Kiton Pure Blue V (KPB V) on renal functions of rats and on sodium transport across isolated frog skin have been investigated. The experiments failed to show any natriuretic or diuretic effects of the purified dyes on the rat kidney. In the continuous infusion experiments, which lasted 3 1/2 h, the amount of the dye infused was equivalent to a passage time measurement every 3 min. In rapid injection experiments LG V was injected every 5 min for 1 h. The dyes did not have any effect on insulin clearance either. Previously reported effects of the dyes can be partly explained by the presence of sodium sulfate in commercially available dyes. Experiments with LG V showed that the dye also has no effect on the potential difference or short circuit current across the isolated frog skin. This supports their usefulness as renal test dyes.

Mortar cohesión. The effect of additives

This study was concerned with the hydration of clinker compounds in the presence of different additives; it appeared that accelerating additives, such as calcium chloride and silicic acid, produce longer fibers of tobermorite, whereas inhibitors, such as sugar, produce shorter fibers of tobermorite. This same effect was observed in the hydration of anhydrite, in which large crystals of gypsum were produced in the presence of sodium sulphate. So the cohesion in mortars of cement and anhydrite is explained in terms of the role of fibers.