The composition of reducing sugars in aqueous solution : glyceraldehyde, erythrose, threose

1980 ◽  
Vol 33 (5) ◽  
pp. 1001 ◽  
Author(s):  
SJ Angyal ◽  
RG Wheen

In the syrupy state, DL-glyceraldehyde, D-erythrose and D-threose consist mainly of mixtures of dimeric forms. Their aqueous solutions also contain some dimers; glyceraldehyde is present mainly as the aldehydrol, and the tetroses as mixtures of the furanoses and the aldehydrol. All the solutions contain some (> 1 %) of the aldehydo form. The proportion of the monomeric forms has been determined, from the 1H n.m.r. spectra, at various temperatures.

In a preliminary paper one of us, in conjunction with Prof. Heilbron and Prof. Barker, described some observations on the action of ultra-violet light on pure aqueous solutions of carbonic acid. It was found that traces of formaldehyde were present in these solutions after insolation, provided that a stream of the gas were passed through the water during the exposure to the light. These results differed from those which had previously been recorded by Moore and Webster, who had stated that the presence of a catalyst such as colloidal ferric or uranium hydroxide was necessary. The observation by Moore and Webster that formaldehyde in aqueous solution is converted by ultra-violet light into reducing sugars was fully confirmed, and the view was put forward that the mechanism of the photosynthesis of carbohydrates from carbonic acid consisted of two stages, first, the formation of formaldehyde, and, second, the conversion of this substance into hexoses.


1984 ◽  
Vol 49 (3) ◽  
pp. 559-569 ◽  
Author(s):  
Jaroslav Nývlt

The metastable zone width of an aqueous solution of KCI was measured as a function of the time and temperature of overheating above the equilibrium solubility temperature. It has been found that when the experiments follow close upon one another, the parameters of the preceding experiment affect the results of the experiment to follow.The results are interpreted in terms of hypotheses advanced in the literature to account for the effect of thermal history of solution. The plausibility and applicability of these hypotheses are assessed for the given cause of aqueous solution of a well soluble electrolyte.


1879 ◽  
Vol 29 (196-199) ◽  
pp. 472-482 ◽  

In order to investigate this subject, I devised and constructed the following apparatus :—A and B are two thin glass basins, 81 millims. internal diameter (= 5,153 sq. millims. of mercury surface), and 6·0 centims. deep; each containing a layer of mercury about 1·0 centim. deep, covered by a layer, about 3 centims. deep, of the aqueous solution to be examined.


2021 ◽  
Author(s):  
Junyi Li ◽  
Zoltán Szabó ◽  
Mats Jonsson

Four different uranyl-(peroxide)-carbonate complexes were identified during studtite and meta-studtite dissolution in aqueous solution containing 10 mM HCO3− by 13C NMR.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhirayr Baghdasaryan ◽  
Arsen Babajanyan ◽  
Levon Odabashyan ◽  
Jung-Ha Lee ◽  
Barry Friedman ◽  
...  

AbstractIn this study, a new optical method is presented to determine the concentrations of NaCl and glucose aqueous solutions by using a thermo-elastic optical indicator microscope. By measuring the microwave near-field distribution intensity, concentration changes of NaCl and glucose aqueous solutions were detected in the 0–100 mg/ml range, when exposed to microwave irradiation at 12 GHz frequency. Microwave near-field distribution intensity decreased as the NaCl or glucose concentration increased due to the changes of the absorption properties of aqueous solution. This method provides a novel approach for monitoring NaCl and glucose in biological liquids by using a CCD sensor capable of visualizing NaCl and glucose concentrations without scanning.


Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2012
Author(s):  
Vitória Régia do Nascimento Lima ◽  
Álvaro Gustavo Ferreira da Silva ◽  
Renata Ranielly Pedroza Cruz ◽  
Luana da Silva Barbosa ◽  
Neilier Rodrigues da Silva Junior ◽  
...  

Contaminated water consumption is one of the greatest risks to human health, especially in underdeveloped and developing countries. Water is a universal right, but millions of people worldwide consume untreated surface water. The objective in this study is to evaluate water purification with Nopalea cochenillifera var. Miúda biomass. Fragments (1, 2, and 3 g) of N. cochenillifera were added to the aqueous solution containing red-yellow Chromic and Podzolic Luvisol simulating turbid water sources in Northeastern Brazil. The total, non-structural (i.e., reducing and non-reducing sugars, alcohol insoluble solids), and structural (i.e., pectin) carbohydrates, adsorption kinetics, turbidity, electrical conductivity, pH, zeta potential, and total coliforms presence were evaluated. Findings show that the Nopalea cochenillifera biomass adsorbed the suspended particles in the aqueous solution, making it more translucent due to the complex and heterogeneous adsorbents’ ion exchange matrix, but the biomass addition did not eliminate total coliforms from the aqueous solution. We concluded that the Nopalea cochenillifera biomass water treatment reduces suspended dissolved particles and turbidity, but it needs to be associated with other treatments to eliminate total coliforms and ensure water safety for human consumption.


2021 ◽  
Author(s):  
Liang Wang ◽  
Peng Gao ◽  
Mengxin Liu ◽  
Ziqing Huang ◽  
Shixia Lan ◽  
...  

Monodisperse polypyrrole/SBA-15 composite (PPy/SBA-15) was fabricated by in-situ polymerization and used for Cr(Ⅵ) adsorption from aqueous solution. PPy/SBA-15 was characterized by numerous approaches. Factors affecting the Cr(Ⅵ) adsorption process included...


1989 ◽  
Vol 42 (3) ◽  
pp. 365 ◽  
Author(s):  
MK Manthey ◽  
SG Pyne ◽  
RJW Truscott

The oxidation of catechol in the presence of two aliphatic and aromatic amines has been investigated. In aqueous solutions of pH 7.0 and 11.7, the substitution pattern of the adduct was dependent on the type of amine used. Aromatic amines produced 4,5-disubstituted o-quinones, whereas aliphatic amines gave either 2,4,5-trisubstituted or 2,4-disubstituted o-quinone adducts. A rationale based upon the stability of vinylogous amides is presented to account for the observed substitution pattern.


2011 ◽  
Vol 239-242 ◽  
pp. 1359-1363
Author(s):  
Chao Hui Zhang ◽  
Si Si Liu ◽  
Yue Tao Sun ◽  
Jun Ming Liu

Aqueous solutions have found broad usages as lubricants, in conjunction with other possible utilizations, such as in metal working and other industries. Due to the inferior lubricity, functional additives are needed to improve their tribological performances among which aqueous surfactants are exclusively included. The film forming property of aqueous solution with polyethoxylated ether added (PEOE) is measured, taking consideration of the influences of the temperature and the concentration. The addition of PEOEs into aqueous solutions will largely increase the film forming capacity. But the concentration has only a minor influence on the lubrication property of the aqueous solutions with PEOEs. The cloud point will strongly alter the film forming characteristics.


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