scholarly journals Adsorption of tartaric acid and malic by active carbons

OENO One ◽  
1995 ◽  
Vol 29 (1) ◽  
pp. 49
Author(s):  
L. Robert ◽  
J. Mourgues ◽  
Arlette Pamar-Robert ◽  
D. Achour ◽  
J. Molinier
Keyword(s):  
Tartaric Acid ◽  
Malic Acid ◽  
Surface Oxidation ◽  
Solution Concentration ◽  
Carbon Surface ◽  
Active Carbons ◽  
Dramatic Decrease ◽  
Acidic Solutions ◽  
Neutral Ph ◽  
Acid Ph

<p style="text-align: justify;">Adsorption of tartaric acid and malic acid by active carbons bas been tested with six samples of carbons. At acid pH ; the adsorbed amounts of tartaric acid and of malic acid are practically the same. For a solution concentration of 20 g/l, adsorbed amounts from 0.008 to 0.29 gramme for one gramme of carbon have been found, variation which may be due to various states of carbon surface oxidation. Increasing the pH of the solutions shows a dramatic decrease of adsorbed amounts, this decrease being more rapid for tartaric acid than for malic acid. At neutral pH, the adsoiption becomes negligible. With acidic solutions containing the two acids altogether, acid malic is more adsorbed than tartaric acid.</p>

The influence of pH on the effects of organic anions in frog skeletal muscle

1977 ◽  
Vol 55 (5) ◽  
pp. 1122-1134 ◽  
Author(s):  
J. G. Foulks ◽  
Florence A. Perry ◽  
P. Tsang
Keyword(s):  
Skeletal Muscle ◽  
Divalent Cations ◽  
Organic Anions ◽  
Frog Skeletal Muscle ◽  
Depressant Effect ◽  
Contractile Responses ◽  
Neutral Ph ◽  
Acid Ph ◽  
Depressant Action ◽  
Carboxylate Anions

The depressant effect of acidity on twitches and K contractures in frog skeletal muscle was greatly accentuated in the presence of organic anions, particularly anions such as butyrate, which also reduced these responses at neutral pH. Conversely, alkaline pH antagonized the depression of contractile responses by butyrate. Most of the effects of acid pH were rapid in onset and were accomplished without any change in membrane resting or action potentials, although depolarization developed in the presence of carboxylate anions when pH was reduced below 6.0. Simultaneous variation in pH and butyrate concentration showed that the undissociated acid exerted a prominent depressant effect only when its concentration reached 1–10 mM, and that the marked depressant action of butyrate at neutral pH was produced primarily by the dissociated anion. Similar experiments showed that the dissociated anion also was largely responsible for the enhanced depolarizing effect of acidity in media containing carboxylates. Acid-induced depolarization was not facilitated in media containing methane sulfonate, but in spite of its low pKa, this anion also increased the sensitivity of contractile responses to the depressant effects of acidity. Hence, the accentuation of the effects of organic anions by acid pH must be exerted on the sequence of membrane events which link excitation and contraction. The effect of acidity was greater when longer apolar hydrocarbon chains were attached to the anionic group for both the carboxylate and the sulfonate series of ions. These depressant effects may be produced by interference with the membrane-stabilizing actions of divalent cations, and may involve increased membrane fluidity.

The Intehaction of Aqueous Solutions of Chlorine with Malic Acid, Tartaric Acid, and Various Fruit Juices: A Source of Mutagens

1988 ◽  
Vol 21 (11) ◽  
pp. 2049-2067 ◽  
Author(s):  
Tak-Lung Chang ◽  
Robert P. Streicher ◽  
Hans Zimmer ◽  
J. W. Munch
Keyword(s):  
Aqueous Solutions ◽  
Tartaric Acid ◽  
Malic Acid ◽  
Fruit Juices

Interdisciplinary study on pottery experimentally impregnated with wine

2014 ◽  
Vol 68 (8) ◽  
Author(s):  
Eugenia Teodor ◽  
Georgiana Badea ◽  
Andreia Alecu ◽  
Larisa Calu ◽  
Gabriel Radu
Keyword(s):  
Capillary Electrophoresis ◽  
Lactic Acid ◽  
Tartaric Acid ◽  
Malic Acid ◽  
High Speed ◽  
White Wine ◽  
Good Resolution ◽  
Fine Grained ◽  
Electrophoresis Method ◽  
Time Required

AbstractExperimentally developed ceramic pots, with two different sizes of grain, were half-filled with wine and subjected to thermal alteration at constant elevated temperature ((60 ± 2)°C) in darkness for 12 weeks. This work sought to characterise the samples thereby obtained from chemical and mineralogical perspectives using scanning electron microscopy and an energy-dispersive X-ray microanalysis system (SEM-EDX), Fourier transform infrared spectroscopy (FTIR) and capillary electrophoresis (CE) with UV detection as an alternative to chromatographic methods, due to its good resolution, automation, simplicity, high speed, low consumption of chemicals and short time required for sample preparation. The capillary electrophoresis method was used for the detection of five wine biomarkers: succinic acid, malic acid, tartaric acid, citric acid and lactic acid. In general, it was noted that the fine-grained ceramic assortment retained the organic material better than the coarser-grained ceramics. An interesting observation derived from this study was that not only could tartaric acid be considered as a biomarker for wine residues in archaeological pottery, but malic acid could also act similarly for white wine and lactic acid for red wine.

Simultaneous Gas Chromatographic Determination of Carboxylic Acids in Soft Drinks and Jams

1985 ◽  
Vol 68 (5) ◽  
pp. 902-905
Author(s):  
Taizo Tsuda ◽  
Hiroshi Nakanishi ◽  
Takashi Morita ◽  
Junko Takebayashi
Keyword(s):  
Benzoic Acid ◽  
Succinic Acid ◽  
Tartaric Acid ◽  
Carboxylic Acids ◽  
Fumaric Acid ◽  
Malic Acid ◽  
Sorbic Acid ◽  
Chromatographic Determination ◽  
Dehydroacetic Acid

Abstract A method was developed for simultaneous gas chromatographic determination of sorbic acid, dehydroacetic acid, and benzoic acid used as preservatives, and succinic acid, fumaric acid, malic acid, and tartaric acid used as acidulants in soft drinks and jams. A sample was dissolved in NH4OH-NH4CI pH 9 buffer solution, and an aliquot of the solution was passed through a QAE-Sephadex A 25 column. The column was washed with water, and the carboxylic acids were eluted with 0.1N HC1. Sorbic acid, dehydroacetic acid, and benzoic acid were extracted with ethyl ether-petroleum ether (1 + 1), and determined on a 5% DEGS + 1% H3PO4 column. Succinic acid, fumaric acid, malic acid, and tartaric acid in the lower layer were derivatized with N,0- bis(trimethylsilyl)acetamide and trimethylchlorosilane, and determined on a 3% SE-30 column. Recoveries from soft drink and jam samples fortified with 0.1% each of 7 carboxylic acids ranged from 92.4 to 102.6% for preservatives, and from 88.1 to 103.2% for acidulants.

scholarly journals The Effects of Salts on the Stability of the Collagen Helix Under Acidic Conditions

1968 ◽  
Vol 21 (4) ◽  
pp. 821 ◽  
Author(s):  
Anne FW oodlock ◽  
BS Harrap
Keyword(s):  
Thermal Stability ◽  
Carboxyl Groups ◽  
Neutral Ph ◽  
Acid Ph ◽  
Helix Stability ◽  
Acidic Conditions ◽  
Anions And Cations ◽  
The Stability ◽  
Thermal Stability Of ◽  
Positively Charged

In the acid pH region, the relative effects of various salts on the thermal stability of the collagen helix are quite different from their effects at neutral pH. The magnitude of the decrease in thermal stability brought about by the salts studied depends mainly on the nature and concentration of the anion and very little on the nature of the cation, whereas at neutral pH the nature of both anions and cations affects the collagen helix stability, the effects of the two ions being roughly additive. The magnitude of the effect of salts at acid pH is much greater than that at neutral pH whereas for a non-ionized denaturant, urea, the magnitudes at both neutral and acid pH are similar. The data are discussed in terms of possible interactions between salts and the positively charged protein with particular consideration of the effects of salts on the pKa of protein carboxyl groups.

Study of the Dynamics of the Adsorption of Trichloroethylene (TCE) on Active Carbons

2019 ◽  
Vol 23 (9) ◽  
pp. 30-35
Author(s):  
A.K. Gorelkina ◽  
T.A. Krasnova ◽  
I.V. Tymoshchuk ◽  
N.V. Gora ◽  
N.S. Golubeva
Keyword(s):  
Mass Transfer ◽  
Functional Groups ◽  
Flow Rate ◽  
Operating Time ◽  
Carbon Surface ◽  
Dynamic Adsorption ◽  
Constant Flow ◽  
Active Carbons ◽  
Coal Surface ◽  
Constant Flow Rate

The dynamics of adsorption of trichloroethylene from aqueous solutions on active carbons (AC) of the SKD-515, ABG, Purolat-Standart grades, differing in composition, method of preparation, structure and chemical state of the surface, was studied. The operating time of the filtering layer before breakthrough decreases in the series SKD-515> ABG> Purolat-Standart coal, which is caused by the porous structure of the coal and the nature of the oxygen-containing functional groups on the carbon surface. It was also noted that adsorption is influenced by the interaction of TCE with functional groups of the coal surface. The efficiency of TCE adsorption on various active carbons at a constant flow rate was studied. It was shown that a decrease in the flow rate of the solution through the filter increases the dynamic adsorption capacity, which indisputably confirms the pore-diffusion inhibition of mass transfer.

Composition of Pomegranate Juice

2012 ◽  
Vol 95 (1) ◽  
pp. 163-168 ◽  
Author(s):  
Dana A Krueger
Keyword(s):  
Citric Acid ◽  
Tartaric Acid ◽  
Malic Acid ◽  
Pomegranate Juice ◽  
Published Data ◽  
Statistical Tools ◽  
Isocitric Acid ◽  
Pee Dee ◽  
Sample Set

Abstract A database of 793 commercial pomegranate juices was analyzed to produce a profile for authentication of pure pomegranate juice. The database consisted of data from a mix of authentic and adulterated samples. Statistical tools were used to reduce the database to a stable sample set of 477 presumably authentic samples. The profile obtained (mean, SD at 16 Brix) are as follows: fructose (g/100 g) 6.83, 0.50; glucose (g/100 g) 6.66, 0.44; sucrose (g/100 g) 0.00, 0.00; sorbitol (g/100 g) 0.00, 0.01; acidity (g/100 g as citric acid) 1.25, 0.32; citric acid (g/100 g) 1.19, 0.30; malic acid (g/100 g) 0.065, 0.034; tartaric acid (g/100 g) 0.00, 0.00; isocitric acid (mg/kg) 63, 21; potassium (mg/kg) 2320, 400; proline (mg/kg) 7, 5; formol value [milliequivalents/100 g] 1.00, 0.24; 13C/12C ratio [o/oo Pee Dee belemnite]–26.4, 0.8. The profile samples had a consistent anthocyanin pattern consisting of four major peaks corresponding to delphinidin-3,5-diglucoside, delphinidin-3-glucoside, cyanidin-3,5-diglucoside, and cyanidin-3-glucoside. Minor peaks corresponding to pelargonidin-3,5-diglucoside and pelargonidin-3-glucoside were also generally present. No maltose, D-malic acid, or tartaric acid were detected in any of the samples. The profile obtained corresponds closely with previously published data.

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