Organic Acids and the Acid Base Relationship: Oxalic Acid in Foods

1934 ◽  
Vol 10 (2) ◽  
pp. 100-105
Author(s):  
E.F. KOHMAN
Keyword(s):  
Oxalic Acid ◽  
Organic Acids ◽  
Acid Base

scholarly journals Characterization of Aerosol Composition, Aerosol Acidity and Organic Acid Partitioning at an Agriculture-Intensive Rural Southeastern U.S. Site

2018 ◽  
Author(s):  
Theodora Nah ◽  
Hongyu Guo ◽  
Amy P. Sullivan ◽  
Yunle Chen ◽  
David J. Tanner ◽  
...  
Keyword(s):  
Oxalic Acid ◽  
Organic Acids ◽  
Organic Acid ◽  
Organic Aerosol ◽  
Water Soluble ◽  
Molar Concentration ◽  
Particle Phase ◽  
Aerosol Composition ◽  
Phase Water ◽  
Acetic Acids

Abstract. The implementation of stringent emission regulations has resulted in the decline of anthropogenic pollutants including sulfur dioxide (SO2), nitrogen oxides (NOx) and carbon monoxide (CO). In contrast, ammonia (NH3) emissions are largely unregulated, with emissions projected to increase in the future. We present real-time aerosol and gas measurements from a field study conducted in an agricultural-intensive region in the southeastern U.S. during the fall of 2016 to investigate how NH3 affects particle acidity and SOA formation via the gas-particle partitioning of semi-volatile organic acids. Particle water and pH were determined using the ISORROPIA-II thermodynamic model and validated by comparing predicted inorganic HNO3-NO3− and NH3-NH4+ gas-particle partitioning ratios with measured values. Our results showed that despite the high NH3 concentrations (study average 8.1 ± 5.2 ppb), PM1 were highly acidic with pH values ranging from 0.9 to 3.8, and a study-averaged pH of 2.2 ± 0.6. PM1 pH varied by approximately 1.4 units diurnally. Formic and acetic acids were the most abundant gas-phase organic acids, and oxalate was the most abundant particle-phase water-soluble organic acid anion. Measured particle-phase water-soluble organic acids were on average 6 % of the total non-refractory PM1 organic aerosol mass. The measured molar fraction of oxalic acid in the particle phase (i.e., particle-phase oxalic acid molar concentration divided by the total oxalic acid molar concentration) ranged between 47 and 90 % for PM1 pH 1.2 to 3.4. The measured oxalic acid gas-particle partitioning ratios were in good agreement with their corresponding thermodynamic predictions, calculated based on oxalic acid’s physicochemical properties, ambient temperature, particle water and pH. In contrast, gas-particle partitioning of formic and acetic acids were not well predicted for reasons currently unknown. For this study, higher NH3 concentrations relative to what has been measured in the region in previous studies had minor effects on PM1 organic acids and their influence on the overall organic aerosol and PM1 mass concentrations.

scholarly journals Determination of citric and oxalic acid in fungi fermentation broth through HPLC-DAD and solid-phase extraction

DYNA ◽  
2020 ◽  
Vol 87 (212) ◽  
pp. 26-30
Author(s):  
Laura Marcela Trujillo Vargas ◽  
Yesid Hernan Vélez Salazar ◽  
Margarita Enid Ramírez Carmona
Keyword(s):  
Oxalic Acid ◽  
Organic Acids ◽  
Solid Phase ◽  
Fermentation Broth ◽  
Preparation Technique ◽  
Liquid Chromatograph ◽  
Ion Exclusion ◽  
Validation Parameters ◽  
Fermentation Broths

This work describes a method for the simultaneous determination of organic acids in fungi fermentation broths. The sample preparation technique and the chromatographic conditions were optimized to enable the monitoring of the fermentation process. The determination of the citric and oxalic acid was done with a high resolution liquid chromatograph adapted to a detector with diode arrangement, an IC-Pak Ion-Exclusion 7μm (7.8 x 300 mm) column and a mobile phase of 0.001N H2SO4 with isocratic elusion. The validation parameters show efficiency, adequate linearity, and standard deviation values (%RSD) from 0.018% and 4.650%. the quantification limits (LDC) were 50.76 mg/L for citric acid and 20.18 mg/L for oxalic acid and the detection limits (LDD) were 0.6 mg/L for both acids. The method was applied in the analysis of organic acids in fermentation broths of Aspergillus niger.

The metachors of polyvalent and associated electrolytes in aqueous solutions

1984 ◽  
Vol 49 (5) ◽  
pp. 1079-1089
Author(s):  
Jiří Čeleda ◽  
Stanislav Škramovský ◽  
Jana Žilková
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Oxalic Acid ◽  
Organic Acids ◽  
Aqueous Solutions ◽  
Preceding Paper ◽  
Weak Electrolytes ◽  
Direct Proportionality ◽  
Very High

The quantity metachor introduced in the preceding paper was evaluated from the experimental data on surface tension of the aqueous solutions for a set of polyvalent and weak electrolytes. The almost complete concentration independence of the metachor and its direct proportionality to the number of the free charges in a dissociated molecule (observed and theoretically substantiated in the above cited paper for strong 1,1-, 1,2- and 2,1-valent electrolytes) has been verified in the present paper also for electrolytes of the higher valency types. The metachor values of fully dissociated 1,1-, 1,2-, 1,3- and 1,4-valent electrolytes follow a ratio (5 ± 1) : (10 ± 1.5) : 15 : 22 cm3 mol-1. Association of the electrolytes decreases correspondingly the metachor value as one can see on the case of electrolytes with bulky ions (NH4SCN, KCH3COO, Na2S2O3, hexacyanoferrates(II) or with the free acids H2SO4, H2CrO4, H3PO4 etc. A weak, in the investigated concentration range neglibility dissociated oxalic acid, consisting of small hydrated hydrophilic molecules, exhibits metachor values close to zero. Dibasic organic acids with a larger number of hydrophobic CH2 groups reach very high negative metachor values, however, their salts again possess metachor values close to 10 cm3 mol-1 - in accordance with the values found for strong 1,2-valent electrolytes. The metachors of ZnCl2 and CdCl2 decrease sharply from the last mentioned value, with increasing concentration while the metachor value of zinc perchlorate remains unchanged at the level corresponding to the fully dissociated salt. This is in agreement with the well known sequence of tendency of the d10-cations to form complexes with the Cl- and ClO-4 anions. All these facts have verified that the metachor can be, in principle, applied for a diagnostic states of the electrolytes in aqueous solutions.

scholarly journals Vertical distribution of particle-phase dicarboxylic acids, oxoacids and α-dicarbonyls in the urban boundary layer based on the 325-meter tower in Beijing

2020 ◽  
Author(s):  
Wanyu Zhao ◽  
Hong Ren ◽  
Kimitaka Kawamura ◽  
Huiyun Du ◽  
Xueshun Chen ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Oxalic Acid ◽  
Vertical Distribution ◽  
Organic Acids ◽  
Anthropogenic Activities ◽  
Ground Surface ◽  
Dicarboxylic Acids ◽  
Ground Level ◽  
Water Soluble ◽  
Motor Vehicles

Abstract. Vertical distribution of dicarboxylic acids, oxoacids, α-dicarbonyls, and other organic tracer compounds in fine aerosols (PM2.5) was investigated from the ground surface (8 m) to 260 m at a 325-meter meteorological tower in Beijing in the summer of 2015. Results showed that the concentrations of oxalic acid (C2), the predominant diacid, were more abundant at 120 m (210 ± 154 ng m−3) and 260 m (220 ± 140 ng m−3) than those at the ground level (160 ± 90 ng m−3). Concentrations of phthalic acid (Ph) decreased with the increase of heights, demonstrating that the vehicular exhausts at the ground surface was the main contributor. Positive correlations were noteworthy for C2/total diacids with mass ratios of C2 to main oxoacids (Pyr, ωC2) and α-dicarbonyls (Gly, MeGly) in polluted days (0.42 ≤ r2 ≤ 0.65), especially at the ground level. In clean days, the ratios of carbon content in oxalic acid to water soluble organic carbon (C2-C/WSOC) showed larger values at 120 m and 260 m than those at the ground surface. However, in polluted days, the C2-C/WSOC ratio mainly reached its maximum at the ground level. These phenomena may indicate the enhanced contribution of aqueous-phase oxidation to oxalic acid in polluted days. Combined with the influence of wind field, total diacids, oxoacids and α-dicarbonyls decreased by 22 %–58 % under the control on anthropogenic activities during the 2015 Victory Parade period. Furthermore, the PMF results showed that the secondary formation routes (secondary sulfate formation and secondary nitrate formation) were the dominant contributors (37–44 %) to organic acids, followed by biomass burning (25–30 %) and motor vehicles (18–24 %). In this study, the organic acids at the ground level were largely associated with local traffic emissions, while the long-range atmospheric transport followed by photochemical aging contributed more to diacids and related compounds in the boundary layer over Beijing than the ground surface.

scholarly journals Enzymatic Browning in Banana Blossoms and Techniques for Its Reduction

Horticulturae ◽  
2021 ◽  
Vol 7 (10) ◽  
pp. 373
Author(s):  
Geerada Kaewjumpol ◽  
Surasak Srisamlee ◽  
Diane M. Beckles ◽  
Kietsuda Luengwilai
Keyword(s):  
Oxalic Acid ◽  
Organic Acids ◽  
Phenylalanine Ammonia Lyase ◽  
Phenolic Content ◽  
Enzymatic Browning ◽  
Total Phenolic ◽  
Consumer Acceptability ◽  
Sodium Metabisulfite ◽  
Pal Activity ◽  
Tissue Browning

Banana blossoms are rich in fiber and nutrients and are a popular plant-based, vegan alternative to fish. However undesirable browning, usually visible at the peduncle cut-end, negatively impacts consumer acceptability of banana blossoms. The aim of this work was to develop safe alternatives to prevent browning in banana blossoms. First, the activities of primary enzymes associated with tissue browning, i.e., polyphenol oxidase (PPO), peroxidase (POD) and phenylalanine ammonia lyase (PAL), were assayed. Our data showed that PPO and POD were the key enzymes responsible for blossom browning as they increased in activity, reaching a maximum at pH 7, as browning developed. In contrast, PAL activity decreased, and total phenolic content did not change as browning progressed, indicating PAL was not induced by cutting and may not be involved in blossom browning. Second, to find antibrowning agents for banana blossoms that can substitute for the use of sodium metabisulfite (SMS), different organic acids of varying concentrations were tested. Among organic acids studied, treatment with 3% (w/v) oxalic acid was the most effective method and thus could be a safe substitution for SMS to prevent browning in banana blossoms.

THE RENAL RESPONSE TO ADMINISTRATION OF ACETAZOLAMIDE (DIAMOX®) DURING SALICYLATE INTOXICATION

PEDIATRICS ◽  
1959 ◽  
Vol 23 (6) ◽  
pp. 1103-1114
Author(s):  
Robert Schwartz ◽  
Francis X. Fellers ◽  
John Knapp ◽  
Sumner Yaffe
Keyword(s):  
Organic Acids ◽  
Neurologic Complications ◽  
Acid Base ◽  
Alkaline Urine ◽  
Acid Urine ◽  
Therapeutic Value ◽  
Before And After ◽  
Salicylate Intoxication ◽  
Acid Base Disturbance ◽  
Base Disturbance

Advanced salicylate intoxication in young children may produce severe acidosis due not only to the production and accumulation of organic acids in tissues, but also to the diminished content of buffer cation which is secondary to the loss of buffer cation during the excretion of organic acids. The excretion of an intensely acid urine all but prevents the excretion of free salicylate and thereby perpetuates the toxic effects of this ion. Despite severe deficit of buffer cation, the kidney responds to administration of a carbonic anhydrase inhibitor with excretion of alkaline urine. The magnitude of the loss of buffer cation is unpredictable both before and after enzyme inhibition. However, the systemic acidosis may be controlled by infusion of solutions of sodium bicarbonate, but frequent determinations of pH and content of carbon dioxide in the serum are mandatory. While the alterations in acid-base disturbance may be controlled during administration of acetazolamide, the occurrence of neurologic complications late in the course must be accepted as a serious additional hazard which may preclude the successful therapeutic value of this agent.

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