Thermodynamics of the Dissociation of Weak Acids

2006 ◽  
pp. 1-27 ◽  
Keyword(s):  
Weak Acids

scholarly journals Quaternary Alloy Quantum Dots as Fluorescence Probes for Total Acidity Detection of Paper-Based Relics

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1726
Author(s):  
Zhuorui Wang ◽  
Cong Cheng ◽  
Yongjuan Cheng ◽  
Lizhen Zheng ◽  
Daodao Hu
Keyword(s):  
Quantum Dots ◽  
Extraction Method ◽  
Quaternary Alloy ◽  
New Method ◽  
Fluorescence Probes ◽  
Total Acidity ◽  
Weak Acids ◽  
Paper Sample ◽  
Composition And Structure ◽  
Alloy Quantum Dots

Traditionally, the acidity of paper-based relics was determined by an extraction method and using a pH meter. This method could not obtain the total acidity of the paper-based relics because it only detected the concentration of free protons in the aqueous soaking solution. To overcome this defect, a new method for determining the total acidity of paper-based relics has been established by using quaternary alloy quantum dots. The quantum dots, CdZnSeS, modified by p-Aminothiophenol (pATP) were prepared, and their composition and structure were characterized. The fluorescence behavior of prepared quantum dots with acidity was investigated. The following results were obtained. The fluorescence of CdZnSeS-pATP quantum dots could decrease with increases in acidity because pATP dissociated from the surfaces of the quantum dots due to protons or undissociated weak acids. Based on this feature, a method for determining the acidity of paper-based relics was constructed, and this method was used to evaluate the acidity of actual paper-based relics. Obviously, for a given paper sample, since both free protons and bound protons can be determined by this method, the acidity measured by this method is more reasonable than that by pH meter.

scholarly journals Humic acids trigger the weak acids stress response in maize seedlings

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Daiane Carvalho Baía ◽  
Fábio L. Olivares ◽  
Daniel B. Zandonadi ◽  
Cleiton de Paula Soares ◽  
Riccardo Spaccini ◽  
...  
Keyword(s):  
Abiotic Stress ◽  
Stress Response ◽  
Intracellular Ph ◽  
Humic Acids ◽  
Abiotic Stress Tolerance ◽  
Molecular Response ◽  
Maize Seedlings ◽  
Weak Acids ◽  
Acetoxymethyl Ester ◽  
Chemical Priming

Abstract Background Plants primed by humic acids showed physiological and molecular response against different abiotic stresses without the presence of stressor agents (salinity, drought, heavy metal toxicity). It is plausible that humic acids themselves can act as chemical priming substances in plants. We hypothesized that humic acids can trigger the weak acids stress response in cell plants acidifying the cytosol and thus eliciting the transduction signalling response cascade. Methods The dose–response curves of maize seedlings roots with different concentrations of humic, acetic and salicylic acids determined the most active and inhibitory concentration. These data were further used to evaluate changes on intracellular pH using BCECF-AM probe (2,7-bis(2-carboxyethyl)-5(and 6)-carboxyfluorescein, acetoxymethyl ester) and differential transcription level of genes related to weak stress response in plants by qPCR real time. Results Humic acids like short chain organic acids decrease the intracellular pH showed by the increased fluorescence of BCECF probe. The drop in cytosolic pH promoted by humic acids was not transient. We observed a high level of protein kinases related to cell energy-sensing and transcription factors associated to transduction of stress signalling. Conclusion The humic acids can be considered as a chemical priming agent, since in the appropriate concentration they can induce the typical plant abiotic stress response of weak acids inducing plant acclimation and enhancing the abiotic stress tolerance.

Development of a Robust Protocol for the Determination of Weak Acids’ pKa Values in DMSO

2020 ◽  
Vol 85 (16) ◽  
pp. 10951-10957
Author(s):  
Sebastian T. Jung ◽  
Joachim Podlech
Keyword(s):  
Weak Acids ◽  
Pka Values ◽  
Robust Protocol

scholarly journals Determination of Trace Inorganic Anions in Weak Acids by Single-Pump Column-Switching Ion Chromatography

2010 ◽  
Vol 48 (7) ◽  
pp. 553-558 ◽  
Author(s):  
H. Zhu ◽  
H. Chen ◽  
Y. Zhong ◽  
D. Ren ◽  
Y. Qian ◽  
...  
Keyword(s):  
Ion Chromatography ◽  
Column Switching ◽  
Inorganic Anions ◽  
Weak Acids
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