scholarly journals Preparation, analytical Studies and application of a New Azodye Derived from Pharmaceutical Materials (Procaine Hydrochloride & Salicylic acid)

2021 ◽  
Vol 2063 (1) ◽  
pp. 012024
Author(s):  
Huda T Thuiny ◽  
Tarek A Fahad ◽  
Asaad A Ali
Keyword(s):  
Salicylic Acid ◽  
Electronic Spectra ◽  
Strong Acid ◽  
Procaine Hydrochloride ◽  
Ionization Constants ◽  
Spectroscopic Techniques ◽  
Strong Base ◽  
Ph Values ◽  
The Subject ◽  
Pharmaceutical Materials

Abstract Procaine hydrochloride was used as an aromatic amine, and salicylic acid (5-[2-(diethylamino)-4-benzoateazo]-2-hydroxybenzoic acid) was used to make a new azodye derived from pharmaceutical materials ( PS ).C.H.N., H1-NMR, I.R., and visible spectroscopic techniques have also been used to characterize dye. At different pH values ( 2 - 12 ), the electronic spectra of this azo dye was investigated in terms of acid-base properties, which included defining isobestic points and determining protonation and ionization constants. The effect of different polarities of solvents on the electronic spectra was the subject of another study. The dye has been used in a variety of applications, including as an indicator for strong acid with strong base and for nitrite determination.

Equivalence Points and Inflexion Points in Acid-Base Titration Curves

1963 ◽  
Vol 16 (5) ◽  
pp. 759 ◽  
Author(s):  
RH Stokes
Keyword(s):  
Strong Acid ◽  
Ionization Constants ◽  
Weak Acids ◽  
Acid Base ◽  
Strong Base ◽  
Titration Curves ◽  
Acid Base Titration

General equations are derived for the relation between pH and stoichiometric degree of neutralization in the titration of monoprotic and diprotic weak acids (or bases) with strong acid or strong base. From these equations the number and position of inflexion points in the curves is derived, and their relation to the equivalence points is shown. Methods for determining ionization constants from inflexion points are discussed.

scholarly journals Novel Resins for Efficient Desalination

Substantia ◽  
2021 ◽  
pp. 39-48
Author(s):  
Tanita Gettongsong ◽  
Mojtaba Taseidifar ◽  
Richard M. Pashley ◽  
Barry W. Ninham
Keyword(s):  
Chemical Properties ◽  
Strong Acid ◽  
Electrolyte Solutions ◽  
Strong Base ◽  
Ph Values ◽  
Surface Charging ◽  
Physico Chemical ◽  
Electrical Conductivities ◽  
Acid And Base ◽  
Chemical Cross Linking

This paper reports the synthesis and properties of new polymer resins containing strong acid and base groups for optimising applications in desalination. Several polyampholytic gels were synthesised with a ratio of 1:1 of strong acid (sulphonate) and strong base (quaternary ammonium) groups and a zwitterionic resin with a 1:1 strong acid and base ratio. The physico-chemical properties of these highly charged resins were studied in electrolyte solutions over a range of pH values, in particular: effects of chemical cross-linking, water and electrolyte swelling; bulk electrical conductivities and surface charging properties in different pH values. The results from absorption of NaCl showed that the resins have considerable potential for more effective desalination than other resin-based techniques.

The optimal extraction and stability of atranorin from lichens, in relation to solvent and pH

2018 ◽  
Vol 50 (4) ◽  
pp. 499-512 ◽  
Author(s):  
Carlo VOS ◽  
Phillip MCKINNEY ◽  
Colby PEARSON ◽  
Erik HEINY ◽  
Gamini GUNAWARDENA ◽  
...  
Keyword(s):  
Hplc Analysis ◽  
Metabolic Response ◽  
Strong Acid ◽  
Strong Base ◽  
Ph Values ◽  
Extraction Solvents ◽  
Acidic Conditions ◽  
The Stability ◽  
Future Work ◽  
Over Time

AbstractAtranorin is a secondary metabolite found in many lichens. This compound can act as a photo-buffer, supporting its use as a marker of metabolic response to changes in light. In preliminary trials, atranorin was found to be unstable over time when in solution, potentially precluding its usefulness in this capacity. The present study tests the stability of atranorin in different extraction solvents and at different pH values over time using HPLC analysis. We found that atranorin is most stable in acetonitrile, among six tested solvents, and that the presence of strong acid or a strong base destabilizes the compound. We propose that atranorin breaks down through transesterification in methanol and ethanol until an equilibrium is reached, while a strong base breaks down atranorin through saponification and under acidic conditions, atranorin concentration significantly increases with time. Although atranorin levels were found to be stable in whole thallus extracts from fresh lichens using a leaching method, chemicals isolated using chromatographic separation showed similar breakdown to an atranorin standard. In future work on lichens atranorin should be extracted in acetonitrile or acetone without an added base or acid to yield the greatest stability and thus provide more accurate concentration values of atranorin with time using HPLC. The interactions of atranorin with acid and with chloroform need further study.

Synthesis, Characterization and Thermal studies of Novel Organomercury Driven from Sulfa Drugs Part 1

2011 ◽  
Vol 7 (2) ◽  
pp. 1338-1347
Author(s):  
Tarek Ali Fahad ◽  
Shaker.A.N. AL-Jadaan
Keyword(s):  
Thermal Decomposition ◽  
Thermal Behavior ◽  
1H Nmr ◽  
Elemental Analysis ◽  
Thermal Studies ◽  
Spectroscopic Techniques ◽  
Sulfa Drugs ◽  
Acid Base ◽  
Ph Values ◽  
Multi Stage

Two new heterocyclic Organmercury compounds   were prepared from the reaction of Sulfamethaxazole and Sulfadiazine with 4-acetaminophenol as a coupler and separated as solids with characteristic colors. these compounds were characterized by F.T.IR-spectroscopy 1H-NMR , Micro-elemental Analysis and UV-Vis spectroscopic techniques . The work involves a study of acid – base properties compounds at different pH values, the ionization and protonation constants were calculated. The thermal behavior of these two compounds   were investigated on the basis of thermogravimetric (TGA) and differential thermogravimetric (DTG) analyses, Thermal decomposition of these compounds is multi-stage processes.

scholarly journals Discovery of a natural cyan blue: A unique food-sourced anthocyanin could replace synthetic brilliant blue

2021 ◽  
Vol 7 (15) ◽  
pp. eabe7871
Author(s):  
Pamela R. Denish ◽  
Julie-Anne Fenger ◽  
Randall Powers ◽  
Gregory T. Sigurdson ◽  
Luca Grisanti ◽  
...  
Keyword(s):  
Protein Design ◽  
Food Industry ◽  
Chemical Structure ◽  
Nutritional Value ◽  
Blue Dye ◽  
Spectroscopic Techniques ◽  
Design Tools ◽  
Enzymatic Transformation ◽  
Food And Beverage ◽  
The Subject

The color of food is critical to the food and beverage industries, as it influences many properties beyond eye-pleasing visuals including flavor, safety, and nutritional value. Blue is one of the rarest colors in nature’s food palette—especially a cyan blue—giving scientists few sources for natural blue food colorants. Finding a natural cyan blue dye equivalent to FD&C Blue No. 1 remains an industry-wide challenge and the subject of several research programs worldwide. Computational simulations and large-array spectroscopic techniques were used to determine the 3D chemical structure, color expression, and stability of this previously uncharacterized cyan blue anthocyanin-based colorant. Synthetic biology and computational protein design tools were leveraged to develop an enzymatic transformation of red cabbage anthocyanins into the desired anthocyanin. More broadly, this research demonstrates the power of a multidisciplinary strategy to solve a long-standing challenge in the food industry.

scholarly journals Analyses of Total Alkaloid Extract ofCorydalis yanhusuoby Comprehensive RP × RP Liquid Chromatography with pH Difference

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaodong Wei ◽  
Hongling Shen ◽  
Lijun Wang ◽  
Qingyan Meng ◽  
Wenjie Liu
Keyword(s):  
Liquid Chromatography ◽  
Total Alkaloid ◽  
Ph Value ◽  
Ammonium Hydroxide ◽  
Peak Capacity ◽  
Strong Base ◽  
Retention Factors ◽  
Ph Values ◽  
Dimension Analysis ◽  
Alternative Approach

A comprehensive two-dimensional (2D) reverse phase (RP) liquid chromatography (LC) method is developed for alkaloid analysis. This offline comprehensive 2D method is developed using different pH values. With a pH value of 10.5, most alkaloids appear in the form of neutral molecules possessing high retention factors based on their polarity, while the alkaloid polarity order is changed when the pH value decreased to 3.0. The performance of pH modulated 2D LC is demonstrated with 8 alkaloid standards which resulted in orthogonal separation. The developed method is then applied to total alkaloid separation inCorydalis yanhusuo. The first-dimension separation is carried out using methanol and water containing 1.0% ammonium hydroxide and a strong base-resistant RP column, which afforded a peak capacity of 94. The second-dimension analysis is carried out with a surface positive charge column providing a peak capacity of 205 using a mobile phase consisting of acetonitrile and water with 0.15% formic acid. 2D analyses of total alkaloid extract fromC. yanhusuoafford a total peak capacity of 9090. Sixteen compounds were tentatively identified based on their ultraviolet spectrum and MS/MS analyses. The proposed method provides an alternative approach to achieve high peak capacity for analysis of alkaloid extract.

scholarly journals Effect of packaged strawberry juice on the surface roughness of nanofilled type composite resin

2013 ◽  
Vol 25 (3) ◽  
Author(s):  
Rizky Amelia ◽  
Opik Taofik Hidayat ◽  
Denny Nurdin
Keyword(s):  
Acid Treatment ◽  
Composite Resin ◽  
Tooth Enamel ◽  
Heat Exposure ◽  
Strong Acid ◽  
Microscopic Structure ◽  
Hard Tissue ◽  
Micro Cracks ◽  
The Subject ◽  
Type Composite

Introduction: The hard tissue of the teeth is resistant to heat and acid,  so that the teeth have an important role as a material consideration of forensic dentistry. The humans have the same shape of the teeth around one in two billion. The stimuli of burn with high temperature and sour can be change the picture of macroscopic and microscopic tooth. This is the subject of an interesting comparison in the interests of justice and identification of dentistry. Methods: This research was a quasi experiment to know a change of microscopic teeth on the hard cases tooth-burning and the case hard acid treatment. The sample used were seven teeth, with details of one normal as a comparison, three teeth burned and three teeth soaked in a solution of water of accu. Observations were made using the microscope at 40x enlarged on each tooth. The tooth was documented by means of a photographed and compared with healthy teeth. Results: The results of this study was obtained by observing and comparing the microscopic structure and the obtained differences in the teeth and treated with the picture of normal teeth. Conclusion: Conclusion of this research is on the tooth are burned was visible loss of enamel at the cement-enamel junction as a result of the process of carbonization heat exposure so as to cause a breach of micro on the outer layer of the tooth enamel and thinning of dentin tubules, while the teeth are in the soak water accu (strong acid) seen change in color of enamel, micro cracks due to defective enamel and depletion of tubulus dentine and loss of boundary between the cementum and dentine.

scholarly journals Utilization of Extract of Sambang Getih Leaves (Hemigraphis colorata. Hall. F) as a Acid-Base Indicator

2020 ◽  
Vol 9 (1) ◽  
pp. 7-15
Author(s):  
Eksari Ekasari ◽  
Purnama Ningsih
Keyword(s):  
Leaf Extract ◽  
Strong Acid ◽  
Weak Base ◽  
Acid Base ◽  
Strong Base ◽  
Unique Color ◽  
Acid Base Titration ◽  
Naoh Solution ◽  
Ph Range ◽  
Color Pigment

Getih sambang leaves (Hemigraphis Colorata. Hall. F) are plants that have a distinctive and unique color, namely the upper surface of the leaf is green and the bottom of the leaf is burgundy where sambang leaves contain anthocyanin compounds. Anthocyanin is the color pigment in plants that forms the basis of the use of natural indicators. This study aims to prove whether getih cucumber leaves can be used as an acid-base indicator, to determine the type of acid-base titration that is suitable for indicators of getih cucumber leaves, and to find out what the pH-changing color route of getih cucumber leaves is. The method used is extraction, namely maceration. Wee leaves are macerated by using methanol as a solvent for 24 hours. The extract was previously tested using HCl solution and NaOH solution as a test to prove the presence of anthocyanin. The results obtained in this study, getih sambang leaf extract can be used as an indicator of acid base, and also the type of acid-base titration that is suitable for use in the indicator of getih leaf extract extract precisely on the titration of strong-base strong acid, and strong weak base-acid It is best used as a substitute for the phenolphthalein indicator. In titration of strong and weak acids and bases, it is good to be used as a substitute for the indicator of methyl orange. The pH range obtained from the getih sambang leaf extract is pH 4-7 (red-purple).

Spatiotemporal control over the co-conformational switching in pH-responsive flavylium-based multistate pseudorotaxanes

2015 ◽  
Vol 185 ◽  
pp. 361-379 ◽  
Author(s):  
Ana Marta Diniz ◽  
Nuno Basílio ◽  
Hugo Cruz ◽  
Fernando Pina ◽  
A. Jorge Parola
Keyword(s):  
Molecular Organization ◽  
Present System ◽  
Spectroscopic Techniques ◽  
Ph Responsive ◽  
Conformational Switching ◽  
Ph Values ◽  
Stable Species ◽  
Ph Dependent ◽  
Spatiotemporal Control ◽  
Kinetics Of

A multistate molecular dyad containing flavylium and viologen units was synthesized and the pH dependent thermodynamics of the network completely characterized by a variety of spectroscopic techniques such as NMR, UV-vis and stopped-flow. The flavylium cation is only stable at acidic pH values. Above pH ≈ 5 the hydration of the flavylium leads to the formation of the hemiketal followed by ring-opening tautomerization to give the cis-chalcone. Finally, this last species isomerizes to give the trans-chalcone. For the present system only the flavylium cation and the trans-chalcone species could be detected as being thermodynamically stable. The hemiketal and the cis-chalcone are kinetic intermediates with negligible concentrations at the equilibrium. All stable species of the network were found to form 1 : 1 and 2 : 1 host : guest complexes with cucurbit[7]uril (CB7) with association constants in the ranges 105–108 M−1 and 103–104 M−1, respectively. The 1 : 1 complexes were particularly interesting to devise pH responsive bistable pseudorotaxanes: at basic pH values (≈12) the flavylium cation interconverts into the deprotonated trans-chalcone in a few minutes and under these conditions the CB7 wheel was found to be located around the viologen unit. A decrease in pH to values around 1 regenerates the flavylium cation in seconds and the macrocycle is translocated to the middle of the axle. On the other hand, if the pH is decreased to 6, the deprotonated trans-chalcone is neutralized to give a metastable species that evolves to the thermodynamically stable flavylium cation in ca. 20 hours. By taking advantage of the pH-dependent kinetics of the trans-chalcone/flavylium interconversion, spatiotemporal control of the molecular organization in pseudorotaxane systems can be achieved.

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