2.5 Kinetic Determination 2.5.1 Kinetic investigation of FVS in acidic degradation The kinetics of the acid degradation of FVS were evaluated in 0.1 M HCl at 70°C for different time periods. Solutions containing 1 mg/mL of the FVS were prepared in water. An appropriate aliquot was transferred into a volumetric flask, and diluted with 0.1 M HCl to give final concentration of 100µg/ml FVS. This solution was heated to 70°C and evaluated for time intervals of 30 min, 60 min and 120 min. Three samples were analyzed for each time interval. After the required time, 1 ml aliquots taken were transferred to a 10 mL volumetric flask and neutralized with 1 mL 0.1 M NaOH using pH meter. This solution was diluted with mobile phase to 20µg/ml of FVS solution for the HPLC analysis. The kinetic determinations were performed in the dark to exclude the possible degradation effect of light. 2.5.2 Kinetic investigation of FVS in oxidative degradation The kinetics of the acid degradation of FVS were evaluated in 3 % H2O2 at 70°C for different time periods. Solutions containing 1 mg/mL of the FVS were prepared in water. An appropriate aliquot was transferred into a volumetric flask, and diluted with 3 % H2O2 to give final concentration of 100µg/ml FVS. This solution was heated to 70°C, evaluated for time intervals of 30 min, 60 min and120 min. Three samples were analyzed for each time interval. After the required time, 1 ml aliquots taken transferred to a 10 ml volumetric flask and this solution was diluted with mobile phase to obtain 20µg/ml of FVS solution for the HPLC analysis. The concentrations of the remaining FVS determined at the different time intervals in the kinetic determinations were used in the plots. The plots were ln of concentra... ... middle of paper ... ...: 119–126 (2005). 22. W. Aman, K. Thoma, International Journal of Pharmaceutics 243: 33–41 (2002). 23. Onoue, Y. Tsuda, Pharmaceutical Research 23:156–164 (2006). 24. H.H. Tønnesen, International Journal of Pharmaceutics 225:1–14 (2001). 25. R.H. Clothier, Alternative to Laboratory Animal 35:515–519 (2007). 26. ICH topic Q2 (R1), Validation of analytical procedures: text and methodology, Geneva, Switzerland, 2005. 27. Bakshi, M., Singh, S., Journal of Pharmaceutical and Biomedical Analysis; 28; 1011–1040 (2002). 28. Swartz, M., Krull, I., LC-GC; 23, 586–593 (2005). 29. ICH-QA1 (R2); Stability Testing of New Drug Substances and Products, Geneva, Switzerland, 2003. 30. Ahuja, S.S., Advance Drug delivery Review; 59, 3–11 (2007). 31. K.A. Connors, G.R. Amidon, V.J. Stella, Chemical stability of Pharmaceuticals, A Handbook for Pharmacists, 2nd ed., Wiley, New York, 1986.
Every 5 minutes, a small amount of mixture was dissolved in acetone (0.5 mL) and was spotted onto a thin layer chromatography (TLC) plate, which contained an eluent mixture of ethyl acetate (2 mL) and hexanes (8 mL). The bezaldehyde disappearance was monitored under an ultraviolet (UV) light. Water (10 mL) was added after the reaction was complete, and vacuum filtrated with a Buchner funnel. Cold ethanol (5 mL) was added drop-by-drop to the dried solid and stirred at room temperature for about 10 minutes. Then, the solution was removed from the stirrer and place in an ice bath until recrystallization. The recrystallized product was dried under vacuum filtration and the 0.057 g (0.22 mmol, 43%) product was analyzed via FTIR and 1H NMR
In this experiment, a mixture of three substances (benzoic acid, 2-naphthol, and 1-4 dimethoxybenzene) will be separated based off acidity strength using the liquid-liquid extraction technique through a separatory funnel. Benzoic acid and 2-napthol will be converted into ionic salts when reacting with their appropriate bases (sodium bicarbonate and sodium hydroxide). Both ionic salts will then form solids through the addition of acidic HCl. Neutral 1,4 – dimethoxybenzene forms a solid through the evaporation of ether. Each compound will then be purified through recrystallization, using the processes of dissolving the solid in either water or methanol, and isolating the solid through vacuum filtration. After a week of evaporation, the compounds will then be examined for both
Before the start of the experiment, the theoretical yield was to be calculated. First, the limiting reagent was determined from the reagents by comparing the amount of moles; the two acids - phosphoric and concentrated sulfuric acid - were found to be the limiting reagent, because their moles combined was less than the amount of moles of 2-methylcyclohexanol. The theoretical yield, which is the amount of product that could be possibly produced after the completion of a reaction (“Calculating Theoretical and Percent Yield”), was found to be 4.4 g. Once the product was achieved, it was determined to have a percent yield of 95%. As a result, the dehydration of 2-methylcyclohexanol has been very successful.
As shown in Fig. 5, the final pH of the NaClO-NH3 solution after simultaneous removal are 5.4, 6.9, 7.2, 7.5, 8.5, 9.6, 10.7, 11.5 and 12.8 with respect to the initial pH of 5, 6, 7, 8, 9, 10, 11, 12 and 13, from which, an interesting law can be concluded as that if the initial pH is an acidic, the final pH is slightly increased; but if the initial pH is an alkaline, the final pH is declined. NaClO-NH3 is macromolecule compounds with a large inter surface area. It contains abundant functional groups such as hydroxyl (OH), carboxyl (COO), quinone, amino (–NH2), etc, which determines that NaClO-NH3 is a salt of strong base and weak acid, as well the ionization equilibrium and hydrolytic equilibrium would be complicated. When the pH of the NaClO-NH3 solution was acidic, the functional groups such as OH, COO and NH2- would react with H+ to generate the NH3 sediment, resulting in a decrease of inter surface area owing to the block and a great loss of NaClO-NH3, then the NOx removal as well as the duration time was decreased. As for the increase of the final pH in the acidic conditions, this was a result of the consumption of H+ by NaClO. The decrease of the
After performing the first Gas Chromatography, we took the organic layer, and mixed it with saturated Sodium Hydroxide. We performed this step to remove the (-OH) group from the Eugenol. The purpose was to make the water as a product, which can also be used as a solvent for the Eugenol that was ionized, for the two substances Acetyl Eugenol and Beta Caryophyllene. Again, we see the density differences in the solvents; we were able to take the organic layer. Finally, we transferred the layer into the beaker and dried, to perform the Gas Chromatography
In order to ensure the most accurate data, a purification was performed by the process of recrystallization. To perform the recrystallization the powder was dissolved in a minimal amount of hot ethanol/H2O solvent that allowed the unknown powder to crystallize properly when cooled. This process allowed for the removal of soluble impurities when suction filtered. A sample of the unknown acid was weighed at 8.24 g, and it was found that 164ml of a 40% ethanol, 60% H20 solvent dissolved the 8.24 g of unknown acid when heated. The beaker containing the dissolved acid was then placed in a beaker containing ice, allowing the unknown acid to recrystallized. After vacuum filtration, the recovered unknown was dried and weighed at 6.92 g. The percent recovery was determined by the following calculation: (8.24--6.92)8.24 x 100% = 16% loss = 84% recovery of unknown.
Materials and Methods: An ion exchange chromatography column was obtained and set up for purification with the addition of 0.5 ml ion exchange matrix. 1 ml
In this experiment, an acid (Benzoic acid), a base (Ethyl 4- Aminobenzoate) and a neutral compound (9-Fluorenone) were extracted from a mixture. HCl was the acid used to separate the base from the mixture, by forming an organic layer, which contained the acid, the neutral compound, and an aqueous layer that contained the base. NaOH was the base that was used to separate the acid from the neutral compound, which resulted in an organic layer containing the neutral compound and an aqueous layer containing the acid. After this a base was then added to the first aqueous layer containing the base, and an acid added to the second aqueous layer containing the acid. The percent recovery of each compound was then evaluated. The basic component, Ethyl
Going into details of the article, I realized that the necessary information needed to evaluate the experimental procedures were not included. However, when conducting an experiment, the independent and dependent variable are to be studied before giving a final conclusion.
This project looks at investigating decay, and the rate of decay on teeth using different sugary substances to speed this process up. Obtaining human teeth were not as available as cat and dog teeth for this project, so cat and dog teeth, removed by a veterinarian during a routine dental procedure, will be used.
The analysis is therefore one of the most effective methods of ensuring that each drug being prescribed to patients is safe. It also ensures that all drug components are understood in terms of their structure and chemical behavior. This understanding is very important in the manufacture of drugs and other pharmaceutical products.
Purpose: The following experiment was conducted to prepare standardized solution of sodium hydroxide solution (NaOH) and to determine the concentration of given unknown sulfuric acid (H2SO4) solution.
Compared to the 0.5 M hydrochloric acid that was less concentrated, the more concentrated 2 M hydrochloric acid c...
The purpose of this project was to discover how the pH level affects corrosion rate. The hypothesis was if the pH level affects the corrosion rate, then the lower the pH level is quicker the corrosion rate would be. This will happen because liquids below the pH level of 7 possess stronger acidic attributes. The effect of pH level on corrosion rate was determined by depositing a copper penny in each of three plastic cups, and then three different liquids by their pH levels, were assigned to be displaced into each cup formulating a chemical reaction to be observed. The results collected during this investigation contradicted with the intended result, this experiment was conducted to determine corrosion rate; Dana Puti Vingear (pH level: 4.5) 4 2/3 days, Tropicana Orange Juice (pH level 3.88) 6 1/3 days, and Sprite (pH level: 3.4) 8 days. The results showed that the hypothesis was refuted. This happened because the preconceived idea was that the liquid with the lowest pH level; Sprite, would have the quickest corrosion rate. Dana Puti Vinegar had the quickest corrosion rate proving the statement wrong, it was discovered that it contains ethanoic acid; acid containing twice the amount of carbon dioxide than a regular acid. To further understand this topic, future research could include; how does the amount of liquid incorporated affect the corrosion rate, how does the temperature of the liquid affect the corrosion rate, and how does the purity of iron affect the corrosion rate?
The sample was subjected to steam distillation as illustrated in Figure 1. A total of 50ml of distillate was collected while recording the temperature for every 5.0 ml of distillate. The distillate was transferred into a 250ml Erlenmeyer flask and 3.0 g of NaCl was added. The flask was cooled and the content was transferred into a 250-ml separatory funnel. Then 25.0ml of hexane was added and the mixture was shaken for 5 minutes with occasional venting. The aqueous layer was discarded and the organic layer was left inside. About 25.0ml of 10% NaOH was then added and the mixture was shaken as before. The aqueous layer was collected and then cooled in an ice bath. It was then acidified with enough 6.00 M HCl while the pH is being monitored with red litmus paper. Another 25.0 ml of hexane was added and the mixture was shaken as before. The hexane extract was saved and a small amount of anhydrous sodium sulfate was added. The mixture was then swirled for a couple of minutes then filtered. A small amount of the final extracted was tested separately with 1% FeCl3 and Bayer’s reagent.