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
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
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.
The goal of this experiment was to convert 2-methylcyclohexanol into 1-methyl-1-cyclohexene, 3-methyl-1-cyclohexene, methylenecyclohexane, and water through the addition of phosphoric acid and sulfuric acid. This was done through distillation where a mixture of 2-methylcyclohexanol, phosphoric acid, and sulfuric acid was distilled for 30 minutes in a reflux apparatus. Sulfuric acid being a strong acid acts as a catalyst in this reaction. Phosphoric acid also acts as a catalyst in this reaction. The distillate was then added to a centrifuge tube along with 1-2 ml of saturated sodium chloride. The bottom layer in the centrifuge tube was then extracted and dried using anhydrous sodium sulfate. This bottom layer was then distilled again in
Note to environmentalists: The sulfuric acid was completely neutralized and properly discarded. Credits I would like to thank all the people who helped me with this project. I would especially like to thank my mother, for letting my go through an abundance of Baking Soda, Vinegar, and many of our other household items. I would like to thank my Father for helping me understand the science of this project, and my whole family for helping me do well. I'd also like to give credit to the following Brands of substances I used: Arm & Hammer Drano Revco Aspirin Mylanta Seaway And any other products I may have used along the way.
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.
In this lab, Thin Layer Chromatography was used to identify the components of a certain drug. To do this, the compound in question, Motrin was tested against six standards in three different solvents. The three solvent were hexanes, ethyl acetate, and 75% ethyl acetate and 25% hexane; the solution of 75% ethyl acetate and 25% hexane was determined to be the best solvent. This is due to the larger variance in RF values. The six standards that Motrin was tested against were Aspirin, ibuprofen, acetaminophen, naproxen sodium, caffeine and a caffeine and ibuprofen mixture. To determine which standard was present in the chosen drug, the retention factors, or RF, were calculated. A UV light was also used to see the distance each sample traveled in
However, because there are so many factors involved during the analysis, this includes for example the reagents grades and suppliers, different instruments variations, and the analysis personnel, therefore, double check of the mentioned method of analysis to confirm that it will meet the predefined requirements and the purposes it was created for is mandatory. This process of confirmation is known as either Verification or Validation
Out of these variables I will use concentration as my input variable and amount of carbon dioxide released as my outcome variable. You can see how I will use and measure these variables in the method section of this investigation. My preliminary results can be found in appendix 1. These show what measurements of the input variables I decided to use and why I decided this.
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.
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.
Furthermore, an additional method to use other hydrochloric acids that have different concentration levels such as 1 M and 2.5 M ones, can improve the outcome of the results. This increases the variation of the independent variable, which accordingly increases the precision of results.
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.
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