Measurement of lipid peroxidation TBARS, a measure of lipid per oxidation, was measured as described by Ohkawa . Briefly, 1 ml of suspension medium was taken from the 10% tissue homogenate. 0.5 ml of 30% Trichloroacetic acid (TCA) was added to it, followed by 0.5 ml of 0.8% thiobarbituric acid (TBA) reagent. The tubes were covered with aluminium foil and kept in shaking water bath for 30 minutes at 80°C. After 30 minutes, tubes were taken out and kept in ice-cold water for 30 minutes.
TLC was used to identify the actual unknown product as well as other products/reactants present in the filtered solution. The procedure was conducted by placing a TLC plate in a developing chamber that is filled with a small amount of solvent. The solvent cannot be too polar because it will cause spotted compounds on the TLC plate to rise up too fast, while a very non-polar solvent will not allow the spots to move. The polarity of the spots also determines how far it moves on the plate; non-polar spots are higher than polar ones. After spots on the TLC form, the Rf values are calculated and used to analyze the similarity of the compounds.
Name Lab Partner’s Name Institution Course: Heat of Fusion of Water Lecturer Instructor Date of Performance Date of Submission Heat of Fusion of Water Abstract The aim of this experiment was to determine the specific heat of fusion for the change of phase from ice to water. A method based on the principle of energy conservation was used in the experiment. Simply, the ice absorbs heat that is equal to that lost by the stirrer, calorimeter, and water. Initially, the ice undergoes a change of phase from solid to liquid (melting point). The experiment was conducted by maintaining all the pieces of ice in a funnel until when the pieces would be used to drain off all the water.
The purpose of this lab was to determine the percent water in magnesium sulfate heptahydrate, or Epsom salt. The experimental percent water is determined to be 42.06% in both trials, making the average also 42.06%. To determine this percent water a heating and cooling procedure was used. First, the vials were cleaned of impurities using the lab oven and were not touched after this point. The 2 vials were then weighed and vial 1 weighed 14.7681 grams and the second vial weighed 14.7451 grams.
During this step, I observed that there were bubbles in the solution, especially at the bottom of the beaker. After adding the HLC, there solution had a slight yellow tint. Next, I mixed 0.529g of sodium acetate in 3mL of water and added 0.679g of acetic anhydride to the aniline solution and immediately added sodium acetate. The solution was cooled in an ice bath for fifteen minutes. During this time, I noticed the formation
Linoleic acid peroxidation was initiated by the addition of 4 mM FeSO4.7H2O, incubated for 60 min at 37oC and terminated by the addition of 2 mL of ice cold trichloroacetic acid (10% v/v). An amount of 1 mL of thiobarbituric acid (1% w/v in 50 mM NaOH) was added to 1 mL of the reaction mixture, followed by heating at 95oC for 60 min. The reaction sample was read at 532 nm.7 The percentage of linoleic acid peroxidation inhibition activity was calculated using the following equation: % Inhibition = [(AB - AA)/AB] x 100, where AB, absorption of blank sample, AA, absorption of test sample. 2.5.4. Metal chelating activity Briefly, 2 mM FeCl2 was added to different concentrations of test sample and reaction was initiated by the addition of 5 mM ferrozine.
6 H2O) in 100 ml distilled water. (vi) 0.2(N) Sodium Hydroxide solution: Dissolve 8.0 gm sodium hydroxide in 1 l distilled water. (vii) Acetic acid: Dilute 1 part of glacial acid with 4 parts of water. (viii) Stock cyanide solution: Dissolve 2.51 gm potassium cyanide (A.R. Grade) in 1 l water, standardize this solution with 0.0192(N) silver nitrate solution.
The P2 tube was then placed in the refrigerated centrifuge at a speed of 15,000g for 30-60 minutes at 4°C. 1ml of the homogenisation buffer was added to the P1 pellet and was vortexed to resuspend it. The supernatant was then removed from the P2 tube and placed into a micro tube labelled ‘S’. 1 ml of the homogenisation buffer was added to the P2 pellet and placed on ice. The pellet was then resuspended again by adding small quantity of glass beads and it was vortexed vigorously until the pellet has disappeared from the bottom of the
SOLUBILITY AND SOLUBILITY PRODUCT OBJECTIVE In this experiment you will determine the solubility and solubility product of a sparingly soluble salt, potassium hydrogen tartrate, and also in four solutions containing a common ion. INTRODUCTION When a salt of low dissolubility dissolves in water, equilibrium is established between the solid solute and the dissolved ions. There are two terms used in discussing this condition. The first is solubility, which is the maximum amount of salt that will dissolve in a given amount of solvent (usually water) at a specified temperature. Solubility is usually expressed in units of molarity (moles/L), but sometimes g solute/ g solvent is used.
Purpose The purpose of this experiment was to evaluate the stoichiometric relationship between the testing agents and to identify the products formed. The relationship was found by completing three acid and base neutralization reactions using phosphoric acid, which is a triprotic acid, with different volumes of sodium hydroxide. Introduction Procedure Phosphoric acid solution with a volume of 1.00 mL and a molarity of 6.00 M was transferred into a 125-mL Erlenmeyer flask using a volumetric pipette. Sodium hydroxide solution with a volume of 6.00 mL and a molarity of 3.00 M was transferred into a 50 mL beaker using a volumetric pipette. While swirling the phosphoric acid solution in the Erlenmeyer flask, the sodium hydroxide solution was added to it a few drops at a time using a disposable plastic pipette.
In this lab, three unknown compounds were separated from a mixture and identified by melting point. Unknown mixture #124 has components of acid, base and neutral compound. The compounds were identified by melting point and matched up with the known melting points from a given list. In order to identify the compound it was important to separate by dissolving the mixture in an organic solvent which was not soluble in water, and then extracting the solution first with HCl, and then dilute sodium hydroxide solution. From the separation mixture, the aqueous layer were obtained and labeled as TT-1 (base), TT-2(acid) and TT-3 (neutral) in three different test tubes for later recovery.
The silver ion TLC was prepared through the following procedure: Silver nitrate was dissolved in 10 ml of distilled water. This aqueous solution of silver nitrate was absolutely mixed with 9 g of silica gel (10 ~ 40 μm particles). Then, a 10 × 5 cm TLC plate was coated with the above slurry and activated for 1 h at 90 °C before use. They were immediately transferred into a desiccator in dark for storage after cooling. 32 100 μL of afore-prepared sample solution and the mixed reference standard were diluted 100 times with ethyl acetate.