Then, a drop of concentrated sulphuric acid was added. The appearance of purple colour, which rapidly changed to violet, indicated the presence of resins (Cuilel, 1994). Test for tannins 2g of both extracts were weighed and placed in test tubes. Two drops of 5% ferric chloride solution was added into the test tubes. The appearance of dark green colour indicated the presence of tannins (Cuilel, 1994).
2 ml of drug solution was added with the reagent and colour was observed Red coloured precipitate showed the presence of alkaloids. Test for Quinine (Bromine - ammonia test) To about 10 ml of (1 gm in 1000) solution of sample was added with 0.25 ml of Br2/H2O and shaken well. Then about 2 ml of dil.NH3 solution was added. No bright colouration showed the absence of quinine. Test for Morphine (Iodic acid test) Morphine liberates iodine from iodic acid which gives blue colouration.
As it was done in the Experiment A, 20 drops of 0.2 M acetic acid and 10 drops of 2% starch solution was mixed well with the juice solution. Before adding the iodine solution, the initial reading of the burette was taken. Then, the titration was started using the iodine solution into the burette with continuous swirling of the flask slowly and carefully. Once the color change started to appear, titration was stopped and final burette reading was recorded. Finally, the amount of vitamin C in the mandarin orange was calculated by using the standardization factor and used iodine solution.
Lastly, final concentrations and dilution factors were calculated by using the appropriate formulas. The final portion of the lab consisted of creating a lined scatterplot in Microsoft Excel with the absorbencies from the standard curve data chart. The chart was created to display the linear trendline, R-squared value, and slope equation. Then four sodas, Big Red, Big K Grape Soda, Faygo Red Pop, and Cherry 7 Up and one unknown sample containing red dye were processed through the absorbency tests, and diluted if necessary in a 1:1 or 1:3 ratio of water to soda. Using the equation determined from the standard curve graph, the concentrations of Red dye #40 was calculated for the sodas and the unknown liquid
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
The mixture was finally made upto 5 mL with distilled water and placed in hot water bath at 95ºC for 1 h. After cooling, 1 mL of distilled water and 5 mL of the mixture of n-butanol and pyridine (15:1, v/v) was added. The mixture was vortexed and after centrifugation at 4000 rpm for 10 minutes, the absorbance of the organic layer (upper layer) was measured in UV-Vis spectrophotometer (Shimatzu) at 532 nm against blank using distilled water. TBA when allowed to react with MDA aerobically formed a colored complex [MDA-(TBA) 2 complex] which was measured with spectrophotometer. MDA concentration (measured as TBARS) was calculated as
Titration of last mixture is performed in company with 0.1 M Na2S2O3 until the obtaining of color in yellow. Next, addition of starch indicator occurs and then titration of mixture in company with Na2S2O3 is realized until observing of color as blue is obtained. All of these procedure is repeated for solution of blank without adding oil. Consequently, quantity of iodine being used for absorption by oil is
An equivalent volume of saline solution was added (NaCl 0.16 M; pH = 7) and it was mixed completely. The resultant solution was centrifugated for 30 minutes at 9000 rpm at 4ºC in a rotor Beckman JA-20, eliminating the pellet. The supernatant was collected to obtain the lipoproteins by gradient density ultracentrifugation: 10ml of the yolk solution were taken and then 0.9 g of potassium bromide (KBr) was added. The bromide was dissolved with a smooth agitation, with care not to denature the proteins. Straight afterwards, saline solution was added (NaCl 0.16 M, pH=7) to the 10ml of the yolk solution with a Pasteur pipette, avoiding the sample diffusion, forming two phases and filling the tube completely.
1 ml = 1 µg CN (x) Chloramine –T: Dissolve 1 gm chloramine – T in 100 ml distilled water. Prepare fresh solution daily. (xi) Pyridine (xii) 1-phenyl–3-methyl– 5-pyrazolone solution: Prepare a saturated aqueous solution (approximately 0.5 gm / 100 ml) by adding the pyrazolone to water at 75 0 C. Agitate occasionally as the solution cools to room temperature. (xiii) Bis–Pyrazolone (3,3-dimethyl-1-diphenyl) (4,4’-bis-2-pyrazolone)-(5,5’