About 0.1 ml of the sample extract was added to a volumetric flask (10 ml) containing 7.5 ml of distilled water and 0.5 ml of Folin-Ciocalteu phenol reagent, 1 ml of 35 % Na2CO3 solution and dilute to 10 ml with distilled water. The mixture was shaken well and kept at room temperature for 30 min. A set of reference standard solutions of gallic acid (20, 40, 60, 80 and 100 μg/ml) were prepared. Absorbance for test and standard solutions were measured against the blank at 725 nm with an UV/Visible spectrophotometer. The tannin content was expressed in terms of mg of GAE /g of extract
After this, HCl was added in an interval of 1ml until there was minimal change in the solution pH. The volume of HCl used and pH for each addition of HCl was recorded and used to draw the titration curve. Calculations: (2) Titration of acetic acid with sodium hydroxide Find the data and titration curve here. (1)Using your titration curve, determine the volume of NaOH required to reach the equivalence point. Identify this volume and the equivalence point on your graph.
Draw a graph with concentration of standards on the x-axis and absorbance on the y-axis 5. Now calculate the concentration of the paracetamol in the volumetric flasks labelled 1, 2 and 3 respectively 6. Calculate the average paracetamol content in each of the tablets as %w/w. To do this divide the mass of paracetamol in each flask by the mass of the ground tablets and multiply this answer by 100 7. Calculate the average paracetamol content in the tablets as mg/tablet by using the %w/w calculated above and the average mass of a
Their average weight (WA) was calculated. Percent weight variation was calculated. Average weights of the tablets along with standard deviation values were calculated.% weight variation = (WA–WI) x 100/ WA The weight variation between tablet ± 5 5. In-Vitro Drug Release Study The drug release study was performed by using type II dissolution apparatus (paddle type) in which phosphate buffer PH 5.8 at rotation speed 50 rpm and the temperature of the bath was maintained at 37.0+0.50C. The volume of the dissolution medium was kept 900ml and after a specified period of time 5ml of sample were taken and filtered by using whatman filter paper size no 1 ,after a filtration diluted with 500 micro liter in 10ml dissolution medium then analyzed quickly in UV double beam spectrometer at 243 nm.
The pH value is continuously measured during both carbonation steps. During the first step the pH value must kept between 10 and 11. To do so, carbon dioxide from the (from the lime kiln process) is introduce at approx. 70 C so that the lime precipitates together with the impurities. If the pH value falls too much due to introduce carbon dioxide the lime decomposes to form hydrogen carbonate.
of the dried membrane. The membrane sample was soaked in de-ionized water for 24 h and then the surface water was carefully wiped off with paper. The water uptake was calculated based on the following formula: Water uptake = (Ww −Wd)/Wd ×100 (2) Where Ww is the weight of wet membrane and Wd is the weight of dried membrane. AEM was obtained by casting the preweighed, QPSU ionomer dissolved in DMF solution onto a glass plate while keeping the thickness of the membrane in the range of 25-30
The mentioned ratio of the two materials were collected in a quartz crucible. Next, de-ionized water was added into the quartz crucible containing the nickel nitrate and urea. The de-ionized water was poured until it made up 50% of the portion of the solution After that, the entire solution was placed in an oven for about 1 hour. This was done to age the mixture and the temperature was maintained at 80oC. The solution was then taken out of the oven to be put in a pre-heated muffle furnace which was maintained at 650oC.
After the specified time, the solutions were completed to mark by using distilled water to achieve a final concentration of 20 µg/mL each, filtered and injected into the HPLC system. Dry Heat Degradation For thermal stress, 10 mg portions of each of VAL and SAC dry powder were placed in porcelain dish in a controlled-temperature oven at 100˚C for 4 hours. After the specified time, the content of the porcelain dish was transferred quantitatively with HPLC-grade methanol into a 10 mL volumetric flask and the volume was made to the mark by using the same solvent. Then, an aliquot of this methanolic stock was diluted to volume with distilled water to obtain a final concentration of 20 µg mL-1. After the preceding treatments, solutions were filtered and injected into the HPLC
One drop of each substance was carefully placed into each well. After all wells were filled with its corresponding substance, the petri dish was immediately covered and the diameter of each solution was measured using a ruler. The initial measurement was recorded as the measurement for zero minute. Every three minutes, the sizes of the diameters were measured and entered in a table until the thirtieth minute. The values in the table were plotted using a line graph to see the differences in the rate of diffusion among the three prepared solutions.
The cement is sieved and the weight of cement-retained on the sieve is noted. Calculate the percentage retained and should range from 0 – 10%. Table 3.2 FINENESS OF CEMENT Observations Test 1 Test 2 Test 3 Weight of cement, gm 1000 1000 1000 Weight of cement-retained, gm 40 35 37.5 Percentage Weight retained, % 4% 3.5% 3.75% Average % Weight retained 3.75% 18.104.22.168 Specific Gravity The specific gravity of cement is defined as the ratio of the weight of a given volume of cement to the weight of an equal volume of water. The specific gravity bottle is used for this experiment. PROCEDURE: The weight of empty bottle is noted i.e.