Sample Preparations Unknown water and reagent blanks are prepared in the same manner. 20 ml test tubes are taken and 5ml of water is pipetted into each of the test tubes. The pesticide standards are now inserted into the test tubes at concentrations of 0.1,0.2,1,2,5,10 and 30 ng/ml-1. The mixtures are mixed and kept in equilibrium for 30 minutes. After the 30 minutes is done, the tests tubes are then immersed in a 100 degrees Celsius methanol water bath for 15 minutes.
This diluted solution will be used in the assay as duplicate samples. Then, 1.0mL of standard glycine solution containing (7.5mg/mL) was diluted to 100mL with water using a volumetric flask. This solution contains 1.0µmole/mL of glycine. 8 tubes were set up according to the following protocol and 2.0mL of ninhydrin reagent was then added to each of the 8 tubes and were placed in a boiling water bath for 20 minutes. After 20 minutes, the tubes from the bath was carefully removed, cooled in a beaker of cold water, then 8.0mL of 50% ethanol was added and mixed well.
In the round-bottom flask (100 mL), we placed p-aminobenzoic acid (1.2 g) and ethanol (12 mL). We swirled the mixture until the solid dissolved completely. We used Pasteur pipet to add concentrated sulfuric acid (1.0 mL) to the flask. We added boiling stone and assembled the reflux. Then, we did reflux for 75 minutes.
The volumetric flask was then filled up to its 100 mL mark with deionized water. The buret was washed out with dionized water and then with the strong base NaOH before being filled up with NaOH. About 20 mL of the unknown weak acid was pipetted into a beaker. The starting volume of the NaOH in the buret was recorded before about 4 mL of the strong base was titrated into the weak acid solution. The final volume was recorded.
(2006), after slight modifications. The fundamental principle of the DPPH method is the reduction of the DPPH radical in an ethanolic solution by an H-donator antioxidant (AH) to form the non-radical form DPPH-H. In a microtube, 10 µL of each fraction at different concentrations (10 - 1000 µg/mL) were mixed with 990 µL of a DPPH solution (0.1mM) prepared daily. The reaction was allowed to develop for 30 minutes in the dark at room temperature, and then the absorbance was read at 515 nm with a spectrophotometer (Spectronic Helios Alpha UV-Visible, Thermo Electron Corporation, U.S.A). The analysis was done in triplicate for each
After which the digestions were examined by gel electrophoresis. The samples were run on a 50 mL 0.9% (w/v) agarose gel in 1X TAE buffer at 100 V until the leading track dye traveled 2/3 the distance of the gel. The gel was then soaked in GelRed for 20 minutes and examined under UV light. To prepare the digestions 10 μL of each digestion was mixed with 2 μL of 6X track dye in a micro centrifuge tube. 12 μL of 1 kb DNA ladder and each digestion was run on the
We then slowly added 25ml of chilled deionised water to the filtrate to initiate crystallization by using a measuring cylinder and a dropping pipette, once we had done this we left it for about 10 minutes to allow crystallization at room temperature. We then weighed a filter paper which we will use later in the experiment. We then collected the crystallized acetylsalicylic acid by vacuum filtration in a Buchner funnel and washed the product with a little ice-cold water. We then pre-weighed a clean, empty watch glass and labelled it with our initials and the date, we did this do we could easily identify that it was ours when we go to weigh it with the crystals on. We
Repeat the experiment. The cola drinks were titrated using the following method: Prepare the beverage in a 250ml volumetric flask. Use a funnel to facilitate the process. Place the beaker on a hot plate so that it boils and place a watch glass on top to prevent the carbon dioxide from the atmosphere getting dissolved in the cola. Once the cola starts to boil, continue to boil it for another 10 minutes so that the carbon dioxide is removed.
in the first step benzoic acid was reacted with excess of thionyl chloride using acetonitrile as a solvent and keeping the mixture on an ice bath for 3-4 hours (labeled as reaction mixture a) In the second step gemcitabine hydrochloride along with 3eq tri-ethyl amine and using ethanol again as a solvent was stirred for 15-20 minutes without ice-bath. next with a poisterizing tube the reaction mixture a was drop wise added to reaction mixture b yielding a third and final, reaction mixture c giving off white fumes of socl2. it is stirred for 19 hours and 15minutes at 80c and colour changes to light yellow The preparation of benzoyl chloride from benzoic acid using thionyl chloride at 0’c is an in-situ preparation procedure: FILTERATION: Evaporate reaction mixture and dissolved in hexane and then filter it. The best TLC system for filterate is ethyl acetate : hexane , 4.5:0.5 3.3.2 PROCESS 2 FIGURE 3.5ACETYL DERIVATIVE PROCEDURE In 75mg of gemzar, 2ml ethanol is added and then solubility is checked. After 5 minutes add 0.1 ml (5 drops) DMF, then add 0.104ml Et3N and add 0.036 ml acetyl chloride and stirr it for 17 hours r at 47C