Solutions discarding

This is a way to do this procedure without having to use one of those crazy tube furnaces stuffed with thorium oxide or manganous oxide catalyst [21]. The key here is to use an excess of acetic anhydride. Using even more than the amount specified will insure that the reaction proceeds in the right direction and the bad side reaction formation of dibenzylketone will be minimalized (don t ask). 18g piperonylic acid or 13.6g phenylacetic acid, 50mL acetic anhydride and 50mU pyridine are refluxed for 6 hours and the solvent removed by vacuum distillation. The remaining residue is taken up in benzene or ether, washed with 10% NaOH solution (discard the water layer), and vacuum distilled to get 8g P2P (56%). 

When an aqueous effluent stream containing organomercurials cannot be recycled, it may be treated with chlorine to convert the organomercury to inorganic mercury. The inorganic compounds thus formed are reduced to metallic mercury with sodium borohydride. The mercury metal is drained from the reactor, and the aqueous solution discarded. The process utilising sodium borohydride is known as the Ventron process (27). 

To the flasks for the crop and soil samples (Section 6.1), add 2mL of 0.01 M Tris-HCl buffer solution (pH 7.7) and 50 and 100 qL of 1M Tris-HCl buffer solution for wheat grain, bariey grain and rice straw, and for soil, respectively. Adjust the pH to about 7.7 (confirm the pH with a pH test paper using the sample of untreated area). Homogenize the residue with ultrasonication and transfer the homogenate to the top of an ion-exchange column. Wash the flask twice with 2mL of 0.01 M Tris-HCl buffer solution and transfer the washings to the column. Elute the column with 40 mL of the same buffer solution. Discard this eluate. 

Wash two or more times with 200 ml. of water and 10 ml. of saturated sodium chloride solution, discarding the aqueous layers. 

To remove excess protein A, centrifuge the preparation at a minimum of 50,000g for 30 minutes to several hours (4°C), depending on the size of the particles and the amount of solution. Discard the supernatant, and resuspend the protein A-gold pellet in 0.01M sodium phosphate, pH 7.4, containing 1 percent PEG. 

Set up the burette as shown. Rinse the burette with about 10 mL of your base solution. Discard the rinse solution in a discard beaker. 

Rinse a clean burette with about 10 mL of NaOH solution. Discard the rinse with plenty of water. Then set up a retort stand, burette clamp, meniscus reader, and funnel. Fill the burette with NaOH solution. Make sure that the solution fills the tube below the tap with no air bubbles. Remove the funnel. 

Rinse the pipette by drawing several millilitres of solution from the beaker into it. Rotate and rock the pipette to coat the inner surface with solution. Discard the rinse. Rinse the pipette twice in this way. It is now ready to fill with standard solution. 

Culea et al. have described an isotope dilution mass spectrometric method for the determination of proeaine in biological samples [96]. 1 mL of Liver homogenate was mixed with 0.2 mL of 1 M hydrochloric acid, 20 pL N-procaine internal standard solution, and 2 mL ethyl acetate for 30 seconds. The mixture was centrifuged for 3 minutes and the supernatant solution discarded. The pH was adjusted to 11 by mixing with sodium... 

When you fdl a buret with fresh solution, it is a wonderful idea to rinse the buret several times with small portions of the new solution, discarding each wash. It is not necessary to fill the buret with wash solution. Simply tilt the buret to allow all surfaces to contact the wash liquid. This same technique should be used with any vessel (such as a spectrophotometer cuvet or a pipet) that is reused without drying. 

Use fresh bovine blood collected in an anticoagulant solution (e-g., sodium citrate solution). Discard any bemdyzed blood. Centrifuge at 1500-1800 g at 15-20%... 

Step 2. Add 1 ml iron carrier into each of the first 2 tubes and stir. Add fresh ammonium hydroxide drop-wise with stirring until a brown iron hydroxide precipitate forms. Centrifuge and thoroughly transfer both supernatant solutions to clean centrifuge tubes. Add 5 ml of water to each precipitate, stir, and centrifuge. Decant each wash solution into the corresponding supernatant solution. Discard precipitate. 

Step 22. Remove the nickel metal strip. Wash it with a few mL of deionized water from a wash bottle and add wash water to the solution. Discard or count the nickel metal strip. Evaporate the solution almost to dryness. 

Assay Preparation Dissolve about 50 mg of sample, accurately weighed, in 100 mL of 60% acetic acid, and mix. Filter the solution, discarding the first 10 mL of the filtrate. 

The mixture is centrifuged and the solution discarded the precipitate is dissolved in dilute hydrochloric acid then diluted with water. It is then made basic with ammonium hydroxide, which results in a second iron hydroxide precipitate forming. 

Immediately before turning off the current, 1 ml of concentrated NH OH is added to the cell and the electro-deposition continued for an additional minute. The current is then turned off, the solution discarded, and the electrode washed with water, then ethanol and air-dried. Following alpha energy analysis, the radiochemical yield, as determined from the radioisotope tracer content and the concentrations of the radionuclides of interest, are calculated. 

Rinsing The cartridge was then washed with 0.75 ml of methanol and the solution discarded. 

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