Trichloroacetic acid solution preparation

Preparation of the trichloroacetic acid solution 16 g trichloroacetic acid were dissolved in 50 ml water. 0.8 ml 33% ammonia solution was (carefully ) added (fume cupboard) and made up to 100 ml with water. 

Ethanol formulations of salicylic acid (20 and 30%) are used for combination peeling (see salicylic acid section). Trichloroacetic acid is prepared as an aqueous solution, since ethanol solutions do not penetrate the skin. It is prepared by mixing the appropriate concentration of crystals with up to 100 cc of distilled water. Ten and fifteen percent TCA is prepared by mixing 10 or 15 g of crystals in up to 100 cc of total volume, respectively. Aqueous solutions of TCA remain stable for up to 6 months unless contaminated. Other methods have been used to formulate TCA peeling solutions however, the weight/volume methods appear to be the most reliable formulation [5]. Premixed TCA solutions are available from a variety of medical... 

Prepare enzyme blanks containing 5.0 mL of Casein Substrate Solution, 3.0 mL of Trichloroacetic Acid Solution, and... 

Sample preparation Honey. Dissolve 1 g honey in 10 mL water, homogenize, filter (0.45 p-m), inject a 50 pL aliquot. Milk, eggs. 5 mL Milk or 0.4 g lyophilized eggs + 10 mL trichloroacetic acid solution (so as to give a final trichloroacetic acid concentration of 3%), homogenize, centrifuge at 5000 rpm for 5 min. Re-extract the residue with 10 mL 3% trichloroacetic acid. Combine the aqueous phases and make up to 25 mL with trichloroacetic acid solution, inject a 50 pL aliquot. 

Sample preparation Weigh out 1 g ground feed, add 1 mL 1 m mL sulfamethazine in water, add 3 mL trichloroacetic acid solution, mix well, sonicate at 40° for 10 min, make up to 500 mL with MeCN 10 mM Na2HP04 adjusted to pH 3 with phosphoric acid 20 80, mix well, filter a 500 p,L aliquot (Costar spin-X (low type) 0.22 p,m cellulose acetate) with centrifuging for 1 min, iiyect a 10 p-L aliquot of the filtrate. (Prepare trichloroacetic acid solution by mixing 87 g trichloroacetic acid with 13 g water, add 0.7 mL of this solution to 99.3 mL acetone.)... 

Sample preparation Vortex 100 aL MeOHiwater 80 20 and 400 ixL trichloroacetic acid solution with 500 aL plasma, centrifuge at 4000 rpm for 4 min, filter (Spin-X) the supernatant. Mix the filtrate with an equal quantity of water and inject a 30 iL ahquot. (Prepare trichloroacetic acid solution as follows. Dissolve 85 g trichloroacetic acid in 15 mlj water. Store this solution in the refi"igerator. Dilute 150 aL of this solution with 100 ml. acetone.)... 

Carboxylic acids vary considerably in strength. Among the strongest is trichloroacetic acid (Ka = 0.20) a 0.10 M solution of C13C—COOH is about 73% ionized. Trichloroacetic acid is an ingredient of over-the-counter preparations used to treat canker sores and remove warts. 

A. Benzenediazonium-2-carboxylate. A solution of 34.2 g. (0.25 mole) of anthranilic acid (Note 1) and 0.3 g. of trichloroacetic acid (Note 2) in 250 ml. of tetrahydrofuran (Note 3) is prepared in a 600-ml. beaker equipped with a thermometer and cooled in an ice-water bath. The solution is stirred magnetically, and 55 ml. (48 g., 0.41 mole) of isoamyl nitrite (Note 4) is added over a period of 1-2 minutes. A mildly exothermic reaction occurs, and the reaction mixture is maintained at 18-25° and stirred for a further 1-1.5 hours. A transient orange to brick-red precipitate may appear (Note 5) which is slowly converted to the tan product. When the reaction is completed, the mixture is cooled to 10°, and the product is collected by suction filtration on a plastic Buchner funnel and washed on the funnel with cold tetrahydrofuran until the washings are colorless. (Caution The filter cake should not be allowed to become dry.) The benzene-diazonium-2-carboxylatc is then washed with two 50-ml. portions of 1,2-dichloroethane to displace the tetrahydrofuran, and the solvent-wet material is used in the next step (Notes 6, 7, and 8). 

The azides of the 1,1 -diphenyl series were prepared by adding hydrogen azide to the appropriate olefin. The reaction is catalyzed by trichloroacetic acid and carried out in benzene solution [56],... 

Trichloroacetic acid (TCA [81.6 g]) and disodium hydrogen orthophosphate dodecahydrate Na2HP04.12H20 (89.6 g) are dissolved in 600 ml water. Paraquat dichloride (l,l-dimethyl-4,4 -bipyridinium dichloride) (70 ml 36%) is then added, and the solution is adjusted to 1,000 ml with distilled water. The mixture is then cooled on ice to prevent formation of large crystals that are slow to dissolve on thawing and is stored at -15 °C. Extractant A is prepared from 5 ml distilled water adjusted to 1,000 ml with stock solution. Extractant B is prepared by adding 10 ml stock solution (0.1 mM ATP) to approximately 950 ml Extractant A and adjusting to 1 1 with further Extractant A. Normally it is advisable to prepare 51 of stock solution so that the same batch of extractant is used for the complete analysis. 

The iotai proteolytic activity of pancreas powder is determined by comparing the quantity of peptides nonprecipitabie by a 556 m/V solution of trichloroacetic acid R released per minute from a substrate of casein solution with the quantity of such peptides released by pancreas powder (protease) UK from the same substrate in the same conditions. For the test suspension and the reference suspen-sion, prepare the suspension and carry out tiie dilution at (W-°C. 

Methionine Sulfoxide Adsorption Check. S35-labeled methionine sulfoxide was prepared by oxidizing methionine-S35 with peroxide (6). Five microliters (ca. 20,000 counts per minute per microliter) of an aqueous solution of the sulfoxide was injected into each of 20 cockroaches. The first 10 were immediately immersed in hot 80% ethanol, and the remainder in hot 5% trichloroacetic acid to be homogenized and extracted. The extraction procedures were similar to those described above, except that precautions to prevent oxidation were not taken and the supernatant liquids, except for the acidified ethanol and ether washes, were not combined but were collected separately in 100-ml. volumetric flasks. The protein residues were hydrolyzed in 6N HC1 and, like the other fractions, were then diluted to 100 ml. with water for radiometric analysis. 

Method. Prepare seven 10-ml centrifuge tubes each containing 2 ml of a 10% solution of trichloroacetic acid. To five of the tubes add 1 ml each of the five standard solutions, and to the other two tubes add 1 ml of normal plasma and 1 ml of the plasma sample respectively. Agitate each tube for a few seconds, and then centrifuge at 3000 rpm for 5 minutes to deposit the protein precipitate. 

Dissolve 10 mg rifampicin (rifamycin SV) in 1.0 ml dimethyl sulfoxide. Prepare also a 5% (w/v) solution of trichloroacetic acid (TCA). 3-107. Place exactly 0.1 ml H-leucine solution (step 3-105) in a 125 ml Erlenmeyer flask and place the flask in the bath. 

The venous peripheral blood of the healthy donor by starting material was used. The sample was prepared in High-Purity Separation Lab., Inha University. The peptides extracts were obtained in the following way [8,9]. Take a fresh sample of the human blood, 9 ml, and it was dissolved in 1 ml of the sodium citrate solution. Centrifuge the blood (10 min, 2280 rmp). Throw away the cell element of the plasma in upper side. Add 0.154 M sodium chloride solution into the part in the lower side with pH 7.4. Repeat 3-5 times with the last procediu e. Collect the fraction of the erythrocytes in bottom side as shown in (Fig.l a). Add 15% trichloroacetic acids (TCA) solution to fraction of the erythrocytes. Centrifuging of the last sample 10 min, 3120 rmp). Analyze a liquid above a deposit (Fig. I b). 

Fig. 28. Hate of deacetylation of C -labeled acetylchymotrypsin (ACHT). (A) Acetylchymotrypsin prepared from NBS-oxidized enzyme with 47% of original activity (B) acetylchymotrypsin prepared from NBS-oxidized enzyme with 10% activity (C) acetylchymotrypsin from unoxidized enzyme. O, buffer pH 8.0 A> buffer pH 8.0 containing ATEE (fifty-fold molar excess of ATEE over the enzyme). The C -content of the various trichloroacetic acid (TCA) precipitates appears to be a true measure of the deacetylation process prior to the addition of TCA. Further dialysis of acid solutions of TCA precipitates against dilute HCl did not lead to any significant change in the C -activity. (D) Appearance of enzyme activity. Acetylchymotrypsin added to a solution of ATEE of pH 8.0 (the figure shown is traced from the actual record of the Cary spectrophotometer). ATEE, 2 X 10 Af ACHT, 10 yug pH 8.0. From Viswanatha and Lawson (1961).

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