Volume of ice

Dimethyl sulphate may be purified (a) by allowing it to stand over anhydrous potassium carbonate until it is neutral to Congo red paper, or (6) by washing, just before use, with an equal volume of ice water, followed by one-third of its volume of cold, saturated sodium bicarbonate solution. 

The cooled reaction mixture can be induced to crystallize its p-nitropropene payload by simply dumping the whole thing in a large volume of ice water [40],... 

During disposal of the tribromide by a recommended procedure involving slow addition to a mixture of soda ash and dry slaked lime, a violent reaction, accompanied by flame, occurred a few seconds after the first drop. Cautious addition of the bromide to a large volume of ice water is suggested for disposal. 

These incubations are often carried out at 37 °C for 1-2 h. At different time points, 20-200 /aL of incubation mixture is withdrawn from each incubation and mixed with equal volume of ice-cold acetonitrile by vortexing. For preparation of acyl glucuronide, ice-cold acetonitrile containing 1% of formic acid is used to minimize acyl-migration [3,14]. After centrifugation at 13 000 rpm for 5-15 min, the supernatant (10-30 /aU) is analyzed by high-performance liquid chromatography (HPUC)-UV-MS. The metabolite of interest is identified based on HPLC retention time, UV spectrum and MS/MS data. Conversion yield is estimated based on UV absorption peak areas. A suitable in vitro enzyme system for scale-up is then... 

Following DNase 1 digestion, the synthesized RNA is extracted with 1 volume of TE-saturated phenol/ chloroform, vortexed for 1 min and centrifuged in a microcentrifuge (12,000 x g) for 5 min. The aqueous phase is transferred to a fresh tube, 1 volume of chloroformusoamyl alcohol (24 1) is added, and the tube is vortexed for 1 min and centrifuged (12,000 x g) for 5 min. The aqueous phase is transferred into a fresh tube and cRNA precipitated by adding an equal volume of 5 M ammonium acetate and 2 volumes of ice-cold ethanol or an equal volume of isopropanol. The precipitation is carried on dry ice for a minimum of... 

The alcohol reaction mixture is extracted with 200 ml. of ether and the ether extract is washed five times with equal volumes of ice water to remove the diglyme. The ether extract is dried over anhydrous magnesium sulfate and the ether is removed by distillation through a short Vigreux column. The residue is distilled under reduced pressure to separate 26.2 g. (85%) of isopinocampheol, b.p. 80-82° (2 mm.). The distillate crystallizes immediately in the collection flask (Note 6). The crystals melt at 50-52° (Note 7). Recrystallization from about 10 ml. of petroleum ether (b.p. 35-37°) affords pure isopinocampheol as needles, m.p. 55-57°, [a] d +32.8° (c, 10 in benzene). 

Mix A solubilized, aqueous tissue sample with an equal volume of ice-cold Soln. A, and then add ice-cold Soln. B up to 3.0 ml. The mixture is left for 10 min in an ice bath. After this centrifuge, leave the acidic solution at 0 °C for 10 min with 4000 x g. Wash the pellet three times by resuspension in ice-cold Soln. C and further centrifugation. 

Suspended the washed cells into appropriate volume of ice-cold 100 mM Tris-HCl (pH 7.4). 

The receiver can be disconnected from the apparatus under a positive pressure of nitrogen from both nitrogen inlets and the neck is closed with a stopcock. The fuming reactive residues in the reaction flask may be destroyed by dilution with petroleum ether (bp 60-80°), followed by slow addition of pentanol or hexanol while cooling in ice-salt. After all reaction has ceased this mixture may be poured into a large volume of ice for disposal. 

Dissolve ca 0.05 g of unknown sample (which should be a low density substance, greenish-yel to brn in color), in acetone and then add a large volume of ice water. The formation of a bright-yel ppt might indicate the presence of DADNPh. In order to be sure, prepare a satd soln of the sample in 200 ml of w and add to this 5 ml of 20% NaOH soln. After mixing, observe if there is an evolution of colorless gas and the soln assumes a reddish-bra coloration. These phenomena take place if the sample is DADNPh... 

In the method described by Urbanski, the oxidized product was drowned, together with acid, in a large volume of ice water and the resulting mixture transferred to a vacuum filter... 

A stirred cold (MeOH/ice bath) soln of free 4-chlorophenylalanine (4.5 g, 22.5 mmol) (obtained by desalting) in coned H2S04 (15 mL) was treated with 100% HN03 (lmL, 25.5 mmol). The mixture was stirred for 2h and then added to 5 volumes of ice. The resultant precipitate was left overnight, filtered, and the nonstoichiometic hydrogen sulfate salt was used directly in the following step. The product obtained in a separate preparation was characterized. 

If desired, the salt may be purified as follows The solid is rapidly dissolved below 10°C in five times its weight of 2% aqueous sodium sulfide containing 1ml of 2N sodium hydroxide. The crystals are washed with 100ml of ice-cold 1 1 alcohol-water, followed by 95% alcohol and by acetone the product is briefly air-dried. An equal volume of ice-cold 95% alcohol is added during the cooling. After standing in ice until precipitation is complete (about 10 minutes), the salt is immediately suction-filtered and washed, first with cold 50% alcohol, then with 95% alcohol, followed by ether. The colorless crystals are dried briefly in air and preserved in a tightly stoppered bottle to prevent hydrolysis due to atmospheric moisture. 

Repeat steps 1 to 6 with three new homogenized food samples, adding 1.5, 3.0, and 4.5 ml of 0.2 mM TMP, respectively, before step 2. In step 3, reduce the volume of ice-cold distilled water added to each pouch accordingly. 

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