Ethanolamine solutions concentration

Block unreacted aldehyde sites by addition of 50 pi of 1M ethanolamine, pH 9.6, per ml of conjugation solution. Approximately a 1M ethanolamine solution may be prepared by addition of 300 pi ethanolamine to 5 ml of deionized water. Adjust the pH of the ethanolamine solution by addition of concentrated HC1, while keeping the solution cool on ice. 

The reagent has been used for the cleavage of picric acid salts of amines. The finely divided yellow picrate is shaken with a mixture of ether and a concentrated aqueous solution of ethanolamine, and the ether solution is drawn off and extracted repeatedly with ethanolamine solution until it is no longer colored. Hiinig and Baron studied the velocity of splitting of quaternary ammonium salts on refluxing with ethanolamine. ... 

Fig. 5-27. Separation of ethanolamines. — Separator column IonPac NS1 (10pm) eluent 0.004 mol/L hexanesulfonic acid + 0.04 mol/L H3B03 flow rate 1 mL/min detection suppressed conductivity injection volume 100 pL solute concentrations ammonium (1), 2.5 ppm monoethanol-amine (2), 5 ppm diethanolamine (3), and 10 ppm triethanolamine (4).

See ref. 16.) Two g of epoxy-activated Sepharose 6B (Pharmacia) are resuspended in 250 ml distilled water for 1 hr at room temperature and washed on a sintered glass filter with 500 ml of 0.3 M sodium carbonate pH 9.5 (buffer I). The gel is then mixed with a solution of 2(X) mg novobiocin (Sigma, St. Louis, MO) in 12 ml buffer I and gently shaken for 20 hr at 37°. Excess epoxy groups are blocked by addition of ethanolamine (final concentration 1 M), and shaking is continued for another 4 hr at 37°. The product is then alternately washed in 250 ml each of 0.5 M NaCl in buffer 1, distilled water, 0.5 M NaCl in 0.1 Af sodium acetate pH 4.0, and distilled water. 

Freezing Point vs. Concentration for Aqueous Ethanolamine Solutions... 

Measure 50 ml of the water sample into each of two 250-ml beakers (if concentration < 10 mg/1 Ca2+ use correspondingly more evaporate to 50 ml) and acidify with perchloric acid (2) (pH 2 - 3). Boil until the carbon dioxide is expelled, and when cool treat with 10 ml of masking solution. Leave the samples to stand for 10 minutes, then add 1 ml of triethanolamine solution and adjust to pH 10.5 with ethanolamine solution (thereby prevent-... 

Where the concentrated sour gas recovered during the regeneration cycle cannot be used as fuel, or otherwise disposed of, it is sometimes further treated by absorption in ethanolamine solution. 

Fig. 4-28. Isocratic separation of ethanolamines and alkali metals on lonPac CSll. - Eluant 35 mmol/L methanesulfonic acid flow rate 0.25 mL/min detection suppressed conductivity solute concentrations 0.25 mg/L lithium (1). 1 mg/L sodium (2).

Fig. 4-33. Separation of ethanolamines on PBDMA-coated silica. — Separator column LiChrosil 1C CA column temperature 40°C eluant 5 mmol/L tartaric acid + 1 mmol/L pyridine-2,6-dicarboxylic acid flow rate 1 mL/min detection direct conductivity injection volume 15 pL solute concentrations 30 mg/L monoethanolamine (1), 50 mg/L diethanolamine (2), and 100 mg/L triethanolamine (3).

Maximum conversion occurs by equilibration at the lowest possible temperature so the reaction is carried out sequentially on two beds of catalyst (a) iron oxide (400°C) which reduces the CO concentration from 11% to 3% (b) a copper catalyst (200°) which reduces the CO content to 0.3%. Removal of CO2 ( 18%) is effected in a scrubber containing either a concentrated alkaline solution of K2CO3 or an amine such as ethanolamine ... 

In a typical experiment, 50 g of NaOH flakes were first dissolved in 120 g of water. The required amount of catalyst was then wet loaded into the caustic solution and 72 g of ethanolamine added. Before heating the autoclave was closed and the air inside purged out with N2. The autoclave was then heated with the set temperature (433 K) reached after about 80 minutes. This time is taken as zero in the plots that follow. The standard operating conditions used for catalyst evaluation unless otherwise stated were as follows temperature 433 K pressure 0.9 MPa ethanolamine concentration 2.9 M NaOH concentration 6.2 M stirrer speed 80 rpm catalyst 8 g with particle size 106-211 pm. 

Recently in our group, model membrane permeation barriers have been constructed with concentrated phospholipid solutions, 10-74% wt/vol soy lecithin (approximate %w/w lipid composition 24% PC, 18% PE, 12% PI cf. Table 3.1) in dodecane, supported on high-porosity, hydrophobic microfilters. This newly formulated lipid has a net negative charge at pH 7.4, which further increases above pH 8, as the ethanolamine groups deionize. Also tested were 10% wt/vol egg lecithin lipid solutions in dodecane (approximate composition 73% PC, 11% PE,... 

Let us consider first lipid-lipid interaction. Urry et al, showed the existence of a positive CD band at 218 m/x and a negative CD band at about 192 m/z in phosphatidyl choline and phosphatidyl ethanolamine dissolved in trifluoroethanol (86). The 192-m/z band was not characterized in detail, but the 218-m/z band is of such position and shape that the addition of lipid and protein CD bands could produce a composite CD band, and hence an ORD Cotton effect, which is red shifted. As noted by Urry, the 218-m/z CD extremum of lecithin must arise from n — 7T transitions in the fatty acid ester groups. Although the optical activities of solutions of deproteinized membrane phospholipids determined at the same concentration as in the intact membrane are negligibly small, in membranes an ordered array of lipids could greatly enhance rotation. Such an effect could yield information on the nature of lipid-lipid association. This can be tested experimentally. Halobacterium cutirubrum offers a unique system since Kates has shown that the lipids in this extreme halophile contain ether bonds rather than ester bonds (43, 44), Hence, the n — tt transition essential to the CD band at 218 m/z in phospholipids does not exist. Nevertheless, we found that the ORD... 

SYNTHESIS To a well stirred solution of 25 g ethanolamine hydrochloride in 75 mL MeOH there was added 4.45 g of 3,4-methylenedioxyphenylacetone (see under MDMA for its preparation) followed by 1.1 g sodium cyanoborohydride. Concentrated HC1 in MeOH was added as required, over the next few days, to maintain the pH at about 6 as determined with external, dampened universal pH paper. The reaction mixture was added to 300 mL HjO and made strongly acidic withanexcessofHCl. Afterwashing with 3x100 mL CH2Q2 the aqueous phase was made basic with 25%... 

Although carbon dioxide must be generated on site for some processes, there is a trend toward carbon dioxide recovery where it is a major reaction by-product and, in the past, has been vented to the atmosphere. An absorption system, such as the use of ethanolamines (q.v.) or hot carbonate or bicarbonate solutions, is used for concentrating the carbon dioxide to over 99% purity. 

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