Chromatography column, water-jacketed

S)-1 -Chloro-Chromatography column, water-jacketed, 37... 

An almost complete separation of D-glucose from D-ribose on the poly(acrylamide) gel Bio-Gel P-2, with water as the eluant, has been reported by John and coworkers.81 A water-jacketed column (127 X 1.5 cm) at a temperature of 65° and gel of very fine particle-size (400 mesh) were used. Only under such conditions, where resolution is optimal, does good separation of monosaccharides by gel chromatography become possible. 

UV irradiation of a dry benzene soln (120 mL) containing 1,1-diarylethene (0.40-0.05 mol) and diphenyldiazomethane (0.15-0.076 mol) was carried out in an immersion-type irradiation vessel equipped with a mercury high-pressure lamp (Philips, HP 125 W) surrounded by a quartz water jacket. The solution was purged with Oj-free Nj for 15 min prior to the photochemical reaction, which was run under dry Nj. Irradiation, performed at 13 °C, lasted for about 15-30 h. The workup procedure consisted of removal of benzene followed in some cases by column chromatography (50 cm) of the oily product on acidic alumina with various solvents and recrystallization of the colorless crystals from EtOH. 

The equipment used in ion exchange separations is similar to that used in column chromatography and can be identical for most separations. Figure 23-2, p. 270, is a diagram of an apparatus with a water jacket and a means to prevent the column from going dry. This is an elaborate apparatus. Most of the time, a broken buret is used. 

Preparation of Monomer 3. A benzene (20 mL) solution containing 2 (0.50 g, 1.8 mmol) and tributylphosphine (0.50 g, 2.5 mmol) was irradiated in water jacketed quartz reaction vessel with a 175 watt medium pressure mercury lamp for 6 h. The solvent was removed under reduced pressure and crude product subjected to column chromatography on alumina. Gradient elution with pet ether/benzene (final 2/1, v/v) produced a yellow-orange band which was collected and the solvents removed to afford pure 3 (0.65 g, 81%). H NMR (CDCI3) 6 4.90 (d, J = 3 Hz, 4 H), 1.66-1.60 (m, 6 H),... 

Delipidate IRBP by hydrophobic chromatography (see Note 4). Pack 70 mL Lipidex-5000 (Packard Instruments Co.) into a water-jacketed column and equilibrate with buffer A at 37°C. Circulate up to 25 mL IRBP solution through the column using a peristaltic pump for 30 min. The resulting delipidated protein is either stored at 4°C and used within a day, or placed back into a solution containing 50% glycerol and stored at -20°C for up to 3 wk. 

A solution of 9-diazo-9f/-fluorene (200 mg, 1.0 mmol) in styrene (20 mL, 18.2 g, 0.17 mol) was placed in a Pyrex outer jacket surrounding a quartz immersion well. After being purged with a dry N2 gas stream for 2 h, the solution was irradiated for 24 h with a Hanovia 450-W medium-pressure Hg lamp placed within the water-cooled immersion well and shielded by a cylindrical uranium glass filter to remove all wavelengths below 330 nm. After removal of excess styrene in vacuo, yellow crystals were observed. Purification by chromatography on a column of silica gel (230-400 mesh) with 20% benzene in hexane as eluant gave 246 mg (92%) of product mp 127 C. 

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