Stainless steel packed columns

The moist crude bromohexadiene is quaternized in water without further purification. The submitters report that, if desired, the crude mixture may be dried over anhydrous calcium chloride and fractionally distilled through a 10-in. stainless-steel-packed column at reduced pressure. Crude bromohexadiene (220-230 g.) from 147 g. (1.50 moles) of l,5-hexadiene-3-ol was found to give the fractions listed in Table I. The yield of the... 

SFC chromatographs represent hybrids between GC and HPLC instruments (Fig. 6.4). In order to deliver the supercritical fluid, syringe pumps or reciprocal pumps are used and maintained above the critical temperature using a cryostat regulated at around 0 "C. In instances where an organic modifier is used, a tandem pump is employed which has two chambers, one for the critical fluid and one for the modifier. The liquid then passes through a coil maintained above the critical temperature so that it is converted into a supercritical fluid. Stainless steel packed columns like those used in HPLC (1 to 4 mm in diameter) or fused silica capillary columns like those used in capillary GC (2 to 20 m in length, internal diameters as low as 50 pm and stationary phase film thickness of at least 1 pm) are used in SFC. 

Smith et al (76,773 analyzed hydralazine in a drug mixture containing hydralazine hydrochloride, hydrochlorothiazide, and an impurity derived from the latter. The column was 1 m x 2.1 mm (ID) stainless steel, packed with a strong anion exchanger on 30 Jm Zipax . The mobile phase was pH 9 2 borate buffer containing 0.005M sodium sulfate (5 methanol), at 1.7 ml per minute. Detection was by ultraviolet absorption at 25 nm. 

Fig. 21.1. Gas-liquid chromatogram of BSTFA-derivatized EO sample (column 6-ft X 1/8-in o.d. stainless steel packed with 3% SP-2100 on 100/120 mesh Supelcoport column programmed from 150° C to 350° C at 4° C/min sample size 2 pL). (Reprinted/redrawn with permission from Analyt. Chem., 56, 603A (1984). Copyright 1984 American Chemical Society.)...

The column, pumps, and piping in contact with the hot fatty add are made from corrosion-resistant stainless steel. The column is a hollow vessel, containing no baffles, trays, or packing material of any kind The quality of the hydrolyzing operation is determined by the degree of split obtained on the fat. lbe fatty acid stream contains very little free glycerin, if any. 

C-18 reverse phase HPLC column, e g., 25 cm x 4.6 mm stainless steel packed with 5 pm Beckman Ultrasphere, or 15 cm x 2.9 mm stainless steel packed with 4 pm Nova Pac C18, or 25 cm x 4.6 mm stainless steel packed with 5 pm Supelco LC-1 or equivalent. 

GC column stainless steel packed with Porapak Q (50/80 mesh). Use a capillary column to prevent coelution of CS2, hexane, and low molecular weight ketones... 

GC column 3 m x 3 mm stainless steel packed with 5% Carbowax 20M on 80/100 mesh acid-washed DMCS Chromosorb W or a silicon coated fused silica. 

M. Konishi, Y. Mori, and T. Amano, High-performance packed glass-lined stainless steel capillary column for microcolumn liquid chromatography, Anal. Chem., 57 2235-2239 (1985). 

A gas chromatograph with flame ionisation detectors was used for the analysis and the column used was 2.4mx3mm stainless steel packed with 5% lmol on Chromosorb W, AW and SCMS treated 80-100 mesh. A temperature programme from 80-120°C at 4°C min-1 was used. 

Gas Chromatographic Analysis. A Hewlett Packard Model 5830A gas chromatograph equipped with a Model 18850A data terminal was used. The column was 1/8" by 10 stainless steel packed with 10% Carbowax 20 M on 100/120 mesh Gaschrom P. An initial oven... 

TCEP on 80/100 mesh Chromosorb P AW (oven temperature 80 °C, injector temperature 120 °C, detector temperature 150 °C, helium carrier flow 40 mL/min) and was interfaced to a Perkin Elmer PEP-1 GC data system. During the evaluation of Chromosorb 107 an analytical column of 6.1-m x 3.2-mm o.d. silanized stainless steel packed with 10 FFAP on 80/100 mesh Chromosorb W AW was used (oven temperature 60 °C, injector and detector... 

Each fraction was evaporated to dryness in 10-ml pear-shaped flasks, redissolved in a small amount of methylene chloride, and gas chromatographed. GC conditions were as follows column, 6 ft X 0.125 in. od stainless steel packed with 3% OV-17 on 100-120 mesh Gas-Chrom Q temperature program, 70-330°C at 12°/min, holding at the flnal temperature for up to 20 min and carrier gas flow rate, 28 ml/min. Fractions containing very little material or with GC patterns very much like adjoining fractions were combined. These fractions were then analyzed on the GC-MS computer system to obtain mass spectral data on the individual components. For certain fractions additional information was gained from ultraviolet spectra. 

A preparative column of dc = 50 mm (50 000 p,m) packed with 15 p,m particles contains approximately 3000 particles over the column diameter. For column stability the column wall plays only a minor role and the packing depends on the mechanical stability of the bed. While the packing pressure to pack analytical columns is often raised to 550 bar (stainless steel microbore columns can only be efficiently packed at 2000bar according to Roumeliotis et al., 1984), the maximum packing pressure for preparative columns seldom exceeds 100 bar. 

Figure 20.5 illustrates the improvements in separation power in going from a packed column (6.4 X 1.8 m) to a very long but fairly wide stainless steel capillary column (0.76 mm X 150 m), to a narrow but shorter glass capillary column (0.25 mm X 50 m). Note that the resolution increases as the column becomes narrower, even when the capillary colunm is shortened. 

Fii. ao.B. Three generations in gas chromatography. Peppermint oil separation on (top) 7-in. X 6-ft packed column (center) 0.03-in. X 500-ft stainless steel capillary column (bottom) 0.25-mm X 50-m glass capillary column. [From W. Jennings, J. Chromatogr. ScL, 17 (1979) 363. Reproduced from the Journal of Chromatographic Science by permission of Preston Publications, A Division of Preston Industries, Inc.]... 

FIGURE 28-4 Improvement in separation effectiveness by gradient elution. Column I m x 2.1 mm Inside-diameter, precision-bore stainless steel packing 1 % permaphase ODS (C,s). Sample 5 pL of chlorinated benzenes in iso-propanol. Detector (JV photometer (254 nm). Conditions lemperature, 60 C, pressure, 1200 psi, (From J, J, Kirkland, Modem Practice of Liquid Chromatography, p, 88, New York Inlerscience. 1971. Reprinted by permission of John Wiley Sons, Inc.)... 

The column is made of carbon steel, but both packings are of stainless steel. The column will operate under vacuum with conditions of 55 kPa and bO C at the top and 60 kPa and 125°C at the bottom. A total of four liquid distributors or redistributors will be used. Estimate the f.o.b. purchase cost of the column, including installed packings, distributors, and redistributors, for a CE cost index of 410. The barometric pressure is 100 kPa. 

Using molecular sieve 13X it is possible to separate paraffinic and naphthenic hydrocarbons according to carbon number (22]. However, the retention of high boiling hydrocarbons was very high. For example, the time required for the elution of hydrocarbons up to Cii in a typical naphtha sample on a packed column is 1.5 h (see Fig. 2-3a [21]). With 10 m X 0.5 mm stainless steel ALOT column with 0.3 p.m porous layer, Cii hydrocarbons elute at 400 °C (see Fig. 2-3b [21]). ALOT column permits to decrease the maximal separation temperature (400 °C instead of 500 °C). 

Column (10-ft x Vs-in stainless steel) packed with 80/100 Supelcoport coated with 20 percent SP 2100, 0.1... 

Column (4-ft X V4-in stainless steel) packed with 50/80 mesh Poropak, type Q. 

Column (10-ft X /s -in stainless steel) packed with 100/120 Supelcoport coated with 10 percent SP 1000. 

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