Column packed, for

Gamma, of a photographic emulsion 769 Gas chromatography 235 apparatus for, 235 column packing for, 238 derivatisation in, 236 detectors for, 240 elemental analysis by, 247 of metal chelates 237, 248 pyrolysis, 237... 

Kirkland J.J., Henderson J.W., Martosella J.D., Bidlingmeyer B.A., Vasta-Rus-sell J., and Adams Jr. J.B., A highly stable alkyl-amide silica-based column packing for HPLC of polar and ionizable compounds, LC-GC, 17 (7), 634,1999. 

Consumables - filter papers, anti-bumping granules, Soxhlet thimbles and column packings for chromatography. 

N. D. Danielson, L. G. Beaver, J. Wangsa, Eluoropoly-mers and Fluorocarbon Bonded Phases as Column Packings for Liquid Chromatography , J. Chromat. 1991, 544,187. 

The details on column packings for polymer HPLC can be found in numerous monographs and (review) papers. The entire monograph devoted to column packings for SEC was edited by Wu [25]. In this section, only general information will be presented. 

This method is important in detecting and determining organic impurities in solvents. Today, gas chromatography-mass spectrometry (GC-MS) is also used to identify impurities. Water is sometimes determined by GC, with a column packed, for example, with Porapak Q. The lower limit of the water determination is 2 ppm. 

M McCoy, K Kalghatgi, FE Regnier, N Afeyan. Perfusion chromatography—characterization of column packings for chromatography of proteins. J Chromatogr A 743 221-229, 1996. 

Bonded-phase column packings for use in normal-phase chromatography are available in which the stationary phase is a polar functional group chemically bonded onto the silica surface. One... 

Kirkland JJ.Truszkowski FA, Ricker RD Atypical silica-based column packings for high-performance liquid chromatography. /. Chromatogr. A (2002) 965 25-34. Kirkland JJ Development of some stationary phases for reversed-phase high-performance liquid chromatography. J. Chromatogr. A (2004) 1060 9-21. 

Mobile phases for SEC fall into two broad categories aqueous buffers for GFC and organic solvents for GPC. In SEC, the mobile phase is selected not to control selectivity but for its ability to dissolve the sample. In addition, the mobile phase should have a low viscosity and be compatible with the detector and column packing. For example, polar solvents such as methanol... 

Confirm identity of column packing. For reproducible analyses, use same column type. (Columns of same type from different suppliers should have similar selectivity, but some will have unique properties.)... 

There has been much recent interest in the development of column packings for RPLC that can be used over a wider pH range. Potential materials include organic polymers, carbon packings and (modified) alumina. Clearly, such stationary phases will be most relevant for the separation of basic solutes. 

Column Packings. Several important factors related to column packings for HPLC have been noted in the preceding section detailing types of elution chromatography. 

Particular attention should be devoted to the selection of the column packing for the separation of TMS derivatives of amino acids as they are, as already mentioned, very sensitive towards moisture and can decompose on supports that have not been deactivated sufficiently. Silicone stationary phases of the SE-30, OV-1, OV-17 and DC-550 type and supports such as Gas-Chrom Q, Chromosorb W HP and Diatoport S have mostly been applied. One of the best GC separations of TMS derivatives of amino acids was obtained by Gehrke and Leimer [256] on a 6 m X 2 mm I.D. column packed with 10%... 

N. H. C. Cooke, B. G. Archer, K. Olsen, and A. Berick, Comparison of 3 and 5 micrometer column packings for reversed phase liquid chromatography, Anal. Chem. 54 (1982), 2277-2283. 

M. Petrovic, S. Tavazzi, D. Barceld, Column-switching system with restricted access pre-column packing for an integrated sample cleanup and LCHdS analysis of alkylphenolic compounds and steroid sex hormones in sediment, J. Chromatogr. A, 971... 

Column packings for gas chromatographic determination of sulphur gases... 

Group 1 metal fluorides have been employed as column packings for the determination of COF2 (and other fluorocarbonyl compounds) in mixtures with tetrafluoroethene [967]. By using a column composed of CsF supported upon CaFj, the tetrafluoroethene is not chemisorbed and is eluted rapidly. The fluorocarbonyl compounds (CF3)jC=0 (b.pt. -28 C), CF3C(0)F (b.pt. -59 C), and COF (b.pt. -84.6 C), however, are eluted in reverse order of boiling temperatures, so that carbonyl difluoride is eluted last [967]. The chemisorption arises from the reversible chemical process [1692] ... 

Materials with carbon on the surface used as column packings for chromatography include carbosils, which are prepared mainly by pyrolysis of aliphatic alcohols [92], aromatic hydrocarbons [93], chloroalkanes [94], and other organic compounds on the surface of silica gel. The carbon deposit obtained under the standard pyrolysis conditions is amorphous and possesses different physicochemical properties than graphitized carbon blacks. The transformation of such amorphous carbon deposit to graphitized carbon black on a silica gel surface is not possible because of the high temperature of the graphitization process (ca.3000 K). 

Schafer, C. Lubda, D. Alkyl Diol Silica Restricted Access Pre-Column Packings for Fast Liquid Chromatography-Integrated Sample Preparation of Biological Fluids, J. Chromatogr. A 909,73-78 (2001). 

For packed columns the efficiency is given by the quality and particle size of the column packing. For wall coated capillaries the efficiency is a matter of the coating film properties. Furthermore, the efficiency depends on the injection mode, solvent effects, flow rate and column dimensions. 

D8. Desty, D. H., and Harbourn, C. L. A., Evaluation of a Commercial alkyl aryl sulfonate detergent as a column packing for gas chromatography. Anal. Chem. 31, 1965-1970 (1959). 

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