Liquid chromatography gradients

Snyder, L. R., Dolan, J. W., and Cox, G. B., Preparative high-performance liquid chromatography under gradient conditions. III. Craig simulations for heavily overloaded separations, J. Chromatogr., 484, 437, 1989. 

Berchtold, M. W., Heizmann, C. W., and Wilson, K. J., Ca2+-binding proteins a comparative study of their behavior during high-performance liquid chromatography using gradient elution in reverse-phase supports, Anal. Biochem., 129, 120, 1983. 

E.W. Hooijschuur, C.E. Kientz and U.A. Brink-man, Determination of alkylphosphonic acids by microcolumn liquid chromatography with gradient elution coupled on-line with flame photometric detection, J. Chromatogr. A, 907, 165-172 (2001). 

For metabolite isolation, 1.5 liters of pooled urine were applied to a XAD-2 resin column first. The ethyl acetate extract obtained containing 85 % of the radioactivity was applied upon evaporation to semipreparative HPLC on a Zorbax RX C18 column (9.4 x 250 mm, 5 pm) using gradient elution. Fractions obtained were further separated by isocratic elution on the semipreparative column. The metabolite fractions obtained were finally purified by preparative thin-layer chromatography. Liquid chromatography/mass spectrometry (LC/MS) and LC/MS/MS analysis was applied to the isolated metabolite fractions for structure elucidation. 

Mori S (1996) Characterization of styrene-acrylonitrile copolymers by size exclusion chromatography/stepwise gradient elution-liquid precipitation chromatography. Int J Polym Anal Charact 2 185-92. 

SEC size-exdusion chromatography RPLC reversed-phase liquid chromatography GPEC gradient polymer elution chromatography ... 

Hydrophilic interaction liquid chromatography in gradient mode with charged aerosol detection can also be used for separating oligosaccharides. As an example, Figure 8.83 shows the separation of maltose oligomers up to DP7 on... 

Chlorofoim/ethanol Liquid adsorption chromatography, silica, gradient, 40-70 C 2281... 

The effects of flow nonuniformities, in particular, can be severe in gas systems when the ratio of bed-to-particle diameters is small in liquid systems when viscous fingering occurs as a result of large viscosity gradients in the adsorption bed when very small particles (<50 Im) are used, such as in high performance liqmd chromatography systems and in large-diameter beds. A lower bound of the axial... 

Figure 9.3 Schematic illustration of the electrophoretic transfer of proteins in the chromatophoresis process. After being eluted from the HPLC column, the proteins were reduced with /3-mercaptoethanol in the protein reaction system (PRS), and then deposited onto the polyacrylamide gradient gel. (PRC, protein reaction cocktail). Reprinted from Journal of Chromatography, 443, W. G. Button et al., Separation of proteins by reversed-phase Mgh-performance liquid cliromatography , pp 363-379, copyright 1988, with permission from Elsevier Science.

Figure 13.7 Selectivity effected by employing different step gradients in the coupled-column RPLC analysis of a surface water containing 0.40 p-g 1 bentazone, by using direct sample injection (2.00 ml). Clean-up volumes, (a), (c) and (d) 4.65 ml of M-1, and (b) 3.75 ml of M-1 transfer volumes, (a), (c) and (d), 0.50 ml of M-1, and (b), 0.40 ml of M-1. The displayed cliromatograms start after clean-up on the first column. Reprinted from Journal of Chromatography, A 644, E. A. Hogendoom et al, Coupled-column reversed-phase liquid chromatography-UV analyser for the determination of polar pesticides in water , pp. 307-314, copyright 1993, with permission from Elsevier Science.

Micellar gradient elution liquid chromatography with electrochemical detection with sodium dodecyl sulfate has been used to separate phenols [186]. 

Figure 5.6 Positive-ion electrospray spectrum obtained from the major component in the LC-MS analysis of a purified recombinant 62 kDa protein using a Cig microbore 50 X 1 mm column and a flow rate of 50 p.lmin . The starting buffer (buffer A ) was 0.1% TEA in water, while the gradient buffer (buffer B ) consisted of 0.1% TEA in acetonitrile-water (9 1 vol/vol). The running conditions consisted of 0% B for 5 min, followed by a linear gradient of 100% B for 55 min. Reprinted from J. Chromatogr., B, 685, McAtee, C. P., Zhang, Y., Yarbough, P. O., Fuerst, T. R., Stone, K. L., Samander, S. and Williams, K. R., Purification and characterization of a recombinant hepatitis E protein vaccine candidate by liquid chromatography-mass spectrometry , 91-104, Copyright (1996), with permission from Elsevier Science.

DALLUGE J J, NELSON B c, THOMAS J B and SANDER L 0 (1998) Selection of column and gradient elution system for the separation of catechins in green tea using high-performance liquid chromatography , J Chromatogr A, 793, 265-74. 

Kaliszan, R., Haber, P., Baczek, T., Siluk, D., Valko, K. Lipophilicity and pKi estimates from gradient high-performance liquid chromatography. 

P. W. High speed gradient elution reversed-phase liquid chromatography. 

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