Ion-exchange HPLC

Proteoglycans (from cultured human muscle cells). Separated by ion-exchange HPLC using a Biogel TSK-DEAE 5-PW analytical column. [Harper et al. Anal Biochem 159 150 1986.]... 

The free oil can be determined by an ion exchange HPLC technique. A solution of the sample in ethyl alcohol is analysed by high-performance ion exchange chromatography using a specially prepared ion exchange resin stationary phase, ethanol mobile phase, and differential refractive index detection. 

Figure 3 shows an ion exchange HPLC analysis of the irradiation experiment performed with the duplex 13. The starting duplex 13 elutes at a retention time of 13 min. The cleaved DNA strand has a retention time of 11 min. Clearly evident again is the clean conversion of the unrepaired duplex 13 into the cleaved, repaired , DNA fragment. 

What is a suppressor and why is one needed in an ion exchange HPLC experiment in which the mobile phase contains ions ... 

A suppressor is a device that selectively removes ions from a flowing solution. In an ion exchange HPLC experiment in which the mobile phase contains ions, a suppressor must be used to remove these ions so that the ions of the mixture can be detected. A conductivity detector measures ions by the conductivity that they induce in the mobile phase, so the mobile phase ions constituent an interference. 

Ion-exchange HPLC can also be useful in the separation of larger nucleic acid molecules. One such application is as an alternative to CsCl density gradient centrifugation in the preparation of plasmids. Plasmid molecules typically consist of between 1000 and 10 000 base pairs. The plasmid is first isolated from the bacterial cell by alkaline lysis and pure plasmid obtained from this crude extract by a one-step chromatographic separation. 

Quality assurance and quality control o Ion exchange HPLC... 

Table 7 Survey of Commercially Available Prepacked Columns for the Ion-Exchange HPLC of Proteins1... 

Reverse-phase and ion-exchange HPLC have been used for the determination of intermediates and subsidiaries of synthetic dyes. However, reverse-phase ion-pair HPLC has been found particularly useful for the separation and detection of these compounds (195). 

Bailey et al. (199) and Singh (200) used ion-exchange HPLC for the separation of amaranth from the intermediates naphthionic acid and R-salt, as well as the side reaction products 2-naph-thol-6-sulfonic acid sodium salt (Schaeffer s salt), 2-naphthol-6,8-disulfonic acid disodium salt (G-salt), and 2-naphthol-3,6,8-trisulfonic acid trisodium salt (NTSA). 

Tartrazine was separated from the intermediates sulfanilic acid, pyrazolone-T, and phenyl-hydrazine-p-sulfonic acid (PHSA) and from the side reaction products DAADBSA and l-(4-sulfophenyl)-3-ethyl carboxy-5-hydroxypyrazolone (EEPT) by ion-exchange HPLC (199,214). 

Lues, J. F. R., Botha, W. C., and Smith, E. J. (1998). Ion-exchange HPLC analysis of a broad spectrum of organic acids from matured Cheddar cheese and assessment of extraction methods. Food Res. Int. 31, 441-447. 

Generation of the dynamic library proved straightforward a mixture containing equimolar amounts of the three substrates 28a-c and two equivalents of sodium pyruvate was incubated in the presence of NANA aldolase (Figures 29.2 and 29.3). Aliquots of the incubation mixture were withdrawn at intervals and analyzed by ion-exchange HPLC. 

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