Cation-exchange liquid chromatography

Stein reported the separation of choline and acetylcholine by a cation-exchange chromatographic method [198]. Four columns were compared by Salamoun et al. for the separation of choline and acetylcholine by cation exchange liquid chromatography [178]. The mobile phase used was 

1 M phosphate buffer (pH 7.4), containing 0.1 mM EDTA and 4mM tetramethylammonium perchlorate, and was eluted at a rate of 0.5mL/ min. The system made use of a reactor cartridge (3 cm x 2.1 mm) containing immobilized choline oxidase and acetylcholineesterase, and electrochemical detection at 0.45 V. The columns were (15 cm x 3 mm 

6 High performance liquid chromatography-mass spectrometry (HPLC/MS) 

Polak and Molenaar described a method for the determination of acetylcholine from brain tissue by pyrolysis-gas chromatography-mass spectrometry [200]. The deuterium-labeled acetyl-choline is pyrolytically demethylated with sodium benzenethiolate, followed by quantitative GC-MS analysis. In this method, care must be taken so that the samples do not contain appreciable amounts of choline since exchange of deuterium-labeled groups between acetylcholine and choline during pyrolysis may yield erroneous results. The same authors have also reported a method for the determination of acetylcholine by slow pyrolysis combined with mass fragment analysis on a packed capillary column [201]. 

Mikes reported the use of a new injection micropyrolysis apparatus for acetylcholine and choline determination by gas chromatography-mass spectrometry [202]. 

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Law, B. and Weir, S., Quantitative structure-retention relationships for secondary interactions in cation-exchange liquid chromatography, ]. Chromatogr. A, 657, 17, 1993. 

Figure 4.8 Cation-exchange liquid chromatography of basic proteins. Column, Asahipak ES502C eluent, 20 min linear gradient of sodium chloride from 0 to 500 mM in 50 mM sodium phosphate buffer pH 7.0 flow rate, 1 ml min-1 temperature, 30 °C detection, UV 280 nm. Peaks 1, myoglobin from horse skeletal muscle (Mr 17 500, pi 6.8-7.3) 2, ribonuclease from bovine pancreas (Mr 13 700, pi 9.5-9.6) 3, a-chymotrypsinogen A from bovine pancreas (Mr 257 000, pi 9.5) and 4, lysozyme from egg white (Mr 14 300, pi 11.0-11.4). (Reproduced by permission from Asahikasei data)...

Boyle et al. [47] have described a method for determining cobalt in non saline waters using cation exchange liquid chromatography. Cobalt was determined directly in 500pL fresh water samples with a detection limit of 20pM per kg. 

Figure 10 Cation exchange liquid chromatography inductively coupled plasma mass spectrometry (LC-ICP-MS) of arsenic species spiked in (a) aqueous solution and (b) urine diluted (1 + 3). Amount of each species injected 0.44 ng. Peaks (1) DMA (2) As (III) (3) MM A (4) As (V) (5) AsB (6) TMAO (7) AsC (8) TMAs. (From Ref. 69.)...

Laussmann T, Meier-Giebing S. Forensic analysis of hallucinogenic mushrooms and khat (Catha edulis FORSK) using cation-exchange liquid chromatography. Forensic Sci Int 2010 195(l-3) 160-4. 

Allenmark, S., and Hedman, L., 1979, Cation-exchange liquid chromatography with amperometric detection as a method for the analysis of endogenous catecholamine concentrations in plasma or serum,/. Liq. Chromatogr. 2 277-286. 

McMurtrey, K. D., Cashaw, J. L., and Davis, V. E., 1980, Analysis of dopamine-derived tetrahydroisoquinoline and tetrahydroprotoberberine alkaloids by cation-exchange liquid chromatography,/. Liq. Chromatogr. 3 663-679. 

Boyle, E. A., B. Handy, and A. Geen. 1987. Cobalt determination in natural waters using cation-exchange liquid chromatography with luminol chemiluminescence detection. Anal. Chem. 59 1499-1503. 

Therefore, the equivalent weight of a coordination compound is related to the charge of the complex cation. Cation exchange, liquid column chromatography can be used to determine the equivalent weight, and thus the charge of your compound. 

Only a few examples can be found in the literature in which ISEs have been used as detectors for ion chromatography. They have been employed to detect nitrate in the presence of nitrite [32] and to detect alkali cations [33]. [34] and a variety of anions [35], [36] after isolation by ion-exchange liquid chromatography. 

From Table 19.1, if follows that mostly commercial columns with different separation mechanisms have been combined, such as strong cation-exchange (SCX) chromatography x reversed-phase (RP) liquid chromatography [40,41] or RP x normal-phase (NP) liquid chromatography (-CN column) [38]. Also, a number of tailor-made columns immobilized with biological macromolecules have been used in the first dimension for TCMs analysis [25,43,45]. Due to a specific interaction with these bio-macromolecules, such separations may provide significantly more information on components. In most of the cases, the two columns have been combined off-line, which is simpler. However, a few are truly comprehensive (LC x LC). 

Ion Exchange Resins - Spectra/Gel Ion Exchange resins are ion exchange media for use in low-pressure liquid chromatography. They are based on a polystyrene/divinylbenzene support and are available for both anion and cation exchange applications. This site will give you a reasonable... 

Figure 12.22 SFC-GC analysis of aromatic fraction of a gasoline fuel, (a) SFC trace (b) GC ttace of the aromatic cut. SFC conditions four columns (4.6 mm i.d.) in series (silica, silver-loaded silica, cation-exchange silica, amino-silica) 50 °C 2850 psi CO2 mobile phase at 2.5 niL/min FID detection. GC conditions methyl silicone column (50 m X 0.2 mm i.d.) injector split ratio, 80 1 injector temperature, 250 °C earner gas helium temperature programmed, — 50 °C (8 min) to 320 °C at a rate of 5 °C/min FID detection. Reprinted from Journal of Liquid Chromatography, 5, P. A. Peaden and M. L. Lee, Supercritical fluid chromatography methods and principles , pp. 179-221, 1987, by courtesy of Marcel Dekker Inc.

Palmer showed that F-2DFG prepared from 61 and F2 could be separated, by liquid chromatography on a cation-exchange resin (Aminex-A5, Rb form), from [ F]fluoride and less-polar impurities, but not from F-2DFM. 

Breter, H.-J., Seibert, G., and Zahn, R. K., Single-step separation of major and rare ribonucleosides and deoxyribonucleosides by high-performance liquid cation-exchange chromatography for the determination of the purity of nucleic acid preparations, ]. Chromatogr., 140, 251, 1977. 

Siezen, R. J., Kaplan, E. D., and Anello, R. D., Superior resolution of y-crystal-lins from microdissected eye lens by cation-exchange high-performance liquid chromatography, Biochem. Biophys. Res. Comm., 127, 153, 1985. 

Alpert, A. J., Cation-exchange high-performance liquid chromatography of proteins on poly(aspartic acid)-silica, /. Chromatogr, 266, 23, 1983. 

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