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Amino columns

Benzodiazepine enantiomers have also been resolved on the Chiralcel OD CSP. Wang et al. utilized this CSP to determine the enantiomeric composition of camazepam and its metabolites [59]. SFC provided improved resolution of the compounds of interest in a shorter period of time than LC. Phinney et al. demonstrated the separation of a series of achiral and chiral benzodiazepines. An amino column was coupled in series with the Chiralcel OD CSP to achieve the desired separation [41]. [Pg.309]

Monomeric HALS have been determined by HPLC [470,663]. Excellent separation was achieved for HALS-type samples (Tinuvin 770 and Chimassorb 944) with NPLC-PDA (230 nm) using an amino column with acetonitrile/water as the mobile phase RPLC using C or cyano columns was not effective [664]. [Pg.249]

Ferretti et al. (1988) used an amino column coupled to a derivatized amylose column (Chiralpak AS) operated in the reverse-phase mode to separate the enantiomers of the antifungal agent voriconazole from several chiral impurities and one achiral impurity. Three of the chiral impurities are the other enantiomer and corresponding diastereomers of voriconazole. More chiral impurities result from a chlorinated voriconazole. Additionally, this multidimensional method could baseline separate all but two of the chiral impurities into their respective enantiomers. These separations are shown in Figure 14.5. [Pg.336]

FIGURE 14.5 Separations involving voriconazole (1), its mirror image (2), related diaster-eomers (3), chlorinated impurities (4), and an achiral impurity 5. (a) Achiral separation of compounds 1-5 on an amino column with hexane/ethanol mobile phase (b) Chiral separation of compounds 1-5 on Chiralpak As column with hexane/ethanol mobile phase (c) Achiral-chiral multidimensional separation with the amino and chiral column coupled in series. Reprinted from Ferretti et al. (1998) with permission from Vieweg Verlag. [Pg.337]

An analytical method for a butterscotch would run as follows dilute the sample 1 2000 and pass through a 0.2-micron filter. The dextrose, fructose, maltose and maltotriose can then be measured directly. In contrast, the same analysis would probably require two chromatograms performed with different mobile phases using the amino-column HPLC method. [Pg.24]

Wei Y, Ding MY. Analysis of carbohydrates in drinks by high-performance liquid chromatography with a dynamically modified amino column and evaporative light scattering detection. Journal of Chromatography A 904, 113-117, 2000. [Pg.228]

Despite the low reproducibility and short life time of the NP columns, they are widely used owing to their better selectivity and resolution power, which enable the separation of (3- and y-isomers easily. The most used stationary phases are silica, aminopropyl- or diol-bonded [476], A more accurate description of the column used can be found in a review about tocol-derivatives analysis by Abidi [477], Kamal-Eldin et al. [478] compare the performance of new silica-type columns, six different silica columns, three amino columns, and one diol column. The new generation column results are much more repeatable and therefore suitable for vitamers analysis. [Pg.612]

Bushway, R. J. (1982). High-performance liquid chromatographic separation of potato glycoalkaloids using a radially compressed amino column. J. Chromatogr., 247,180-183. [Pg.155]

Of the polar bonded-phase packings that have been investigated, the interactions between carotenes and nitrile stationary phases are very weak thus the limitations described for silica apply (164). Amino-bonded phases eluted with iso-octane containing 0.5% stabilized tetrahydrofu-ran separate a- and /3-carotene (unresolved) from y-carotcnc canthaxanthin and /3-cryptoxanthin are not eluted (161). The cis isomers of /3-carotene are separated from the all-trans isomer thus amino columns offer an alternative option to alumina columns for determining all-trans-/3-carotene without its cis isomers interfering. [Pg.363]

Table 5 HPLC Methods for Quantitating Individual C Vitamers in Foods (Ion Exchange, Ion Exclusion, and Amino Columns UV Absorbance Detection)... [Pg.415]

Assuming we have selected the proper mode of chromatography, will the mixture dissolve in the mobile phase Ion-exchange columns must be run in polar-charged solvents. Size separation columns are not, in theory, affected by solvent polarity, and size columns for use in both polar and nonpolar solvents are available. In partition chromatography, we have nonpolar columns that can be run in polar or aqueous solvents, and polar columns that are only run in anhydrous, nonpolar solvents. Intermediate columns such as cyanopropyl or diol can be run in either polar or nonpolar solvents, although often with differing specificity. An amino column (actually a propylamino) acts in methylene chloride/hexane like a less polar silica column but in acetonitrile/water... [Pg.68]

Deoxygenation—Removing oxygen from a solvent by vacuum replacement with nitrogen or helium gas to prevent oxidation of sensitive compounds or columns (such as the amino columns). [Pg.215]

Perkins et al. reported the packed-column SFC of four veterinary antibiotics (levamisole, furazolidone, chloramphenicol, and lincomycin) using an amino column with methanol-modified carbon dioxide as the mobile phase [22]. A baseline separation of all four analytes was obtained in less than 4 min. The effect of several modifiers such as 2-methoxy-ethanol,... [Pg.135]

Gyllenhaal and Vessman have described the packed-column SFC of omeprazole and related compunds using an amino column with triethyla-mine- and methanol-modified carbon dioxide as the mobile phase [42]. Triethylamine (1%) was added to the methanol. The method was compared with an existing HPLC method, and it was concluded that SFC was about... [Pg.139]

G. Vigh and J. Inczedy, Separation of chloramphenicol intermediates by HPLC on micropak-amino columns, J. Chromatogr., 129 81 (1976). [Pg.403]

The HPLC was equipped with a refractive index detector, and a 150 mm x 4.6 mm, 3-p,m Phenomenex amino column. The mobile phase was 70% acetonitrile in water. The flow rate was 1 mL/min. Equal volumes (25 tiL) of standard and sample solutions were injected separately into the system. The amount quantified by capillary GC and HPLC methods were fairly comparable (about 21 g/kg) and both methods were specific, precise, and accurate. However, tlie total run time for HPLC method was less than one-third that of the GC metliod. [Pg.88]

In normal phase HPLC, the cyano and amino columns, in conjunction with the diol bonded phase columns, are now often used in preference to unmodified silica or alumina. Whilst silica can demonstrate remarkable selectivity for the separation of closely related isomers (e.g. E/Z isomers are commonly separated on silica), some of the operational demands of silica limit its usefulness. The difficulty of manufacturing reproducible microcrystalline silica and the possible effect of trace amounts of water on... [Pg.86]

Serial connection of different stationary phases provides some very interesting separations. The combination of different CSPs provides systems capable of resolving a wide range of enantiomers (Sandra et al. [2], Gyllenhaal [2]). Recent applications combining normal-phase bonded-silica (diol, cyano, amino) columns with CSPs in series, to provide concurrent structural... [Pg.1524]

For reactivation of an amino column that had become exhausted as a result of reaction with actone, see... [Pg.198]

The neutral lipids, fraction 1, is refractionated with a second amino column after evaporation and reconstitution with hexane. [Pg.213]

The hexane extract is applied to the second amino column. The cholesteryl esters are eluted with hexane, with the second column attached to the first to trap cholesterol from sorbent 1, which elutes with triglycerides. [Pg.213]


See other pages where Amino columns is mentioned: [Pg.248]    [Pg.251]    [Pg.248]    [Pg.43]    [Pg.123]    [Pg.618]    [Pg.642]    [Pg.131]    [Pg.88]    [Pg.228]    [Pg.668]    [Pg.89]    [Pg.76]    [Pg.161]    [Pg.161]    [Pg.137]    [Pg.130]    [Pg.263]    [Pg.138]    [Pg.576]    [Pg.558]    [Pg.1560]    [Pg.1738]    [Pg.867]    [Pg.213]   
See also in sourсe #XX -- [ Pg.136 ]




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