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Protein-based chiral columns

Chiral separations result from the formation of transient diastereomeric complexes between stationary phases, analytes, and mobile phases. Therefore, a column is the heart of chiral chromatography as in other forms of chromatography. Most chiral stationary phases designed for normal phase HPLC are also suitable for packed column SFC with the exception of protein-based chiral stationary phases. It was estimated that over 200 chiral stationary phases are commercially available [72]. Typical chiral stationary phases used in SFC include Pirkle-type, polysaccharide-based, inclusion-type, and cross-linked polymer-based phases. [Pg.221]

The Ki for HSA binding to racemic warfarin has been reported for 3-6 pM by various techniques, including frontal analysis and equilibrium dialysis, and is temperature- and pH-dependent. See Loun, B., Hage, D.S. Chiral separation mechanisms in protein-based HPLC columns. 1. Thermodynamic studies of (R)- and (S)-warfarin binding to immobilized human serum albumin. Anal. Chem. 1994, 66, 3814-3822. [Pg.155]

Yang, J. and Hage, D.S., Effect of mobile phase composition on the binding kinetics of chiral solutes on a protein-based HPLC column Interactions of d- and L-tryptophan with immobilized human serum albumin, J. Chromatogr. A, 766, 15-25, 1997. [Pg.383]

The use of polysaccharide-based CSPs instead of protein-based CSPs often increases the peak efficiency and facilifafes faster separafions. Papini ef al. [159] recently developed a method for the enantioseparation of lorazepam and on a Chiralpak OD-R column and an enzymatic hydrolysis was used to determine the amount of the glucoronide metabolite of lorazepam present. The separation was performed in 7 min with an LOQ of 1 and 10 ng/mL for lorazepam in plasma and urine, respectively. Another relatively fast separation for chiral analysis was published by Lausecker and Eischer [188]. They developed a method for determination of the drug candidate R483 within... [Pg.525]

TABLE 1 Various Protein-Based Commercial Chiral Columns... [Pg.228]

K. M. Kirkland, K. L. Neilson, D. A. Me Combs, and J. J. DeStef-ano, Optimized HPLC separations of racemic drugs using ovomucoid protein-based chiral column, LC-GC, 10 322 (1992). [Pg.106]

Before starting a preparative chiral separation it is essential to identify a chiral stationary phase (CSP) exhibiting good chiral recognition ability. This is usually done with an analytical column because it is less substance- and time-consuming. A stationary phase mostly composed of silica gel with only a few chiral elements will be rapidly overloaded. In this event, even if the phase exhibits useful properties for analytical purposes, it will not be appropriate for preparative applications this is the case for protein-based phases [102, 103], Most chiral stationary phases have relatively low saturation capacity, so the enantiomer separations are usually done under strongly nonlinear conditions [103], Accordingly, the accurate determination of the adsorption isotherms of the two enantiomers on a CSP is of fundamental importance to allow computer-assisted optimization to scale up the process. [Pg.44]

The type-I sites have, in protein based CSPs, identical behavior toward the two enantiomers, and cannot distinguish between them. Many columns contain mostly type-I sites. On type-I sites all possible molecular interactions, between the analyte molecules and atoms or groups of atoms belonging to the adsorbent surface, take place. These interactions can originate from the nonchiral parts of the protein and/or from the adsorbent (silica) matrix. The energies of each interaction on type-I sites are small. The other type of adsorption sites have, in protein based CSPs, much higher adsorption energy and are enantioselective (chiral). These sites, type-II sites, are responsible for the enantiomeric separations. On most CSPs the type-II sites are relatively few. [Pg.48]

Most chiral HPLC analyses are performed on CSPs. General classification of CSPs and rules for which columns may be most appropriate for a given separation, based on solute structure, have been described in detail elsewhere. Nominally, CSPs fall into four primary categories (there are additional lesser used approaches) donor-acceptor (Pirkle) type, polymer-based carbohydrates, inclusion complexation type, and protein based. Examples of each CSP type, along with the proposed chiral recognition mechanism, analyte requirement(s), and mode of operation, are given in Table 3. Normal-phase operation indicates that solute elution is promoted by the addition of polar solvent, whereas in reversed-phase operation elution is promoted by a decrease in mobile-phase polarity. [Pg.372]

Loun B, Hage DS. Chiral separation mechanisms in protein-based HPLC columns, n. Kinetic studies of R- and S-warfarin binding to immobilized human serum albumin. Anal Chem 1996 68 1218-25. [Pg.22]

TABLE 4 Protein-Based Chiral Columns Commonly Used in Pharmaceutical HPLC Method Development Screening Systems... [Pg.265]


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Protein column

Protein-based

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