TY - JOUR

T1 - A visual approach to stationary phase selectivity classification based on the Snyder-Dolan Hydrophobic-Subtraction Model

AU - Zhang, Yu

AU - Carr, Peter W.

PY - 2009/9/25

Y1 - 2009/9/25

N2 - A novel type of stationary phase selectivity classification "triangle" has been developed based on the Snyder-Dolan (S-D) Hydrophobic-Subtraction Model, wherein the apices of a set of four triangles represent the relative contributions of steric hindrance (χS), hydrogen-bonding acidity (χA), hydrogen-bonding basicity (χB), cation-exchange capacity (χC) to selectivity. We found that "effective selectivity" of a stationary phase is mathematically given by the ratio of system dependent interaction coefficients but not their absolute values. Thus by normalizing the S*, A, B and C terms of the S-D model by H, we were able to obtain four parameters which fully define the chromatographic selectivity of the stationary phases. By examining the parameters in groups of three, we can represent all the result in a set of four "selectivity triangles". The distinctive feature of this approach compared to the S-D phase classification scheme is that it allows the visualization of column selectivity by plotting three-dimensional data in a two-dimensional space. Moreover, it very clearly shows that the RPLC columns thus far characterized cover only a small fraction of separation selectivity space leaving a great deal of room for researchers to develop novel RPC materials. Various applications of these "selectivity triangles" will be discussed in this paper.

AB - A novel type of stationary phase selectivity classification "triangle" has been developed based on the Snyder-Dolan (S-D) Hydrophobic-Subtraction Model, wherein the apices of a set of four triangles represent the relative contributions of steric hindrance (χS), hydrogen-bonding acidity (χA), hydrogen-bonding basicity (χB), cation-exchange capacity (χC) to selectivity. We found that "effective selectivity" of a stationary phase is mathematically given by the ratio of system dependent interaction coefficients but not their absolute values. Thus by normalizing the S*, A, B and C terms of the S-D model by H, we were able to obtain four parameters which fully define the chromatographic selectivity of the stationary phases. By examining the parameters in groups of three, we can represent all the result in a set of four "selectivity triangles". The distinctive feature of this approach compared to the S-D phase classification scheme is that it allows the visualization of column selectivity by plotting three-dimensional data in a two-dimensional space. Moreover, it very clearly shows that the RPLC columns thus far characterized cover only a small fraction of separation selectivity space leaving a great deal of room for researchers to develop novel RPC materials. Various applications of these "selectivity triangles" will be discussed in this paper.

KW - Classification scheme

KW - HPLC

KW - Reversed phase

KW - Selectivity

KW - Stationary phase

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U2 - 10.1016/j.chroma.2009.06.048

DO - 10.1016/j.chroma.2009.06.048

M3 - Article

C2 - 19700166

AN - SCOPUS:69249187781

VL - 1216

SP - 6685

EP - 6694

JO - Journal of Chromatography A

JF - Journal of Chromatography A

SN - 0021-9673

IS - 39

ER -