### Abstract

In addition to the expression, k' = (t(m)-t(o))/t(o) (1-t(m)/t(mc)), we propose the expression k'' = (t(m)-t(o))/(t(mc)-t(o)) to calculate the capacity factor in micellar electrokinetic chromatography (MEKC), where t(m), t(o), and t(mc) are the migration time of the analyte, the flow marker, and the micelles, respectively. The k' and k'' values that were obtained from simulated data as well as from MEKC analysis of different peptides (in 100 mM sodium dodecyl sulfate/0.1 N sodium borate buffer at pH 11.0) were calculated and compared. The k'' value is equal to zero for an analyte remaining in the aqueous phase whereas :it is equal to one for an analyte always staying in the micellar phase. By applying k'' a finite capacity factor can be obtained for an analyte, indicating its partition between the two moving phases (aqueous and micellar) even in those cases when t(m) equals t(mc). The slope of the curve k'' as a function of t(m) is constant through the whole migration window and therefore peak compression does not occur when applying k'' to calculate the capacity factor. A given difference in k'' corresponds the same difference in migration times and this value does not depend on the position within the migration window. Since k'' is a normalized parameter it is easy to evaluate the significance of a given difference in capacity factor or to estimate the relative position of an analyte with a given capacity factor in the migration window by applying k''. Therefore, k'' seems to be an adequate parameter to calculate the capacity factor in MEKC and, similar to k', it also refers to the hydrophobicity of the analyte.

Original language | English |
---|---|

Pages (from-to) | 762-765 |

Number of pages | 4 |

Journal | Electrophoresis |

Volume | 17 |

Issue number | 4 |

DOIs | |

Publication status | Published - ápr. 1996 |

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### ASJC Scopus subject areas

- Clinical Biochemistry

### Cite this

**Calculation of modified capacity factor in micellar electrokinetic chromatography.** / Idei, M.; Kiss, E.; Kéri, G.

Research output: Article

*Electrophoresis*, vol. 17, no. 4, pp. 762-765. https://doi.org/10.1002/elps.1150170423

}

TY - JOUR

T1 - Calculation of modified capacity factor in micellar electrokinetic chromatography

AU - Idei, M.

AU - Kiss, E.

AU - Kéri, G.

PY - 1996/4

Y1 - 1996/4

N2 - In addition to the expression, k' = (t(m)-t(o))/t(o) (1-t(m)/t(mc)), we propose the expression k'' = (t(m)-t(o))/(t(mc)-t(o)) to calculate the capacity factor in micellar electrokinetic chromatography (MEKC), where t(m), t(o), and t(mc) are the migration time of the analyte, the flow marker, and the micelles, respectively. The k' and k'' values that were obtained from simulated data as well as from MEKC analysis of different peptides (in 100 mM sodium dodecyl sulfate/0.1 N sodium borate buffer at pH 11.0) were calculated and compared. The k'' value is equal to zero for an analyte remaining in the aqueous phase whereas :it is equal to one for an analyte always staying in the micellar phase. By applying k'' a finite capacity factor can be obtained for an analyte, indicating its partition between the two moving phases (aqueous and micellar) even in those cases when t(m) equals t(mc). The slope of the curve k'' as a function of t(m) is constant through the whole migration window and therefore peak compression does not occur when applying k'' to calculate the capacity factor. A given difference in k'' corresponds the same difference in migration times and this value does not depend on the position within the migration window. Since k'' is a normalized parameter it is easy to evaluate the significance of a given difference in capacity factor or to estimate the relative position of an analyte with a given capacity factor in the migration window by applying k''. Therefore, k'' seems to be an adequate parameter to calculate the capacity factor in MEKC and, similar to k', it also refers to the hydrophobicity of the analyte.

AB - In addition to the expression, k' = (t(m)-t(o))/t(o) (1-t(m)/t(mc)), we propose the expression k'' = (t(m)-t(o))/(t(mc)-t(o)) to calculate the capacity factor in micellar electrokinetic chromatography (MEKC), where t(m), t(o), and t(mc) are the migration time of the analyte, the flow marker, and the micelles, respectively. The k' and k'' values that were obtained from simulated data as well as from MEKC analysis of different peptides (in 100 mM sodium dodecyl sulfate/0.1 N sodium borate buffer at pH 11.0) were calculated and compared. The k'' value is equal to zero for an analyte remaining in the aqueous phase whereas :it is equal to one for an analyte always staying in the micellar phase. By applying k'' a finite capacity factor can be obtained for an analyte, indicating its partition between the two moving phases (aqueous and micellar) even in those cases when t(m) equals t(mc). The slope of the curve k'' as a function of t(m) is constant through the whole migration window and therefore peak compression does not occur when applying k'' to calculate the capacity factor. A given difference in k'' corresponds the same difference in migration times and this value does not depend on the position within the migration window. Since k'' is a normalized parameter it is easy to evaluate the significance of a given difference in capacity factor or to estimate the relative position of an analyte with a given capacity factor in the migration window by applying k''. Therefore, k'' seems to be an adequate parameter to calculate the capacity factor in MEKC and, similar to k', it also refers to the hydrophobicity of the analyte.

KW - Micellar elektrokinetic chromatography

KW - Modified capacity factor

UR - http://www.scopus.com/inward/record.url?scp=0029891678&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029891678&partnerID=8YFLogxK

U2 - 10.1002/elps.1150170423

DO - 10.1002/elps.1150170423

M3 - Article

C2 - 8738340

AN - SCOPUS:0029891678

VL - 17

SP - 762

EP - 765

JO - Electrophoresis

JF - Electrophoresis

SN - 0173-0835

IS - 4

ER -