Modeling of overloaded gradient elution of nociceptin/orphanin FQ in reversed-phase liquid chromatography

Nicola Marchetti, Francesco Dondi, A. Felinger, Remo Guerrini, Severo Salvadori, Alberto Cavazzini

Research output: Article

18 Citations (Scopus)

Abstract

The Reversed-phase (RP) gradient elution chromatography of nociceptin/orphanin FQ (N/OFQ), a neuropeptide with many biological effects, has been modeled under linear and non-linear conditions. In order to do this, the chromatographic behavior has been studied under both linear and nonliner conditions under isocratic mode at different mobile phase compositions - ranging from 16 to 19% (v/v) acetonitrile (ACN) in aqueous trifluoracetic acid (TFA) 0.1% (v/v) - on a C-8 column. Although the range of mobile phase compositions investigated was quite narrow, the retention factor of this relatively small polypeptide (N/OFQ is a heptadecapeptide) has been found to change by more than 400%. In these conditions, gradient operation resulted thus to be the optimum approach for non-linear elution. As the available amount of N/OFQ was extremely reduced (only a few milligrams), the adsorption isotherms of the peptide, at the different mobile phase compositions examined, have been measured through the so-called inverse method (IM) on a 5 cm long column. The adsorption data at different mobile phase compositions have been fitted to several models of adsorption. The dependence of the isotherm parameters on the mobile phase composition was modeled by using the linear solvent strength (LSS) model and a generalized Langmuir isotherm that includes the mobile phase composition dependence. The overloaded gradient separation of N/OFQ has been modeled by numerically solving the equilibrium-dispersive (ED) model of chromatography under a selected gradient elution mode, on the basis of the previously determined generalized Langmuir isotherm. The agreement between theoretical calculations and experimental overloaded band profiles appeared reasonably accurate.

Original languageEnglish
Pages (from-to)162-172
Number of pages11
JournalJournal of Chromatography A
Volume1079
Issue number1-2 SPEC. ISS.
DOIs
Publication statusPublished - jún. 24 2005

Fingerprint

Liquid chromatography
Reverse-Phase Chromatography
Phase composition
Adsorption
Isotherms
Chromatography
Peptides
Neuropeptides
Adsorption isotherms
Acids
nociceptin

ASJC Scopus subject areas

  • Analytical Chemistry

Cite this

Modeling of overloaded gradient elution of nociceptin/orphanin FQ in reversed-phase liquid chromatography. / Marchetti, Nicola; Dondi, Francesco; Felinger, A.; Guerrini, Remo; Salvadori, Severo; Cavazzini, Alberto.

In: Journal of Chromatography A, Vol. 1079, No. 1-2 SPEC. ISS., 24.06.2005, p. 162-172.

Research output: Article

Marchetti, Nicola ; Dondi, Francesco ; Felinger, A. ; Guerrini, Remo ; Salvadori, Severo ; Cavazzini, Alberto. / Modeling of overloaded gradient elution of nociceptin/orphanin FQ in reversed-phase liquid chromatography. In: Journal of Chromatography A. 2005 ; Vol. 1079, No. 1-2 SPEC. ISS. pp. 162-172.
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