title: Improved chromatographic response function in HILIC analysis: application to mixture of antidepressants.
abstract: This paper presents exploration of chromatographic behavior in HILIC system by experimental design and improved chromatographic response function denoted as N(CRF)*. As a model mixture six antidepressants were chosen: selegiline, mianserine, sertraline, moclobemide, fluoxetine and maprotiline. Due to complexity of retention mechanisms in HILIC system, detailed examination of experimental space assessing the influence of important factors (acetonitrile content in the mobile phase, buffer concentration and pH of the mobile phase) and their interactions was done by applying 3(3) experimental design. N(CRF)* is developed and designed to be the only output of the system which simultaneously measures the separation of all the examined substances, the chromatographic run duration and the quality of the obtained peaks shape. It allowed objective estimation of overall chromatogram quality and excluded the arbitrary judgment in ambiguous situations. The applied function highlighted the influence of investigated factors on entire mixture and enabled identification of experimental regions where the chromatographic behavior was satisfactory. Applied experimental design strategy combined with N(CRF)* proved to be valuable assistance in HILIC separation of complex mixtures.
authors.affiliation: University of Belgrade, Faculty of Pharmacy, Department of Drug Analysis, Vojvode Stepe 450, 11000 Belgrade, Serbia.
authors.forename: Tijana
authors.initials: T
authors.lastname: Rakić
authors.forename: Biljana
authors.initials: B
authors.lastname: Jančić Stojanović
authors.forename: Anđelija
authors.initials: A
authors.lastname: Malenović
authors.forename: Darko
authors.initials: D
authors.lastname: Ivanović
authors.forename: Mirjana
authors.initials: M
authors.lastname: Medenica
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D000465:Algorithms; D000928:Antidepressive Agents / Q000032:analysis* / Q000737:chemistry; D005591:Chemical Fractionation; D002853:Chromatography, Liquid / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D012107:Research Design; D012996:Solutions
chemical_list: D000097:Acetonitriles; D000928:Antidepressive Agents; D012996:Solutions; C032159:acetonitrile