title: Suitability of ionic liquids as mobile-phase additives in HPLC with fluorescence and UV detection for the determination of heterocyclic aromatic amines.
abstract: The effects of several ionic liquids (ILs) as mobile-phase additives in HPLC with fluorescence and UV-Vis detection for the determination of six heterocyclic aromatic amines were evaluated using two different C(18) stationary phases with moderate silanol activity. The studied ILs were 1-butyl-3-methylimidazolium tetrafluoroborate, 1-hexyl-3-methylimidazolium tetrafluoroborate and 1-methyl-3-octylimidazolium tetrafluoroborate. The optical behaviour of heterocyclic aromatic amines in presence of ILs was studied and the silanol-suppressing potency of ILs was evaluated for the two stationary phases studied. Several chromatographic parameters were evaluated in the presence or absence of ILs, or using triethylamine, the most common mobile-phase additive. The best results were achieved using 1 mM 1-butyl-3-methylimidazolium tetrafluoroborate as mobile-phase additive and NovaPak column. In these conditions and with 18% of ACN in the mobile phase, analytical performance of the chromatographic methods using fluorescence and UV-Vis were evaluated, obtaining good precision in all cases (RSD lower than 6.6%) and low LOD (0.001-0.147 microg/mL with UV-Vis and 0.001-0.006 ng/mL with fluorescence detection).
authors.affiliation: Department of Analytical Chemistry, Nutrition and Food Science, University of La Laguna, La Laguna, Spain.
authors.forename: Aurora
authors.initials: A
authors.lastname: Martín-Calero
authors.forename: Gracian
authors.initials: G
authors.lastname: Tejral
authors.forename: Juan H
authors.initials: JH
authors.lastname: Ayala
authors.forename: Venerando
authors.initials: V
authors.lastname: González
authors.forename: Ana M
authors.initials: AM
authors.lastname: Afonso
mesh_terms: D000588:Amines / Q000032:analysis / Q000737:chemistry; D002243:Carbolines / Q000032:analysis* / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006571:Heterocyclic Compounds / Q000032:analysis / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: C419324:1-butyl-3-methylimidazolium tetrafluoroborate; C534649:1-methyl-3-octylimidazolium bromide; D000588:Amines; D002243:Carbolines; D006571:Heterocyclic Compounds; D007093:Imidazoles; D052578:Ionic Liquids; D011084:Polycyclic Aromatic Hydrocarbons; D012821:Silanes; C082343:silanol; C017821:2-amino-3-methyl-9H-pyrido(2,3-b)indole; C019133:3-amino-1-methyl-5H-pyrido(4,3-b)indole; C019132:3-amino-1,4-dimethyl-5H-pyrido(4,3-b)indole; C017822:2-amino-9H-pyrido(2,3-b)indole