title: Two fluoroalcohols as components of basic buffers for liquid chromatography electrospray ionization mass spectrometric determination of antibiotic residues.
abstract: Two fluoroalcohols--1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) and 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol (HFTB)--were evaluated for the first time as volatile buffer acids in the basic mobile phase for reversed-phase chromatography with electrospray ionization-mass spectrometric (LC-ESI-MS) detection of five antibiotics. Chromatographic separation as well as positive and negative ion ESI-MS intensities using these novel buffer components were compared to traditional buffer systems. Overall, the highest signal intensities and best chromatographic separation for the five antibiotics (ciprofloxacin, norfloxacin, ofloxacin, sulfadimethoxine and sulfamethoxazole) were achieved using 5 mM HFIP as the buffer acid to methanol : water mobile phase (pH of the aqueous component adjusted to 9.0 with ammonium hydroxide). Comparable results were achieved using 5 mM HFTB (pH adjusted to 9.0 with ammonium hydroxide). The suitability of HFIP for analysis of antibiotic residues in lettuce is demonstrated.
authors.affiliation: University of Tartu, Institute of Chemistry, 14a Ravila Street, 50411 Tartu, Estonia. karin.kipper@gmail.com
authors.forename: Karin
authors.initials: K
authors.lastname: Kipper
authors.forename: Koit
authors.initials: K
authors.lastname: Herodes
authors.forename: Ivo
authors.initials: I
authors.lastname: Leito
authors.forename: Lembit
authors.initials: L
authors.lastname: Nei
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis*; D002853:Chromatography, Liquid / Q000379:methods*; D002939:Ciprofloxacin / Q000032:analysis; D004350:Drug Residues / Q000032:analysis*; D018545:Lactuca / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods; D009643:Norfloxacin / Q000032:analysis; D015242:Ofloxacin / Q000032:analysis; D020005:Propanols; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation / Q000379:methods*; D013412:Sulfadimethoxine / Q000032:analysis; D013420:Sulfamethoxazole / Q000032:analysis; D006845:Hydrocarbons, Fluorinated
chemical_list: D000900:Anti-Bacterial Agents; D002939:Ciprofloxacin; D009643:Norfloxacin; D015242:Ofloxacin; D020005:Propanols; D013412:Sulfadimethoxine; D013420:Sulfamethoxazole; C001337:hexafluoroisopropanol; D006845:Hydrocarbons, Fluorinated