title: Microemulsion electrokinetic chromatography with on-line atmospheric pressure photoionization mass spectrometric detection.
abstract: In the present paper we report, for the first time, the successful on-line coupling of microemulsion electrokinetic chromatography (MEEKC) with mass spectrometric (MS) detection using an atmospheric pressure photoionization interface. Microemulsions (MEs) including mostly volatile ingredients and classical MEs based on nonvolatile buffer components and sodium dodecyl sulfate (SDS) as surfactant were compared with respect to their compatibility with MS detection. The investigations performed revealed that MEs with up to 3% SDS and buffers containing sodium borate can be employed without significant suppression of the MS signals. A test mixture of nine substances could be separated by MEEKC using a ME consisting of 0.8% octane, 2% SDS, 6.6% butanol, and 90.6% of 20-mmol ammonium hydrogencarbonate buffer (pH 9.5). Operating the MS instrument in the MS(2) mode provided improved signal/noise ratios for analytes leading to characteristic MS-MS transitions. Thereby, limits of detection ranging between 0.5 (carbamazepine) and 5 microg mL(-1) (phenacetin) could be obtained.
authors.affiliation: Institute of Analytical Chemistry, Johannes Kepler University, Altenbergerstrasse 69, A-4040 Linz, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Himmelsbach
authors.forename: Manuela
authors.initials: M
authors.lastname: Haunschmidt
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Buchberger
authors.forename: Christian W
authors.initials: CW
authors.lastname: Klampfl
mesh_terms: D001274:Atmospheric Pressure; D002220:Carbamazepine / Q000032:analysis; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000295:instrumentation / Q000379:methods*; D004655:Emulsions; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D015394:Molecular Structure; D010615:Phenacetin / Q000032:analysis; D010777:Photochemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012967:Sodium Dodecyl Sulfate / Q000032:analysis; D013997:Time Factors
chemical_list: D004655:Emulsions; D002220:Carbamazepine; D012967:Sodium Dodecyl Sulfate; D010615:Phenacetin