title: Standard addition strip for quantitative electrostatic spray ionization mass spectrometry analysis: determination of caffeine in drinks.
abstract: Standard addition strips were prepared for the quantitative determination of caffeine in different beverages by electrostatic spray ionization mass spectrometry (ESTASI-MS). The gist of this approach is to dry spots of caffeine solutions with different concentrations on a polymer strip, then to deposit a drop of sample mixed with an internal standard, here theobromine on each spot and to measure the mass spectrometry signals of caffeine and theobromine by ESTASI-MS. This strip approach is very convenient and provides quantitative analyses as accurate as the classical standard addition method by MS or liquid chromatography.
authors.affiliation: Laboratoire d׳Electrochimie Physique et Analytique, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015 Lausanne, Switzerland.
authors.forename: Elena
authors.initials: E
authors.lastname: Tobolkina
authors.affiliation: Laboratoire d׳Electrochimie Physique et Analytique, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015 Lausanne, Switzerland.
authors.forename: Liang
authors.initials: L
authors.lastname: Qiao
authors.affiliation: Section of Chemistry and Chemical Engineering/Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, Station 6, CH-1015 Lausanne, Switzerland.
authors.forename: Christophe
authors.initials: C
authors.lastname: Roussel
authors.affiliation: Laboratoire d׳Electrochimie Physique et Analytique, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015 Lausanne, Switzerland. Electronic address: hubert.girault@epfl.ch.
authors.forename: Hubert H
authors.initials: HH
authors.lastname: Girault
mesh_terms: D001628:Beverages / Q000032:analysis*; D002110:Caffeine / Q000032:analysis*; D000697:Central Nervous System Stimulants / Q000032:analysis*; D002853:Chromatography, Liquid / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D055672:Static Electricity; D013805:Theobromine / Q000032:analysis*; D014665:Vasodilator Agents / Q000032:analysis
chemical_list: D000697:Central Nervous System Stimulants; D014665:Vasodilator Agents; D002110:Caffeine; D013805:Theobromine
keywords: Caffeine; Electrostatic spray ionization; Mass spectrometry; Quantitative analysis