title: Determination of roquefortine C in blue cheese using on-line column-switching liquid chromatography.
abstract: A method is described for the determination of roquefortine C in (blue) cheese. After liquid-liquid extraction with a mixture of hydrochloric acid and methanol, and filtration, an aliquot is analysed using column-switching reversed-phase liquid chromatography. The recovery of roquefortine C in Fetta cheese is about 85%, the calibration curve is linear from 10 to 2500 ng g(-1) (r2 = 0.998), and the detection limit is about 10 ng g(-1). In different batches of Danish Blue concentrations of 1000-2000 ng g(-1) of roquefortine C are found. As regards the stability of roquefortine C its half-life in diffuse daylight is ca. 50 min, while after irradiation with ultraviolet light, it is about 10 min.
authors.affiliation: Free University, Department of Analytical Chemistry, Amsterdam, The Netherlands.
authors.forename: E
authors.initials: E
authors.lastname: Noroozian
authors.forename: F
authors.initials: F
authors.lastname: Lagerwerf
authors.forename: H
authors.initials: H
authors.lastname: Lingeman
authors.forename: U A
authors.initials: UA
authors.lastname: Brinkman
authors.forename: M A
authors.initials: MA
authors.lastname: Kerkhoff
mesh_terms: D000085:Acetates / Q000737:chemistry; D002021:Buffers; D002138:Calibration; D002611:Cheese / Q000032:analysis*; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods*; D004355:Drug Stability; D004873:Ergolines / Q000032:analysis* / Q000528:radiation effects; D006576:Heterocyclic Compounds, 4 or More Rings; D006851:Hydrochloric Acid / Q000737:chemistry; D007211:Indoles; D000432:Methanol / Q000737:chemistry; D009183:Mycotoxins / Q000032:analysis*; D010879:Piperazines; D012044:Regression Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013472:Sunlight; D014466:Ultraviolet Rays
chemical_list: D000085:Acetates; D002021:Buffers; D004873:Ergolines; D006576:Heterocyclic Compounds, 4 or More Rings; D007211:Indoles; D009183:Mycotoxins; D010879:Piperazines; C012536:roquefortine; C007650:ethyl acetate; D006851:Hydrochloric Acid; D000432:Methanol