title: [Screening method for 29 forbidden or limited synthetic pigments in cheese by liquid chromatography/quadrupole time-of-flight mass spectrometry].
abstract: A screening method for 29 forbidden or limited synthetic pigments in cheese samples was established by liquid chromatography/quadrupole time-of-flight mass spectrometry (LC/Q-TOF MS). The pigments were extracted by n-hexane/water (3:1, v/v). After extraction, the n-hexane extract, water extract and residue, were obtained. The n-hexane extract was then cleaned-up by gel permeation chromatography (GPC). The water extract was extracted by acetonitrile, and the residue by ammonia water/methanol (1:99, v/v). The results showed that the 29 synthetic pigments with a wide range of polarities were extracted effectively with the recoveries between 70% and 95%, and matched well by Q-TOF MS precision mass searching to the mass spectral library with matching scores between 59. 66 and 99. 47. The quantitative analysis of the 29 pigments was carried out by Target MS/MS. The limits of detection (LODs) for 8 Sudan dyes were 0.4-2.5 micro/kg while for 21 water-soluble synthetic pigments were 20-80 microg/kg. The screening method is suitable for a wide range of synthetic pigments, and can be applied to food samples with proteins and fat in matrix.
authors.affiliation: Chinese Academy of Inspection and Quarantine, Beijing 100123, China.
authors.forename: Yansheng
authors.initials: Y
authors.lastname: Zhao
authors.forename: Minli
authors.initials: M
authors.lastname: Yang
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.forename: Feng
authors.initials: F
authors.lastname: Feng
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Chu
authors.forename: Ying
authors.initials: Y
authors.lastname: Dong
mesh_terms: D002611:Cheese / Q000032:analysis*; D002853:Chromatography, Liquid / Q000379:methods*; D005504:Food Analysis / Q000379:methods*; D005505:Food Coloring Agents / Q000032:analysis*; D005506:Food Contamination / Q000032:analysis; D013058:Mass Spectrometry / Q000379:methods*
chemical_list: D005505:Food Coloring Agents