title: Identification and determination of 34 water-soluble synthetic dyes in foodstuff by high performance liquid chromatography-diode array detection-ion trap time-of-flight tandem mass spectrometry.
abstract: An accurate method combining high performance liquid chromatography (HPLC) with diode array detection (DAD) and ion-trap time-of-flight mass spectrometry (IT-TOF/MS) was developed for simultaneous identification and quantification of 34 water-soluble synthetic dyes in foodstuff. Fragmentation patterns of synthetic dyes were proposed based on IT-TOF/MS. The molecular ion [M+H](+) was not observed in the conventional single-stage mass spectra for most of synthetic dyes. The single-stage mass spectra of synthetic dyes all afforded the diagnostic ions [(M-nNa+nH)+H](+) or [(M-nNa+nH)-H](-) in the positive or negative mode. Doubly charged ions were the characteristic ions of azo dyes. An HPLC-DAD method was developed to analyze 34 synthetic dyes in foodstuffs. The limits of detection (LOD) for the dyes were 0.01-0.05 μg/mL. The recoveries were between 76.1% and 105.0% with a RSD ranging from 1.4% to 6.4%. This method was successfully applied to analyzing the 34 water-soluble synthetic dyes in 21 commercial foods.
authors.affiliation: Food Safety Laboratory, Division of Metrology in Chemistry, National Institute of Metrology, Beijing 100029, China. Electronic address: lxq_1979@163.com.
authors.forename: Xiu Qin
authors.initials: XQ
authors.lastname: Li
authors.affiliation: Food Safety Laboratory, Division of Metrology in Chemistry, National Institute of Metrology, Beijing 100029, China.
authors.forename: Qing He
authors.initials: QH
authors.lastname: Zhang
authors.affiliation: Food Safety Laboratory, Division of Metrology in Chemistry, National Institute of Metrology, Beijing 100029, China.
authors.forename: Kang
authors.initials: K
authors.lastname: Ma
authors.affiliation: Food Safety Laboratory, Division of Metrology in Chemistry, National Institute of Metrology, Beijing 100029, China.
authors.forename: Hong Mei
authors.initials: HM
authors.lastname: Li
authors.affiliation: Food Safety Laboratory, Division of Metrology in Chemistry, National Institute of Metrology, Beijing 100029, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Guo
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004396:Coloring Agents / Q000737:chemistry*; D005503:Food Additives / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014867:Water
chemical_list: D004396:Coloring Agents; D005503:Food Additives; D014867:Water
keywords: Foodstuff; Fragmentation patterns; HPLC–DAD–IT-TOF/MS; Identification and determination; Synthetic dyes