title: [Determination of biurea in flour and its products by liquid chromatography-tandem mass spectrometry].
abstract: A novel method was established for the determination and identification of biurea in flour and its products using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The biurea was extracted with water and oxidized to azodicarbonamide by potassium permanganate. The azodicarbonamide was then derivatized using sodium p-toluene sulfinate solution. The separation was performed on a Shimpak XR-ODS II column (150 mm x 2.0 mm, 2.2 microm) using the mobile phase composed of acetonitrile and 2 mmol/L ammonium acetate aqueous solution (containing 0.2% (v/v) formic acid) with a gradient elution program. Tandem mass spectrometric detection was performed in multiple reaction monitoring (MRM) scan mode with a positive electrospray ionization (ESI(+)) source. The method used stable isotope internal standard quantitation. The calibration curve showed good linearity over the range of 1-20 000 microg/kg (R2 = 0.999 9). The limit of quantification was 5 microg/kg for biurea spiked in flour and its products. At the spiking levels of 5.0, 10.0 and 50.0 microg/kg in different matrices, the average recovery o biurea was 78.3%-108.0% with the relative standard deviations (RSDs) < or = 5.73%. The method developed is novel, reliable and sensitive with wide linear range, and can be used to determine the biurea in flour and its products.
authors.forename: Ya
authors.initials: Y
authors.lastname: Wang
authors.forename: Junsu
authors.initials: J
authors.lastname: Wang
authors.forename: Lu
authors.initials: L
authors.lastname: Xiang
authors.forename: Cunxian
authors.initials: C
authors.lastname: Xi
authors.forename: Dongdong
authors.initials: D
authors.lastname: Chen
authors.forename: Tao
authors.initials: T
authors.lastname: Peng
authors.forename: Guomin
authors.initials: G
authors.lastname: Wang
authors.forename: Zhaode
authors.initials: Z
authors.lastname: Mu
mesh_terms: D001736:Biureas / Q000032:analysis*; D002853:Chromatography, Liquid; D005433:Flour / Q000032:analysis*; D005506:Food Contamination / Q000032:analysis*; D053719:Tandem Mass Spectrometry
chemical_list: D001736:Biureas