title: Determination of Tinopal CBS-X in rice papers and rice noodles using HPLC with fluorescence detection and LC-MS/MS.
abstract: To date there have been no reports of methods to determine Tinopal CBS-X. We developed a rapid and simple method to determine the Tinopal CBS-X content in rice noodles and rice papers using HPLC equipped with fluorescence detection. Heating the rice noodles and rice papers to 80°C after adding 75% methanol solution induced the release of Tinopal CBS-X from processed rice products. Tinopal CBS-X was separated using an isocratic mobile phase comprising 50% acetonitrile/water containing 0.4% tetrabutyl ammonium hydrogen sulphate at pH 8.0. The samples suspected to be positive by HPLC analysis were then confirmed by LC-MS/MS analysis. This study also investigated the Tinopal CBS-X content of three rice noodle products and two rice papers. The limits of quantification for rice papers and rice noodles were 1.58 and 1.51 µg kg(-1), respectively, and their correlation curves showed good linearity with r(2) ≥ 0.9997 and ≥ 0.9998, respectively. Moreover, rice papers had recoveries of 70.3-83.3% with precision ranging from 5.0% to 7.9%, whereas rice noodles had slightly lower recoveries of 63.4-78.7% and precisions of 8.5-11.5%. Only one rice noodle product contained Tinopal CBS-X, at around 2.1 mg kg(-1), whereas it was not detected in four other samples. Consequently, Tinopal CBS-X from rice noodles and rice papers can be successfully detected using the developed pre-treatment and ion-pairing HPLC system coupled with fluorescence detection.
authors.affiliation: a Division of Food Additives and Packaging, Department of Food Safety Evaluation , Ministry of Food and Drug Safety , Cheongwon-gun , Chungcheongbuk-do , Korea.
authors.forename: Kyung Yuk
authors.initials: KY
authors.lastname: Ko
authors.forename: Chae A
authors.initials: CA
authors.lastname: Lee
authors.forename: Jae Chon
authors.initials: JC
authors.lastname: Choi
authors.forename: Meehye
authors.initials: M
authors.lastname: Kim
mesh_terms: D001557:Benzenesulfonates / Q000737:chemistry*; D057886:Bleaching Agents / Q000737:chemistry; D002853:Chromatography, Liquid / Q000379:methods*; D005453:Fluorescence; D005504:Food Analysis; D005506:Food Contamination; D012275:Oryza / Q000737:chemistry*; D010209:Paper; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D001557:Benzenesulfonates; D057886:Bleaching Agents; C056656:Tinopal CBS-X
keywords: HPLC; Tinopal CBS-X; adulteration; rice noodles; rice papers