title: Determination of 4(5)-methylimidazole in soy sauce and other foods by LC-MS/MS after solid-phase extraction.
abstract: A method for the determination of 4(5)-methylimidazole (4MeI) in naturally brewed soy sauce was developed for the first time using solid-phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). SPE on silica-based reversed-phase cartridges with heptafluorobutyric acid as an ion-pairing reagent was used for the efficient cleanup of 4MeI. A multimode ODS column was employed for the chromatographic separation. To subtract the matrix effect during LC-MS/MS analysis, a standard addition method was used. The levels of 4MeI found in naturally brewed soy sauce were extremely low (ranging from <0.002 to 0.023 μg/g), whereas those in soy sauces containing caramel color were generally high (ranging from 0.43 to 4.8 μg/g). The method proved to be useful for the analysis of 4MeI in other foods such as caramel colors, drinks, and Worcestershire sauce.
authors: Research and Development Division, Kikkoman Corporation, 399 Noda, Noda, Chiba 278-0037, Japan. hyamaguchi@mail.kikkoman.co.jp
authors: Hitomi
authors: H
authors: Yamaguchi
authors: Tsutomu
authors: T
authors: Masuda
mesh_terms: D002273:Carcinogens / Q000032:analysis; D002853:Chromatography, Liquid; D005504:Food Analysis / Q000379:methods*; D007093:Imidazoles / Q000032:analysis*; D015203:Reproducibility of Results; D052616:Solid Phase Extraction; D045730:Soy Foods / Q000032:analysis*; D053719:Tandem Mass Spectrometry
chemical_list: D002273:Carcinogens; D007093:Imidazoles; C023439:4-methylimidazole