title: Rapid determination of nitroimidazole residues in honey by liquid chromatography/tandem mass spectrometry.
abstract: We developed a rapid and efficient means of determining residues of four nitroimidazoles-i.e., dimetridazole, ipronidazole, metronidazole, and ronidazole-and three hydrophilic metabolites- i.e., 2-hydroxymethyl-1-methyl-5-nitroimidazole, 1 -methyl-2-(2'-hydroxyisopropyl)-5-nitroimidazole, and 1-(2-hydroxyethyl)-2-hydroxymethyl-nitroimidazole--in honey. We applied a QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) procedure improved to suit a nitroimidazole analysis, which is fast (approximately 30 min) and uses less organic solvent. The procedure involves initial single-phase extraction of 5 g of honey with acetonitrile containing 1% acetic acid, followed by liquid-liquid partitioning involving the addition of 5 g sodium chloride, 1.5 g trisodium citrate dihydrate, and 4 g magnesium sulfate. Moreover, matrix from honey was reduced by an SPE method with an alumina-N cartridge. The samples were analyzed using LC/MS/MS. Chromatographic separation of these nitroimidazoles and metabolites was performed in the gradient mode on a pentafluorophenylpropyl-bonded silica column (150x2.0 mm, 3 pm particle size) at 40 degrees C. The mobile phase consisted of a 0.01% acetic acid solution and acetonitrile, and the flow rate was 0.2 mL/min. The method was validated using honey spiked with these nitroimidazoles from 0.1 to 0.5 microg/kg. The overall recovery of the seven nitroimidazoles ranged from 76.1 to 98.5%; intra- and interassay CV values were <9.5 and <14.2%, respectively. The LOQ ranged from 0.1 to 0.5 microg/kg. LC/MS/MS coupled with the QuEChERS method showed good potential as a method for determining nitroimidazole residues in honey.
authors: Tokyo Metropolitan Institute of Public Health, Tokyo 169-0073, Japan. Maki_l_Kanda@member.metro.tokyo.jp
authors: Maki
authors: M
authors: Kanda
authors: Takeo
authors: T
authors: Sasamoto
authors: Kazue
authors: K
authors: Takeba
authors: Hiroshi
authors: H
authors: Hayashi
authors: Tomoko
authors: T
authors: Kusano
authors: Yoko
authors: Y
authors: Matsushima
authors: Takayuki
authors: T
authors: Nakajima
authors: Setsuko
authors: S
authors: Kanai
authors: Ichiro
authors: I
authors: Takano
mesh_terms: D002138:Calibration; D002853:Chromatography, Liquid / Q000379:methods*; D005506:Food Contamination; D006722:Honey / Q000032:analysis*; D057230:Limit of Detection; D009593:Nitroimidazoles / Q000032:analysis*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D009593:Nitroimidazoles