RESUMEN
To develop the liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for measuring mitomycin C in rat plasma, samples were processed using solid-phase extraction, with the internal standard being carbamazepine. A reversed phased C18 column was utilized for the LC-MS/MS study, and mobile phases consisting of 0.1 % formic acid in acetonitrile and water were injected into it at a rate of 0.3 mL/min. Multiple reaction monitoring in positive-ion mode with precursor-product ion pairs 335.3 â 242.3 (mitomycin C) and 237.1 â 194.1 (carbamazepine) was employed to quantify the compounds. The linear range in plasma was found to be 10-4000 ng/mL (r2 = 0.992). The inter-batch and intra-batch precision were <14.3 % (LLOQ: 14.7 %) and 13.4 % (LLOQ: 16.1 %), respectively. The recovery and the matrix effect of mitomycin C in plasma were 113 % and 111 %, respectively. Mitomycin C was stable under the conditions of this assay method. In the end, this approach proved effective in a pharmacokinetic investigation with the intravenous and oral administration of mitomycin C to rats.
RESUMEN
The Okchon black shale, which is part of the Guryongsan Formation or the Changri Formation of Cambro-Ordovician age in Korea provides a typical example of natural geological materials enriched with potentially toxic elements such as U, V, Mo, As, Se, Cd, and Zn. In this study, the Dukpyung and the Chubu areas were selected to investigate the migration and enrichment of As and other toxic elements in soils and crop plants in areas covered with black shale. Rock and soil samples digested in 4-acid solution (HCl+HNO3+HF+HClO4) were analyzed for As and other heavy metals by ICP-AES and ICP-MS, and plant samples by INAA. Mean concentration of As in Okchon black shale is higher than those of both world average values of shale and black shale. Especially high concentration of 23.2 mg As kg(-1) is found in black shale from the Dukpyung area. Mean concentration of As is highly elevated in agricultural soils from the Dukpyung (28.2 mg kg(-1)) and the Chubu areas (32.6 mg kg(-1)). As is highly elevated in rice leaves from the Dukpyung (1.14 mg kg(-1)) and the Chubu areas (1.35 mg kg(-1)). The biological absorption coefficient (BAC) of As in plant species decreases in the order of rice leaves > corn leaves > red pepper = soybean leaves = sesame leaves > corn stalks > corn grains. This indicates that leafy plants tend to accumulate As from soil to a greater degree than cereal products such as grains.