Text data of Fig. 4 (A) averaged mass spectrum per a pixel extracted from tumor region of BPA dosed brain tissue section (B) enlarged mass spectrum around m/z 210.093 ([BPA+H]+) (C) mass images obtained from each peak around m/z 210 in a mass window of 0.02 Da and (D) mass image obtained from m/z 210.084 in a mass window of 0.1 Da. The peaks around m/z 210.093 were separated and each peak width was approximately 0.02 Da. The mass image obtained from m/z 210.084 in a mass window of 0.02 Da clearly revealed distribution of BPA in tumor region and inside the tumor.