Progress about the recent mass spectrometry is remarkable. The amounts of sample decrease by the high sensitivity of the detector. Therefore, the various problems which influence a sample were occurred. The following problem occurs in the ion which forms a protonated molecule ([M+H]+). It is the occurrence of the adduct ions that were the cleavage sample, dilution solvent, and the sample. If the amount or concentrations of sample are raised, the ionization efficiency of the sample of the purpose rises. But, the material which forms a protonated molecule makes proton bound dimer([M+H+M]+) and a multiple molecule protonated([nM+H]+) occur easily. Because many ion clusters appear, an analysis is made difficult. Hydroperoxides forms [M+H+M]+,[nM+H]+, [M+H+A]+, [M+H+B]+, and [B+H]+ easily. M, A, and B are the sample, adduct reagent and cleavage material, respectively. By this report, the formation of the proton bound molecules were examined.