The injection volume of the sample is just 2uL. The sample does not dissolve well in water/100% methanol/or mixture of water-methanol. The sample dissolves well in DMSO.
You should only inject solutions and/or samples which are 100% soluble in the mobile phase used for the analysis. Damage and/or contamination to the LC/MS/MS system can result.
You can try some other solvents like Acetonitrile, THF or combination of these solvents. Using DMSO is not a good choice in LC-MS. Otherwise dissolve in as less DMSO as possible and dilute with mobile phase then inject into your system.