S.No. Retention time Detected ion Mass (m/z) Theoretical Value (m/z) Main ions of MS2 Elementary Composition
1 3.49 [M-H]+ 133.0670 133.0653 133[M-H],105[M-H-28] C9H9O
2 3.68 [M-H]+ 239.0913 239.0919 239[M-H],223[M-H-16],
206[M-H-16-17],195[M-H-44],149
C12H15O5
3 3.68 [M-H]+ 177.1278 177.1279 177 C12H17O
4 3.99 [M-H]+ 177.1276 176.1279 177 C12H17O
5 4.37 [M-H]+ 175.1100 175.1123 175 C12H15O
6 4.80 [M-H]+ 221.1167 221.1178 221 [M - H], 177 [M - H - 44], 134 [M - H - 44 - 43] C13H17O3
7 6.04 [M-H]+ 473.2163 473.2175 473,255,216 C26H33O8
8 6.78 [M-H]+ 205.1235 205.1229 205[M-H],161[M-H-44] C13H17O2
Table 2: Mass spectrometry data and mass fragments for ibuprofen oxidation products