Chemical ionization mass spectra of linear alcohol polyethoxy carboxylates and polyethylene glycol dicarboxylates

The chemical ionization (CI) mass spectra of propylated linear alcohol polyethoxy carboxylates (LAEC) and polyethylene glycol dicarboxylates (PEGDC) have been determined. Olefin displacement of the alkyl chain from the [M + H]⁺ ions of propylated LAEC formed the protonated polyethoxy carboxyl propyl ester, which then underwent a characteristic fragmentation by first losing water and then ethylene oxides. The fragmentation pattern for PEGDC [M + H]⁺ ions was similar to that of LAEC, except that the initial steps were displacement of one terminal propyl formate (HCOOC₃H₇) followed by a neutral loss of CH₂O. Strong peaks due to protonated molecules were observed in both LAEC and PEGDC. Product‐ion mass spectra obtained from chemical ionization gas chromatographic/triple‐stage quadrupole mass spectrometric studies supported the proposed fragmentation mechanisms.