This posts describes techniques we find useful for the identification of a wide variety of surfactants in commercial products. More recently, I have found that accurate mass MS/MS data and molecular formulae searches in CAS can be very useful. Especially in you search one of the lower MW species in a PEG series using “Known Unknown” approach in SciFinder.
One could also use the Kendrick Mass Defect to determine the endgroup using the Kendrick Mass of ethylene oxide, C2H4O (44.02621). However, I have not included these Kendrick Mass Defects for the PEG type surfactants in my table. My tables only include the Residual Molecular Weight (RMW) indices for determining the endgroups. The Kendrick Mass Defect would only work with accurate mass data. On the other hand, my RMW values will work for nominal mass data.
We originally developed many different techniques for the identification of surfactants in commercial latex plants. After we no longer needed the technology, I developed a course for PittCon and have included some links below:
Class Powerpoint presentation:
Spreadsheet of Surfactants and RMW’s:
Creating MS/MS Libraries of Surfactants:
ASMS Poster 2004: