Surfactant pyrolysis mass spectrometry

Although bituminous coals do not appreciably retain surfactant in the separation procedure (<0.01%), the sub-bituminous coals apparently do. It s presence in the separated fractions has been inferred from nmr and pyrolysis/mass spectrometry, but the amount retained is uncertain (4). 

The mass spectral data selected for multivariate analysis represented a suite of 30 microlayer and bulk surface seawater surfactant samples (fraction FI Frew et al. (2006)) including seven from waters off Monterey and Santa Barbara, California and 23 collected along a transect from Delaware Bay on the U. S. east coast to the Sargasso Sea. Sample extracts were analysed in triplicate by desorption-electron ionisation (DEI) mass spectrometry (Boon 1992 Frew et al. 2006). Individual DEI mass scans were summed over the full desorption/pyrolysis interval, reduced to integer masses, and averaged for processing by multivariate analysis. Elasticities were estimated quasi-statically from surface pressure-area (El A) isotherm measurements in a KSV 2200 Langmuir film balance (Frew et al. 2006). The elasticity data were subsampled at fixed surface pressure intervals (0.5 mN m"1) for comparison with the results of the multivariate analysis. 

Pyrolysis GC becomes a much more effective tool if it is combined with mass spectroscopy. Pyrolysis GC-MS is very useful for the characterization of complex copolymers of all sorts and is a valuable supplement to infrared and nuclear magnetic resonance spectrometry for study of surfactants. Although direct pyrolysis can be used, successful pyrolysis GC of ethoxylates generally requires the addition of cleavage reagents to the sample before heating. The distinction between reaction GC and pyrolysis GC is thus blurred. 

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