Pyrolysis-gas chromatography/mass spectrometry of poly(acrylic acid) in the presence of mixture of N,O-bis(trimethylsilyl)trifluoroacetamide and trimethylchlorosilane

A mixture of N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and trimethylchlorosilane (TMCS) (99 : 1) is a highly sensitive derivatization reagent for carboxylic acid by gas chromatography/mass spectrometry (GC/MS), and Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) of poly(acrylic acid) (PAA) at 500 °C in the presence of the above silyl reagent was conducted. It was found that the peak height of the trimethylsilyl derivative of acrylic acid (AA-TMS) was about ninety-five times that of the peak height of acrylic acid, which is one of the pyrolysates of PAA, without any derivatization reagent. The mechanism for the formation of AA-TMS was considered to be as follows. The carboxyl group of PAA and the mixture of BSTFA and TMCS reacted rapidly at room temperature. The reaction product was then pyrolyzed and AA-TMS was liberated.