Abstract
Mass spectrometric identification of pyrolyzates from quaternary ammonium salts was investigated with a Hitachi RMU-6E spectrometer coupled with a K-53 gas chromatograph {5% OV-101, 2m × 3 mm i. d., (100 250)°C, 4°C/min}. Gas chromatography was carried out on a Shimadzu GC5A PF equipped with an FID {5% OV-101, 2m × 3 mm i. d., (100280)°C, 4°C/min}. Aqueous solutions of alkyl- and benzyl-trimethylammonium salts, benzylethyl- and benzylphenyl-dimethylammonium salts, benzalkonium salts and alkylpyridinium salts were applied to a gas chromatograph with the temperature range of (250300)°C at the injection port. Gas chromatographic and GC-MS methods gave identical chromatograms. Long chain quaternary ammonium compounds such as alkyltrimethylammonium salts and alkylpyridinium salts gave alkyldimethylamines and alkyl halides by pyrolysis. Quaternary ammonium compounds with ethyl, phenyl or benzyl groups attached to the nitrogen atom yielded different decomposition products. The carbon-nitrogen bond cleavage occurs preferentially in the following decreasing order; benzyl>methyl>ethyl: Pyrolysis of benzalkonium chlorides at 300°C yields methyl chloride, benzyl chloride, a series of alkyldimethylamines and alkylbenzylmethylamines. The mechanisms of pyrolysis for these salts were discussed from the above results.
