An evaluation of triple quadrupole ms/ms for on-line analyses of trace sulfur compounds from oil shale processing

reportIn order to effectively reduce sulfur gas content from shale processing to environmentally acceptable levels, H2S, COS, S02 and CH3SH plus trace sulfur compounds must be removed. Of these, the trace sulfur compounds have not been well characterized but should be known to ppm levels In order to optimize gas clean-up procedures. Most techniques for analysis of trace sulfur components In oil shale gases have limitations. The applications we describe using triple quadrupole mass spectrometric techniques (TQMS) appears to have overcome many problems of trace sulfur analysis. Basically a TQMS produces a mass spectrum of a mass spectrum and Is, therefore, highly sensitive, selective and specific. Tests on a Finnlgan TQMS at the University of Florida and on a totally computerized TQMS designed at LLNL using pure standards, mixed gas standards and Fisher assay gas grab samples show that we can quantitatively as well as qualitatively detect the following components: methyl mercaptan = <1 ppm; ethyl mercaptan = 3 ppm; n-propyl mercaptan = <1 ppm; isopropyl mercaptan = 4 ppm; carbonyl sulfide - 1 ppm; carbon disulfide = 4 ppm; didimethyl disulfide = <1 ppm; thiophene = <1 ppm; and 2 or 3 methyl thiophene =