On the conversion of a mass selective detector from gas chromatography/mass spectrometry application to stand-alone, on-line, real-time mass spectrometry application

Abstract

Development of initial versions of hardware and software for a Hewlett-Packard HP-5971A mass selective detector (MSD) was performed in order to improve its capabilities for monitoring gaseous waste streams. The development allowed for initial evaluation of the feasibility of the conversion of the MSD from an integrated gas chromatography/mass spectrometry (GC-MS) detector to a stand-alone, on-line, real-time mass spectrometry (SOR-MS) detector. Chemical compound quantitation is accomplished via mass spectrometric step heights, rather than gas chromatographic peak areas or heights. Contributions of more than one chemical compound to a single M/Z ratio are accounted for by nonlinear deconvolution of the mass spectrum, provided a calibration can be obtained for all contributing chemical compounds. The enhanced MSD was tested by a number of calibration and monitoring experiments in order to evaluate the potential and limitations of the conversion. With sufficient care and awareness of the potential and limitations, it appears to be possible to convert the GC-MS detector to a SOR-MS detector. In particular, this conversion could allow for simple monitoring of reactive chemical compounds.