A Comprehensive GC-MS Reference Data System For Toxicological and Biomedical Purposes

Abstract

The need for practical, useful and reliable GC-MS reference data is no less important today than it was five years ago when mass spectrometry identification of drugs and metabolites was in its infancy. The three tables of reference data for 450 drugs and metabolites represent an integrated system for identification, and significantly supplement an earlier publication (1). The most important additions are the chemical ionization data and the facility of an interactive mini-computer by which the library can be manipulated. A master alphabetical list of library compounds (Table I) is cross indexed with an El base peak table (for El spectral data) and a molecular weight table (for CI spectral data) which are rapid and simple to use. The data can be used manually by time-share computer or through a dedicated interactive data system. The El spectra are presented as a digital code unique to each compound with matching GC relative retention times, and the CI spectra as the protonated molecule ion and most abundant fragment ions. The experimental detail and rationale in generating the data by a GC-quadrupole mass spectrometer system is discussed and the practical routine of identification is described through case examples, including a description of an interactive computer capability. The choice of library compounds was dictated by the needs of toxicologists and pharmacologists faced with the demanding problem of specific identification and characterization of sub-microgram amounts of drugs, metabolites and biochemicals.