A simple comparison of mass spectral search results and implications for environmental screening analyses

A simple assessment of the ability of environmental laboratories to perform automated library searching procedures on mass spectra of unknown pollutan ts was conducted. In this assessment, 10 laboratories analyzed a hexane sol ution containing eight organic chemicals using gas chromatography/mass spec trometry and searched their acquired mass spectral data against mass spectr al reference libraries. The search results were used to evaluate the simila rity of the lists of tentative identifications (TIDs) among the laboratorie s and to compare the observed searching success to the searching success re ported in the literature using high-quality mass spectral data. A high degr ee of similarity was observed among the lists of TIDs reported by the labor atories for each chemical. The searching success observed in this study was slightly lower than that reported in the literature based on higher-qualit y mass spectral data. This simple comparison suggests that laboratories per forming routine environmental analyses can successfully perform automated s earching procedures for unknown sample components, and that the mass spectr al searching component of analytical methods designed to screen for unknown organic pollutants should be successful, i.e., obtain similar and reproduc ible results among laboratories.