Comprehensive Targeted and Non-Targeted Analysis of Various Indoor Dust Samples Using LC-HRMS with Ion Mobility

New Environmental Monitoring Techniques for Organics
Oral Presentation

Prepared by , L. Mullin, A. Ladak

Contact Information: [email protected]; 508-482-4639


ABSTRACT

Dust analysis has been implemented to assess the degree of exposure to various compound classes such as flame retardants, pesticides and other environmental contaminants. Here, we demonstrate the analysis of dust extracts representing various indoor environments (industrial and domestic) using a comprehensive HRMS approach, incorporating ion mobility to provide additional separation capability of the complex samples. Non-targeted data acquisition was performed on an UPLC- IMS QTof in ESI positive and negative polarities with HRMS-ion mobility enhanced MSE acquisition mode. Following acquisition, identifications were made against a target list based on known values from running solvent standards including accurate mass fragments, RT, and an ion mobility derived measurement collisional cross section (CCS). Additional investigation of sample variability was achieved using the multivariate approaches of PCA and OPLS-DA. Significant exact mass retention time pairs leading to these sample variations were then submitted for elemental composition and isotope scoring calculation, followed by a ChemSpider database search. Using the compounds proposed structures, theoretical fragmentation was performed and high-collision energy spectrum was matched to the fragment structures and scored. The combined targeted and non-targeted processing approach resulted in numerous compounds being tentatively identified in the various house and industrial dust samples, including perfluorinated compounds, flame retardants and pharmaceuticals. Trending of compound groups across the industrial and domestic dust samples was also assessed.