The reported uses of chemical warfare agents (CWA) over the last years emphasize the need for analytical tools to support forensic investigations by enabling the identification of the toxic compounds, the samples comparison (batch-matching) and the sourcing of the agent employed. Complementary to specific targeted detection approaches on known compounds, untargeted approaches can provide further information to identify the source or the synthetic route of CWAs. Nerve agents, a class of CWAs is mainly composed of organophosphorus compounds that can be produced by various synthesis routes. In this work, we present an original analytical methodology based on high-resolution mass spectrometry for the sourcing of synthetic chemicals based on the specificity of synthesis by-products, impurities, and other compounds. Crude chlorpyrifos (CP) samples (an organophosphorus pesticide) produced using different reactants and synthesis protocols were used as a first use case. CP chemical attribution signatures-based profiling can be used to readily differentiate samples of material and associate them with a particular source of reagents and/or synthetic pathway. Inspired by untargeted metabolomic-based tracer discovery strategies, 7 crude CP synthetic samples were randomly analyzed with minimal sample preparation to keep as much chemical information as possible. Analyses were performed on a Waters Synapt G2-Si Q-ToF mass spectrometer coupled to an Acquity I Class liquid chromatographic (LC) system. Positive electrospray (PI-ESI) was found to be the most suitable ionization mode for analyzing those samples. Furthermore, PI-ESI provided valuable structural information on the potential tracers thanks to the high number of ions formed. After the analysis of the crude materials using optimized analytical conditions, data was extracted, aligned, and processed using the collaborative portal workflow4metabolomics (XCMS). Statistical analyses highlighted a set of significant features discriminating each synthetic pathway thanks to rich annotation using LC (retention times), mass spectrometry spectra (accurate mass measurement), isotopic patterns, and IMMS (CCS values) to propose putative structures. MS/MS analyses were then conducted for unambiguous identification of the various discriminant compounds allowing to reveal the synthetic route used. This workflow will be used in a near future for the classification of unknown samples based on the discriminating compounds.