Odorants in the organophosphorus pesticide contaminated soils：identification, prioritization, and quantification using GC-HRMS based on target and non-target screening

Odorants from the pesticide site remediation were complex and changeable, and the screening of key odorous substances was the prerequisite for the process of odor control. In the study, a novel odorants identification method based on the targeted and non-targeted approach by gas chromatography-quadrupole/electrostatic field orbitrap high-resolution mass spectrometer (GC Orbitrap/MS) was established to investigate the low-concentration odor pollution in three organophosphorus pesticide sites. The comprehensive odor characterization method was developed and applied in the light of olfactory threshold, flavor characteristics, molecular structure, response value, and detection rate. 98 pollutants were screened out using target analysis, and 149 substances were identified with confidence levels of at least 2 based on non-target analysis. Based on the analysis results, 42 odorants were screened out by the synthetic evaluation method for priority control, including phenols, aldehydes, ketones, esters, organic sulfide, amines, nitriles, amide, acylchlorides, ethers, heterocyclic, halogenated benzene and polycyclic aromatic hydrocarbons. The limit of detection (LOD) of 42 odorants was from 0.010 to 0.100 ng L−1, which was lower than other detection methods. This research provided a new technology for identification of odorants in pesticide sites.