Data acquisition methods for non-targeted screening in environmental analysis

Human production and consumption activities lead to vastly release of numerous chemicals into environments. Non-targeted screening methods are powerful tools for identifying huge number of contaminants in complex environmental matrices. The quality of data spectra acquired by high-resolution mass spectrometry (HRMS) enormously determines the efficiency of non-targeted identification of unknowns. The data-dependent and -independent acquisition methods display promising applications in omics science, but their application in the much more complicated environmental analysis remains challenging. This paper comprehensively reviews two major types of data acquisition methods, namely data-dependent acquisition (DDA) and data-independent acquisition (DIA), for liquid chromatography combined with HRMS. The principles, classification, advantages and disadvantages of two acquisition methods are systematically summarized. Their applications in non-target screening of environmental contaminants are also discussed and compared to provide the foundation for selection of data acquisition methods. We also provide an outlook on the optimization of the workflow of future data acquisition methods.