Abstract:

The risk of unknown chemical substances in foods is the unanticipated risk outside the food safety regulations,
which is a significant public health issue for food safety monitoring authorities and has attracted more public concern in
recent years. In many cases, we should identify such substances rapidly in order to take measures and means to prevent the
spread of the risk. Thus, the demand for the development and the applications of more efficient and more powerful tools
to analyze unknown chemical contaminants in foods is increasing. In this article, based on the general sample preparation
techniques, comprehensive screening and confirmation methods and the databases for screening and confirmation, the
advantages and limitations of the rapid screening and confirmation methods for the risk of unknown chemical substances in
foods are discussed. The general sample preparation techniques such as QuEChERS, solid phase microextraction (SPME)
and turbulent flow chromatography (TFC) ensure that different types, different materials are extracted and purified as much
as possible. The comprehensive screening and confirmation methods for the applications of different types of high-resolution
mass spectrometry and nuclear magnetic resonance enable the screening of several hundreds of compounds with high
sensitivity within one run. The databases allows automated screening and confirmation of unknown chemical substances.
The future research trends in this field are also introduced.

Key words: risk of unknown chemical substances in foods, general sample preparation techniques, comprehensive screening and confirmation technologies, database