Non-targeted analysis as a tool for searching transformation products

Contaminations of environment with xenobiotics is one of the major problems to be faced for environment preservation and sustainability. The monitoring of target compounds based on mass spectrometry and selected reaction monitoring mode is often insufficient to definitely assess the quality of environmental samples. Also potentially harmful non-target pollutants simultaneously present must be taken into account. Non-targeted analysis is expanding at a rapid pace, as researchers develop new instrumental and informatics approaches to cover an increasingly comprehensive section of chemical space. This chapter provides an overview of the state of the art of the application of liquid chromatography and mass spectrometry to the environmental analysis of xenobiotic transformation products. The chapter begins with comparison of targeted and non-targeted analysis. Following are sections covering techniques and instruments and metrological issues. Procedures for identification outlined next are divided into target identification by methods and unknown/non-target analysis. For the latter, information support, such as mass spectral libraries and chemical databases, programs of formula generation, and spectral prediction/interpretation, is reviewed. Finally, identification and determination of transformation products of selected xenobiotics in the environment and some general trends are briefly noted.