In recent years, an enormous amount of research effort has focused on ultra-sensitive and selective analysis of micro pollutants in the environment.Rapid advances in instrumental technology, especially ultra high-pressure liquid chromatography coupled with mass spectrometry, have enabled detection and quantification of trace level contaminants even parts per trillion or quadrillion levels.Using ultra high-pressure separation, instrumental run time has been significantly reduced.Fast chromatography and highly selective mass spectrometry have made environmental chemistry analysis extremely sensitive and selective giving researchers and regulatory agencies powerful tools to monitor the pollutants in such low concentrations.This type of chemical analysis often requires a list of target chemicals, i.e.analyte list, to prepare reference materials or standards for accurate quantification.However, targeted analysis is not always the best approach to address impacts of chemical pollution.