common analytical techniques used for quantitative determinations in environmental chemistry include classical wet chemistry, such as gravimetric, titrimetric and electrochemical methods. more sophisticated approaches are used in the determination of trace metals and organic compounds. metals are commonly measured by atomic spectroscopy and mass spectrometry: atomic absorption spectrophotometry (aas) and inductively coupled plasma atomic emission (icp-aes) or inductively coupled plasma mass spectrometric (icp-ms) techniques. organic compounds are commonly measured also using mass spectrometric methods, such as gas chromatography–mass spectrometry (gc-ms) and liquid chromatography-mass spectrometry (lc/ms). non-ms methods using gcs and lcs having universal or specific detectors are still staples in the arsenal of available analytical tools.