ISO 15680:2003 specifies a general method for the determination of volatile organic compounds (VOCs) in water by purge-and-trap isolation and gas chromatography (GC). Annexes A, B and C provide examples of analytes that can be determined using ISO 15680:2003. They range from difluorodichloromethane (R-12) up to trichlorobenzene, including all non-polar organic compounds of intermediate volatility. Detection is preferably carried out by mass spectrometry in the electron impact mode (EI), but other detectors may be applied as well. The limit of detection largely depends on the detector in use and the operational parameters. Typically detection limits as low as 10 ng/l can be achieved. The working range typically is up to 100 micrograms per litre. ISO 15680:2003 is applicable to drinking water, ground water, surface water, seawater and to (diluted) waste water.