1. Scope 1.1 This practice covers the identification of organic compounds by gas chromatography/mass spectrometry (GC/ MS) (electron impact) that are present or extracted from water and are capable of passing through a gas chromatograph without alteration. The practice is intended primarily for solutions for which 10 ng or more of any component of interest can be introduced onto a gas chromatographic column. This practice has the advantage of providing tentative identifications of volatile and semi-volatile organics, but is restricted to ( ) compounds for which reference spectra can be obtained and ( ) compounds that can be separated by gas chromatography (GC). These restrictions are imposed on the practice, but are not a limitation of the technique. The practice is written for, but not restricted to, analysis using automated data acquisition and handling. 1.2 Although a detection amount of 10 ng is suggested for the practice, this amount can only be considered an approximate guide. The actual detection limits for each component must be determined in each laboratory. Actual detection amounts will vary with the complexity of the sample, the kind and condition of the GC/MS system, the sample preparation technique chosen, and the application of cleanup techniques to the sample extract, if any. 1.3 The practice is applicable to the identification of many organic constituents of natural and treated waters. It includes all modes of sample introduction, including injection of organic extracts, direct aqueous injection, and purge and trap techniques. 1.4 The practice is applicable to either packed or capillary column gas chromatography, including wide-bore capillary columns. Because of their greatly enhanced resolution, capillary columns are recommended. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.