DIN 38407-44:2018-02

This standard specifies a method for the determination of dissolved polynuclear NSO heterocyclics in groundwater and surface water. The lower limit of application amounts to 0,1 µg/l water sample. Lower limits of quantification can only be achieved to a limited extent in low-polluted samples by enriching larger volumes (maximum 1 l). The method is also suitable for the analysis of aqueous extracts/eluates from solids. The group of NSO heterocyclics are aromatic hydrocarbons in which at least one carbon atom is substituted by a nitrogen, sulphur or oxygen atom. NSO heterocyclics are often associated with polycyclic aromatic hydrocarbons (PAHs) and can be found in particular in the groundwater of tar-contaminated contaminated sites (for example, former coking plants or gas works, tar oil processing plants). The composition can vary considerably, depending on the respective history of use of the contaminated site. Other known sources are combustion processes and sewage treatment plants. This standard describes the determination of selected NSO heterocyclics using gas chromatography coupled with mass spectrometry after solid phase enrichment. Determination of isoquinoline using this draft standard is possible. However, the recovery rates are critical due to the special features of enrichment by SPE and gas chromatography of this substance. Determination of indole using this draft standard is analytically possible. Experience has shown that indole in water samples can be subject to rapid transformation processes. There is currently no known general method of preservation. This document has been prepared by Working Group NA 119-01-03-02-20 AK "Analytik NSO-Heterozyklen" ("Analysis of NSO heterocyclics") at Working Committee NA 119-01-03 AA "Wasseruntersuchung" ("Water examination") at DIN Standards Committee Water Practice (NAW).