Nitrosamines are a class of nitrogen containing compounds with a known occurrence in wastewater. They may also be created in deionization and are a potential contaminant in water for reuse. The World Health Organization has issued a guideline for NDMA in drinking water at 0.1 g/L. NDMA may occur in chlorinated effluents and other wastewaters at concentrations of 0.02 g/L and higher. Other methods for nitrosamines employ solid phase extraction, which may not be applicable to wastewaters that contain particulate matter or a high organic load.
This test method covers the LCMSMS detection and quantitation of N-nitrosamines after direct injection. It has been validated for groundwater, surface water, wastewater influents, and wastewater effluents. This test method is not limited to these aqueous matrices; however, the applicability of this test method to other aqueous matrices must be demonstrated.
This test method is applicable to nitrosamines that can be chromatographed and detected using a mass spectrometry procedure.
Analyte concentrations from 0.05 g/L up to approximately 5 g/L may be determined without dilution of the sample. Analytes with insufficient sensitivity will not be detected, but they can be measured with acceptable accuracy and precision when present in sufficient amounts. In addition, newer instruments, or instruments of improved sensitivity may be used to lower detection limits
Analytes that are not separated chromatographically, but that have different mass spectra and noninterfering quantitation ions, can be identified and measured in the same calibration mixture or water sample. Analytes that have very similar product ions cannot be individually identified and measured in the same calibration mixture or water sample unless they have different retention times.