Analysis of N-nitrosamines in Water by Gas Chromatography, Electron Ionization Tandem Mass Spectrometry

Poster Presentation

Prepared by D. Walker, R. Hunnold, M. Curtis, C. Marvin
Agilent Technologies, Inc., 2850 Centerville Road, Wilmington, DE, 19808, United States

Contact Information: [email protected]; 916-458-2940


Nitrosamines like NDMA are inadvertent by-products of wastewater treatment through chlorination. EPA method 521 (2004) outlines employing ion trap MS based liquid CI/MS/MS measurements for the detection of N-nitrosamines, but these types of instruments are no longer commercially available from the manufacturer. This work demonstrates the applicability of EI GC/MS/MS measurement for the detection of N-nitrosamines in drinking water. Bench-top GC–MS/MS with EI is rapidly gaining prominence in many environmental and water quality control laboratories around the world. Accordingly, a sensitive and reliable analytical method for the analysis of N-nitrosamines using triple quadrupole GC–MS/MS with EI is of particular interest to the water industry. Current developments in GC-MS triple quadrupole technology deliver very high sensitivity and selectivity also in the small molecule mass range and allow the detection of nitrosamines meeting and exceeding current detection levels attained using CI/MS/MS measurements. This work shows advances in instrumentation and the resulting sensitivity to achieve detection limits below those currently specified in EPA Method 521. The analytical method was developed using an Agilent 7890B GC coupled to a Model 7010 GC/MS/MS operated in positive electron ionization mode. The GC was configured with a MMI (multi-mode inlet), 30 meter DB-1701 column, and a 7693 A/S. The analysis time was less than 15 minutes. Calibration curves were set up using 5 levels from 0.08 ng/L to 20 ng/L with linearity of 0.999 for all compounds.