Use of automated solid-phase extraction and GC-MS/MS to evaluate nitrosamines in water matrices

An analytical method for detecting nitrosamines was demonstrated in various water matrices, finished drinking, surface, and treated wastewater effluent. The method uses automated solid-phase extraction (ASPE) followed by analysis with GC-MS/MS using positive chemical ionization (PCI), quantitation was performed using isotope dilution. N-nitrosodimethylamine (NDMA) occurrence was evaluated in effluent from an Australian facility over a three-month period and ranged from 11 to 14 ng/L. Automated flow rates and solvent switching systems are more consistent than manual systems. The automated programming provides a batch run time of 1 hr, 45 min. ASPE achieves a high degree of sample throughput and maintains reproducibility. The technique demonstrates improved sample throughput over traditional methods of extraction.