Formation of nitrosamines, particularly NDMA, is prevalent in water treatment plants using chloramine as a disinfectant. NDMA is classified as a B2 carcinogen based on the induction of tumors at multiple sites in different mammal species exposed to NDMA by various routes. EPA 521 has been provided as the validated extraction and analytical procedure for monitoring of nitrosamines in drinking water. However, this method was developed using large volume injections (20 µL) and ion trap spectrometers in MS/MS chemical ionization (CI) mode (with methanol or acetonitrile). To avoid the complexity of large volume injections and CI, we present the alternative gas chromatography triple quadrupole electron ionisation method. Additionally, calibrants were prepared via an auto-sampler, from 1000 µg/ml commercially available standards.
Crystal Yeong (Ph.D.)
Senior Field Application Chemist
Shimadzu (Asia Pacific) Pte Ltd
Crystal Yeong is a senior field application chemist for GC and GCMS at Shimadzu (Asia Pacific) Pte Ltd in Singapore. She has experience in forensic applications, nitrosamines impurities detection and PAH analyses in edible oils. Prior to joining Shimadzu, she was a lab analyst with the Ministry of Home Affairs, Singapore. Crystal holds a PhD in Inorganic Chemistry and B.Sc. in Chemistry & Biological Chemistry from Nanyang Technological University.