N-Nitrosamines form as byproducts during
oxidative
water treatment and occur as impurities in consumer and industrial
products. To date, two methods based on chemiluminescence (CL) detection
of nitric oxide liberated fromN-nitrosamines via
denitrosation with acidic triiodide (HI3) treatment or
ultraviolet (UV) photolysis have been developed to enable the quantification
of totalN-nitrosamines (TONO) in environmental water
samples. In this work, we configured an integrated experimental setup
to compare the performance of HI3-CL and UV-CL methods
with a focus on their applicability for TONO measurements in wastewater
samples. With the use of a large-volume purge vessel for chemical
denitrosation, the HI3-CL method achieved signal stability
and detection limits comparable to those achieved by the UV-CL method
which utilized a microphotochemical reactor for photolytic denitrosation.
Sixty-six structurally diverseN-nitroso compounds
(NOCs) yielded a range of conversion efficiencies relative toN-nitrosodimethylamine (NDMA) regardless of the conditions
applied for denitrosation. On average, TONO measured in preconcentrated
raw and chloraminated wastewater samples by the HI3-CL
method were 2.1 ± 1.1 times those measured by the UV-CL method,
pointing to potential matrix interferences as further confirmed by
spike recovery tests. Overall, our comparative assessment of the HI3-CL and UV-CL methods serves as a basis for addressing methodological
gaps in TONO analysis.