with LC-MS/MS method with enhanced
sensitivity and recovery for DPhA, NDPhA,
and phenazine was developed, providing
a tool for future studies on identification
of precursors, formation, and occurrence
of nitrosamines and phenazine-type of
DBPs and toxicity of mixed nitrosamines
and phenazines when they are co-present
in water.
The developed methods were validated and
used to analyze representative source waters
and disinfected waters from collaborating
utilities from North America and Australia.
In all cases where appropriate analytical
methods could be developed, the predicted
DBPs were detected in drinking water. In
addition, two heterocyclic amines, one
presenting as an N-chloramine, were also
detected. Table 1 lists these DBPs and the
concentration ranges that were detected in
up to 18 water systems evaluated.
Future research should include a
comprehensive survey to determine the
extent and magnitude of occurrence of
these DBPs that can be monitored by these
new methods.
The published report, Analytical Methods for
Predicted DBPs of Probable Toxicological
Significance (2011, order #4089), is available
on the Water Research Foundation Website
at www.WaterRF.org.
Table 1
Predicted DBPs that have been shown to occur in drinking water
Predicted DBP
Haloquinones (HQs)
n-Nitrosamines
NDMA
n-Nitrosomorpholine
n-Nitrosodiphenylamine
Heterocyclic amines
Phenazine
n-Chlorophenazine
Frequency
of detection
18/18
18/18
13/18
7/18
7/18
18/18
18/18
12/18
8/18
6/18
1/18
14/16
14/16
6/38
6/38
NS
NS
Range of
concentrations, ng/L
2.2–275
0.5–37.9
0. 9–6. 5
2.9–91
100–2950
<3–2100
<4–2520
<2–210
8
< 2.4–130
<0.07–2.2
<0. 11–1. 8
NQ
NQ
Notes
Favored with chlorine
(enhanced with O3)
Favored with chlorine
Formation potential detected with
other waters in lab experiment
Favored with chloramine
Favored pH > 8
Favored pH < 8
Major product
