es5b05755_si_001.pdf (1.45 MB)
Evaluating a Tap Water Contamination Incident Attributed to Oil Contamination by Nontargeted Screening Strategies
journal contribution
posted on 2016-02-10, 00:00 authored by Beili Wang, Yi Wan, Guomao Zheng, Jianying HuThe
present study applied nontargeted screening techniques as a
novel approach to evaluate the tap water samples collected during
the “4.11” tap water pollution incident occurred on
April 11, 2014 in Lanzhou in west China. Multivariate analysis (PCA
and OPLS-DA) of about 3000 chemical features obtained in extracts
of tap water samples by ultrahigh-pressure liquid chromatography quadrupole
time-of-flight mass spectrometry (UPLC-QTOF-MS) analysis showed significantly
different chemical profiles in tap water from pollution regions versus
reference regions during the event. These different chemical profiles
in samples from different regions were not observed in samples collected
during the nonpollution period. The compounds responsible for the
differences in profiles between regions were identified as naphthenic
acids (NAs) and oxidized NAs (oxy-NAs) after the sample extracts underwent
bromination to explore saturations, dansylation to identify hydroxylations
and corresponding MS/MS mode analysis. A consistent finding was further
observed in the targeted analysis of NA mixtures, demonstrating that
the Lanzhou “4.11” tap water pollution incident could
be attributed to oil spill pollution, and NA mixtures would be a marker
for oil contamination. Such evaluations can help to rapidly discriminate
pollution sources in accidental pollution events and contribute to
regular water monitoring management of water safety issues.