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8
Table 3. Method performance upon analysis of rainwater and rainwater runoff of US EPA priority PAHs.
Sample Source
Direct
Collection
Apartment Complex
FIU Biscayne Bay Campus
Sample
Description
Reference
Rainwater
Partially Flooded Parking Lot
Parking
Lot A
Parking Lot B
PAH
MDL
(ng/L)
RL
(ng/L)
Measured
Conc
(ng/L)
Measured
Conc
(ng/L)
Duplicate
(ng/L)
Ave±
σ
(ng/L)
Measured
Conc
(ng/L)
Measured
Conc
(ng/L)
Measured
Conc
in Fortified
Matrix
Experiment
(ng/L)
Fortification
Level
(ng/L)
% Rec
Acenaphthene
15 45
-
-
-
-
-
105
110
95
Acenaphthylene
16 49
-
-
-
-
-
119
110
109
Antracene
29 86
-
-
-
-
-
118
110
107
Benz[
a
]anthracene 12 36
-
190
202
196±6
-
-
105
110
96
Benzo[
b
]
fluoranthene,
perylene
34 102
-
112
108
110±2
-
-
216
220
98
Benzo[
g,h,i
]
perylene
19 57
-
60
61
60.4±0.7
-
-
124
110
113
Benzo[
k
]
fluoranthene
21 63
-
<RL
<RL
-
-
105
110
96
Crysene
11 33
-
153
169
161±8
-
-
112
110
101
Dibenz[
a,h
]
anthracene
16 48
-
-
-
-
-
137
110
124
Fluoranthene
12 36
-
410
387
399±12
-
-
104
110
95
Fluorene
7.9 24
-
<RL
<RL
-
-
100
110
91
Indeno[1,2,3-
cd
]
pyrene
26 78
-
<RL
<RL
-
-
130
110
118
Naphthalene
20 60
-
-
-
-
-
91
110
83
C1-naphthalenes
13 40
-
-
-
-
-
209
220
95
C2-naphthalenes
15 44
-
-
-
-
-
111
110
101
Phenanathrene
19 57
-
183
186
184±1
-
-
116
110
105
Pyrene
17 50
-
293
315
304±11
-
-
117
110
107
Total PAH
0
1401
1428
1415±14
0
0
% Recovery
Average
102±10
Examples of Environmental Applications
The developed methodology was tested by analyzing a
group of multi-origin environmentally relevant water
samples. Seawater collections were made from seven sites
in northern Biscayne Bay. Naphthalene and
alkylnaphthalenes were detected in two of the sites in
which activity of small vessels was observed (Table 2).
The elevated water solubility of naphthalenes relative to
other PAHs
1
may increase their permanence in the water
long enough to be detected by the grab sampling
performed. Although the method sensitivity was not
enough to detect background concentrations in samples
where no active boating was observed, a capability of fast
detection of focalized emission of petroleum-derived
products was demonstrated.
Suspended particles in rainwater runoff resulting from the
erosion of impervious surfaces have been documented as
an important source of PAHs in the environment.
25,26
To assess the performance of the developed methodology
for this type of monitoring, rainwater and runoff samples
from the drainage openings at three parking lots were
collected during a heavy rain event in June 2013. As can
be seen in Table 3, PAHs were detected in runoff from
only the partially flooded parking lot located in a
residential complex. Chromatograms for the priority
PAHs detected in that sample are compared with reference
rainwater in Figure 3, showing that interference-free
detection and positive identification were obtained for
these analytes except for benzo[
b
]fluoranthene, which is
not resolved from perylene by this methodology as
discussed before. Also, since no PAHs were observed in
the reference rainwater, this data strongly suggests that the
parking lot was the source of the contamination. The high
number of parent PAHs detected, the predominance of
heavy PAHs such as fluoranthene and pyrene, and their
relative concentrations are in agreement with previous
reports of PAHs in rainwater runoff from coated parking
lots,
27
suggesting that the presented methodology is
applicable for this type of study.
− Below MDL,
<RL
Detection below reporting limit (RL=3×MDL)