Page 25 - Performance Verification Statement for the Chelsea UV Aquatracka Fluorometer
Basic HTML Version
Ref. No. [UMCES]CBL 2013-014
ACT VS12-01
A summary of the physical and water quality conditions experienced over the duration of
the moored deployment are presented in Table 3. Water temperature ranged from 25.3 to 29.4
°C and salinity varied from 3.9 to 9.9. Chlorophyll and CDOM are quite high at this location
and can contribute significantly to the fluorescent properties of the ambient seawater.
Table 3.
Ancillary physical and water quality conditions for the moored field deployment test conducted
in Winans Cove, Baltimore Harbor, Baltimore, MD.
Site
Temperature
(
o
C)
Salinity
Chlorophyll
(µg/L)
CDOM
Turbidity
(NTU)
Baltimore
Harbor
Min
25.3
3.9
2.6
1.17
1.3
Max
29.4
9.9
44.8
2.48
6.0
Mean
27.0
8.2
16.6
1.52
3.0
The time series response of the Aquatracka UV-HC during the moored deployment in
Baltimore Harbor is shown in Figure 9. During the deployment 33 discrete reference samples
were collected and analyzed for hydrocarbon. Only three samples, one on 8/22 and two on 8/24
had any detectable level of hydrocarbons as analyzed by TestAmerica using GC-FID. The
instrument response was relatively consistent over the deployment showing a range from 3100 –
3300 mV. There was no apparent tracking of instrument response to variation in temperature or
salinity (Fig. 9, panel B), or with chlorophyll, CDOM, or Turbidity despite substantial variation
in these parameters (Table 3 and Fig. 9, panel C).
Representative EEM fluorescent maps for reference samples collected on five different
dates are shown in figure 10. EEM characteristics were fairly consistent over time and
fluorescence intensity maxima are quite offset from the optical window range of the filter set.
The average EEM
QSE
for the reference samples yielding non-detects was 732.7 (±183.3) cps
while EEM
QSE
for the two 25 and 35 ppb reported TPH detects were 760.5, 749.5 and 818.4 cps
respectively, higher, but within the environmental range observed during this deployment. The
Aquatracka UV-HC response averaged 3228 mV during non-detect periods and 3163, 3250 and
3239 mV at the 25 ppb and 35 ppb reported TPH detects. Consequently, there was no apparent
tracking of instrument response to TPH and marginally to EEM
QSE
for this optical configuration.
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