Ref. No. [UMCES] CBL 2013-020
ACT VS12-03
flame graphite detector (GCFID) or gas chromatography with a mass spectrometer (GCMS)
depending on concentration levels.
Field Tests
Moored Deployment
A moored application test was conducted at the Maritime Environmental Resource
Center barge facility located within Winans Cove, Baltimore Harbor, MD (39.2614N,
76.6008W). The moored test was planned for a duration of four continuous weeks; however, the
test was cut short after 18 days due to the passage of Hurricane Irene. In addition, the
deployment was interrupted after day two due to a breakage in the mooring structure. The
mooring was re-established on August 18
th
and operated for 9 days prior to retrieval.
Instrument Setup
– The test instruments was programmed to record data at the highest frequency
that the instruments’ battery would maintain over the deployment period. The internal clock was
set to local time and synchronized against the time standard provided by
. A
photograph of each individual instrument and the entire instrument rack was taken just prior to
deployment and just after recovery to provide a qualitative estimate of biofouling during the field
tests. Prior to deployment, the test instrument was exposed to freshly prepared reference
solutions (QS and NDSA) made up in DI water both before and after deployment as an estimate
of instrument reliability. The post-deployment reading was taken after the instruments were
cleaned according to manufacturer specifications.
Reference samples were collected on three days of each week at four separate times
spaced at one-hour intervals. Reference field samples were collected within 1 m from the sensor
window. The water samplers were soaked at sampling depth for 1 minute prior to sampling. All
sampling times were recorded on logsheets and entered into a database for final data
comparisons. Two standard 4L Van Dorn trace metal compatible water samplers were used to
collect duplicate water samples for reference measurements. The standard reference sample suite
was processed, stored, and shipped as described above. Once per week, Type I lab water was
loaded into the clean Van Dorn sampler, taken to the sampling locale and a corresponding set of
field blank sample bottles filled to provide monitoring for potential environmental
contamination.
Vertical Profiling
The vertical profiling application was conducted at two test sites in the northern Gulf of
Mexico onboard the R/V
Acadiana
(Louisiana Universities Marine Consortium). One profile was
conducted just outside Terrebonne Bay (29.0465N, 90.5568W) to provide a contrast of high
CDOM coastal waters. Five profiles were conducted at a second site that was located near a
known shipwreck site leaking oil (28.5675N, 90.9813W). To avoid contamination between casts,
the CTD rosette was cleaned with a dilute, non-fluorescent, surfactant solution between profiles.
For each profile, reference samples were collected during the upcast at five discrete depths
spaced throughout the water column. On each cast, one of the five discrete depths was sampled
in replicate with two independent water collection bottles. At each of the selected depths, the
rosette was paused for 1 minute to ensure that the test instrument had stabilized prior to water
sampling. The rosette and test instrument assembly were lowered and raised at a standard rate
of approximately 0.25 m/sec. All test instrument and reference sample data are
shown for the
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