Ref. No. [UMCES]CBL 2013-015
ACT VS12-02
Laboratory Tests
Performance against surrogate standards and challenge environmental variables
Laboratory tests of response factor, precision, range, and reliability were conducted at
Moss Landing Marine Lab. Challenge compounds utilized in laboratory characterizations of
instrument performance are listed in Table 1 and cover the range of optical detection windows
utilized by participating hydrocarbon sensors. Laboratory challenges were performed in
insulated 500 L, black acrylic tanks in a dark room using filtered deionized water (DI) as the
background medium. Test tanks have been preconditioned by several years of use with
deionized and seawater exposures and cleanings. Temperature was maintained at 15 ± 1
o
C with
Nestlab recirculating chillers and copper heat exchange tubing. Water was continuously
circulated with submersible pumps (
ca
10 L/min) placed at opposite ends of the tank.
Temperature was monitored at opposite ends of the tank at sensor detector level by two
calibrated RBR 1060 recording thermometers. Each test level began with a 30 minute
equilibration, and reference water samples were collected at 10 minute intervals over the
following 30 minute exposure. Instrument response, reported as the average of 5 minutes of
readings encompassing reference sample times, was used to characterize instrument response at
each challenge level. Instrument response factors are calculated by regression of mean
instrument output against challenge compound concentrations. Precision tests were conducted
by monitoring the variance of instrument response over the 5 minute periods. Originally
proposed turbidity and CDOM interference tests, and temperature response factors, were not
conducted.
Table 1.
Challenge compounds for laboratory evaluations of hydrocarbon sensors.
Compound
Ex
Em
Carrier
Stock (ppm)
Carbazole
270
342, 358
methanol
5000
1,5-Naphthalene
Disulfonic Acid
270
380
0.05 M H
2
SO
4
5000
Quinine Sulfate
350
450
0.05 M H
2
SO
4
5000
Basic Blue 3
250, 320
430
water
5000
Diesel Fuel
SPEX CRM
250-300
350-500
methanol
5000
Performance against crude oils and dispersants in a Wave Tank Test
A test application of instrument response against crude oil compounds, with and without
addition of dispersant, was performed in a simulated water column using the DFO/US EPA
Wave Tank Facility located at the Bedford Institute of Oceanography, Dartmouth, Nova Scotia,
Canada. Reference samples were collected from the tank to allow real-time characterization of
the sample water with three-dimensional Excitation/Emission spectroscopy (EEMS).
Instrument performance was examined against two types of crude oil, Arabian Light
(weathered 7%) and Alaskan North Slope, run under two conditions including the pure oil
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