|
Items in cart [0] |
Questions? Call 888-624-8373 |
PAPERBACK PDF BOOK Free Resources |
||||||||||||||||
|
||||||||||||||||
|
|
|||||||||||||||
| ||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||
| Copyright © 2009. National Academy of Sciences. All rights reserved. Terms of Use and Privacy Statement |
Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 94
94
PART A
Chemical Methods
~ NTRODUCTION
There have been many signif icant advances in the application of chemical
analyses to all aspects of petroleum pollution in the marine environment
since the last National Research Council (1975) publication. However,
no one method of analysis can measure all components of petroleum or
answer all requirements for research and monitoring. Many techniques
have been applied to oil spill studies, monitoring of long term sources
of input such as Sewage effluents and production platforms, and experi-
mental studies of the fate and effects of petroleum in the marine
environment. Concurrently, new equipment has been developed for the
variety of sampling problems that have been encountered, and instru-
mental techniques for real-time monitoring of petroleum components in
water near oil spills have been successfully tested.
The analytical methods applied to oil spill studies usually combine
low resolution but relatively easily applied techniques, such as
ultraviolet (W) fluorescence spectrometry, with high resolution but
more costly and time-consuming techniques, such as glass capillary/gas
chromatography/mass spectrometry (GC2/MS) computer systems. This
also applies to monitoring of chronic inputs and analytical chemistry
in support of exper imental studies of fate and effects.
Two important issues that have sometimes been overlooked are (a)
choosing the method (s) that will satisfactorily solve the analytical
problem at hand; for example, gross levels of hydrocarbons in tissues
as determined by nonspecific measurements such as ultraviolet fluor-
escence have minimal use when the problem is to distinguish between
chronic background hydrocarbon pollution of combustion origin, chronic
petroleum pollution, biogenic hydrocarbon inputs, and additions of
petroleum hydrocarbons from a recent oil spill; and (b) quality control
within and between laboratories. This latter point has been emphasized
repeatedly as a priority item, but funding practices by federal agencies
generally paid scant attention to this problem until a few years ago.
The 1975 NRC report called attention to this, and recently the American
Chemical Society (ACS) has issued guidelines for data acquisition and
data quality evaluation in environmental chemistry (Keith et al., 1983),
which address this fundamental issue for all types of environmental
analytical chemistry.
The current status of quality control and laboratory intercomparison
is not yet adequate to accomplish detailed comparisons of data sets
from different laboratories or to be sure which specific chemicals in
various petroleum fractions are responsible for observed effects.
Generally, only compar isons of qual itative trends or large differences
of factors of 10 or more are valid within quality control or inter-
laboratory comparison experiences proof to 1979-1980. Although
progress has been made, much more needs to be accomplished.
Two major developments in our knowledge of inputs, fates, and
effects of petroleum in the marine environment since the 1973 litera-
ture review for the 1975 NRC report have an important bearing on
OCR for page 95
95
analytical chemistry considerations. First, studies of polycyclic
aromatic hydrocarbon sources and fates over the past ~ O years have
increased markedly and have revealed the global significance of chronic
low level polynuclear aromatic hydrocarbons (PAM) inputs related to the
incomplete high temperature combustion of fossil fuels. In many cases,
analytical methods must try to distinguish between petroleum PAR inputs
and pyrogenic PAH inputs. Second, present evidence substantiates a
concern expressed in the 1975 NRC report that petroleum hydrocarbons
readily undergo structural alterations by photochemical and biochemical
metabolic oxidation. Postspill analytical programs based only on hydro-
carbon measurements in seawater, sediments, and tissues cannot measure
an important set of transformation products.
Acute needs have developed (1) to manage data and make them acces-
sible (needs that have only occasionally been addressed in specific
programs), (2) to evaluate existent data much more thoroughly to enable
future efforts to be more targeted, and (3) to link divergent analytical
developments. This latter concern arises from the fact that varieties
of analytical techniques are being separately developed for petroleum
chemistry research, marine chemistry research, forensic applications
(e.g., U.S. Coast Guard techniques!, general environmental chemistry
research, and environmental regulatory or surveillance (e.g., U.S.
Environmental Protection Agency (EPA) priority pollutant) methodologies.
An overview of the literature confirms this and raises concerns that,
in our efforts to monitor the environment, the methods being developed
for and information derived from the various programs are diverging.
This is apparent in the groups of marine chemistry and other environ-
mental chemistry literature, citations from one omitting relevant
literature from the other. Regulatory definitions of petroleum
hydrocarbons must be more firmly based in current knowledge of the
composition of petroleum inputs, fates, and effects in the environment.
The review of analytical techniques, methods, and strategies that
follows has drawn from marine and nonmarine analytical chemistry and
organic biogeochemical studies alike. Due to the great pool of recent
literature, attempts have been made to include mainly post-1975 litera-
ture unless only pre-1975 information Is available. AS no single
literature reference comprehensively covers many of the topics dis-
cussed, a number of references are cited in many cases. Several recent
reviews have aided in this preparation and should be consulted for
additional details: Petrakis and Weiss (1980), R.C. Clark and Brown
(1977), Farrington et al. (1976a, 1980), R.A. Brown and Weiss (1978),
Pancirov and Brown (1981), and Malins et al. (1980~.
SAMPLING AND SAMPLE PRESERVATION
The nature and the quality of information derived from marine environ-
mental samples are dependent on the quality of sampling methods used
and the care taken in utilizing these methods. Of primary concern in
both petroleum hydrocarbon baseline and oil spill samplings is the
avoidance of sample contamination and cross contamination. R.C. Clark
and Brown (1977) presented details of quality assurance aspects of
collection techniques, which included attention to the cleanl iness of
OCR for page 96
96
sampl ing dear ices, subsampl ing implements, and star age conta iner s and
the exclusion of field (shipboard) contaminants from the samples.
Details of collection methods of seawater, sediments, biota, and
waterborne oil samples were presented in R.C. Clark and Brown ~1977) ,
D.R. Green (1978), and ASTM Method D 3325-78. Sampling strategies have
been developed for each spill scenar lo, and usually provide for pre-
impact (baseline) and postimpact samplings, reference samplings
(unimpacted sites), and a postspill time series to examine details of
recovery (e.g., Boehm et al., 1981b; Atlas et al., 1981; Teal et al.,
1978; Burns and Teal, 1979; Keizer et al., 1978) .
Sediments
Recent laboratory and f ield studies have revealed new, important
subtleties related to sediment sampling, both in spill and nonspill
situations. Gearing et al. (1980), in controlled experiments, and
Boehm et al. (1981b) , in a field assessment, pointed to the importance
of sampling newly deposited hydrocarbon-bearing sediment (i.e., floe)
in oil spill studies. Thompson and Eglinton (1978b) showed that
different particle sizes and types within a given sediment have
differing hydrocarbon compositions. Determination of petroleum and PAR
chemical composition associated with dif ferent types and sizes of
sediment particles may yield important information on availability of
certain compounds for biological uptake in benthic communities.
A variety of sediment samplers has been used to obtain "surface
sediment. These include box corers, which are most useful in soft
bottoms and acquire a relatively undisturbed core of sediment; grab
samplers (e.g., Smith-MacIntyre and Van Veen), which are useful in all
sediment types, but may be subject to sample washout in gravelly or
shelly sediment; gravity corers, which utilize a core liner (polyear-
bonate) to obtain a cylindrical core of sediment which may be subdivided
for analysis; hydrostatically damped corers in multiple arrays
(Pamatmat, 1971; Wakeham and Carpenter, 19761, which have damped rates
of sediment penetration; sediment boundary layer suspension (floe)
collectors (Bryant et ale , 1980~; diver and other manual collectors
(Atlas et al., 1981; D'Ozouville et al., 1979~. The selection of the
sampling device is dictated by the sediment type being sampled and the
informational needs of the particular program.
Sediment Traps
The design of sediment traps to ensure efficient collection and
postcollection preservation of sedimenting material is an area of
intense research and debate (e.g., Wakeham et al., 1980; W.D. Gardner,
1980; Jannasch et al. , 1980~. Traps have been utilized to examine the
fluxes of suspended organics, including hydrocarbons, to open ocean and
coastal sediments. The deployment of unsophisticated sediment traps in
spill situations has provided critical information on the fate of
OCR for page 97
97
spilled oil (Boehm et al., 1981b; Johanssen et al., 1980; Boehm and
F lest, 1980a) .
Mar ine Organisms
A var iety of sampling devices exists for the collection of pelagic and
benthic marine organisms (R.C. Clark and Brown, 1977; Grice et al.,
1972 ~ . These include plankton nets, trawls, and dredges of var. fed
design (see Biological Methods section). Extreme care must be taken to
avoid sample contamination from the sampling device, from the ship and
ship's discharges, from the sample containers, and from oil in the
water column. For example , collection of uncontaminated pelagic biota
samples from a ship during a spill event is very difficult, and it is
difficult to distinguish ingested from external oil (American Petroleum
Institute, 19771. Diver collections are preferable in these cases.
Again, the choice of sampling device and the sampling design depend on
the nature of the organism and the program's statistical design. For
example, in order to examine the relation of oil in the sediment to its
bioaccumulation in benthic organisms, animal samples should ideally be
obtained in close proximity to the sediment sample, with either divers
in subtidal areas or manually in intertidal areas, and from the same
sampling device (e.g., box corer).
A n sample ~ of mar ine organisms for analyses is def ined by both
analytical and statistical considerations. An estimated 1-10 g dry
weight (100 g wet) are usually needed for prespill analysis and for
spill-impacted samples to achieve analytical detection limits. However,
the optimum sample size (i.e., number of organisms per sample) is dic-
tated by several considerations, including whether information on a
population at a certain station is required, or knowledge of individual-
to-individual variation is desired (Boehm, 19781.
Seawater
Sampling of seawater to obtain information on hydrocarbon levels, in
both baseline and spill-related samples, is the most difficult of
samplings due to (1) the potential for contamination from the surface
film (Gordon and Keizer, 19741, (2) the potential for contamination
from the sampling device (Boehm and Fiest, 1978; Zsolnay, 1978a) or
from associated rigging and the sampling ship or platform, and {3
possible problems with compar ing data from samples obtained with
different sampling devices (Levy, 1979a; Boehm, 1980a).
Use of the various available devices for obtaining seawater samples
for petroleum hydrocarbon determinations has been reviewed recently by
D.R. Green (19781. Examples of the problems encountered are contamina-
tion by certain plastics and "O. rings. In addition, accumulator
systems (e.g., octadecylsilicic reversed phase adsorbents [May et al.,
1975; Eisenbeiss et al., 1978; Saner et al., 19791, XAD-2 macroreticular
resins [Ehrhardt, 1978] , and polyurethane foam [e.g., deLappe et al.,
19801) have been used with varying results to concentrate hydrocarbons
OCR for page 98
98
on solid phases. Alternatively, large volume water samples (10-90 L),
which pass through the surface in a closed position, must be used to
achieve analytical detection 1 imits which allow sub-part-per-billion
~ug/L) levels of hydrocarbons to be detected (e.g., deLappe et al. ,
1980; Boehm, 1980a; Farrington et al., 1976a) . Chester et al. (1976)
and Keizer et al. (1977) utilized simple devices to obtain 4-10 L of
sample using glass bottles which manually open below the surface.
Recently, pumping systems have been applied successfully to the subsur-
face measurement of petroleum in the water column below surface oil
slicks (Fiest and Boehm, 1981; Boehm and Fiest, 1980b; McAuliffe et
al., 1980; J.C. Johnson et al., 19781.
The use of discrete versus continuous sampling systems is dictated
by the sampling scenario. Continuous pumping systems can be used for
separation of dissolved and particulate water column samples (Ehrhardt,
1978; Goutz and Saliot, 1980; deLappe et al., 1980; Boehm and Fiest,
1980b), although water from discrete samplers can be pressure filtered
through glass fiber filters (Boehm, 1980a; J.R. Payne et al., 1980a).
Ehrhardt (1976, 1978) and deLappe et al. (1980) describe continuous
seawater pumping systems which pass large volumes of water through
in-line glass fiber filters upstream of XAD-2 resin and polyurethane
foam. Dissolved and particulate size fractionations are important in
discerning the fate and pathways of biological uptake of spilled oil
(Zurcher and Thuer, 1978; Boehm and Fiest, 1980b) and distribution of
petroleum hydrocarbons in seawater in nonspill studies (Goutz and
Saliot, 1980; Boehm, 1980a). However, the terms "dissolved and
~particulate" are operational in nature due to possibilities of passage
of colloidal-sized particles through the filter and the likelihood of
changing the pore size of the filter as filtration proceeds.
Sampling for Low-Molecular-Weight Hydrocarbons
Samples (sediment, seawater, biota) to be analyzed for low-molecular-
weight hydrocarbons require special handling. After collection, water
samples should be treated to avoid agitation or inclusion of air bubbles
in storage bottles. Water samples should fill sample bottles and be
sealed with a Teflon cap, leaving no headspace, and be refrigerated
until analysis proceeds (Brooks et al., 1980~. Sediment samples should
also fill sampling containers and they should be frozen. Alternatively,
sediments can be transferred immediately to containers holding
"poisoned {e.g., sodium azide) hydrocarbon-free seawater, the container
headspace flushed with helium or nitrogen and the container inverted at
near-freezing temperature (Bernard et al., 19781. Biota samples should
be frozen until subsampled for purgeable organics (Environmental
Protection Agency, 19801.
Sample Preservation
There is a general lack of information on the longevity of petroleum
hydrocarbons in stored, unextr acted samples of all types. Thus, the
OCR for page 99
99
procedures descr ibed are based, in most cases, on first principles,
with r egard to minimiz ing processes that will alter the compounds of
interest.
All samples (sorbents, filters, sediments, tissues) should be
frozen at -10 ° to -20°C after collection. Water samples, however, are
impractical to freeze and can be solvent extracted aboard ship or
preserved in the dark with a bacterial retardant (chloroform, methylene
chloride, mercuric chloride, sodium aside). However, care should be
exercised in the choice of preservation technique. Samples obtained
for multiple use in chemical and biological studies should be preserved
in a manner that does not mitigate against certain measurements; e.g.,
sodium aside would not be acceptable for samples to be used in a
variety of biochemical or physiological studies. Volatilization of
hydrocarbon components and microbial and photochemical oxidation of
organic matter in samples are the primary concerns to be addressed in
postsampling preservation. ASTM Method D 3325-78 presents a standard
method for storing waterborne oil samples. The effects of long term
(months to years) storage of samples under "preserved conditions is
largely unknown, although Medeiros and Farrington (1974) determined
that, after 18 months of storage of oil-spiked cod liver lipid extract,
analytical results for some major hydrocarbons were unchanged.
SP TLLED OIL CHARACTERI ZATIONS
As the behavior and environmental fate of spilled oil are dependent on
the physical and chemical properties of the oil and the meteorological/
oceanographic conditions, there is a need for full character ization of
an authentic sample of the source of oil and a ser ies of oil samples
from the water's surface and from oiled beaches. These oil samples
will serve as reference materials for environmental analyses and also
may be used in damage assessment studies and in judicial proceedings.
In addition, rapid analytical information should be obtained during
of Ashore spill scenar ios to predict the physical, chemical, and toxico-
logical properties of oils after being waterborne and as they may
impact sensitive shorelines. Offshore and shoreline countermeasure
strategies often hinge on the knowledge of the physical properties of
spilled oil, actual and predicted.
Sample Collection and Preservation
The original 1975 NRC collection guidelines should be adhered to and
supplemented by ASTM Methods D 3325-78 and D 3694-78, U.S. Coast Guard
( 1977 ~ considerations of collection, sample documentation, and
chain-of-custody procedures, and sample preservation.
Several authentic cargo samples should be collected in all cases
along with waterborne oil samples. Replication is important, as
floating oil patches exhibit significant heterogeneity. If possible,
floating oil patches or slicks should be marked with buoys and sampled
periodically until dissipation or landfall . Samples should be taken
OCR for page 100
100
from small boats or helicopters, as it is often impractical for large
ships to enter large oil patches. Cross-contamination should be
avoided, especially while sampling in areas of heavy contamination
wherein gear and clothing may become oiled. Gloves, protective
clothing, and activated charcoal trap respirators should be used while
working in heavy oil, and personnel should be monitored by a trained
medical stat f .
The samples should be taken in suf f icient quantities to permit
replicate physical and chemical analyses. One hundred milliliters of
sample are needed for some physical tests (e.g., viscosity), so
wherever possible, liter-sized jars should be filled with sample.
Sample documentation should be made on prespecif led, durable, water-
proof tags (e.g., U.S. Coast Guard, 1977) to include information on
collection location, date, time, name of collector, and sampling
device. All collections should be logged in a master log and given a
unique sample number . Consecutive number ing National Oceanic and
Atmospher ic Administration, 1980 ~ us ing collector codes has proven
extremely efficient in sample collection operations, and avoids
ambiguous situations which occur during all collections when several
people or groups are sampling concurrently.
Preservation of oil samples involves the containment of low boiling
components and the retardation of degradation through postsampling
photochemical and microbial degradation.
Analytical Methods
Physical and chemical information should be obtained as soon as possible
after the spill occurs.
Field Information
The existence, extent, and mapping of subsurface oil concentrations may
be acquired during spill events through the use of in situ (towed)
fluorometers (Environmental Devices Company, 1977; Calder et al., 1978)
or continuous pumping through shipboard fluorometers (e.g., Boehm and
Fiest, 1980b). Several important physical measurements, such as the
determination of water content of oil {i.e., emulsification state) and
the specific gravity of oil, can be made using simple devices (National
Oceanic and Atmospheric Administration, 1977~. This information is
valuable to countermeasure strategies (i.e., use of dispersants,
application of booms, estimations of cleanup efficiency).
Laboratory Information (Short Time Frame: Days to Weeks)
Samples shipped to the laboratory should be subjected to a series of
routine physical property tests to determine the oil's characteristics
and behavior. These include accurate specific gravity, viscosity, pour
point, and fractional distillation temperatures. ASTM procedures exist
OCR for page 101
101
for all of these measurements (R.C. Clark and Brown, 19771. In addi-
tion, useful parameters associated with the emulsification process are
the asphaltene and wax contents of whole oil.
Ideally, chemical testing in the laboratory should include class
separation to obtain information on the initial and changing relative
proportions of saturated hydrocarbon, aromatic hydrocarbon, and polar
and asphaltic fractions. Oils should initially be dissolved in methyl-
ene chloride, or s imilar solvent with water r emoved by phase separ at ion
and drying over sodium sulfate. The extract is then deasphalted by
precipitation by pentane addition (ASTM Method D 893-80), and a portion
of the pentane is charged to and elated on silica gel, silica gel/
alumina, or other column (see Measurements and Detailed Analysis of
Environmental Samples section). A class separation and characterization
sequence based on initial normal phase high pressure liquid chromatog-
raphy (HPLC) (equivalent to silica gel column chromatography) followed
by detailed capillary GC analysis (Gas Chromatography section) and
analytical HPLC (High Pressure Liquid Chromatography section) has been
described by Crowley et al. (19801. Laboratory-derived data should
include GC analysis, preferably capillary GC, of the hydrocarbon
fractions so as to determine the boiling range and overall composition
of the oil.
Laboratory Information {Long Time Frame: Weeks to Months)
Techniques of petroleum character ization include those that der ive
detailed compositional information as well as those that obtain
information used to match waterborne oils with suspected cargoes
through TR (infrared spectrometry), W/F (ultraviolet fluorescence
spectrometry), GC (gas chromatography), FID (flame ionization detector)
element specific detectors, and trace metal (Ni/V) measurements (U.S.
Coast Guard, 1977; ASTM Methods D 3415-79, D 3414-79, D 3650-78,
D 3328-78, D 3327-79) .
Gas chromatography with f lame ionization and sulfur- or nitrogen-
specif ic detectors yields considerable information on the molecular
weight range of hydrocarbon components, and is one of the more powerful
methods for broadly characterizing crude oils (Crowley et al., 1980;
Rasmussen, 1976; Clark and Jurs, 1979) and refined products (e.g., Ury,
1981~. Graphical plots of the relative saturated and aromatic compo-
sitions of oil samples (Patton et al., 1981; Atlas et al., 1981; Boehm
and Fiest, 1980b) complement specific calculated parameter ratios in
descr ibing the oil's chemical properties.
IR measurements, in addition to having forensic use, can be used to
characterize major compound groups and to evaluate weathering in a gross
way by the appearance of carboxyl and hydroxyl functional groups
(Rashid, 1974; Blumer et al., 1973; W.E. Reed, 19771.
Mass spectrometr ic (MS) class and group (or subclass) analyses pro-
v icing quantitative information on some 25 molecular types have proven
very useful in compar ing oil types and in readily evaluating the chemi-
cal character istics of fresh and weathered oils (Robinson and Cook,
1969; Petrakis et al., 1980; ASTM Method D 2786-71~.
OCR for page 102
102
GC/MS techniques have been used to identify fresh and weathered
oils based on detailed compositions (Hood and Er ickson, 1980; Albaiges
and Albrecht, 1979; Atlas et al., 1981; W.E. Reed, 1977; Calder et al.,
1978; Overton et al., 1980b; DeLeon et al., 1980; Schmitter et al.,
1981) .
HPLC is another technique for character iz ing oils on the teas is of
their aromatic hydrocarbon content (e.g ., Crowley et al ., 1980 ~ . A
combination of IR and HPLC analyses, to quantify and characterize
saturated and aromatic petroleum hydrocarbons, respectively, has been
used in conjunction with Go for analysis (Riley and Bean, 19791.
Further long-time-frame characterizations of spilled oils include
the techniques of carbon and sulfur isotope ratios (Koons et al., 1971;
Hartman and Hammond, 1981; Sweeney et al., 1980), proton and 13C
nuclear magnetic resonance spectroscopy {Petrakis et al., 1980), and
elemental (C, H. N. S) analysis (e.g., W.E. Reed, 1977; National
Research Council, 1975~. Additionally, many of the analytical
techniques used by petroleum chemists may effect more detailed char-
acterizations (Terrell, 1981~. Examples of detailed multiple-technique
characterizations of oils are given by W.E. Reed (1977) for weathered
tars, W.E. Reed and Kaplan (1977) for marine petroleum seeps, and
Overton et al. (1980b) for Ixtoc I oil.
MEASUREMENTS AND DETAILED ANALYSIS OF ENVIRONMENTAL SAMPLES
Gener al
The analysis of a particular sample of water, sediment, tissue, air,
etc., for petroleum hydrocarbons must be preceded by matching the
particular informational need with the proper analytical technique.
For example, information may be needed on the gross amount of oil in
the dosing system of a toxicological study or on concentrations of an
individual aromatic toxicant (e.g., naphthalene) and its metabolites
(e.g., naphthol) in a marine fish.
Single analytical techniques (e.g., W , GC) can be used for certain
applications when the analyt ical end is to examine absolute levels or
compound assemblages (nonpoint sources), but multiple techniques (e.g.,
W + GC ~ IR) are required for forensic purposes in matching environ-
mental compositions of petroleum to specific point sources. Figure 3-1
illustrates various analytical options for environmental samples. The
proper choices of separation and analytical techniques are at the heart
of environmental petroleum hydrocarbon chemistry.
In general, the less chemically specif ic techniques require less
sample processing and manipulation. With increased processing, the
level of analytical detail, and hence compositional and quantitative
information, increases.
The field of oil pollution chemistry has expanded rapidly in the
past 5-10 years without great attention to intercomparabil ity of
measurements between different laboratories using similar techniques
and between different analytical techniques used to generate data. The
generation of analytical data continues at a rapid pace at different
OCR for page 103
103
SAMPLE 1.) PRETREaTMENT (DRYING, IdOMOGENIZATION, e
I l 2.) EXTRACT WITH SOLVENTS
SUBSAMPLE FOR
VOLAT I LE
HY DROCARBON S
GAS STR I PP I NG
GAS EQUI LlBRiUM
Dl RECT I NJ ECT I ON
PU RG E AN D TRAP
G C
, ~
H IGH L IPI D SAMPLES
1.) SAPON I f I CAT I ON
2.) aLUMINA PRE COLUMN
SAPONIFIED
LIPI DS
-
T OT A L
NON - SAPON ~ f I ABLE
ORGAN I CS
1
F3
POLAR
FRACT I ON S
TLC
HPLC
GC2/MS
| SATURATES |
r ~
~,
STRA I G HT BR~ ~E D
2 ~! ~ CY~Ll C
GC ~Gr 2
le. )
~,
~ .
| TOTAL EXTRAC~L_~= GRAViMETRIC (Oil ~ Grease)
ORGAbJ I C S
- ~ UV/ F
LOW LIPIt) SAMPLES
POLAR ITY SE PARATIO \IS
1.) COLUMN OR TH IN LAYER
CHROMATOGRAPHY ( Florisil,
Silica Gel, Clay)
. ~
HYDROCARBON
FRACT IONS
- GRAVIMETRY
_ - GC2
- GC 2/~s
~IZE SEPARATION |
| MOLECULAR SIEVES |
ARO MAT~
OLEF I NS
. .
GRAV I M ET R Y
I R
UV / F
GC2
GC2/i'S
S I ZE SEPARATION
- GEL PERMEATION
- CHROMATOGRAPHY
, HPLC or SEPHAC)E X)
(
| OLEFINS 1 | AROMGTICS |
1 F21 1
GC2
GC2/MS
FIGURE 3-1 Analytical options for analysis of petroleum compounds in
sediment, tissue, particulate matter, and water.
levels of sophistication. Recently the ACS Subcommittee on Environ-
mental Analytical Chemistry published its "Guidelines on Data Acqui
sition and Data Quality Evaluation,~ which expressed three interwoven
strategies of modern trace analysis: (1) the development of sensitive,
specific, and validated methods;
{2) the use of protocols that describe
OCR for page 104
104
the details of the measurement process and sampling procedures; and (3)
the use of quality assurance procedures to monitor the quality of the
data as it is developed. At the heart of all data generation should be
procedures of rigorous quality assurance including routine determina-
tions of procedural blanks, instrument calibration and standardization,
analytical precision on replicates, recovery of spikes, detection
limits, and comparison of results with other laboratories (intercalibra-
tions) {MacDougall and Crummett, 1980~. These guidelines should become
part of all petroleum hydrocarbon studies. In addition, the precision
of environmental analytical measurements has three components: (1)
instrumental variation (replicate analyses of the same solution), (2)
analytical variability (analysis of replicates of the same homogenate,
or subsamples), and (3) sampling variability (replicate analyses of
sampling replicates).
Numerous methodologies have been used in conjunction with oil
pollution studies, and the efficacy of the various methods used, for
example, in extracting and fractionating organic matter from sediment
and in performing detailed analysis of hydrocarbons, has only recently
(since 1975) come under rigorous study through both intralaboratory
experiments and thorough intercalibration exercises.
Extraction of Organic Matter
(High Molecular Weight, Cll+) Hydrocarbons
Sediments
Several different solvent extraction methods are commonly used for the
extraction of petroleum hydrocarbons from sediments. No standard
method exists, but most methods involve the combined use of polar and
nonpolar solvents to effect an efficient extraction of organic matter.
Geochemical and oil spill sediment samples differ in the ease of
extraction of hydrocarbons from the sediment matrix, the latter
containing loosely bound petroleum hydrocarbons. Thus while one of the
rigorous extraction procedures is necessary to extract, for example,
low to moderate levels (less than 10 ug/g) of PAH from a s~lt/clay
sediment, simpler techniques may suffice for spill samples. As it is
often important to discern levels of incremental addition of low to
moderate levels of oil to sediments containing some prior history of
anthropogenic pollution, the rigorous solvent extraction methods (e.g.,
Soxhlet, tumbler/shaker) are most appropriate for all environmental
samples.
Sediment extraction techniques include organic
_ solvent extractions
(e.g., D.W. Brown et al., 19801, alkali digestions followed by solvent
extractions (Environmental Protection Agency, 1980; Farrington and
Tripp, 1975), headspace gas stripping (May et al. , 1975) , and steam
distillation (veith and Kiwas, 1977; Bellar et al., 1980) . Solvent
extractions employ (1) the use of the Soxhlet extractor with a com
bination of polar and nonpolar solvents (e.g., Hites et al. , 1980;
Farrington and Tripp, 1975; Lake et al ., 1980 ; Environmental Protection
Agency, 1980), (2) the reflux of sediment with organic solvents (e.g.,
OCR for page 124
124
monitoring programs, and (3) standard certified reference materials.
The most significant intercalibration exercises presently underway or
previously undertaken address type (1) exercises, involving enough
laboratories to enable statistical analysis of data. Type {3) materials
with National Bureau of Standards (NBS) certification, containing known
amounts of specified constituents, have been requested by scientists in
environmental studies. To date, only one such sample has been prepared,
due to uncertainties of sample homogeneity, storage stability and matrix
ef feats, and definitive analytical methods. A new standard reference
material (SAM 1580), "Organics in Oil Shale,. is intended primarily for
evaluating reliability of analytical methods for the determination of
three PAR and two pl.~.enolic compounds in an oil matrix. Thus, most exer-
cises involve type (2) programs. A summary of major petroleum hydro-
carbon intercalibration studies undertaken in the 1976-1981 period is
shown in Table 3-2. Interiaboratory precision has improved signifi-
cantly over the past 5 years or so, as techniques for both analyzing
samples and running intercalibration exercises have improved.
The roots of a well-conducted intercomparison program lie in the
homogeneity of the sample and the comparability of data (i.e., the
reporting of the same components by all participating laborator ies on
the same basis, corrected for recovery) . Dur ing the last 5 years, the
ability to conduct intercalibration exercises and to analyze samples
rigorously and achieve comparable results have both improved markedly.
Bearing in mind that there is no fright answer" in such exercises using
environmental samples, a group of laboratories in the United States has
obtained generally tightly grouped results based on GC2 {and GC2/MS)
determined alkane and polynuclear aromatic hydrocarbon levels in sedi-
ments (MacLeod et al., 1981a). While statistical evaluations are still
in progress, laboratories probably can achieve comparable (within a
factor of 2 and often much better) analytical results. Coefficients of
variation for individual aromatic hydrocarbon determinations in the
Duwamish II study were, for example, +14% for fluorene, +17% for
phenanthrene and fluoranthrene, and +39% for perylene, for the six data
sets (MacLeod et al., 1981a) and were as good for n-alkane values.
The International Council for the Exploration of the Seas (ICES)
intercalibration studies, while not as rigorously controlled as the
Duwamish exerc ises ~ see Table 3-2 ), have yielded compar able f luor es-
cence-based data on sediments with a coefficient of variation for
"total petroleum" in the 10-308 range. This level of agreement was
reached by using specified quantification methods, i.e., prescribed
Integrated Global Ocean Station Systems (IGOSS) wavelengths. The
ICES-sediment exercise yielded comparable W-, OR-, and GC-based Total
hydrocarbon. concentrations.
Intercalibrations on biological mater ials have posed more serious
problems, with even W-based data (ICES study) yielding poor results,
probably due to both analytical problems and quantification techniques.
The GC- and GC/MS-based EPA megamussel study currently under way (no
f inal data available) specifies individual compounds and aromatic
isomer ic groupings for reporting.
The emerging view appears to be that, for the most part, comparabil-
ity of petroleum hydrocarbon and PAM results is beginning to depend
OCR for page 125
125
~q
v
3
U]
~:
C)
0
1
~D
C)
~3
c
o
.,.
v
C)
v
~:
~4
o
o
a,
v
o
U]
1
E C24
V) ~
~:
o
a~ ·-
C: V
· - ~
~i N
O · -
00
Q
V) O
~O ~
£ ~
~; ~ V
E ~Z u,
1 _1 1
C
0, 0 ~E
C} O
~ U]
O ~· -
C) O ~ _ ~o
v ~ :~ 0 ~r
C) O ~ ~1 1 c: C: Q.
~ ~ ~ · - ~· - ~· - ~n ~ 0
a) ~ 1 ~ eq - ~ ~ ~
c: ~n · - ~:>' ~ v l::
Q ~ n ~ ~v ~ ~ ~ 3
o4,~ ~ ~ ~ v -- Q ·~4 dP E O
~ ~ ·^ ~ ~ ~ o o
O :>t ~ ~ ~ ~· - ~ ~ ~ E
C) ~ ~ ~ - - ~ L4 ~ +1 ~ o
,'
3 · -
fO t: ~n ~ S~ u ~ ~a
eQ ~ u, ~ `: ~ ~ r ~ ~ ~
~5 ~: ~ ~ a! o :> v +1 ~ ~ ~ v
·- O -~ E ·- a, -.- `~5
>- - · - v ~ £ 11 ~ ~ ~
. - v o ~: ~ V ~ ~ ~ ~ 3
V ~ ~Ll ~ ~ ~ V
1 3
V ~ :s m ~ ~- ~ ~ ~ 0
1 1 1 1
C:
O
v
V 4
~ ~Ll · ~a
· - 0 ~ ~ 0 o
a, co
cr, 0
~o ~ ~ ~. -
E4 - :e ~ - 3 -
`: 0
· - a,
V ~
~ O
· - V
~4
O · -
V O
· ~ D
O ~ ~ ~a, a,
Z P, ~ ~
C)U
C,) _ _~ ~· - _
· - ~ ~ ~O ~ C) ~ ~O
1 `4
O JJ ~S - ~ ~ ~ - 4
`4 ~C: ~ ~C ~ ~ ~`::
~= ~- ~3 ~ ~ ~ ~3
05 ~- - Y ~ ~O ~ · - O
s ~ ~ ~· - - m v ~ ~ ~m vE ~
^ ~ a,~ ~ eq `. ~ ~ ~ q~ ~ c
- ~ ~ tn I ~ I v ~ V E
:>. cl o ~ e
~ ~ ~ ~c ~ ~C u, ~ ~ ~C a'
~- :>, ~ ~ v ~ ~ ~ tn
v ~ Q ~ ~ ~ ~ 0 `: v C ~ v ~
) re 3 ~ ~ ~ ~ ~ ~ C ~ ~ 3 ~ ~ ' -
a =~~ - = ~ 4~= ~- ~ c ~ v ~,
v ~: c:- c ·- v ~ ~ ~ ·-
~ ~ ~ O ~ ~ ~ ~ ~ ~ 0 ~ ~ 0 v
· - 0 3 £ D - - C} · - EE ~ ~ ~ ~ c: ~ v ~ Q, ~
v v 0 ~ ~ ~ t: ~ 0 v 0 ~ E ~ :r: JJ 0 ~ E a~ :r
0 ~ S~ ~ ~ ~ O ~ Ll O O ~ O ~ ~: O O ~ O ~ ~
~·r1 V) ~tS C.~ ~ ~ ~ ~ ~o E~ ~: -~ ~ ~ ~ a,,
0
C ~
=: m
··· ··~ e
~ ~ C~
V ~ - ~ 0 y
V3 ~.,4 ~ V 0
c0 ~ 0 ~ -~ c
{D ~ U) ·~~ ~ V ~ _~ _t
E ~ 0 ~Y L. E ~ ~ ~ a,
~ Y s - - ~u' ~ · - ~ Q 0
=~ - V 3 3 ~ v ~C s" ~ 0
a, =- - 0 ~1 C ~ ~ ~ 3
U) 0 3 ~ ~:-- u' U, m
P.
~'S ~
mm
m zm2
v4
a'
~ ~ E E ~
v ~ - - - - ~n
cn ~n 0
~m ~m ~m 3
cn m ~n z 0 2 E:
OCR for page 126
126
4 ~, ~
~ C C 1 C C
1 1 a~ ~a ~1 ~C5 q5 0 1 ~a
C ~:> ~o
o ~o ~ ~- - o ~s ~. - ~ ~
. - ~ V ~ ~o ~ ~ ~ - -
eq C ~S ~qJ ~ 3 ~ 3 tn
c ~ _ eqeQ a~ ~ ~ ~ ~ ~ c
_ 0 ~ ~ ~3 4 ~u, ~ o 4) O
~- = ~ ~ ~s
to ~0 - ~O ~O ~- =
E ~ 0 ~ ~u' u' n ~ c
C ~s ~ ~ ~ ~ ~ ~ ~ £ O
:' ~ U C ~ U O C ~C
O 0~ ~O C ~ ~ C ~ O
Q. 3 ~V ~ Ll ta o u~ t) ~ ~ o
~ ~- - ~ ~- ~ ~· -
O q4 oo ~ V -4 ~ ~ ~ JJ ~ O ~ ~ a
0 ~t) 0 c ta c: ~ 0 ~ ~l ~l 41 ~ ~ 4J
O ~ ~ ~ s Q. ~ ~0 ~ ·' ~
E :~ ~1 ~ a' ~ V ~ v ~ ~ ~=. - ~ o
.~4 ~ ~ ~o ~ ~ ~ O ~ ~C 0 -
~n ~ ~ ~ ~ ~ ~O c ~ u ~
ad ~ ~ ~ C ~ Ul
V 4J V ~Q, 0 ~ 0 1 C ~ ~ ~ u' C ~-
~n ~ ~a ~ 4 ~0 ~ a' 0 Q O Q 4~ E
~Q ~ _ 0 0 ~O c x 0 ~ ~ ~4 0 ~ 0 ~ ~Q 3 ~ O
~; ee ~ £ O ~ ~ ~ ~ Q' 4~ ~ O P4 ~ ~ ~ ~ c
1 1 1 1 1 1 1
._
_
0
c o'
cv ~0 ~ ~ ~ ~a,
a,m · · ~ · ~c m^
- - O ~ ~ ~ ~s
· ~ ~ le co ~ ~ a)~ co ~ ~
3 V 0` ~ ~3 ~ ~ c
· dJ Io ~ ~ ~ ~ O
cz:a ~ ~: ~,- ~ ~,~
cr
C: Ul
_
Q. 0
q~
0 ~ ~
~ 0
·
O
Z P. ~
C)
V u4
~ 0
:~ ~
_
~Q
~S m
Q.
u, ~
-
o
v
-
r~
1
a, u~
~r~
o
~ N
O -
0
Q
C~ ~
u, 0
c~
ca
1 o
~n 1 0 1 ~ S
V U] 00 ~ U] eq 1 ·' V 4
c: ~ _ c
V ~ ~O ~
~ ~ ~ It ~-~ c: ~ ~a 0 0 c ~ u ~·-
0 ~ ~ 0 ~ ~ C ~ 0 0 eq
~ ~ 0 ~ ~ tn ~ ~ 0 ~ ~`: ~
S E ~C E! ~ 40 ~ 3 v ~O E
Q. O 0 ·` ~ O ~ .- 4~ ~ ~ ~ O
C) ~ ^ 0 ~ V ~ _ [Q ~ c ~ ~ c)
~4 ~ -4 ~ ~ 0 _ c ~ ~ ~ O
V _ ~ 0 ~ Ve~ ~ ~q ~ ~ O ~ ~V
_ ~ ~ ~ v c ~a~ tU ~a 0 -
4J ~ ~ ~ JJ 0 ~ ~ L4 C
c ~ ~ ~ c ~ ~ ~ ~ ~ c - -
3 ~ tR Q ~: :~ ~ ~ O C V 3 Q) O --
~ O ~ ~ ~ O- ~m ~ ~ ~ ~ 0 0 C 0 C
- ~4 E! ~ ~ ~ ~ ~4 O:
:> ~ t) O ~:> ~ O O ~ ~ ~ ~ ~3 c
V 41 ~ C, V ~ V O ~ ~ 3
0 ~ ~ v ~ t~ a, ~ ~ ~y O
c C: ~ ~ _ c `: :~ ~ ~c c Q'
.Q O ~ ~ aQ O ~ - 0 ~ ~C
· ·· · ~
1 ~
~C1_I ~4J N 0 ftS 45
C J ~C J ~_ _ (U ~_ id J~ ~J I J~
- c _ c ~ 0 ~n c c ~ `: 0 x c
a,
E ~ E: ~ c ~Q) ~ ~ ~ ES n E
:1 ~3 ~ C _ ~0 4 ~tn 0
4~= ~ =_ ~3 ~ c ca ~ ta ~ ~ O
~ ~o ~ ~ ~ 0 :' o 0 ~ 0 c
D3 0 D3 0- ~ E ~ s ~ tn ~ ~ ~ ~ o'
~;
~;
g O :~
u, ~ 3
,_' , ~X O
m m ~z
s =:
~4 0 ~n
O .,' _
~ ~E ~ ~u
lE 3 3 ~;r ~
~ ~:, 3 ~:Y:
2 u' ~Ca
OCR for page 127
127
q~
1 0 C)
o . -
o ~. -
o ~ o
C
tU ~- 4> 3
_
C ~
c tn 0 ~c :'
O ~
C V a,, . -
a' c u' ~
rG E ~ ~ - -
0 3
0 ~a, n tn
0 ~ ~
~ t) _ 0
U]
3 -4 ~ ~ ~ ~ ~ 4~
O ~O ~ ~ X O C
.c lll ~o :>~ + 1-- ~ ~
u~ E ~t~ ~ -~: V C
1 1 1
o
CD
3 · _ C
O ~ ~· -
·a a
4
-
n
~o
' ~
a'
-
C
JJ
~:
C ~0
E
Q 3
Q. O
O O
C) ~ -I
4
3 ~a) 3
.= Ll ~ ~
t: ~ ~ eq
O ~ ~ - -
C L. C) O `:
E~ ~ P~
-
. . ~m
·r4
~ t) 0X
s ~ ~ s _
· - ~ ~ ~ ~
V _ ~ ~`:
0 ~4 3 ~ ~ X
t) O C O ~ ~ -4 ~
O ~ ~P.
~·. ~ ~ ~ ~ ~ ~ - -
go~ ~ X ~ ~ - Y ~ C
eg' ~ ~ ~ ~ .- ~ ~ o~ ~`:
3~ ~ `24 3 L' ~ ~ ~ ~ ~_
£ 1 ~ ~ ~ {~) 1 ~ oo ~ 1
c
o
~s: E ~4
P4 0 U)
~S Z
a,
U]
:s
E u~
E~
~: ~O
c. ~a ~
Q.
~n
;^
o
·-
c
z
OCR for page 128
128
more on the quantification process ~ i .e ., how individual component GC
peaks are quantified) than on the extraction and process ing steps
(i.e. , several extraction procedures will suffice). This is true for
the Duwamish I and II sediment studies, wherein differing extraction
methodologies were used (D.W. Brown et al., 1980; MacLeod et al.,
1981a), and may be emerging as the reason behind variability in the
more difficult, interference-prone biotic measurements.
Clearly, further intercomparisons are required, addressing (1)
comparability of results based on simpler, more universally available
methods (i.e., W fluorescence), (2) comparability of more rigorous
techniques (i.e., GC and GC/MS), (3) intercomparability of the methods,
and (4) the location within the analytical technique for discrepancy.
Laboratories should be urged to participate in intercalzbration pro-
grams in a nonthreatening atmosphere at the start of the environmental
chemistry program, to enable the refinement of analytical techniques so
as to achieve results within a determined statistical range. The NBS
SRM oil shale, samples such as Duwamish I and II sediments, and the
ICES sediment appear to be most appropriate for this purpose.
REMOTE DETECTION AND MEASUREMENT OF OIL SPILLS
Remote sensing devices used to monitor marine pollution are becoming
more sensitive and reliable than they were just 5 years ago. The use
of both airplanes and satellites as platforms for remote sensing
devices has been explored. ICES and NOAA, as well as other organiza-
t~ons, have been involved in the development of satellite-carried
equipment for sensing oceanographic parameters (Apel, 1978; Kniskern et
a-l., 1975; Koffler, 1975; N.R. Anderson, 1980; Klemas, 1980~. However,
satellite monitoring is not without problems. Geosynchronous satellites
do provide repeatable coverage, but the resolution is not great enough
to be of practical use. The NASA ad hoc committee on remote sensing
concluded that the physical parameter requirements for oil spill
monitoring are at least an order of magnitude greater than the remote
sensing data which are now available {Croswell and Fedors, 1979~. In
addition, Goldburg (1979) concluded that sensors in airplanes are more
feasible and cost efficient than satellite remote sensing, thus, the
focus on airborne sensors in this section.
The U.S. Coast Guard has developed remote sensing "packages to aid
in the detection of oil slicks. The two prototypes of the current
package, AOSS I and AOSS II (Airborne Oil Surveillance Systems ~ and
TI), are described more fully in Bentz (1980), Maurer and Edger ton
(1975), and G.P. White and Arecchi (1975~. The third-generation aerial
reconnaissance system, designated AIREYE {for aerial remote instrumenta-
tion), will be installed in Falcon 20-G jet planes and includes side-
looking airborne radar (SLAR,, an IR/ W scanner, a computerized data
recording system, and an aerial reconnaissance camera (N.R. AndersOn,
1980~. By including sensors utilizing three portions of the electro-
magnetic spectrum, the number of false alarms due to kelp beds, wake
scars, and the weather can be kept to a minimum (J.R. White et al.,
19791.
.
OCR for page 129
129
Remote sens ing devices can be divided into two categor ies: those
based on passive (natural) reflectance and emission of some part of the
electromagnetic spectrum, and those based on an active (man-induced)
electromagnetic excitation of the ocean sur face and the collection of
reflected radiation. The passive group includes microwave, IR, and W
collectors. Those devices that depend on man-induced electromagnetic
radiation include radar, W fluorescence systems, and laser backscatter
sensors. Table 3-3 (from N.R. Anderson [1980] and Maurer and Edger ton
[19751) reviews the types of remote sensing devices and the false
alarms g iven by each.
Passive microwave systems measure radiation waves naturally emitted
or reflected by the sea surface. Microwave brightness is a function of
surface roughness and the dielectric constant of the surface. Thin oil
films have a calming effect on the water surface, which results in a
modification of the microwave structure and thus a lower brightness
temperature. Thick films (~0.1 mm) emit more microwave energy than
unpolluted water does; thus, the film thickness can be determined from
the relative brightness temperature. Passive microwave systems can
penetrate weather and are independent of lighting conditions. Disad-
vantages include coarse resolution and a limited swath (Maurer and
Edgerton, 1975~.
Infrared sensors detect apparent temperature differences between
oil and water due to the physical properties of the two substances.
Oil and water have different reflectance properties in the 2- to 4-pm
spectral range (G.P. White and Arecchi, 19751. In the near IR range
(0.6-1.1 um), the radiance from an oil slick is 20-100% greater than
the radiance from water, and at night, oil gives 50% greater radiance
than water does (Catoe, 1972~. Thermal IR (1.1-14 um) sensing is
limited to specific atmospheric windows where the atmosphere is trans-
parent enough to allow the waves to pass through without significant
absorption (Catoe, 1972~. Thermal infrared sensing can also be used 24
hours a day, and IR waves can penetrate haze but not clouds. Odd local
thermal structures {e.g., an upwelling) can cause false alarms (Maurer
and Edgerton, 1975~.
Passive ultraviolet collectors can detect oil patches because oil
reflects more W light than water does. The greater amount of W
radiation that water absorbs, the cooler it appears in relation to the
oil slick it surrounds. Passive W collectors require some ambient
sunlight, but the light range can be extended if the collector is used
in conjunction with a low light level television (LLLTV). False alarms
from this system include kelp patches (Maurer and Edger ton, 1975), and
atmospheric aerosols limit its use in hazy weather (Catoe, 19721.
One of the more widely used active sensing systems is radar. It is
used with a great deal of success to detect offending ships and oil
slicks on the sea surface. SLAR has a swath of up to 80 km (40 km on
each side of the airplane). SLAR detects the capillary wave-damping
effect caused by oil on the sea surface, so this technique becomes
ineffective on flat, calm or extremely rough seas. Another disadvantage
of SLAR is that it does not "see" a strip directly beneath the plane.
An IR/ W line scanner is often used to overcome this problem (J.R.
White et al., 1979).
OCR for page 130
130
TABLE 3-3 Oil Spill Detection by Remote Sensing: Sensors and Spectral Regions
Sensor Spectral
Approach Region
Active
reflectance
Microwave radar,
1.05-5 cm
Laser backscatter
W fluorescence,
0.4 m
Passive W , 0.4 m
reflectance
Visible
0.4-0.65 m
Near IR, 0.65 m
Passive Thermal IR,
emission 3-14 m
Microwave,
0.2-1 cm
False Alarmsa
Natural organic slicks
Wind slicks, ship wakes
Pollutant organic slicks
(detergents, sewage sludge)
Kelp/debris
Dense cloud cells
Unrippled water under calm
conditions
Natural organic slicks
Suspended sol ids
Natural organic slicks
Pollutant organic slicks
Suspended sol ids
Shallow water
Broken cloud deck
Natural organic slicks
Other pollutant slicks
Natural organic slicks
Pollutant organic slicks
Ship wakes
Thermal discharges and
effluents
Upwelling
Foam patches
Kelp/debris
Dense cloud cells
Has all of the listed sensors detect oil on water, natural petroleum seeps
would be a false target for each sensor.
SOURCE: N.R. Anderson (1980) and Mauer and Edgerton (1975).
A laser backscatter sensor (Dichromatic Lidar Polarimeter), which
transmits at two coaxially aligned, vertically polarized wavelengths,
has been developed (G.P. White and Arecchi, 1975) . Depolarization
occurs at the sea surface, and the two wavelengths are backscattered
differentially. The backscatter is collected, and the magnitude of
returned radiation and the depolarization ratios are used to determine
the presence of oil. Hoge and Swift (1980) used a laser-induced water
OCR for page 131
131
Raman backscatter sensor to detect the presence
that oil depressed the Raman backscatter, which
of oil. They found
r eturned to normal
after the sensor was over water once again. Oil film thickness could
also be determined using this method .
Probably the most promising remote sensing device currently being
developed is the laser-induced W fluorescence sensor. Laser-induced
fluorescence systems not only differentiate oil from water but also can
discriminate between oils as well (Kim and Hickman, 1973; Rayner et
al., 1978; Fantasia et al., 1971; Fantasia and Ingrao, 1973; Horvath et
al., 1971; O'Neil et al., 1975; Measures et al., 1975; Rung and Itzkan,
19761. A W laser excites the sea surface, and the fluorescence return
~ s collected. A photomultiplier tube converts the fluorescence to an
electrical signal, and then a fluorescence spectrum can then be printed
out.
Field trials by Fantasia et al. (1971), Horvath et al. (1971), and
Rayner et al. (1978) have shown that, not only can oil fluorescence be
detected over background fluorescence, but oil can be classified into
three groups: diesel fuel, crude oil, and bunker fuel. O'Neil et al .
(1980) reported that oil shows increased W absorbance with decreasing
excitation wavelength; thus, thinner oil layers can be detected. The
shorter wavelengths also show greater structure in the fluorescence
spectra, which gives greater discrimination power and allows
c lass if ication of d if fer ent o its .
Attempts have been made to detect oil in the water column using W
fluorescence sensors. These have been almost totally unsuccessful
because there is so much nonpetroleum suspended organic matter in
seawater and, because water absorbs so much W light, there is very
little fluorescence emitted (F.E. Hoge, personal communication, 1981)
\
MONITORING FOR PETROLEUM HYDROCARBONS
The success of any monitor ing program depends on the proper selection
of environmental parameters to be measured, the proper choice of
analytical techniques to be used, the comparabil ity of analytical
results over time and between labor ator ies, and the statistical
validity of the measurements (i.e., what level of sampling and
analytical effort will detect change) (Risebrough et al., 1980~.
also the Introduction to this chapter.)
When the amounts of oil are large, simple analytical techniques
(e.g., IR, gravLmetry) or remote sensing may suffice. However, at low
levels, analytical strategies become critical. A specific property of
the oil such as W/F may be determined and "equivalent oil concentra-
tions" obtained. Alternatively, individual components in a single
class of compounds (e.g ., aromatic hydrocarbons) may be quantif led.
Measurements of specific properties, although more widely performable
by more laborator ies, rely on tenuous assumptions regarding cal iteration
of -the methods . Monitor ing of individual compounds is more expensive
and requires extensive quality control and intercalibration. However,
much useful information for dif ferentiation between hydrocarbon sources
can be obtained, along with determination of the extent and severity of
.
OCR for page 132
132
pollution. If seawater is the targeted environmental compartment, then
W /F may suffice due to low background levels. In cases where correla-
tion analysis of hydrocarbon and other parameters is used as a monitor-
ing tool' then these simpler techniques may differentiate impacted from
nonimpacted sediments (Boehm and Quinn, 1978~. However, most monitoring
scenarios call for specific chemical component measurements, perhaps
guided by specific property techniques {see Figure 3-3~.
Several far-reaching analytical monitoring programs have been
initiated in recent years which address two main concerns: (1)
detection of environmental change (i.e., environmental degradation or
improvement) due to petroleum hydrocarbon (and other pollutant) inputs
to the system, and (2) assessment of the temporal recovery of an oil
spill stressed system. A third concern only loosely being addressed
due to constraints of time and data handling is the identification of
"new pollutants.. One example of the former type of program is the
U.S. EPA Mussel Watch program (National Academy of Sciences, 1980;
Farrington et al., 1983), which utilizes the sentinel organism approach.
Mussels on the mid-Atlantic, northeast, and west coasts, and oysters on
the southern and Gulf coasts are analyzed for specific petroleum
hydrocarbons and other pollutants, the rationale being that mussels
reflect the water quality over an integrated time scale. Emphasis in
the hydrocarbon program is on analysis of specific aromatic compounds
(currently up to 4 rings) and alkylated aromatics to determine absolute
levels of these compounds, their changing levels, and sources of
observed hydrocarbons (i.e., whether from pyrolytic or petroleum
sources). Intercalibrations have been underway in this program
(Galloway et al., 19837.
NOAA's Northeast (U.S.) Monitoring Program attempts to link chemical
to biological parameters over time. The focus is on the analysis of
sediments as a major sink for pollutants, and a selected set of organ-
isms for individual PAH {and polychlorinated biphenyls (PCB) and metals)
compounds. This program attempts to utilize several preexisting data
bases (BLM-Benchmark; NOAA-MESA [New York Bight]), although in the past
no uniform techniques of measurement have been utilized nor inter-
calibrations stressed.
ICES monitoring programs, in existence since 1977, have focused on
metal and organochlorine residues in sediments and several fish and
invertebrate species. Petroleum hydrocarbon information is beginning
to be derived from this program, mainly based on specified W /F
analysis, but presumably to be complemented by high resolution tech-
niques as well. Residue levels are evaluated in terms of human health
concerns . The ICES ~coordinated" monitor ding programs include part of
NOAA's Northeast (U.S.) program as well. This program now proposes to
keep the following regions under annual surveillance: Irish Sea; German
Bight, Southern Bight of the North Sea; the Estuaries of the Forth,
Thames, Rhine, Scheldt, and Clyde; the Skagerrak, Kattegat, and Oslo
fjords; plus certain parts of the Gulf of Saint Lawrence and New York
Bight. The ICES program has three monitoring rationales: (1) the
provision of a continuing assurance of the quality of marine foodstuffs
with respect to human health, (2) the provision, over a wide geo-
graphical area, of an indication of the health of the marine environ
OCR for page 133
133
ment in the entire ICES North Atlantic area, and {3) to provide an
analysis of trends in pollutant concentrations. Intercalibration
exercises for petroleum (see Petroleum Hydrocarbon Intercalibration/
Intercomparison Programs section) are underway, although many dis-
crepancies in methodology need to be resolved.
Monitoring for the recovery of systems following oil spills has
been conducted for many spills. Once a choice of sampling stations and
measurements has been made, the same concerns face these programs as
well as the "baseline-type" programs. Examples of spill monitor ing
programs are: Arrow shill (Keizer et al ., 1978 ), West Falmouth shill
(Teal et al., 1978), Tsesis spill (Linden et al., 1980; Boehm et al.,
1981b), Amoco Cadiz spill (Atlas et al., 1981), and Iranian Crude-
Norway spill (Grahl-Nielson et al., 1978) . All relied on detailed
chemical measurements of sediment and/or biota to monitor
based on the decrease and/or modif ication of petroleum residues .
- ~ recovery
CONCLUSIONS AND RECOMMENDATIONS
Conclusions
No single method of analysis provides a measure of total petroleum in
water, sediment, or tissue because of the extreme complexity of the
composition of petroleum. Unfortunately, apparent economic necessity
has often forced analysts to the less expensive and less discriminating
methods of analysis with attendant generation of a substantial amount
of data which can only be interpreted with large uncertainty.
However , improved methodology for measuring fossil fuel compounds
has been rapidly developed or applied since the 1975 NRC report. The
range of selectivity and sensitivity makes it essential to choose the
correct methods for a particular problem and to recognize the inter-
pretation limits for the data.
Recommendations
Quality Control and Intercomparison of Data
The rapid increase in the number of analysts and the demand for larger
sets of data require careful quality control and intercomparison of
~ ~ ~ ~ ~ ~ ~ ~~~~ NRC report.
data, now even more than at the time of the 1975
We recommend that rigorous quality assurance protocols be
integrated into the analysis of hydrocarbon and other fossil fuel
compounds in environmental samples. The value of standard solutions,
spiked samples, spiked extracts, and sample homogenates for quality
control and intercomparison has been demonstrated in a few studies.
OCR for page 134
134
Identification of Sources of Input
Many studies of petroleum inputs or distr ibution in the mar ine environ-
ment have not appl fed analytical techniques to identify sources mor e
exactly. The terms "petroleums" and petroleum hydrocarbons" are often
used incorrectly and too loosely when describing data resulting from
less discr imitating analyses. This Is especially true in regard to
inclusion of pyrogenic source hydrocarbons within the data for
petroleum.
Application of Analytical Methods
We recommend the application of analytical methods with sufficient
sensitivity and resolution to identify the various sources of input,
e.g., high resolution glass capillary/gas chromatography/mass
spectrometry/computer systems analysis or high performance liquid
chromatography analysis coupled with mass spectrometry computer systems.
Nonhydrocarbon Compounds in Petroleum
Because many of the nonhydrocarbon compounds in petroleum are bio-
log~cally active, we recommend a more concerted effort to measure these
compounds in studies of inputs, fates, and effects
_
Metabolites and Photochemical Reaction Products
The concern about the biological activity of several metabol ites and
photochemical reaction products as indicated in the fates and effects
sections leads us to recommend research into methods for measuring
these compounds in samples from laboratory and field studies. These
methods would be used in studies of biogeochemical processes acting on
fossil fuel compounds and in studies of biological effects. We do not
advocate extensive analytical chemistry data-gathering exercises in
monitoring program measurements of metabolites and reaction products
until such time as research has clearly demonstrated the usefulness of
such an approach. Rather, we recommend the investigation of biochemical
or physiological parameters as potentially more useful for determining
where biologically active compounds have been or are present.
Remote Sensing
Sensors of various types have been tested from aircraft and show
promise for providing useful information in the measurement of the
areal extent and thickness of slicks. We recommend further testing in
conjunction with sea truth measurements to evaluate this concept
further.
Representative terms from entire chapter:
petroleum hydrocarbon
