ASTM D5412-93(2005)
(Test Method)Standard Test Method for Quantification of Complex Polycyclic Aromatic Hydrocarbon Mixtures or Petroleum Oils in Water
Standard Test Method for Quantification of Complex Polycyclic Aromatic Hydrocarbon Mixtures or Petroleum Oils in Water
SIGNIFICANCE AND USE
This test method is useful for characterization and rapid quantification of PAH mixtures including petroleum oils, fuels, creosotes, and industrial organic mixtures, either waterborne or obtained from tanks.
The unknown PAH mixture is first characterized by its fluorescence emission and synchronous scanning spectra. Then a suitable site-specific calibration standard with similar spectral characteristics is selected as described in Annex A1. This calibration standard may also be well-characterized by other independent methods such as gas chromatography (GC), GC-mass spectrometry (GC-MS), or high performance liquid chromatography (HPLC). Some suggested independent analytical methods are included in References (1–7)3 and Test Method D 4657. Other analytical methods can be substituted by an experienced analyst depending on the intended data quality objectives. Peak maxima intensities of appropriate fluorescence emission spectra are then used to set up suitable calibration curves as a function of concentration. Further discussion of fluorescence techniques as applied to the characterization and quantification of PAHs and petroleum oils can be found in References (8–18).
For the purpose of the present test method polynuclear aromatic hydrocarbons are defined to include substituted polycyclic aromatic hydrocarbons with functional groups such as carboxyl acid, hydroxy, carbonyl and amino groups, and heterocycles giving similar fluorescence responses to PAHs of similar molecular weight ranges. If PAHs in the more classic definition, that is, unsubstituted PAHs, are desired, chemical reactions, extractions, or chromatographic procedures may be required to eliminate these other components. Fortunately, for the most commonly expected PAH mixtures, such substituted PAHs and heterocycles are not major components of the mixtures and do not cause serious errors.
SCOPE
1.1 This test method covers a means for quantifying or characterizing total polycyclic aromatic hydrocarbons (PAHs) by fluorescence spectroscopy (Fl) for waterborne samples. The characterization step is for the purpose of finding an appropriate calibration standard with similiar emission and synchronous fluorescence spectra.
1.2 This test method is applicable to PAHs resulting from petroleum oils, fuel oils, creosotes, or industrial organic mixtures. Samples can be weathered or unweathered, but either the same material or appropriately characterized site-specific PAH or petroleum oil calibration standards with similar fluorescence spectra should be chosen. The degree of spectral similarity needed will depend on the desired level of quantification and on the required data quality objectives.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D5412 – 93 (Reapproved 2005)
Standard Test Method for
Quantification of Complex Polycyclic Aromatic Hydrocarbon
Mixtures or Petroleum Oils in Water
This standard is issued under the fixed designation D5412; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D3650 Test Method for Comparison of Waterborne Petro-
leum Oils By Fluorescence Analysis
1.1 This test method covers a means for quantifying or
D4489 Practices for Sampling of Waterborne Oils
characterizing total polycyclic aromatic hydrocarbons (PAHs)
D4657 Test Method for Polynuclear Aromatic Hydrocar-
by fluorescence spectroscopy (Fl) for waterborne samples.The
bons in Water
characterization step is for the purpose of finding an appropri-
E131 Terminology Relating to Molecular Spectroscopy
ate calibration standard with similiar emission and synchro-
E169 Practices for General Techniques of Ultraviolet-
nous fluorescence spectra.
Visible Quantitative Analysis
1.2 This test method is applicable to PAHs resulting from
E275 Practice for Describing and Measuring Performance
petroleum oils, fuel oils, creosotes, or industrial organic
of Ultraviolet and Visible Spectrophotometers
mixtures.Samplescanbeweatheredorunweathered,buteither
E388 Test Method for Wavelength Accuracy of Spectral
the same material or appropriately characterized site-specific
Bandwidth of Fluorescence Spectrometers
PAH or petroleum oil calibration standards with similar fluo-
E578 Test Method for Linearity of Fluorescence Measuring
rescence spectra should be chosen. The degree of spectral
Systems
similarity needed will depend on the desired level of quantifi-
E579 TestMethodforLimitofDetectionofFluorescenceof
cation and on the required data quality objectives.
Quinine Sulfate in Solution
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3. Terminology
responsibility of the user of this standard to establish appro-
3.1 Definitions—For definitions of terms used in this test
priate safety and health practices and determine the applica-
method, refer to Terminology D1129, Terminology E131, and
bility of regulatory limitations prior to use.
Practice D3415.
2. Referenced Documents
4. Summary of Test Method
2.1 ASTM Standards:
4.1 This test method consists of fluorescence analysis of
D1129 Terminology Relating to Water
dilute solutions of PAHs or petroleum oils in appropriate
D1193 Specification for Reagent Water
solvents (spectroquality solvents such as cyclohexane or other
D2777 Practice for Determination of Precision and Bias of
appropriate solvents, for example, ethanol, depending on
Applicable Test Methods of Committee D19 on Water
polarity considerations of the sample). The test method re-
D3325 Practice for Preservation ofWaterborne Oil Samples
quiresaninitialqualitativecharacterizationstepinvolvingboth
D3326 Practice for Preparation of Samples for Identifica-
fluorescence emission and synchronous spectroscopy in order
tion of Waterborne Oils
to select appropriate calibration standards with similar fluores-
D3415 Practice for Identification of Waterborne Oils
cence spectra as compared to the samples (see Annex A1 for
the definition of spectral similarity). Intensities of peak
This test method is under the jurisdiction of ASTM Committee D19 on Water
maxima of suitable emission spectra are then used to develop
andisthedirectresponsibilityofSubcommitteeD19.06onMethodsforAnalysisfor
calibration curves for quantification.
Organic Substances in Water.
Current edition approved Dec. 1, 2005. Published January 2006. Originally
NOTE 1—Although some sections of the characterization part of this
approved in 1993. Last previous edition approved in 2000 as D5412 – 93 (2000).
test method are similar to Test Method D3650, there are also significant
DOI: 10.1520/D5412-93R05.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Withdrawn. The last approved version of this historical standard is referenced
the ASTM website. on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D5412 – 93 (2005)
differences (See Annex A1). Since the purpose and intent of the two test it must fluoresce in a spectral region where it will not interfere with the
methods are different, one should not be substituted for the other. quantification process. Compounds that could be used are dyes that
fluoresce at longer wavelengths than the emission of the PAH mixture.
5. Significance and Use
6.2 If the PAH mixture to be analyzed is a complex mixture
5.1 This test method is useful for characterization and rapid
such as an oil or creosote, it is assumed that a well-
quantification of PAH mixtures including petroleum oils, fuels,
characterized sample of the same or similar material is avail-
creosotes,andindustrialorganicmixtures,eitherwaterborneor
able as a calibration standard so the fluorescent fraction of the
obtained from tanks.
mixture can be ratioed against the total mixture. Otherwise,
5.2 The unknown PAH mixture is first characterized by its
since the samples and standards are weighed, the nonfluores-
fluorescence emission and synchronous scanning spectra.Then
cent portion of the mixture would bias the quantification
asuitablesite-specificcalibrationstandardwithsimilarspectral
although the characterization portion of the test method for
characteristics is selected as described in Annex A1. This
PAHs given in Annex A1 would be unaffected.
calibration standard may also be well-characterized by other
7. Apparatus
independent methods such as gas chromatography (GC), GC-
mass spectrometry (GC-MS), or high performance liquid
7.1 Fluorescence Spectrometer—An instrument recording
chromatography (HPLC). Some suggested independent ana-
in the spectral range of 250 nm to at least 600 nm for both
lytical methods are included in References (1–7) and Test
excitation and emission responses and capable of scanning
MethodD4657.Otheranalyticalmethodscanbesubstitutedby
both monochromators simultaneously at a constant speed with
an experienced analyst depending on the intended data quality
a constant wavelength offset between them for synchronous
objectives. Peak maxima intensities of appropriate fluores-
scanning. The instrument should meet the specifications in
cence emission spectra are then used to set up suitable
Table 1. (Also known as spectrofluorometer or fluorescence
calibration curves as a function of concentration. Further
spectrophotometer). Consult manufacturer’s instrument manu-
discussion of fluorescence techniques as applied to the char-
als for specific operating instructions.
acterization and quantification of PAHs and petroleum oils can
NOTE 5—Although the characterization section of this test method
be found in References (8–18).
(given in Annex A1) is similar to Test Method D3650 in many respects,
5.3 For the purpose of the present test method polynuclear
there are differences in the purpose and intents of the two test methods.
aromatic hydrocarbons are defined to include substituted poly-
The purpose of the characterization step of this test method is to find an
oil with similar fluorescence properties as the sample in order to serve as
cyclic aromatic hydrocarbons with functional groups such as
an appropriate calibration standard for quantification. Other differences
carboxyl acid, hydroxy, carbonyl and amino groups, and
between the test methods are instrumentation requirements and the use of
heterocycles giving similar fluorescence responses to PAHs of
synchronous spectra as well as emission spectra for this test method.
similar molecular weight ranges. If PAHs in the more classic
7.2 Excitation Source—A high-pressure xenon lamp (a
definition, that is, unsubstituted PAHs, are desired, chemical
150-W continuous xenon lamp or a 10-W pulsed xenon lamp
reactions, extractions, or chromatographic procedures may be
has been proven acceptable). Other continuum sources (either
required to eliminate these other components. Fortunately, for
continuousorpulsed)havingsufficientintensitythroughoutthe
the most commonly expected PAH mixtures, such substituted
ultraviolet and visible regions may also be used.
PAHs and heterocycles are not major components of the
7.3 Fluorescence Cells—Standard cells made from
mixtures and do not cause serious errors.
fluorescence-free fused silica with a path length of 10 mm and
6. Interferences
a height of at least 45 mm. Stoppered cells may be preferred to
prevent sample evaporation and contamination.
6.1 The fluorescence spectra may be distorted or quantifi-
7.4 Data Recording System—Preferably the instrument
cation may be affected if the sample is contaminated with an
should be interfaced to a suitable computer system compatible
appreciable amount of other fluorescent chemicals that are
with the instrument and with suitable software for spectral data
excited and which fluoresce in the same spectral regions with
manipulation. Use of a strip chart or X-Y recorder with a
relatively high fluorescence yields. Usually the fluorescence
response time of less than 1 s for full-scale deflection is
spectra would be distorted at levels greater than 1 to 2 % of
acceptable.
such impurities before the quantification would be seriously
affected.
TABLE 1 Specifications for Fluorescence Spectrometers
NOTE 2—Caution: Storage of samples in improper containers (for
Wavelength Reproducibility
example, plastics other than TFE-fluorocarbon) may result in contamina-
Excitation monochromator 62nmorbetter
Emission monochromator 62nmorbetter
tion.
Gratings (Typical Values)
NOTE 3—Spectroquality solvents may not have low enough fluores-
Excitation monochromator minimum of 600 lines/mm
cence background to be used as solvent blanks. Solvent lots vary in the
blazed at 300 nm
content of fluorescent impurities that may increase with storage time even
Emission monochromator minimum of 600 lines/mm
for unopened bottles.
blazed at 300 nm or 500 nm
NOTE 4—This test method is normally used without a matrix spike due
Photomultiplier Tube
S-20 or S-5 response or equivalent
to possible fluorescence interference by the spike. If a spike is to be used,
Spectral Resolutions
Excitation monochromator spectral bandpass of 2.5 nm or less
Emission monochromator spectral bandpass 2.5 nm or less
The boldface numbers in parentheses refer to the list of references at the end of Maximum bandpasses for both monochromators at least 10 nm
this standard.
D5412 – 93 (2005)
7.5 Micropipet, glass, 10 to 50-µL capacity. (keep this for a second extraction). Collect the cyclohexane
7.6 WeighingPans,5to7-mmdiameter,18-mmthick,made extract in a 10-mL volumetric flask. Add 5.0 mL of cyclohex-
of aluminum or equivalent. Check pans for contamination.
ane to the aqueous layer and perform a second extraction.
Combine the two extracts and dilute to 10.0 mL with cyclo-
8. Reagents and Materials
hexane.
8.1 Purity of Reagents—Use spectroquality grade reagents
9.4.1.2 For field use, it has proven satisfactory to use a
in all instances unless otherwise stated. Since the goal is to
reagent bottle instead of a separatory funnel. Pour 50.0 mL of
have as low a fluorescence blank as possible, and since
the sample in the bottle and add 5.0 mLof cyclohexane, shake
different brands and lots of spectroquality solvent may vary,
for 2 min and collect most of the top layer with a Pasteur pipet.
check reagents frequently.
It is important to collect most of the top layer to maximize
8.2 Purity of Water— References to water mean Type IV
percentrecovery(tilttheflasktoseetheseparationbetweenthe
water conforming to Specification D1193. Since fluorescent
two layers more easily). Add 5.0 mL of cyclohexane to the
organic impurities in the water may introduce an interference,
aqueous layer and perform a second extraction. Combine the
check the purity of the water by analyzing a water blank using
two cyclohexane extracts and dilute to 10.0 mL with cyclo-
the same instrumental conditions as for the solvent blank.
hexane.
8.3 Acetone, spectroquality, (CH COCH ).
3 3
8.4 Cyclohexane, spectroquality or HPLC grade. The fluo-
9.4.1.3 See 12.6 to check extraction recoveries. Other ex-
rescencesolventblankmustbeaslowaspossibleandlessthan
tractionmethodscanbeusedatthediscretionoftheanalyst,by
5 % of the intensity of the maximum emission peak for the
adding an appropriate solvent exchange step to cyclohexane
lowest concentration of PAHs analyzed. Dispense cyclohexane
and by checking for recoveries and interferences.As is always
during the procedure from either a TFE-fluorocarbon or glass
the case, the analyst shall demonstrate method performance
wash bottle, but, for prolonged storage, store cyclohexane only
when changing the method. At the mg/L level or above, the
in glass.
PAH mixture might not be totally in solution. If the PAH
8.5 Nitric Acid (1+1)—Carefully add one volume of con-
mixture is emulsified in water, is sparingly soluble in water, or
centrated HNO (sp gr 1.42) to one volume of water.
if the concentration of the unknown must be known more
8.6 TFE-Fluorocarbon Strips, 25 mm by 75 mm, 0.25-mm
accurately, it may be necessary to evaporate the solution to
thickness. Use TFE strips when sampling neat PAH films on
dryness or to extract the PAH mixture into a suitable solvent,
water as described in Practice D4489.
followed by evaporation, weighing, and redissolving in cyclo-
9. Sampling and Sample Preparation
hexane.
9.1 Collect a representative sample (see Practice D4489 for
9.4.1.4 At the mg/L level or above, the PAH mixture in
water samples).
water might not be totally in solution.
9.2 Preserve samples in containers as specified in Practice
9.5 Sample bottles must be made of glass, precleaned with
D3325. Do not cool samples below 5°C to avoid dewaxing of
dilute nitric acid (1 + 1) and sealed with plastic screw caps
oil or creosote samples.
having TFE-fluorocarbon liners. Solutions must be prepared in
9.3 Neat PAH samples (including surface films or layers on
precleaned volumetric flasks. Because many aromatics are
water) require only dilution in spectroquality cyclohexane.
subject to photodegradation, flasks must be low-actinic (am-
Prepare initial concentration for the unknown at 100 µg/mLfor
ber) or covered with aluminum foil. Volumetric flasks and
a check of the fluorescence signal. Further dilu
...
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