ASTM D5412-93(2011)e1
(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
5.1 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.
5.2 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)4 and Test Method D4657. 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).
5.3 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 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 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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Designation:D5412 −93 (Reapproved 2011)
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.
ε NOTE—Editorial corrections were made throughout in March 2014.
1. Scope D3325 Practice for Preservation of Waterborne Oil Samples
D3326 Practice for Preparation of Samples for Identification
1.1 This test method covers a means for quantifying or
of Waterborne Oils
characterizing total polycyclic aromatic hydrocarbons (PAHs)
D3415 Practice for Identification of Waterborne Oils
by fluorescence spectroscopy (Fl) for waterborne samples.The
D3650 Test Method for Comparison of Waterborne Petro-
characterization step is for the purpose of finding an appropri-
leum Oils By Fluorescence Analysis
ate calibration standard with similiar emission and synchro-
D4489 Practices for Sampling of Waterborne Oils
nous fluorescence spectra.
D4657 TestMethodforPolynuclearAromaticHydrocarbons
1.2 This test method is applicable to PAHs resulting from 3
in Water (Withdrawn 2005)
petroleum oils, fuel oils, creosotes, or industrial organic
E131 Terminology Relating to Molecular Spectroscopy
mixtures.Samplescanbeweatheredorunweathered,buteither
E169 PracticesforGeneralTechniquesofUltraviolet-Visible
the same material or appropriately characterized site-specific
Quantitative Analysis
PAH or petroleum oil calibration standards with similar fluo-
E275 PracticeforDescribingandMeasuringPerformanceof
rescence spectra should be chosen. The degree of spectral
Ultraviolet and Visible Spectrophotometers
similarity needed will depend on the desired level of quantifi-
E388 Test Method for Wavelength Accuracy and Spectral
cation and on the required data quality objectives.
Bandwidth of Fluorescence Spectrometers
1.3 The values stated in SI units are to be regarded as E578 Test Method for Linearity of Fluorescence Measuring
Systems
standard. No other units of measurement are included in this
standard. E579 Test Method for Limit of Detection of Fluorescence of
Quinine Sulfate in Solution
1.4 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-
bility of regulatory limitations prior to use. method, refer to Terminology D1129, Terminology E131, and
Practice D3415.
2. Referenced Documents
4. Summary of Test Method
2.1 ASTM Standards:
D1129 Terminology Relating to Water 4.1 This test method consists of fluorescence analysis of
D1193 Specification for Reagent Water dilute solutions of PAHs or petroleum oils in appropriate
D2777 Practice for Determination of Precision and Bias of solvents (spectroquality solvents such as cyclohexane or other
Applicable Test Methods of Committee D19 on Water
appropriate solvents, for example, ethanol, depending on
polarity considerations of the sample). The test method re-
quiresaninitialqualitativecharacterizationstepinvolvingboth
This test method is under the jurisdiction of ASTM Committee D19 on Water
fluorescence emission and synchronous spectroscopy in order
andisthedirectresponsibilityofSubcommitteeD19.06onMethodsforAnalysisfor
to select appropriate calibration standards with similar fluores-
Organic Substances in Water.
Current edition approved May 1, 2011. Published June 2011. Originally cence spectra as compared to the samples (see Annex A1 for
approved in 1993. Last previous edition approved in 2005 as D5412 – 93 (2005).
the definition of spectral similarity). Intensities of peak
DOI: 10.1520/D5412-93R11E01.
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 The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D5412−93 (2011)
cence background to be used as solvent blanks. Solvent lots vary in the
maxima of suitable emission spectra are then used to develop
content of fluorescent impurities that may increase with storage time even
calibration curves for quantification.
for unopened bottles.
NOTE1—Althoughsomesectionsofthecharacterizationpartofthistest NOTE 4—This test method is normally used without a matrix spike due
to possible fluorescence interference by the spike. If a spike is to be used,
method are similar to Test Method D3650, there are also significant
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
quantification process. Compounds that could be used are dyes that
methods are different, one should not be substituted for the other.
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,
since the samples and standards are weighed, the nonfluores-
5.2 The unknown PAH mixture is first characterized by its
cent portion of the mixture would bias the quantification
fluorescence emission and synchronous scanning spectra.Then
although the characterization portion of the test method for
asuitablesite-specificcalibrationstandardwithsimilarspectral
PAHs given in Annex A1 would be unaffected.
characteristics is selected as described in Annex A1. This
calibration standard may also be well-characterized by other
7. Apparatus
independent methods such as gas chromatography (GC), GC-
7.1 Fluorescence Spectrometer—An instrument recording
mass spectrometry (GC-MS), or high performance liquid
chromatography (HPLC). Some suggested independent ana- in the spectral range of 250 nm to at least 600 nm for both
excitation and emission responses and capable of scanning
lytical methods are included in References (1-7) and Test
MethodD4657.Otheranalyticalmethodscanbesubstitutedby both monochromators simultaneously at a constant speed with
a constant wavelength offset between them for synchronous
an experienced analyst depending on the intended data quality
objectives. Peak maxima intensities of appropriate fluores- scanning. The instrument should meet the specifications in
Table 1. (Also known as spectrofluorometer or fluorescence
cence emission spectra are then used to set up suitable
spectrophotometer.) Consult manufacturer’s instrument manu-
calibration curves as a function of concentration. Further
als for specific operating instructions.
discussion of fluorescence techniques as applied to the char-
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,
there are differences in the purpose and intents of the two test methods.
5.3 For the purpose of the present test method polynuclear
The purpose of the characterization step of this test method is to find an
aromatic hydrocarbons are defined to include substituted poly-
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
synchronous spectra as well as emission spectra for this test method.
heterocycles giving similar fluorescence responses to PAHs of
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
a height of at least 45 mm. Stoppered cells may be preferred to
6. Interferences
prevent sample evaporation and contamination.
6.1 The fluorescence spectra may be distorted or quantifi-
cation may be affected if the sample is contaminated with an
appreciable amount of other fluorescent chemicals that are
TABLE 1 Specifications for Fluorescence Spectrometers
excited and which fluoresce in the same spectral regions with
Wavelength Reproducibility
relatively high fluorescence yields. Usually the fluorescence
Excitation monochromator ±2 nm or better
spectra would be distorted at levels greater than 1 to 2 % of
Emission monochromator ±2 nm or better
such impurities before the quantification would be seriously Gratings (Typical Values)
Excitation monochromator minimum of 600 lines/mm
affected.
blazed at 300 nm
Emission monochromator minimum of 600 lines/mm
NOTE 2—Caution: Storage of samples in improper containers (for
blazed at 300 nm or 500 nm
example, plastics other than TFE-fluorocarbon) may result in contamina-
Photomultiplier Tube
tion.
S-20 or S-5 response or equivalent
NOTE 3—Spectroquality solvents may not have low enough fluores-
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 a list of references at the end of Maximum bandpasses for both monochromators at least 10 nm
this standard.
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D5412−93 (2011)
7.4 Data Recording System—Preferably the instrument Fig. A2.6 to show that humic acid does not interfere with the
should be interfaced to a suitable computer system compatible test method even at high (µg/L) levels). This usually becomes
with the instrument and with suitable software for spectral data a problem only at PAH levels in the low µg/Lrange. Extraction
manipulation. Use of a strip chart or X-Y recorder with a methods (or separation by column chromatography) are listed
response time of less than 1 s for full-scale deflection is in Practice D3326.
acceptable. 9.4.1 An extraction method that proved satisfactory for the
collaborative test is as follows:
7.5 Micropipet, glass, 10 to 50-µL capacity.
9.4.1.1 Pour50.0mLofthesampleintoaseparatoryfunnel,
7.6 Weighing Pans,5to7-mmdiameter,18-mmthick,made
add 5.0 mL of cyclohexane and shake for 2 min. Vent the
of aluminum or equivalent. Check pans for contamination.
separatory funnel occasionally. Withdraw the aqueous layer
(keep this for a second extraction). Collect the cyclohexane
8. Reagents and Materials
extract in a 10-mL volumetric flask. Add 5.0 mL of cyclo-
8.1 Purity of Reagents—Use spectroquality grade reagents
hexane to the aqueous layer and perform a second extraction.
in all instances unless otherwise stated. Since the goal is to
Combine the two extracts and dilute to 10.0 mL with cyclo-
have as low a fluorescence blank as possible, and since
hexane.
different brands and lots of spectroquality solvent may vary,
9.4.1.2 For field use, it has proven satisfactory to use a
check reagents frequently.
reagent bottle instead of a separatory funnel. Pour 50.0 mL of
the sample in the bottle and add 5.0 mLof cyclohexane, shake
8.2 Purity of Water—References to water mean Type IV
for 2 min and collect most of the top layer with a Pasteur pipet.
water conforming to Specification D1193. Since fluorescent
It is important to collect most of the top layer to maximize
organic impurities in the water may introduce an interference,
percentrecovery(tilttheflasktoseetheseparationbetweenthe
check the purity of the water by analyzing a water blank using
two layers more easily). Add 5.0 mL of cyclohexane to the
the same instrumental conditions as for the solvent blank.
aqueous layer and perform a second extraction. Combine the
8.3 Acetone, spectroquality, (CH COCH ).
3 3
two cyclohexane extracts and dilute to 10.0 mL with cyclo-
8.4 Cyclohexane, spectroquality or HPLC grade. The fluo-
hexane.
rescencesolventblankmustbeaslowaspossibleandlessthan
9.4.1.3 See 12.6 to check extraction recoveries. Other ex-
5 % of the intensity of the maximum emission peak for the
tractionmethodscanbeusedatthediscretionoftheanalyst,by
lowest concentration of PAHs analyzed. Dispense cyclohexane
adding an appropriate solvent exchange step to cyclohexane
during the procedure from either a TFE-fluorocarbon or glass
and by checking for recoveries and interferences.As is always
wash bottle, but, for prolonged storage, store cyclohexane only
the case, the analyst shall demonstrate method performance
in glass.
when changing the method. At the mg/L level or above, the
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 Practices D4489.
followed by evaporation, weighing, and redissolving in cyclo-
hexane.
9. Sampling and Sample Preparation
9.4.1.4 At the mg/L level or above, the PAH mixture in
9.1 Collectarepresentativesample(seePracticesD4489for
water might not be totally in solution.
water samples).
9.5 Sample bottles
...
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