ASTM E2143-01(2006)e1
(Practice)Standard Practice for Using Field-Portable Fiber Optics Synchronous Fluorescence Spectrometer for Quantification of Field Samples for Aromatic and Polycyclic Aromatic Hydrocarbons
Standard Practice for Using Field-Portable Fiber Optics Synchronous Fluorescence Spectrometer for Quantification of Field Samples for Aromatic and Polycyclic Aromatic Hydrocarbons
SIGNIFICANCE AND USE
This technique is designed for on-site rapid screening and characterization of environmental soil and water samples resulting in significant cost savings for environmental remediation projects. Remote analysis can be made with optical fibers when situations warrant or demand use of this option.
Quantification of total AHs and PAHs in these environmental samples is accomplished by having a subset of the samples analyzed by an alternate technique and generating a site-specific calibration curve.
Synchronous fluorescence provides sufficient spectral information to characterize the AHs and PAHs present as benzene, toluene, ethylbenzene and xylene(s) (BTEX), the aromatic portion of total petroleum hydrocarbons (TPH), or large aromatic ring systems up to at least seven fused rings, such as might be found in creosote.
SCOPE
1.1 This test method covers a rapid method for the screening of environmental samples for aromatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs). The screening takes place in the field and provides immediate feedback on limits of contamination by substances containing AHs and PAHs. Quantification is obtained by the use of appropriately characterized, site-specific calibration curves. Remote sensing by use of optical fibers is useful for accessing difficult to reach areas or potentially dangerous materials or situations. When contamination of field personnel by dangerous materials is a possibility, use of remote sensors may minimize or eliminate the likelihood of such contamination taking place.
1.2 This test method is applicable to AHs and PAHs present in samples extracted from soils or in water. This test method is applicable for field screening or, with an appropriate calibration, quantification of total AHs and PAHs.
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.
Contact ASTM International (www.astm.org) for the latest information
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Designation:E2143 −01(Reapproved2006)
StandardTest Method for
Using Field-Portable Fiber Optics Synchronous
Fluorescence Spectrometer for Quantification of Field
Samples for Aromatic and Polycyclic Aromatic
Hydrocarbons
This standard is issued under the fixed designation E2143; 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.
´ NOTE—Changed the standard category in September 2006.
1. Scope D5412 Test Method for Quantification of Complex Polycy-
clicAromatic Hydrocarbon Mixtures or Petroleum Oils in
1.1 Thistestmethodcoversarapidmethodforthescreening
Water
of environmental samples for aromatic hydrocarbons (AHs)
E131 Terminology Relating to Molecular Spectroscopy
and polycyclic aromatic hydrocarbons (PAHs). The screening
E388 Test Method for Wavelength Accuracy and Spectral
takes place in the field and provides immediate feedback on
Bandwidth of Fluorescence Spectrometers
limits of contamination by substances containing AHs and
E578 Test Method for Linearity of Fluorescence Measuring
PAHs. Quantification is obtained by the use of appropriately
Systems
characterized, site-specific calibration curves. Remote sensing
E579 Test Method for Limit of Detection of Fluorescence of
by use of optical fibers is useful for accessing difficult to reach
Quinine Sulfate in Solution
areas or potentially dangerous materials or situations. When
contamination of field personnel by dangerous materials is a
3. Terminology
possibility, use of remote sensors may minimize or eliminate
the likelihood of such contamination taking place.
3.1 For definitions of terms used in this test method refer to
1.2 This test method is applicable toAHs and PAHs present Terminology D1129 and E131.
in samples extracted from soils or in water. This test method is
applicable for field screening or, with an appropriate 4. Summary of Test Method
calibration, quantification of total AHs and PAHs.
4.1 This test method consists of extracting the AHs and
1.3 This standard does not purport to address all of the
PAHs from soil samples or preparation of water samples
safety concerns, if any, associated with its use. It is the
followed by synchronous fluorescence analysis with a field-
responsibility of the user of this standard to establish appro-
portable instrument. The samples require serial dilutions of
priate safety and health practices and determine the applica-
samplestoestablishalinearresponse.Thesemeasurementsare
bility of regulatory limitations prior to use.
made using standard fluorescence cuvettes. While some opti-
mization of selectivity can be accomplished by varying the
2. Referenced Documents
wavelength difference between excitation and emission
2.1 ASTM Standards: monochromators, generally spectra generated from petroleum
D1129 Terminology Relating to Water
contaminants with a wavelength difference such as 6 or 18 nm
D4489 Practices for Sampling of Waterborne Oils
provide good results and no preliminary spectra are required
(see Test Method D5412).
4.2 Different soils have varying partition coefficients.
This test method is under the jurisdiction of ASTM Committee E13 on
Therefore, representative samples of a subset of the extracts or
Molecular Spectroscopy and Separation Science and is the direct responsibility of
Subcommittee E13.09 on Fiber Optics, Waveguides, and Optical Sensors. the water samples should be analyzed by gas chromatography
Current edition approved Sept. 18, 2006. Published September 2006. Originally
(GC) or other appropriate methods. The purpose is to establish
approved in 2001. Last previous edition approved in 2001 as E2143 – 01. DOI:
a site-specific calibration curve to be used for quantification of
10.1520/E2143-01R06E01.
2 total AHs and PAHs in the environmental samples of interest.
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
4.3 When desirable, determination of AHs and PAHs may
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. be made remotely using an optical fiber.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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E2143−01(Reapproved2006)
5. Significance and Use capable of scanning both monochromators at a constant speed
with a constant wavelength offset between them for synchro-
5.1 This technique is designed for on-site rapid screening
nous scanning. The bandwidth of the monochromators should
and characterization of environmental soil and water samples
be less than one half the wavelength offset between the
resulting in significant cost savings for environmental reme-
monochromators or smaller. The spectrometer should be ca-
diation projects. Remote analysis can be made with optical
pable of remote sensing via optic fiber. The detector should be
fibers when situations warrant or demand use of this option.
a photomultiplier tube or a device with similar sensitivity and
5.2 Quantification of total AHs and PAHs in these environ-
response time. Occasionally field work requires the spectrom-
mental samples is accomplished by having a subset of the
eter to be battery powered. The instrument should meet the
samples analyzed by an alternate technique and generating a
specifications in Table 1.
site-specific calibration curve.
7.2 Excitation Source—A pulsed (9.9 W) Xenon lamp or
5.3 Synchronous fluorescence provides sufficient spectral
other source having sufficient intensity throughout the ultra-
information to characterize the AHs and PAHs present as
violet and visible regions can be used.
benzene, toluene, ethylbenzene and xylene(s) (BTEX), the
7.3 Cuvette Sample Holder—Sample holders should be
aromatic portion of total petroleum hydrocarbons (TPH), or
fabricated to hold commercially available, fluorescence-free,
large aromatic ring systems up to at least seven fused rings,
fused silica cuvettes.
such as might be found in creosote.
7.4 Optical Fiber Holder—A stage that allows correct
positioning of the optical fiber with respect to the emission and
6. Interferences
excitation monochromators. The device may also be used to
6.1 Thesynchronousfluorescencespectrumcanbedistorted
optically match each fiber and the respective monochromator.
or quantification may be affected if there is a contaminant
present that produces a synchronous peak in the same vicinity 7.5 Computer System—The instrument should be interfaced
to a computer system that is compatible with the instrument
as the material of interest. Often spectroquality solvents
contain impurities that produce background signals. Solvent and has suitable software for spectral data manipulation.
blanks should be used to verify a low fluorescence background
7.6 Cuvette—A standard 12 by 12 by 31 mm fluorescence-
so the background can be subtracted from the sample’s
free fused silica cuvette. Four sides of the cuvette should be
spectrum.
polished.
6.2 There are naturally occurring compounds that fluoresce,
7.7 Optical Fiber—Fused silica fiber (preferably a high
which may interfere with the detection of petroleum
hydroxide) is required for transmission of the ultraviolet
compounds, present in the sample. Humic acid from leaf mold
wavelengths required for accurate spectroscopic analysis. In
is an example of such a compound. Its strongest emission
general, this material has good thermal characteristics, can be
occurs in the near ultraviolet range.
obtained with low fluorescence background, and is readily
6.3 Absorption of the exciting light by the sample itself available commercially.
(self-filtering effect) produces erroneous results. Analysis of
7.8 Glassware—A 10 mL and 2 mL disposable pipet, both
serial dilutions of the sample detects this effect and ensures an
marked with 0.1 mL gradations. A glass disposable test tube,
accurate analysis is made. Once linearity is established, then
capable of holding volumes of liquid greater than 15 mL. The
integration of the spectrum produces accurate results.
testtubecapsshouldbepolytetrafluoroethylenelinedtoreduce
potential contamination.
6.4 Certain solvents used for extraction of the soil samples
could quench or absorb the fluorescence and raise the limit of
7.9 Scale—Aportable scale capable of measuring2gofsoil
detection. Care should be taken to avoid halogenated solvents
to the nearest 0.1 g.
or solvents containing other quenchers. The user of this test
7.10 Centrifuge—A portable centrifuge, capable of holding
method should bear this in mind when selecting an appropriate
the test tubes described in 7.8.
solvent.
NOTE 1—Storage of samples in improper containers, such as plastics
other than polytetrafluoroethylene (or TFE-fluorocarbon), may result in
TABLE 1 Desirable Performance Standards of a Field Portable
contamination.
Fluorescence Spectrometer
NOTE2—Thistestmethodisnormallyusedwithoutaninternalstandard
Characteristic Desirable Range Typical
due to possible interference by the internal standard.
Monochromator
6.5 Certain optical fibers may generate a fluorescence back-
Bandwidth 1–5 nm 3 nm
Wavelength accuracy ± 0.5–2 nm ± 1.0 nm
ground. These should be avoided whenever possible. If they
Reproducibility ± 0.1– 1 % ± 0.2 %
must be used, a background spectrum should be generated and
subtracted from any samples measured.
Interface
Data collection computerized laptop PC
Instrument control control and data
7. Apparatus
Source
7.1 Fluorescence Spectrometer—An instrument recording
Broad band 200–1000 nm Xenon lamp
in the spectral range of at least 250 to 650 nm is required for
Low-power consumption 5–75 W 10 W
both excitation and emission spectrum measurements and
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E2143−01(Reapproved2006)
7.11 Shaker—A portable shaker, capable of mixing the soil blank. Other options for calibration may include the use of
and solvent in the test tubes described in 7.8. plastic standards, sealed solutions of anthracene or other
commercially available standards.
7.12 Filter Apparatus—A syringe with disposable 100-µm
glass detachable filters.
11. Procedure
8. Reagents and Materials
11.1 Water Samples—Analyze the water sample over an
appropriate wavelength region using a synchronous scan with
8.1 Purity of Reagents—Spectroquality grade reagents
should be used in all instances unless otherwise stated. a wavelength offset between the monochromators of 18 nm.
Other wavelength offset between the monochromators values
8.2 Purity of Water—ASTM Grade 3 or Grade 4 water
may be used when appropriate.
should be used.
11.1.1 Subtract the spectrum of a distilled water blank from
8.3 Solvents—High purity solvents should be used. Solvents
the spectrum of the water sample.
should be of sufficient purity so as to not generate a back-
11.1.2 Integrate the area under the spectrum of the sample
ground fluorescence spectrum when analyzed as a blank.
over the appropriate wavelength region to determine the
Solvents such as hexane, cyclohexane and methylcyclohexane,
relative value.
ethanol,methanol,etc.mustnotabsorbinthespectralregionof
11.1.3 Determine if the sample is in the linear range. The
interest.
determination of linear range is done by performing a 1:1
dilution. Subtract the spectrum of a distilled water blank from
9. Sampling and Sample Preparation
the spectrum of the 1:1 dilution. Integrate the area under the
9.1 Water Samples—Collect water samples in accordance
spectrum of the sample over the appropriate wavelength
with Practice D4489, as applicable.
region. If the integrated value is half of the original value, then
9.1.1 If the water samples contain visible particles, then the
the sample is in the linear range; otherwise, perform subse-
samples may be either centrifuged or filtered depending on the
quent dilutions until the linear range is established.
nature of the particles. Large, dense particles can usually be
11.2 SoilSamples—Analyze the soil sample extract over the
centrifuged to the bottom of the sample container, while finer
appropriate wavelength region using a synchronous scan with
particles must be filtered. The water samples should be
a wavelength offset between the monochromators of 18 nm.
centrifuged in the containers in which they are sampled, in
11.2.1 Subtract the spectrum of a solvent blank from the
order to avoid volatilization of the organic hydrocarbons. The
spectrum of the soil sample.
water samples should be filtered into the cuvette for analysis.
11.2.2 Integrate the area under the spectrum of the sample
9.1.2 Add approximately 2.5 mL of the water sample into
over the appropriate wavelength region to determine the
the cuvette using a disposable pipet and place the cuvette into
relative value.
the instrument sample holder.The sample is ready for analysis.
11.2.3 Determine whether the sample is in the linear range
9.2 SoilSamples—Collect the sample using accepted proce-
according to 11.1.3.
dures already established by ASTM Committee D18.
9.2.1 Obtain a representative 2-g soil sample from the 11.3 Quantitative Analysis—After several soil or water
samples have been analyzed by the instrument, pick several
samplecontainer.Thesampleshouldbeweigheddirectlyinthe
samples representing a range of concentrations (at least three:
test tube.
high, medium, and low) and include solvent blanks and
9.2.2 Add 10 mL of the appropriate solvent to the soil
samples of known composition. These samples should be
sample in the test tube using a disposable pipet.
analyzed by the laboratory using the appropriate method, such
9.2.3 Shake the sample until greater than 90 % of the
as total petroleum hydrocarbons using the Environmental
sampleissuspendedinthesolvent.Followthisshakingprocess
ProtectionAgency (EPA), gasoline range organics (GRO), and
bycentrifugingthesampleinordertoseparatethesolventfrom
diesel range organics (DRO) methods or total polycyclic
the soil.
aromatic hydrocarbons. Many of the approved EPA methods
9.2.4 Pour the extract into a second test tube. At this point
also include aliphatic hydrocarbons in the analysis. If the
some particles may be present in the extract, thus filtration will
relative proportion of aromatic hydrocarbons to aliphatic
be required to remove them.
hydrocarbons remains constant then the correlation graphs
9.2.5 If the quality check in 13.6 indicates a need for
described in 11.3.1 can be developed.
additional extraction, then the additional extraction will be
performed at this time. 11.3.1 For each sample analyzed by the laboratory, plot the
laboratory concentration versus the instrument concentration
10. Preparation of Apparatus
on
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