ASTM D7343-07
(Practice)Standard Practice for Optimization, Sample Handling, Calibration, and Validation of X-ray Fluorescence Spectrometry Methods for Elemental Analysis of Petroleum Products and Lubricants
Standard Practice for Optimization, Sample Handling, Calibration, and Validation of X-ray Fluorescence Spectrometry Methods for Elemental Analysis of Petroleum Products and Lubricants
SIGNIFICANCE AND USE
Accurate elemental analyses of samples of petroleum and petroleum products are required for the determination of chemical properties, which are in turn used to establish compliance with commercial and regulatory specifications.
SCOPE
1.1 This practice covers information relating to sampling, calibration and validation of X-ray fluorescence instruments for elemental analysis, including all kinds of wavelength dispersive (WDXRF) and energy dispersive (EDXRF) techniques. This practice includes sampling issues such as the selection of storage vessels, transportation, and sub-sampling. Treatment, assembly, and handling of technique-specific sample holders and cups are also included. Technique-specific requirements during analytical measurement and validation of measurement for the determination of trace elements in samples of petroleum and petroleum products are described. For sample mixing, refer to Practice D 5854. Petroleum products covered in this practice are considered to be a single phase and exhibit Newtonian characteristics at the point of sampling.
1.2 Applicable Test Methods—This practice is applicable to the XRF methods under the jurisdiction of ASTM Subcommittee D02.03 on Elemental Analysis: D 2622, D 4294, D 5059, D 6334, D 6443, D 6445, D 6481, D 7039, D 7212, and D 7220 and those under the jurisdiction of the Energy Institute’s Test Method Standardization Committee: IP 228, IP 336, IP 352, IP 407, IP 433, IP 447, IP 475, IP 489, IP 496, IP 497, IP 503, IP 531, and IP 532.
1.3 Applicable Fluids—This practice is applicable to petroleum and petroleum products with vapor pressures at sampling and storage temperatures less than or equal to 101 kPa (14.7 psi). Use Practice D 4057 or IP 475 to sample these materials. Refer to Practice D 5842 when sampling materials that also require Reid vapor pressure (RVP) determination.
1.4 Non-applicable Fluids—Petroleum products whose vapor pressure at sampling and sample storage conditions are above 101 kPa (14.7 psi) and liquefied gases (that is, LNG, LPG, etc.) are not covered by this practice.
1.5 Sampling Methods—The physical sampling and methods of sampling from a primary source are not covered by this guide. It is assumed that samples covered by this practice are a representative sample of the primary source liquid. Refer to Practice D 4057 or IP 475 for detailed sampling procedures.
1.6 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.7 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
Designation: D7343 − 07
Designation:558/07
Standard Practice for
Optimization, Sample Handling, Calibration, and Validation
of X-ray Fluorescence Spectrometry Methods for Elemental
Analysis of Petroleum Products and Lubricants
This standard is issued under the fixed designation D7343; 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 above 101 kPa (14.7 psi) and liquefied gases (that is, LNG,
LPG, etc.) are not covered by this practice.
1.1 This practice covers information relating to sampling,
calibration and validation of X-ray fluorescence instruments 1.5 Sampling Methods—The physical sampling and meth-
ods of sampling from a primary source are not covered by this
for elemental analysis, including all kinds of wavelength
dispersive (WDXRF) and energy dispersive (EDXRF) tech- guide. It is assumed that samples covered by this practice are
a representative sample of the primary source liquid. Refer to
niques. This practice includes sampling issues such as the
selection of storage vessels, transportation, and sub-sampling. Practice D4057 or IP 475 for detailed sampling procedures.
Treatment, assembly, and handling of technique-specific
1.6 The values stated in SI units are to be regarded as the
sample holders and cups are also included. Technique-specific
standard. The values given in parentheses are for information
requirements during analytical measurement and validation of
only.
measurement for the determination of trace elements in
1.7 This standard does not purport to address all of the
samples of petroleum and petroleum products are described.
safety concerns, if any, associated with its use. It is the
For sample mixing, refer to Practice D5854. Petroleum prod-
responsibility of the user of this standard to establish appro-
ucts covered in this practice are considered to be a single phase
priate safety and health practices and determine the applica-
and exhibit Newtonian characteristics at the point of sampling.
bility of regulatory limitations prior to use.
1.2 Applicable Test Methods—This practice is applicable to
2. Referenced Documents
the XRF methods under the jurisdiction ofASTM Subcommit-
tee D02.03 on Elemental Analysis: D2622, D4294, D5059,
2.1 ASTM Standards:
D6334,D6443,D6445,D6481,D7039,D7212,andD7220and
D2622 Test Method for Sulfur in Petroleum Products by
those under the jurisdiction of the Energy Institute’s Test
Wavelength Dispersive X-ray Fluorescence Spectrometry
Method Standardization Committee: IP228, IP336, IP352, IP
D4057 Practice for Manual Sampling of Petroleum and
407, IP 433, IP 447, IP 475, IP 489, IP 496, IP 497, IP 503, IP
Petroleum Products
531, and IP 532.
D4294 Test Method for Sulfur in Petroleum and Petroleum
Products by Energy Dispersive X-ray Fluorescence Spec-
1.3 Applicable Fluids—This practice is applicable to petro-
trometry
leum and petroleum products with vapor pressures at sampling
D5059 Test Methods for Lead in Gasoline by X-Ray Spec-
and storage temperatures less than or equal to 101 kPa (14.7
troscopy
psi). Use Practice D4057 or IP 475 to sample these materials.
D5842 Practice for Sampling and Handling of Fuels for
Refer to Practice D5842 when sampling materials that also
Volatility Measurement
require Reid vapor pressure (RVP) determination.
D5854 Practice for Mixing and Handling of Liquid Samples
1.4 Non-applicable Fluids—Petroleum products whose va-
of Petroleum and Petroleum Products
por pressure at sampling and sample storage conditions are
D6299 Practice for Applying Statistical Quality Assurance
and Control Charting Techniques to Evaluate Analytical
Measurement System Performance
This practice is under the jurisdiction of ASTM Committee D02 on Petroleum
Products and Lubricants and is the direct responsibility of Subcommittee D02.03 on
Elemental Analysis. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Aug. 1, 2007. Published September 2007. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
This practice was jointly prepared by ASTM International and the Energy Standards volume information, refer to the standard’s Document Summary page on
Institute. DOI: 10.1520/D7343-07. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7343 − 07
D6334 Test Method for Sulfur in Gasoline by Wavelength 3. Significance and Use
Dispersive X-Ray Fluorescence
3.1 Accurate elemental analyses of samples of petroleum
D6443 TestMethodforDeterminationofCalcium,Chlorine,
and petroleum products are required for the determination of
Copper, Magnesium, Phosphorus, Sulfur, and Zinc in
chemical properties, which are in turn used to establish
Unused Lubricating Oils and Additives by Wavelength
compliance with commercial and regulatory specifications.
Dispersive X-ray Fluorescence Spectrometry (Mathemati-
cal Correction Procedure)
4. Sample Handling
D6445 Test Method for Sulfur in Gasoline by Energy-
4.1 It is necessary to use precautions to minimize the
Dispersive X-ray Fluorescence Spectrometry (Withdrawn
possibility of contamination of trace elemental analysis
2009)
samples. Good laboratory practices in this area include:
D6481 Test Method for Determination of Phosphorus,
4.1.1 Samples received by the laboratory and required for
Sulfur, Calcium, and Zinc in Lubrication Oils by Energy
trace element analysis should be stored in a designated specific
Dispersive X-ray Fluorescence Spectroscopy
location for storage while awaiting analysis. This area, when-
D7039 Test Method for Sulfur in Gasoline and Diesel Fuel
ever possible, should not contain samples that could contami-
by MonochromaticWavelength Dispersive X-ray Fluores-
nate those requiring trace element analysis.
cence Spectrometry
4.1.2 All laboratory equipment used specifically for trace
D7212 Test Method for Low Sulfur in Automotive Fuels by
element analysis should be free of any source of contamina-
Energy-Dispersive X-ray Fluorescence Spectrometry Us-
tion. This may require that specific equipment be used only for
ing a Low-Background Proportional Counter
trace element analysis.
D7220 Test Method for Sulfur in Automotive, Heating, and
4.1.3 Analyses of blank samples are highly recommended.
Jet Fuels by Monochromatic Energy Dispersive X-ray
4.1.4 Sample preparation should be carried out in a clean
Fluorescence Spectrometry
area. This area should use surfaces that can be decontaminated
2.2 Energy Institute Standards: easily if a spillage occurs.
IP 228 Determination of lead content of gasoline – X-ray 4.1.5 Operators should wear clean, fresh, protective gloves
for sample preparation for trace element analysis. Tests should
spectrometric method
IP 336 Determination of sulfur content – Energy-dispersive be run to confirm that the gloves do not contain interfering
elements or elements of interest, since they may cause con-
X-ray fluorescence method
tamination. The development of clean area sample handling
IP 352 Determination of lead content of automotive
protocols is encouraged.
gasoline- Energy-dispersive X-ray fluorescence spectrom-
etry method
5. Sample Preparation
IP 407 Determination of barium, calcium, phosphorus,
sulfur and zinc by wavelength dispersive X-ray fluores-
5.1 Choice of Sample Carrier—XRF testing requires a
cence spectrometry
sample cell and a support film to hold the liquid sample in
IP 433 Determination of vanadium and nickel content –
place during analysis.The choice of the sample cell or cup, the
Wavelength dispersive X-ray fluorescence spectrometry
material in which it is held, and the type of support film used
IP 447 Determination of sulfur content - Wavelength disper-
can all influence the result.
sive X-ray fluorescence spectrometry
5.1.1 Sample Cell—The most common cell is a plastic cup,
IP 475 Methods of test for petroleum and its products ofwhichvariousdesignsareavailable.Thesedesignsallowfor
IP 489 Determination of low lead contents in gasolines - a variety of sample types to be measured either in a liquid or
powder form. It is important to check that the cup type used is
Wavelength dispersive X-ray fluorescence spectrometry
best suited for the compositions of samples to be analyzed.
IP496 Determination of sulfur content of automotive fuels –
Liquid sample cups usually have a seal that ensures the film is
Energy-dispersive X-ray fluorescence spectrometry
sealed to a level above that of the liquid in the cell and that the
IP497 Determination of sulfur content of automotive fuels -
film is taut with no wrinkles.
Wavelength dispersive X-ray fluorescence spectrometry
5.1.1.1 Within XRF spectrometers heat is produced, both
IP 503 Determination of chlorine and bromine content -
from the spectrometer components themselves and from the
Wavelength dispersive X-ray fluorescence spectrometry
interaction of X-rays with the sample. Petroleum products that
IP531 Determination of sulfur content of automotive fuels –
are not stable due to volatility should only be placed into
Low-background proportional counter energy-dispersive
vented sample cups or special sealed sample cups specifically
X-ray fluorescence spectrometry method
designed for volatile samples (see 8.3).
IP 532 Determination of the sulfur content of automotive
5.1.1.2 The cup size may be important. Depending on the
fuels – Polarized X-ray fluorescence spectrometry
film type used to support the liquid, different films will sag due
to the weight of sample and relax due to chemical interaction,
or heat, or both. To reduce this sagging effect, the smallest
The last approved version of this historical standard is referenced on
diameter sample cups should be used. Cups with diameters
www.astm.org.
well in excess of the area detected by the spectrometer are
Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR,
U.K., http://www.energyinst.org.uk. likely to increase errors due to sagging.
D7343 − 07
5.1.1.3 A number of petroleum products require heating to 5.1.3.5 It is necessary to verify that the sample does not
ensure homogenization prior to analysis or to enable transfer to dissolve the film or permeate through it. This is especially
the sample cell; examples include fuel oils and wax products. importantforgasoline-rangesamples,whenanewproductisto
The sample cup should be able to withstand the temperature be analyzed, or when a new kind of film is used for a sample
used in this process. In general, most plastic sample cells type. This verification can be done as follows:
should withstand temperatures up to 70°C. (1) Prepare a specimen cup and fill it with a typical
specimen.
5.1.2 Sample Cell Holder—Many manufacturers recom-
(2) Place the cell on a clean tissue and wait for 30 to 60
mend metal holders to hold sample cups while they are
min.
transferred into the XRF instrument. These holders can be
(3) Remove the cell, and inspect the tissue and the under-
made from aluminum, stainless steel, or other materials. It is
side of the film. Both should be dry.
important to recognize that these represent a potential spectral
(4) This test does not need to be repeated for every
contamination to the analysis either if the spectrometer is to
measurement when the analyst is certain that the film and the
determine an analyte that the holder is made from or if the
material to be analyzed are compatible.
material from the holder causes an interference with the
5.1.3.6 Use of Multiple Films—A common method of en-
analyte. Generally, this is not a problem for elements with
atomic number <30. For elements with atomic number >30 it suringthatspectrometersarenotcontaminatedbyleakingfilms
is to use a second film in the sample cup holder of the
is advisable to check the potential contamination from the
sample cup holder using a blank. instrument.Thisprovidesahighlevelofsecurity,andformany
systems is essential to avoiding costly down times if a sample
5.1.3 Sample Support Films—Many support films are avail-
should leak. The use of this second film will increase both the
able from both XRF instrument manufacturers and accessory
detection limits as well as the errors of measurement. Some
suppliers. It is important to examine the film types specified in
petroleum products can permeate through polymer films and,
any method being used. There are four criteria that should be
while this may not be a problem for any single analysis, the
considered when selecting a X-ray transmission sample sup-
buildup on a second protective film in some cases may cause
port film:
drift of analysis results. When trace level determinations are
(1) Thickness of film,
required and the optimum performance in both precision and
(2) Composition of film,
detection limit are required, the use of secondary films should
(3) Chemical and physical resistance of film to the liquid
be given careful consideration. If they are considered essential,
intend for analysis, and
they should be inspected or replaced for every analysis as part
(4) Element contaminants contained within the film.
of standard operating procedures.
5.1.3.1 Film thickness typically ranges from 2 to6µfor
most applications. Consideration should be given to the varia-
6. Sample Stability
tions in thickness from batch to batch of films. For thinner
films,therelativevarianceinfilmthicknessisoftenhigherthan
6.1 Sample stability during measurement is essential for
that of the thicker films, thus precision of analysis can be
accurate determinations. Pay particular care, since a sample
affected more if thinner films are used. One way to avoid this
can undergo physical change during analysis. An example of
is to recalibrate or adjust calibrations using monitors each time
this is catalyst residues in fuel oils that can settle during
a new batch of film is used.
measurement. When this type of situation can occur or is
5.1.3.2 Film types are composed of different polymer ma-
suspected, maintaining constant masses, heating times (in the
terials.Those containing oxygen or nitrogen will absorb lighter
case of fuel oils), mixing times, transfer time from preparation
elements more than those that do not. Examples of oxygen and
to measurement, and the determination of low atomic number
nitrogen containing polymers are polyester and polyamide. For elements first in a sequential analysis scheme should be used.
the determination of elements lighter than sulfur, these films
6.2 This procedure will not eliminate the particulate settling
should be avoided in favor of polymers containing only carbon
problem; filt
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