Standard Test Methods for Lead in Gasoline by X-Ray Spectroscopy

SCOPE
1.1 These test methods cover the determination of the total lead content of a gasoline within the following concentration ranges:
Test Methods A and B cover the range of 0.10 to 5.0 g Pb/US gal. Test Method C covers the range of 0.010 to 0.50 g Pb/US gal.
1.1.1 These test methods compensate for normal variation in gasoline composition and are independent of lead alkyl type.
1.2 Test Method A (formerly in Test Method D2599)-Sections 5-9. Test Method B (formerly in Test Method D2599)-Sections 10-14. Test Method C (formerly in Test Method D3229)-Sections 15-19.
1.3 The values stated in SI are to be regarded as the standard. For reporting purposes the values stated in grams per U.S. gallon are the preferred units in the United States. Note that in other countries, other units can be preferred.
1.4 This standard does not purport to address all of the safety problems, 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. For specific hazard statements, see 5.1, 6.4, 6.6.1, 11.1, 11.2, and 16.2.

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ASTM D5059-98 - Standard Test Methods for Lead in Gasoline by X-Ray Spectroscopy
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 5059 – 98
Designation: 228/79
Standard Test Methods for
Lead in Gasoline by X-Ray Spectroscopy
This standard is issued under the fixed designation D 5059; 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 (e) indicates an editorial change since the last revision or reapproval.
These test methods have been approved by the sponsoring committees and accepted by the cooperating organizations in accordance with
established procedures.
1. Scope D 3229 Test Method for Low Levels of Lead in Gasoline by
Wavelength Dispersive X-Ray Spectrometry
1.1 These test methods cover the determination of the total
D 3341 Test Method for Lead in Gasoline-Iodine
lead content of a gasoline within the following concentration
Monochloride Method
ranges:
D 4057 Practice for Manual Sampling of Petroleum and
0.010 to 5.0 g Pb/US gal
Petroleum Products
0.012 to 6.0 g Pb/UK gal
0.0026 to 1.32 g Pb/L
3. Summary of Test Method
Test Methods A and B cover the range of 0.10 to 5.0 g Pb/US
3.1 There are three alternative test methods, as follows.
gal. Test Method C covers the range of 0.010 to 0.50 g Pb/US
3.1.1 Test Method A (Bismuth Internal Standard Method
gal.
High Concentration)—One volume of sample is mixed thor-
1.1.1 These test methods compensate for normal variation
oughly with an equal volume of bismuth internal standard
in gasoline composition and are independent of lead alkyl type.
solution. The mixture is placed in the X-ray beam and the
1.2 Test Method A (formerly in Test Method D 2599)—
intensities of the lead L-a radiation at 1.175 Å and the bismuth
Sections 5-9.
L-a radiation at 1.144 Å are determined. The lead concentra-
Test Method B (formerly in Test Method D 2599)—Sections
tion of the sample is measured by comparing the ratio of gross
10-14.
counting rate at 1.175 Å with the gross counting rate at 1.144
Test Method C (formerly in Test Method D 3229)—Sections
Å to a previous prepared calibration curve of concentration
15-19.
versus the same ratios.
1.3 The values stated in SI are to be regarded as the
3.1.2 Test Method B (Scattered Tungsten Radiation
standard. For reporting purposes the values stated in grams per
Method)—The ratio of the net X-ray intensity of the lead L-a
U.S. gallon are the preferred units in the United States. Note
radiation to the net intensity of the incoherently scattered
that in other countries, other units can be preferred.
tungsten L-a radiation is obtained on a portion of the sample.
1.4 This standard does not purport to address all of the
The lead content is determined by multiplying this ratio by a
safety concerns, if any, associated with its use. It is the
calibration factor obtained with a standard lead solution of
responsibility of the user of this standard to establish appro-
known concentration.
priate safety and health practices and determine the applica-
3.1.3 Test Method C (Bismuth Internal Standard Method,
bility of regulatory limitations prior to use. For specific hazard
Low Concentration)—Twenty millilitres of sample is mixed
statements, see 5.1, 6.4, 6.7.1, 11.1, 12.2, and 18.2.
thoroughly with two milliliters of bismuth internal standard
2. Referenced Documents solution. The mixture is placed in the X-ray beam of a
spectrometer and the intensities of the lead L-a radiation at
2.1 ASTM Standards: 1
1.175 Å, the bismuth L-a radiation at 1.144 Å, and a back-
D 2599 Test Method for Lead in Gasoline by X-Ray Spec-
2 ground at 1.194 Å are determined. A blank, made with
trometry
iso-octane and bismuth internal standard, is run using the same
procedure. The lead concentration is measured by determining
These test methods are under the jurisdiction of Committee D-2 on Petroleum the ratio of the net counting rate at 1.175 Å to the gross
Products and Lubricants and are the direct responsibility of Subcommittee D02.03
counting rate at 1.144 Å for the sample, subtracting the
on Elemental Analysis. Originally published as D 2599 – 67T and D 3229 – 73.
Current edition approved Apr. 10, 1998. Published October 1998. Originally
published as D 5059 – 90. Last previous edition D 5059– 92.
2 3
Discontinued—See 1992 Annual Book of ASTM Standards, Vol 05.02. Annual Book of ASTM Standards, Vol 05.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D5059–98
almost indefinitely. The 2-ethylhexanoic acid stabilizes isooctane, toluene,
comparable ratio found for the blank, and comparing to a
and benzene solutions of the bismuth 2-ethylhexoate which are otherwise
previously prepared calibration curve of concentration versus
stable for only a day or two. Normal octanoic acid does not stabilize
the same ratios.
solution.
4. Significance and Use
6.4 Iso-octane:
4.1 These test methods determine the concentration of lead
NOTE 5—Warning: Extremely flammable.
(from alkyl addition) in gasoline. These alkyl additives im-
6.5 Solvent, capable of dissolving the bismuth internal
prove the antiknock properties.
standard. Mixed xylenes and dodecane have been found
4.2 Test Method C is used to ensure compliance of trace
suitable to use.
lead as required by federal regulations for lead-free gasoline
6.6 Hydrocarbon-Soluble Lead—Either tetraethyllead
(40 CFR part 80).
(TEL) or a lead-containing compound (for example, lead
naphthenate) with a certifiable lead concentration.
TEST METHOD A (BISMUTH INTERNAL
STANDARD) 6.7 Lead (Pb) Standard Solution—Dissolve tetraethyllead
(TEL) (Note 6), lead naphthenate (see Note 7), or other suitable
5. Apparatus
lead containing compound in iso-octane (see Note 5), toluene,
5.1 X-ray Spectrometer, capable of measuring radiations or a mixture of these two solvents. This standard solution shall
mentioned in 3.1.1 and of being operated under the following contain an accurately known lead concentration of approxi-
instrumental conditions or other giving equivalent results: mately the following magnitude:
Tube Voltage 50 kV 5 g Pb/US gal at 15.5°C (60°F),
Tube Current 20 to 45 mA
6 g Pb/UK gal at 15.5°C (60°F), or
Analyzing Crystal Lithium Fluoride (LiF)
1.3 g Pb/L at 15.5°C
Optical Path Air, Helium ( Note 1)
6.7.1 Keep the standard solution refrigerated when not in
Detector Proportional or Scintillation
use.
NOTE 1—Warning: Compressed gas under pressure.
NOTE 2—The X-ray spectrometer and manner of use should comply
NOTE 6—Warning: TEL is toxic by ingestion.
with the regulations governing the use of ionizing radiation or recommen-
NOTE 7—A lead naphthenate solution of same lead concentration has
dations of the International Commission of Radiological Protection, or
also proven satisfactory as a calibration material. Concentrated TEL is not
both.
used to make up standard solutions. The concentrated solution is too
acutely toxic to be handled safely under normal laboratory conditions.
6. Reagents and Materials
NOTE 8—When this lead standard solution is prepared with TEL, the
6.1 Purity of Reagents—Reagent grade chemicals shall be lead concentration can be determined with Test Method D 3341.
used in all tests. Unless otherwise indicated, it is intended that
6.8 Toluene
all reagents conform to the specifications of the Committee on
NOTE 9—Warning: Flammable. Vapor harmful.
Analytical Reagents of the American Chemical Society where
such specifications are available. Other grades may be used,
7. Calibration
provided it is first ascertained that the reagent is of sufficiently
7.1 Make dilutions of the lead (Pb) standard solution to give
high purity to permit its use without lessening the accuracy of
0.10, 1.00, 2.00, 3.00, 4.00 and 5.00 g Pb/US gal at 15.5°C
the determinations.
(60°F) or 0.10, 1.00, 2.50, 3.50, 5.00, and 6.00 g Pb/UK gal at
6.2 Hydrocarbon-Soluble Bismuth
15.5°C (60°F) or 0.025, 0.264, 0.529, 0.793, 1.057, 1.322 g
NOTE 3—Bismuth 2-Ethylhexoate has been found suitable to use. Other
Pb/L at 15°C in toluene, iso-octane, or a mixture of these
bismuth containing materials that are hydrocarbon-soluble may also be
solvents.
used when they are certified to conform to 6.1.
7.2 Allow the lead standards and bismuth internal standard
6.3 Bismuth Internal Standard Solution—Dilute the
solutions to come to room temperature.
hydrocarbon-soluble bismuth with a suitable solvent. If bis-
7.3 Pipet accurately 10 mL of each standard into separate
muth 2-ethylhexoate is used, add 2-ethylhexanoic acid as a
glass-stoppered bottles or flasks and add an equal, accurately
stabilizer (see Note 4) to obtain a solution containing the
measured volume of the bismuth internal standard solution to
following:
each one. Mix thoroughly.
3.00 g Bi/US gal at 15.5°C (60°F), or
7.4 Place one of these solutions in the sample cell using
3.60 g Bi/UK gal at 15.5°C (60°F), or
techniques consistent with good operating practice for the
0.793 g Bi/L at 15°C.
spectrometer employed. Place the cell in the instrument, allow
the spectrometer atmosphere to reach equilibrium (if appropri-
NOTE 4—Some stability difficulties have been experienced with bis-
ate), and determine the counting rate at the lead L-a line
muth 2-ethylhexoate internal standard solution. If the standard is blended
to contain 5 % 2-ethylhexanoic acid, the standard has been found to last (1.175 Å) and at the bismuth L-a line (1.144 Å).
NOTE 10—When possible, collect at least 100 000 counts at each line.
When sensitivity or concentration, or both, makes it impractical to collect
“Reagent Chemicals, American Chemical Society Specifications,” Am. Chemi-
this many counts, the technique that allows the greatest statistical
cal Soc., Washington, DC. For suggestions on the testing of reagents listed by the
precision in the time allotted for each analysis should be used. Sample
American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH
stability should also be considered in determining counting rate. Variation
Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National
Formulary. U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD. in counting rates should be observed and if the counting rate tends to go
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D5059–98
in one direction only, the sample is probably decomposing. If this occurs,
TEST METHOD B (SCATTERED TUNGSTEN
shorter counting times should be used consistent with acceptable statistical
RADIATION)
precision.
11. Apparatus
7.5 Determine the ratio, R, for each standard as follows:
11.1 X-ray Spectrometer, capable of measuring radiations
R 5 A/B (1)
mentioned in 3.1.2 and of being operated under the following
where:
instrumental conditions or others giving equivalent results:
A = counting rate at 1.175 Å, and
Tube Voltage 50 kV
B = counting rate at 1.144 Å.
Tube Current 20 to 45 mA
Tube Target Tungsten
7.6 Plot a calibration curve relating R to the grams of lead
Analyzing Crystal Lithium Fluoride (LiF)
per gallon.
Optical Path Air, Helium (Warning—See Note 1)
Collimation Fine
NOTE 11—Many modern X-ray spectrometer instruments will plot and
Pulse Height Analyzer Threshold discrimination set as low as pos-
store the calibration curve, slope, and related information in the instrument
sible consistent with the removal of noise with
computer system, as an alternative to hand-plotting this information. respect to the detector employed.
Detector Proportional or Scintillation
Counting Technique Fixed Time
8. Quality Control Checks
11.1.1 Two restrictions are imposed upon the period of the
8.1 Confirm the calibration of the instrument each day it is
fixed time: namely, that it is 30 s or greater, and that it is such
in use by analyzing a quality control (QC) sample containing a
that the count on the position of minimum intensity (back-
quantifiable concentration of lead, that is, independent of the
ground at A = 1.211 Å) should exceed 200 000.
calibration curve. It is advisable to analyze additional QC
samples as appropriate, such as at the beginning and end of a
NOTE 13—The X-ray spectrometer and manner of use should comply
batch of samples or after a fixed number of samples, to ensure with the regulations governing the use of ionizing radiation or recommen-
dations of the International Commission of Radiological Protection, or
the quality of the results. Analysis of result(s) from these QC
both.
samples can be carried out using control chart techniques.
When the QC sample result causes the laboratory to be in an
12. Reagents and Materials
out-of-control situation, such as exceeding the laboratory’s
12.1 Iso-octane (Warning—See Note 4).
control limits, instrument re-calibration may be required. An
12.2 Lead (Pb) Standard Solution—Dissolve tetraethyllead
ample supply of QC sample material shall be available for the
(TEL) (Note 6), lead naphthenate (see Note 7), or other suitable
intended period of use, and shall be homogeneous and stable
lead containing compound in iso-octane (see Note 5), toluene,
under the anticipated storage conditions. If possible, the QC
or a mixture of these two solvents. When TEL is used, refer to
sample shall be representative of samples typically analyzed
Note 8. This standard solution shall contain an accurately
and the average and control limits of the QC sample shall be
known lead concentration of approximately the following
determined prior to monitoring the measurement process. The
magnitude:
QC sample precision shall be checked against the ASTM
5 g Pb/US gal at 15.5°C (60°F)
method precision to ensure data quality.
6 g Pb/UK gal at 15.5°C (60°F)
1.3 g Pb/L at 15.5°C
9. Procedure
12.2.1 Keep the standard solution refrigerated when not in
9.1 Obtain sample in accordance with Practice D 4057.
use.
9.2 Prepare the samples to be analyzed as described in 7.3
and 7.4 for the standard lead solutions and determine the ratio,
13. Calibration
R, as described in 7.5.
13.1 Place the standard lead solution in the sample cell
9.3 Determine the lead content of the samples by relating
using techniques consistent with good operating practice for
the R values obtained to the previously determined calibration
the spectrometer employed. Insert the cell in the X-ray beam
curve.
using the instrumental conditions described in Section 10 and
allow the spectrometer atmosphere to reach equilibrium (when
10. Report
appropriate). Take one intensity reading at e
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