ASTM D3341-00
(Test Method)Standard Test Method for Lead in Gasoline-Iodine Monochloride Method
Standard Test Method for Lead in Gasoline-Iodine Monochloride Method
SCOPE
1.1 This test method determines total lead in gasolines containing lead alkyls at concentrations between 0.026 and 1.3 g Pb/L, and 0.12 and 6.0 g Pb/UK gal, 0.1 and 5.0 g Pb/US gal.
1.2 The preferred units are grams per litre although both gram per US gallon and grams per UK gallon are acceptable due to their widespread use in the industry.
1.3 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 Sections 6 and 8.
General Information
Relations
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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
American National Standard
Designation:D3341–00
Standard Test Method for
Lead in Gasoline—Iodine Monochloride Method
This standard is issued under the fixed designation D 3341; 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.
1. Scope to pH 5 using sodium acetate-acetic acid buffer. The lead
content of the buffered solution is determined by titration with
1.1 This test method determines total lead in gasolines
EDTA using xylenol orange as indicator.
containing lead alkyls at concentrations between 0.026 and 1.3
gPb/L,and0.12and6.0gPb/UKgal,0.1and5.0gPb/USgal.
4. Significance and Use
1.2 The preferred units are grams per litre although both
4.1 This test method determines the concentration of lead
gram per US gallon and grams per UK gallon are acceptable
alkyl additives in gasoline. These additives improve the anti-
due to their widespread use in the industry.
knock properties.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
5. Apparatus
responsibility of the user of this standard to establish appro-
5.1 Separatory Funnel, borosilicate glass, capacity 250 mL,
priate safety and health practices and determine the applica-
glass-stoppered with preferably an iodine flask type of neck.
bility of regulatory limitations prior to use. For specific hazard
5.2 Erlenmeyer Flask, borosilicate glass, capacity 500 mL.
statements, see Sections 6 and 8.
6. Reagents and Materials
2. Referenced Documents
6.1 Purity of Reagents—Reagent grade chemicals shall be
2.1 ASTM Standards:
2 used in all tests. Unless otherwise indicated, it is intended that
D 1193 Specification for Reagent Water
all reagents shall conform to the specifications of the Commit-
D 4057 Practice for Manual Sampling of Petroleum and
3 tee onAnalytical Reagents of theAmerican Chemical Society,
Petroleum Products
where such specifications are available. Other grades may be
D 6299 Practice for Applying Statistical Quality Assurance
used, provided it is first ascertained that the reagent is of
Techniques to Evaluate Analytical Measurement System
sufficiently high purity to permit its use without lessening the
Performance
accuracy of the determination.
6.2 Purity of Water—Unless otherwise indicated, references
3. Summary of Test Method
to water shall be understood to mean reagent water as defined
3.1 A known volume of the sample is diluted with heavy
by Type III or Type IV of Specification D 1193.
distillate and shaken with aqueous iodine monochloride re-
6.3 Ammonia Solution (1 + 1)—Mix 1 volume of concen-
agent. Any tetraalkyl lead compounds present react with the
trated ammonia solution (rel dens 0.90) with 1 volume of
iodine monochloride and are extracted into the aqueous phase
distilled water.
as the dialkyl lead compounds. The aqueous extract is sepa-
6.4 Bromthymol Blue Indicator Solution—Dissolve0.1gof
rated from the gasoline and evaporated to low bulk to decom-
bromthymol blue in 50 mL of ethanol and dilute to 100 mL
pose free iodine monochloride. Any organic matter present is
with distilled water.
removed by oxidation with nitric acid, which also serves to
6.5 EDTA, Standard Solution (0.005 M)—Dissolve approxi-
convert the dialkyl lead compounds into inorganic lead com-
mately 3.75 g of diaminoethanetetra-acetic acid, disodium salt,
pounds.The residue is dissolved in distilled water and buffered
in 2-Lof distilled water. Determine the molarity of the solution
by standardization with lead nitrate solution as follows:
This test method 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. Reagent Chemicals, American Chemical Society Specifications, American
Current edition approved Nov. 10, 2000. Published November 2000. Originally Chemical Society, Washington, DC. For suggestions on the testing of reagents not
published as D 3341 – 74. Last previous edition D 3341 – 91 (Reapproved 1995). listed by the American Chemical Society, see Analar Standards for Laboratory
Annual Book of ASTM Standards, Vol 11.01. Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Annual Book of ASTM Standards, Vol 05.02. and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
Annual Book of ASTM Standards, Vol 05.03. MD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D3341
6.5.1 Using a pipet, transfer 25.0 mL of the standard lead 8. Procedure
nitrate solution to a 250-mL Erlenmeyer flask. Dilute to about
8.1 Transfer 50 mL of the iodine monochloride reagent and
75 mL with distilled water and add several drops of bromthy-
25 mL of heavy distillate to the 250-mL separatory funnel.
mol blue indicator solution. Titrate with 1 + 1 ammonia solu-
Measure the temperature of the sample to the nearest 0.5°C
tionuntilthecolorofthesolutionjustchangestoblue;thenadd
(1°F) (Note 1). Using a pipet (Warning—Never suck leaded
10mLofsodiumacetate-aceticacidbuffersolutionand5drops
gasoline or corrosive liquids into a pipet by the mouth.),
ofxylenolorangeindicatorsolution.Inthepresenceofleadthe
transfer 25 6 0.05 mL of the sample of the gasoline to the
solution will have a rose color.Titrate with the EDTAsolution.
separatory funnel. Immediately stopper the funnel and shake
The color changes near the end point, this being indicated by a
the contents for 60 s. Allow the funnel to stand for several
sharp change from orange to a permanent bright lemon-yellow.
minutes, until the two phases have separated and run the lower
6.5.2 Record the titre and calculate the molarity of the aqueous phase into a 500-mL Erlenmeyer flask made of
EDTA solution. The addition of excess EDTA produces no borosilicate glass. Wash the gasoline phase by shaking with
further color change at the end point. three separate 20-mL portions of distilled water and add the
washings to the Erlenmeyer flask.
6.6 Heavy Distillate—A straight-run, lead-free, petroleum
distillate of low bromine number, with approximately 10 %
NOTE 1—For cool gasolines having a Reid vapor pressure above 7.0 lb
distilling at 400°F (205°C) and 90 % at 460°F (240°C)
cool the sealed sample container to approximately 60°F (15°C) before
(Warning—Combustible.).
removing the sample for analysis.
6.7 Iodine Monochloride Reagent (1.0 M) (Warning—
8.2 Placeseveralglassbeadsintheflask,coverthemouthof
Iodine monochloride will react with ammonium ions under
the flask with a small ribbed watch glass, and place on a hot
certain conditions to yield nitrogen triiodide, which is explo-
plate. Heat the contents and allow to boil until the volume of
sive. Take care, therefore, that this reagent does not come into
the solution is 15 to 20 mL. Without removing the flask from
contactwithammoniaorammoniumsalts.)Dissolve111.0gof
the hot plate, add 5 mL of concentrated nitric acid down the
potassium iodide (KI) in approximately 400 mL of distilled
side of the flask and evaporate the contents almost to dryness
water. Add 445 mL of concentrated hydrochloric acid (sp gr
to oxidize any organic material present. Repeat the nitric acid
1.18) and cool to room temperature. Add 75.0 g of potassium
treatment, evaporating almost to dryness until all the organic
iodate (KIO ) slowly and with stirring, until all the free iodine
matter has been removed and a white residue remains. Finally
initially formed has just redissolved to give a clear orange-red
remove the watch glass and evaporate the solution to dryness.
solution (the amounts of KI and KIO are calculated to give a
3 Remove the flask from the hot plate and allow the contents to
slight excess of iodate; if a greater excess is present, this will
cool.
cause precipitation of lead and indifferent end points in the
8.3 Add about 200 mL of distilled water to the flask and
EDTA titration). Cool to room temperature and dilute to 1 L
swirl to dissolve the residue. The residue may be quickly
with distilled water. Store in a glass-stoppered bottle
dissolved by heating the solution, but this must be cooled
(Warning—Do not use rubber stoppers to stopper vessels
before titrating.Add 5 drops of bromthymol blue indicator and
containing iodine monochloride solutions.).
titrate with 1 + 1 ammonia solution until the color just changes
6.8 LeadNitrate,StandardSolution(0.005M)—Weighwith
to blue; then add 10 mL of sodium acetate-acetic acid buffer
an accuracy of 60.001 g about 1.7 g of lead nitrate (Pb(NO )
solution and 5 drops of xylenol orange indicator solution. In
2) that h
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.