ASTM D4046-14(2019)
(Test Method)Standard Test Method for Alkyl Nitrate in Diesel Fuels by Spectrophotometry (Withdrawn 2019)
Standard Test Method for Alkyl Nitrate in Diesel Fuels by Spectrophotometry (Withdrawn 2019)
SIGNIFICANCE AND USE
4.1 In diesel fuel, the presence of alkyl nitrates such as amyl nitrate, hexyl nitrate, or octyl nitrate causes a higher residue value than observed in untreated fuel, which can lead to erroneous conclusions as to the coke forming propensity of the fuel. The presence of such alkyl nitrate in the fuel can be determined using this test method. This test method can be used to determine the amount of alkyl nitrate that has been added to diesel fuel to improve Cetane Number. The test method is applicable as a basis for judging compliance with specifications covering any alkyl nitrate.
SCOPE
1.1 This test method covers a procedure for the determination of 0.03 % to 0.30 % by volume of alkyl nitrate in diesel fuels.
1.2 This test method can be used for the determination of any alkyl nitrate in diesel fuel provided that standards used for calibration contain the same alkyl nitrate ester as the test specimens to be analyzed.
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see Section 7.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
WITHDRAWN RATIONALE
This test method covers a procedure for the determination of 0.03 % to 0.30 % by volume of alkyl nitrate in diesel fuels.
Formerly under the jurisdiction of Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants, this test method was withdrawn in November 2019 because it is not being used in the industry. This standard was used for the determination of cetane improvers in diesel. Most of the concerns with the use of cetane improvers and diesel fuel storage stability are from the time when higher sulfur diesel fuels were used. Cetane improvers have also been shown to affect the thermal stability of the fuels. Current cetane improvers do not include this chemical any longer. Hence, there is no need for this standard.
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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: D4046 − 14 (Reapproved 2019)
Standard Test Method for
Alkyl Nitrate in Diesel Fuels by Spectrophotometry
This standard is issued under the fixed designation D4046; 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 hydroxide to form the yellow salt. The color is measured
spectrophotometrically at 452 nm, and the concentration of
1.1 This test method covers a procedure for the determina-
alkyl nitrate is determined by reference to the slope of the
tion of 0.03 % to 0.30 % by volume of alkyl nitrate in diesel
calibration curve.
fuels.
1.2 This test method can be used for the determination of
4. Significance and Use
any alkyl nitrate in diesel fuel provided that standards used for
4.1 In diesel fuel, the presence of alkyl nitrates such as amyl
calibration contain the same alkyl nitrate ester as the test
nitrate, hexyl nitrate, or octyl nitrate causes a higher residue
specimens to be analyzed.
value than observed in untreated fuel, which can lead to
1.3 The values stated in SI units are to be regarded as
erroneous conclusions as to the coke forming propensity of the
standard. No other units of measurement are included in this
fuel. The presence of such alkyl nitrate in the fuel can be
standard.
determined using this test method. This test method can be
1.4 This standard does not purport to address all of the
used to determine the amount of alkyl nitrate that has been
safety concerns, if any, associated with its use. It is the
added to diesel fuel to improve Cetane Number. The test
responsibility of the user of this standard to establish appro-
method is applicable as a basis for judging compliance with
priate safety, health, and environmental practices and deter-
specifications covering any alkyl nitrate.
mine the applicability of regulatory limitations prior to use.
For specific hazard statements, see Section 7.
5. Interferences
1.5 This international standard was developed in accor-
5.1 Other nitrate esters, inorganic nitrate ions, and nitrogen
dance with internationally recognized principles on standard-
oxides will interfere.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
6. Apparatus
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
6.1 Absorption Cells, matched, having a 1.000 cm 6
0.002 cm path length.
2. Referenced Documents
6.2 Separatory Funnel, Squibb-type glass stoppered with
2.1 ASTM Standards:
TFE-fluorocarbon stopcock, 125 mL capacity.
D1193 Specification for Reagent Water
6.3 Shaking Machine, automatic, capable of multiple
3. Summary of Test Method
samples and 250 oscillations⁄min.
3.1 The determination is based on the simultaneous hydro-
6.4 Spectrophotometer, capable of measuring absorption in
lysis of the ester in 65 % sulfuric acid solution and nitration of
the region of 452 nm 6 5 nm.
m-xylenol by the nitric acid liberated. The nitroxylenol is
extracted from the reaction mixture and reacted with sodium
6.5 Volumetric Flask, 10 mL and 100 mL capacity.
6.6 Measuring Pipet, 1 mL, 3 mL, 4 mL, and 10 mL.
This test method is under the jurisdiction of ASTM Committee D02 on
6.7 Buret, 10 mL capacity.
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.03 on Elemental Analysis.
Current edition approved April 15, 2019. Published April 2019. Originally
7. Reagents
approved in 1981. Last previous edition approved in 2014 as D4046 – 14. DOI:
10.1520/D4046-14R19.
7.1 Purity of Reagents—Reagent grade chemicals shall be
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
used in all tests. Unless otherwise indicated, it is intended that
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
all reagents conform to the specifications of the committee on
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. Analytical Reagents of theAmerican Chemical Society, where
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4046 − 14 (2019)
such specifications are available. Other grades may be used, 8.6 Secure the stopper with springs or rubber bands and
provided it is first ascertained that the reagent is of sufficiently shake the separatory funnel and its content for 30 min on the
high purity to permit its use without lessening the accuracy of automatic shaking machine set at fast speed.
the determination.
NOTE 1—The amount of contact the sample has with the H SO
2 4
determines the extent of hydrolysis. Therefore, the speed and time of
7.2 Purity of Water—Unless otherwise indicated, references
shaking should be the same for both the samples and the calibration
to water shall be understood to mean reagent water conforming
standards.
to Type II of Specification D1193.
8.7 To each separatory funnel add 25 mL of isooctane.
7.3 Acetic Acid, reagent grade.
8.8 Shake the separatory funnel for 1 min by hand. Allow
7.4 Alkyl Nitrate.
the layers to separate and discard the acid (bottom) layer. Add
7.5 Alkyl Nitrate, Standard Solution—Pipet 3.0 mL of the 25 mLof distilled water and again shake for 1 min to wash out
alkyl nitrate to be determined into a 100 mL volumetric flask residual acid. Discard the water (bottom) layer.
and dilute to volume with diesel fuel.
8.9 Pipet 10.0 mL of NaOH solution into the separatory
7.6 Diesel Fuel, additive-free (Warning—Flammable.). funnel, shake for 1 min and allow the phases to separate for at
least 10 min or when phases separate cleanly (see Note 2).
7.7 Isooctane (2,2,4-trimethylpentane). (Warning—
Drain a few drops
...
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