ASTM D4046-91(2005)

Standard Test Method for Alkyl Nitrate in Diesel Fuels by Spectrophotometry

SIGNIFICANCE AND USE
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 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 the 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 and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see Section 7.

General Information

• Status: Historical
• Publication Date: 30-Apr-2005
• ICS: 75.160.20 - Liquid fuels
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.03 - Elemental Analysis

Relations

• Replaces: ASTM D4046-91(2000)e1 - Standard Test Method for Alkyl Nitrate in Diesel Fuels by Spectrophotometry
• Effective Date: 01-May-2005
• Replaced By: ASTM D4046-11 - Standard Test Method for Alkyl Nitrate in Diesel Fuels by Spectrophotometry
• Effective Date: 01-Jun-2011
• Referred By: ASTM D524-15(2019) - Standard Test Method for Ramsbottom Carbon Residue of Petroleum Products
• Effective Date: 01-May-2005
• Referred By: ASTM D4530-15(2020) - Standard Test Method for Determination of Carbon Residue (Micro Method)
• Effective Date: 01-May-2005
• Referred By: ASTM D189-06(2019) - Standard Test Method for Conradson Carbon Residue of Petroleum Products
• Effective Date: 01-May-2005
• Referred By: ASTM D7578-20 - Standard Guide for Calibration Requirements for Elemental Analysis of Petroleum Products and Lubricants
• Effective Date: 01-May-2005

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:D4046–91(Reapproved 2005)
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 4. Significance and Use
1.1 This test method covers a procedure for the determina- 4.1 Thistestmethodcanbeusedtodeterminetheamountof
tion of 0.03 to 0.30 volume % of alkyl nitrate in diesel fuels. alkyl nitrate that has been added to diesel fuel to improve
1.2 This test method can be used for the determination of Cetane Number. The test method is applicable as a basis for
any alkyl nitrate in diesel fuel provided that standards used for judging compliance with specifications covering any alkyl
calibration contain the same alkyl nitrate ester as the test nitrate.
specimens to be analyzed.
5. Interferences
1.3 The values stated in SI units are to be regarded as the
5.1 Other nitrate esters, inorganic nitrate ions, and nitrogen
standard.
1.4 This standard does not purport to address all of the oxides will interfere.
safety concerns, if any, associated with its use. It is the
6. Apparatus
responsibility of the user of this standard to establish appro-
6.1 Absorption Cells, matched, having a 1.000 6 0.002-cm
priate safety and health practices and determine the applica-
path length.
bility of regulatory limitations prior to use. For specific hazard
6.2 Separatory Funnel, Squibb-type glass stoppered with
statements, see Section 7.
TFE-fluorocarbon stopcock, 125-mL capacity.
2. Referenced Documents
6.3 Shaking Machine, automatic, capable of multiple
samples and 250 oscillations/min.
2.1 ASTM Standards:
D1193 Specification for Reagent Water 6.4 Spectrophotometer, capable of measuring absorption in
the region of 452 6 5 nm.
3. Summary of Test Method
6.5 Volumetric Flask, 10- and 100-mL capacity.
3.1 The determination is based on the simultaneous hydro- 6.6 Measuring Pipet, 1-mL, 3-mL, 4-mL, and 10-mL.
lysis of the ester in 65 % sulfuric acid solution and nitration of 6.7 Buret, 10-mL capacity.
m-xylenol by the nitric acid liberated. The nitroxylenol is
7. Reagents
extracted from the reaction mixture and reacted with sodium
7.1 Purity of Reagents—Reagent grade chemicals shall be
hydroxide to form the yellow salt. The color is measured
spectrophotometrically at 452 nm, and the concentration of used in all tests. Unless otherwise indicated, it is intended that
all reagents conform to the specifications of the committee on
alkyl nitrate is determined by reference to the slope of the
calibration curve. Analytical Reagents of theAmerican Chemical Society, where
such specifications are available. Other grades may be used,
provided it is first ascertained that the reagent is of sufficiently
high purity to permit its use without lessening the accuracy of
This test method is under the jurisdiction of ASTM Committee D02 on
the determination.
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
D02.03 on Elemental Analysis.
Current edition approved May 1, 2005. Published May 2005. Originally
´1 3
approved in 1981. Last previous edition approved in 2000 as D4046 – 91 (2000) . Reagent Chemicals, American Chemical Society Specifications, American
DOI: 10.1520/D4046-91R05. Chemical Society, Washington, DC. For suggestions on the testing of reagents not
For referenced ASTM standards, visit the ASTM website, www.astm.org, or listed by the American Chemical Society, see Analar Standards for Laboratory
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Standards volume information, refer to the standard’s Document Summary page on and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
the ASTM website. MD.
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D4046–91 (2005)
alkaline, add an additional 10.0 mL of NaOH solution and correct
7.2 Purity of Water—Unless otherwise indicated, references
calculations for the increased solution volume.
to water shall be understood to mean reagent water conforming
to Type II of Specification D1193.
8.10 Subtract the absorbance of the blank from that of each
7.3 Acetic Acid, reagent grade.
standard to obtain corrected absorbance values. Calculate the
7.4 Alkyl Nitrate.
slope of the curve as follows:
7.5 Alkyl Nitrate, Standard Solution—Pipet 3.0 mL of the
Slope, C 5 A/B (1)
alkyl nitrate to be determined into a 100-mL volumetric flask
and dilute to volume with diesel fuel. where:
A = sum of the volume percent alkyl nitrate standards and
7.6 Diesel Fuel, additive-free (Warning—Flammable.).
B = sum of corrected absorbances.
7.7 Isooctane (2,2,4-trimethylpentane). (Warning—
Flammable.).
9. Procedure
7.8 Isopropyl Alcohol, reagent grade. (Warning—
9.1 Pipet 1.0 mL of test specimen into a 10-mL volumetric
Flammable.).
flask and dilute to volume with isopropyl alcohol.
7.9 m-Xylenol Solutions—Dilute 4 mL of m-xylenol (2,4-
9.2 Pipet1.0mLofthesampletests
...