ASTM D4808-23

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D4808 − 17 D4808 − 23
Standard Test Methods for
Hydrogen Content of Light Distillates, Middle Distillates,
Gas Oils, and Residua by Low-Resolution Nuclear Magnetic
Resonance Spectroscopy
This standard is issued under the fixed designation D4808; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope*
1.1 These test methods cover the determination of the hydrogen content of petroleum products ranging from atmospheric
distillates to vacuum residua using a continuous wave, low-resolution nuclear magnetic resonance spectrometer. (Test Method
D3701 is the preferred method for determining the hydrogen content of aviation turbine fuels using nuclear magnetic resonance
spectroscopy.)
1.2 Three test methods are included here that account for the special characteristics of different petroleum products and apply to
the following distillation ranges:
Test Method Petroleum Products Boiling Range, °C (°F)
(approximate)
A Light Distillates 15–260 (60–500)
B Middle Distillates 200–370 (400–700)
Gas Oils 370–510 (700–950)
C Residua 510+ (950+ )
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. The
preferred units are mass %.
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 healthsafety, health, and environmental practices and determine
the applicability of regulatory limitations prior to use. For specific warning statements, see Sections 6.27.2 and 6.47.4.
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.
2. Referenced Documents
2.1 ASTM Standards:
These test methods are under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and are the direct responsibility of
Subcommittee D02.03 on Elemental Analysis.
Current edition approved June 1, 2017Nov. 1, 2023. Published June 2017November 2023. Originally approved in 1988. Last previous edition approved in 20122017 as
D4808 – 01 (2012).D4808 – 17. DOI: 10.1520/D4808-17.10.1520/D4808-23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4808 − 23
D3701 Test Method for Hydrogen Content of Aviation Turbine Fuels by Low Resolution Nuclear Magnetic Resonance
Spectrometry
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products
D5291 Test Methods for Instrumental Determination of Carbon, Hydrogen, and Nitrogen in Petroleum Products and Lubricants
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this test method, refer to Terminology D4175.
4. Summary of Test Methods
4.1 A test specimen is compared in a continuous wave, low-resolution nuclear magnetic resonance (NMR) spectrometer with a
reference standard sample. The spectrometer records in a nondestructive fashion the absolute concentration of hydrogen atoms in
the reference standard and test sample. The absolute hydrogen concentrations reported by the integrator on the NMR instrument
for the standard and test specimens are used as a means of comparing the theoretical hydrogen content of the standard with that
of the sample, the result being expressed as the hydrogen content (on a mass % basis) of the sample.
4.2 To ensure an accurate measure of the absolute hydrogen content of the reference standard and sample, it is necessary to ensure
that the measured hydrogen integrator counts are always directly proportional to the absolute hydrogen content of the standard and
sample.
4.3 Undercounting of the reference standard with respect to the sample is avoided in Test Methods B and C by dilution of the
standard with a relaxation reagent solution. Undercounting of highly viscous or solid test samples is avoided by dissolving the
sample in a non-hydrogen containing solvent, which ensures that all of the weighed sample is in a fluid and homogeneous solution
at the time of measurement. An elevated sample temperature at the time of measurement also ensures a homogeneous liquid-phase
sample.
5. Significance and Use
5.1 The hydrogen content represents a fundamental quality of a petroleum product that has been correlated with many of the
performance characteristics of that product.
5.2 This test method provides a simple and more precise alternative to existing test methods, specifically combustion techniques
(Test Methods D5291) for determining the hydrogen content on a range of petroleum products.
6. Apparatus
NOTE 1—This test method has been written around the Newport Analyzer Mark IIIF or its replacement version, the Newport 4000 (Oxford Analytical
Instruments, Ltd., Oxford, England), and the details of the test method are to be read in conjunction with the manufacturer’s handbook. These instruments
have demonstrated statistically indistinguishable performance in these standard test methods and in Test Method D3701. Any similar instrument is
acceptable, provided that the new instrument is adequately correlated and proved to be statistically similar. As of the mid-1990s, however, the Newport
4000 instrument is no longer being manufactured by the vendor. No newer models are currently being manufactured as replacements for the Newport
4000 instrument.
6.1 Nuclear Magnetic Resonance Spectrometer:
6.1.1 A low-resolution, continuous wave instrument capable of measuring a nuclear magnetic resonance signal due to hydrogen
atoms in the sample and includes an excitation and detection coil of suitable dimensions to contain the test cell; an electronic unit,
to control and monitor the magnet and coil, and containing: circuits, to control and adjust the radio-frequency level and
audio-frequency gain; and integrating counter, with variable time period in seconds.
6.1.2 Test Methods B and C also require that the instrument has the ability to equilibrate samples within the probe at an elevated
temperature (50 °C).
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6.2 Conditioning Block—A block of aluminum alloy drilled with holes of sufficient size to accommodate the test cells with the
mean height of the sample being at least 20 mm below the top of the conditioning block, capable of holding the sample at the given
test temperature (see Fig. 1).
6.3 Test Cells—Nessler-type tubes of approximately 100 mL capacity with a nominal external diameter of 34 mm and a nominal
internal diameter of 31 mm marked at a distance of 51 mm above the bottom of the tube by a ring around the circumference. The
variation between the internal diameters of the test cells used for the sample and reference material should not be greater than
60.5 mm.
NOTE 2—To avoid potential difficulties with tightness when the test cell is introduced into the magnet coil, users are cautioned to avoid test cells that have
nominal external diameters that are greater than 34.2 mm.
6.4 Polytetrafluoroethylene (PTFE) Plugs, for closing the test cells and made from pure PTFE.
6.5 Insertion Rod—A metal rod with a threaded end used for inserting and removing the PTFE plugs from the test cells (see Fig.
1).
6.6 Analytical Balance—A top pan-type balance, capable of weighing the test cells in an upright position to an accuracy of at least
0.001 g.
6.7 Beakers, 150 mL and 50 mL with pour spouts.
6.8 Glass Stirring Rod, approximately 250 mm length.
FIG. 1 Conditioning Block and Insertion Rod
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7. Reagents and Materials
7.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents shall conform to the specifications of the Committee on Analytical Reagents of the American 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 the determination.
7.2 Reference Standard—n-Dodecane. (Warning—Flammable.)
7.3 Relaxation Reagent Solution, prepared from ferric acetylacetonate (Fe(C H O ) − MW = 353.16, reagent grade)—Prepare
5 7 2 3
a fresh 0.02 M Fe(C H O ) solution by dissolving 1.77 g of Fe(C H O ) in 250 mL TCE. If any of the Fe(C H O ) remains
5 7 2 3 5 7 2 3 5 7 2
undissolved, filter the solution, and use the filtrate in subsequent steps.
7.4 Tetrachloroethylene (TCE). (Warning—Cancer-suspect agent.)
8. Sampling
8.1 Take a homogeneous sample in accordance with Practice D4057 or D4177. Mix the sample prior to taking a representative
aliquot as the test specimen. Middle distillates, gas oils, and residue can require heating to facilitate mixing to obtain a
homogeneous test specimen, as described in 8.2.2.29.2.2.2 and 8.3.29.3.2.
9. Preparation of Test Specimen and Standard
9.1 Test Method A—Light Distillates
9.1.1 Take a clean and dry test cell and PTFE plug, and weigh them together to the nearest 0.001 g and record the weight. Add
30 mL 6 1 mL of the reference standard or test specimen to the tube, taking extreme care to prevent splashing the liquid above
the line inscribed on the tube. Use a pipet for this operation.
9.1.2 Using the insertion rod, push the PTFE plug into the tube until it is about 3 cm above the liquid surface, being careful to
keep the tube upright. A gentle twisting or rocking of the plug as it is inserted usually aids the escape of air from the test cell and
ensures that the lip of the PTFE plug is turned up around the entire circumference. Take care to ensure that this is so, since a plug
that is not properly inserted allows sample evaporation and gives rise to erroneous results.
NOTE 3—If difficulties are encountered in the insertion of the PTFE plug, this operation is facilitated by inserting a length of thin (less than 0.2 mm
diameter) and clean copper wire down the inside surface of the test cell until it is approximately 4 cm from the graduation mark, and then pushing the
PTFE plug down past the wire which is then removed.
9.1.3 Unscrew the insertion rod carefully and remove without disturbing the plug and without contacting the liquid with the under
surface of the plug.
9.1.4 Weigh the test cell containing the test specimen or standard and plug. Record this mass as M or M , respectively, to the
S R
nearest 0.001 g.
9.1.5 Place the test cell in the sample conditioning block to equilibrate.
9.1.6 Use procedures 8.1.19.1.1 through 8.1.59.1.5 to prepare both the reference and sample test cells.
9.2 Test Method B—Middle Distillates, Gas Oils
9.2.1 Reference Standard Preparation:
Reagent Chemicals, American Chemical Society Specifications,ACS Reagent Chemicals, Specifications and Procedures for Reagents and Standard-Grade Reference
Materials, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed by the American Chemical Society, see Analar Standards for
Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC),
Rockville, MD.
D4808 − 23
9.2.1.1 Take a clean and dry test cell with PTFE plug and a 150 mL beaker with glass rod. Weigh the test cell with plug and beaker
with glass rod to the nearest 0.001 g and record as tare masses.
9.2.1.2 Add 20 g of the reference standard, n-dodecane, to the beaker. Record this mass to the nearest 0.001 g as S .
M
9.2.1.3 To the beaker add 8.6 g TCE and 4.7 g of relaxation rea
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