ASTM D4808-01(2012)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D4808 − 01 (Reapproved 2012)
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.Anumber 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 Turbine Fuels by Low Resolution Nuclear Magnetic
Resonance Spectrometry
1.1 These test methods cover the determination of the
D4057Practice for Manual Sampling of Petroleum and
hydrogen content of petroleum products ranging from atmo-
Petroleum Products
spheric distillates to vacuum residua using a continuous wave,
D5291Test Methods for Instrumental Determination of
low-resolution nuclear magnetic resonance spectrometer. (Test
Carbon, Hydrogen, and Nitrogen in Petroleum Products
Method D3701 is the preferred method for determining the
and Lubricants
hydrogen content of aviation turbine fuels using nuclear
magnetic resonance spectroscopy.)
3. Summary of Test Methods
1.2 Threetestmethodsareincludedherethataccountforthe
3.1 A test specimen is compared in a continuous wave,
special characteristics of different petroleum products and
low-resolution nuclear magnetic resonance (NMR) spectrom-
apply to the following distillation ranges:
eter with a reference standard sample. The spectrometer
Test Method Petroleum Products Boiling Range, °C (°F)
records in a nondestructive fashion the absolute concentration
(approximate)
of hydrogen atoms in the reference standard and test sample.
A Light Distillates 15–260 (60–500)
B Middle Distillates 200–370 (400–700)
The absolute hydrogen concentrations reported by the integra-
Gas Oils 370–510 (700–950)
torontheNMRinstrumentforthestandardandtestspecimens
C Residua 510+ (950+ )
are used as a means of comparing the theoretical hydrogen
1.3 The values stated in SI units are to be regarded as
contentofthestandardwiththatofthesample,theresultbeing
standard. No other units of measurement are included in this
expressed as the hydrogen content (on a mass % basis) of the
standard. The preferred units are mass %.
sample.
1.4 This standard does not purport to address all of the
3.2 Toensureanaccuratemeasureoftheabsolutehydrogen
safety concerns, if any, associated with its use. It is the
content of the reference standard and sample, it is necessary to
responsibility of the user of this standard to establish appro-
ensurethatthemeasuredhydrogenintegratorcountsarealways
priate safety and health practices and determine the applica-
directly proportional to the absolute hydrogen content of the
bility of regulatory limitations prior to use. For specific
standard and sample.
warning statements, see Sections 6.2 and 6.4.
3.3 Undercounting of the reference standard with respect to
2. Referenced Documents the sample is avoided in Test Methods B and C by dilution of
the standard with a relaxation reagent solution. Undercounting
2.1 ASTM Standards:
ofhighlyviscousorsolidtestsamplesisavoidedbydissolving
D3701Test Method for Hydrogen Content of Aviation
the sample in a non-hydrogen containing solvent, which
ensures that all of the weighed sample is in a fluid and
1 homogeneoussolutionatthetimeofmeasurement.Anelevated
These test methods are under the jurisdiction of ASTM Committee D02 on
Petroleum Products, Liquid Fuels, and Lubricants and are the direct responsibility sample temperature at the time of measurement also ensures a
of Subcommittee D02.03 on Elemental Analysis.
homogeneous liquid-phase sample.
Current edition approved April 15, 2012. Published May 2012. Originally
approved in 1988. Last previous edition approved in 2006 as D4808–01(2006).
4. Significance and Use
DOI: 10.1520/D4808-01R12.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
4.1 The hydrogen content represents a fundamental quality
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
of a petroleum product that has been correlated with many of
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. the performance characteristics of that product.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4808 − 01 (2012)
4.2 This test method provides a simple and more precise
alternative to existing test methods, specifically combustion
techniques (Test Methods D5291) for determining the hydro-
gen content on a range of petroleum products.
5. Apparatus
NOTE 1—This test method has been written around the Newport
AnalyzerMarkIIIForitsreplacementversion,theNewport4000(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 per-
formance 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.
5.1 Nuclear Magnetic Resonance Spectrometer:
5.1.1 Alow-resolution,continuouswaveinstrumentcapable
of measuring a nuclear magnetic resonance signal due to
hydrogen atoms in the sample and includes an excitation and
detectioncoilofsuitabledimensionstocontainthetestcell;an
electronicunit,tocontrolandmonitorthemagnetandcoil,and
containing: circuits, to control and adjust the radio-frequency
level and audio-frequency gain; and integrating counter, with
variable time period in seconds.
5.1.2 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).
5.2 Conditioning Block—Ablock 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
FIG. 1 Conditioning Block and Insertion Rod
top of the conditioning block, capable of holding the sample at
the given test temperature (see Fig. 1).
5.3 Test Cells—Nessler-type tubes of approximately
100-mL capacity with a nominal external diameter of 34 mm
all reagents shall conform to the specifications of the Commit-
andanominalinternaldiameterof31mmmarkedatadistance
tee onAnalytical Reagents of theAmerican Chemical Society,
of 51 mm above the bottom of the tube by a ring around the
where such specifications are available. Other grades may be
circumference.Thevariationbetweentheinternaldiametersof
used, provided it is first ascertained that the reagent is of
thetestcellsusedforthesampleandreferencematerialshould
sufficiently high purity to permit its use without lessening the
not be greater than 60.5 mm.
accuracy of the determination.
NOTE2—Toavoidpotentialdifficultieswithtightnesswhenthetestcell
6.2 Reference Standard—n-Dodecane . (Warning—
is introduced into the magnet coil, users are cautioned to avoid test cells
Flammable.)
that have nominal external diameters that are greater than 34.2 mm.
6.3 Relaxation Reagent Solution, prepared from ferric
5.4 Polytetrafluoroethylene (PTFE) Plugs, for closing the
acetylacetonate (Fe(C H O ) − MW = 353.16, reagent
test cells and made from pure PTFE.
5 7 2 3
grade)—Prepare a fresh 0.02 M Fe(C H O ) solution by
5 7 2 3
5.5 Insertion Rod—Ametalrodwithathreadedendusedfor
dissolving 1.77 g of Fe(C H O ) in 250 mLTCE. If any of
5 7 2 3
inserting and removing the PTFE plugs from the test cells (see
the Fe(C H O ) remains undissolved, filter the solution, and
5 7 2
Fig. 1).
use the filtrate in subsequent steps.
5.6 Analytical Balance—Atop pan-type balance, capable of
6.4 Tetrachloroethylene (TCE). (Warning—Cancer-suspect
weighing the test cells in an upright position to an accuracy of
agent.)
at least 0.001 g.
5.7 Beakers, 150 mL and 50 mL with pour spouts.
5.8 Glass Stirring Rod, approximately 250-mm length. 3
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
6. Reagents and Materials listed by the American Chemical Society, see Analar Standards for Laboratory
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
6.1 Purity of Reagents—Reagent grade chemicals shall be
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
used in all tests. Unless otherwise indicated, it is intended that MD.
D4808 − 01 (2012)
7. Sampling 8.2.1.5 Continue as in 8.1.2 and 8.1.3.
8.2.1.6 Weigh the test cell containing the reference solution
7.1 Take a homogeneous sample in accordance with Prac-
and plug. Record the mass of the reference solution to the
tice D4057. Mix the sample prior to taking a representative
nearest 0.001 g as M .
aliquot as the test specimen. Middle distillates, gas oils, and
8.2.1.7 Weigh the beaker and glass rod containing the
residue can require heating to facilitate mixing to obtain a
unusedsolution,andrecordthemassoftheremainingsolution
homogeneous test specimen, as described in 8.2.2.2 and 8.3.2.
to the nearest 0.001 g as M .
8.2.1.8 Place the test cell containing reference solution into
8. Preparation of Test Specimen and Standard
the conditioning block to equilibrate.
8.1 Test Method A—Light Distillates
8.2.2 Test Specimen Preparation:
8.1.1 Take a clean and dry test cell and PTFE plug, and
8.2.2.1 Take a clean and dry test cell with PTFE plug and a
weigh them together to the nearest 0.001 g and record the
150-mLbeaker with glass stirring rod.Weigh the test cell with
weight. Add 30 6 1 mL of the reference standard or test
plug and the beaker with glass rod to the nearest mg, and
specimen to the tube, taking extreme care to prevent splashing
record as tare masses.
the liquid above the line inscribed on the tube. Use a pipet for
8.2.2.2 Add 20 g of the test specimen to the beaker. Record
this operation.
this mass to the nearest 0.001 g as S . All samples shall be
M
8.1.2 Using the insertion rod, push the PTFE plug into the
homogeneous prior to sampling. If the sample is viscous or
tube until it is about 3 cm above the liquid surface, being
contains waxy materials, heat the sample in its container to
carefultokeepthetubeupright.Agentletwistingorrockingof
approximately 60°C and mix with a high-speed shear mixer
the plug as it is inserted usually aids the escape of air from the
prior to sampling.
test cell and ensures that the lip of the PTFE plug is turned up
8.2.2.3 To the beaker containing sample, add 13.3 g ofTCE
aroundtheentirecircumference.Takecaretoensurethatthisis
(40% dilution of the test sample with TCE). Mix the solution
so, since a plug that is not properly inserted allows sample
thoroughly, using the glass rod.
evaporation and gives rise to erroneous results.
NOTE 5—For some samples, it is necessary to heat and stir until the
NOTE 3—If difficulties are encountered in the insertion of the PTFE
sample is completely homogeneous. Maintain the liquid level with
plug, this operation is facilitated by inserting a length of thin (less than additional TCE during heating if necessary.
0.2-mm diameter) and clean copper wire down the inside surface of the
8.2.2.4 Continue as in 8.2.1.4 through 8.2.1.8.
testcelluntilitisapproximately4cmfromthegraduationmark,andthen
pushing the PTFE plug down past the wire which is then removed.
8.3 Test Method C—Residue
8.3.1 Take a clean and dry test cell with PTFE plug, a
8.1.3 Unscrew the insertion rod carefully and remove with-
150-mL beaker, and a glass rod. Weigh each of them to the
out disturbing the plug and without contacting the liquid with
nearest 0.001 g, and record as tare weights.
the under surface of the plug.
8.3.2 Add15gofreferencestandardortestspecimentothe
8.1.4 Weigh the test cell containing the test specimen or
beaker. Record this mass to the nearest 0.001 g as S . All
standardandplug.Recordthismassas M or M ,respectively,
M
S R
samplesshallbehomogeneouspriortosampling.Ifthesample
to the nearest 0.001 g.
is viscous or contains waxy materials, heat the sample in its
8.1.5 Place the test cell in the sample conditioning block to
container to approximately 60°C and mix with a high-speed
equilibrate.
shear mixer prior to sampling.
8.1.6 Useprocedures8.1.1through8.1.5toprepareboththe
8.3.3 To the beaker, add 17.2 g of TCE and 5.3 gof
reference and sample test cells.
relaxation reagent solution (60% dilution with 1 mg of
8.2 Test Method B—Middle Distillates, Gas Oils
relaxation reagent per 1 mL). Mix thoroughly using the glass
8.2.1 Reference Standard Preparation:
stirring rod (see 6.4).
8.2.1.1 Take a clean and dry test cell with PTFE plug and a
8.3.4 Continue, as described in 8.2.1.4 through 8.2.1.8.
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
9. Preparation of Apparatus
tare masses.
9.1 Read and follow the manufacturer’s instructions for
8.2.1.2 Add 20 g of the reference standard, n-dodecane, to
preparing the instrument to take measurements. Take special
the beaker. Record this mass to the nearest 0.001 g as S .
M
care to prevent the instrument and conditioning block from
8.2.1.3 To the beaker add 8.6 gTCE and 4.7 g of relaxation
experiencing rapid temperature fluctuations; for example,
reagent solution, as described in 6.3, consisting of TCE and
avoid direct sunlight and drafts resulting from air conditioning
Fe(C H O ) (40% dilution of reference standard with 1 mg
5 7 2 3
or fans.
relaxationreagent/mL).Mixthoroughlyusingtheglassstirring
rod.
9.2 Adequate temperature equilibration of the instrument
probe assembly after adjustment to an elevated temperature is
NOTE 4—Burets can also be used to aid the addition of TCE and
essential. Due to the size of test specimen and probe assembly
relaxation reagent solutions.
specified by these methods, adequate thermal equilibration
8.2.1.4 Transferthissolutionfromthebeakertothetestcell,
may require several hours.
using the glass rod to prevent splashing the liquid above the
lineinscribedonthetestcell.Fillthetestcelltotheprescribed 9.3 Theresultsobtainedduringtheuseoftheinstrumentare
level, just below this mark. susceptible to error arising from changes in the local magnetic
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