1、Designation: D4808 01 (Reapproved 2012)D4808 17Standard Test Methods forHydrogen Content of Light Distillates, Middle Distillates,Gas Oils, and Residua by Low-Resolution Nuclear MagneticResonance Spectroscopy1This standard is issued under the fixed designation D4808; the number immediately following
2、 the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved f
3、or use by agencies of the U.S. Department of Defense.1. Scope Scope*1.1 These test methods cover the determination of the hydrogen content of petroleum products ranging from atmosphericdistillates to vacuum residua using a continuous wave, low-resolution nuclear magnetic resonance spectrometer. (Tes
4、t MethodD3701 is the preferred method for determining the hydrogen content of aviation turbine fuels using nuclear magnetic resonancespectroscopy.)1.2 Three test methods are included here that account for the special characteristics of different petroleum products and applyto the following distillat
5、ion ranges:Test Method Petroleum Products Boiling Range, C (F)(approximate)A Light Distillates 15260 (60500)B Middle Distillates 200370 (400700)Gas Oils 370510 (700950)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 i
6、n 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 responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regul
7、atorylimitations prior to use. For specific warning statements, see Sections 6.2 and 6.4.1.5 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards,
8、Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D3701 Test Method for Hydrogen Content of Aviation Turbine Fuels by Low Resolution Nuclear Magnetic ResonanceSpectrometryD4057 Practice for Manual S
9、ampling of Petroleum and Petroleum ProductsD4177 Practice for Automatic Sampling of Petroleum and Petroleum ProductsD5291 Test Methods for Instrumental Determination of Carbon, Hydrogen, and Nitrogen in Petroleum Products and Lubricants3. Summary of Test Methods3.1 A test specimen is compared in a c
10、ontinuous wave, low-resolution nuclear magnetic resonance (NMR) spectrometer witha reference standard sample. The spectrometer records in a nondestructive fashion the absolute concentration of hydrogen atomsin the reference standard and test sample. The absolute hydrogen concentrations reported by t
11、he integrator on the NMR instrument1 These test methods are under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and are the direct responsibility ofSubcommittee D02.03 on Elemental Analysis.Current edition approved April 15, 2012June 1, 2017. Published Ma
12、y 2012June 2017. Originally approved in 1988. Last previous edition approved in 20062012 asD480801(2006).D4808 01 (2012). DOI: 10.1520/D4808-01R12.10.1520/D4808-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book
13、 of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.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. Becauseit may not be technic
14、ally possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this st
15、andardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1for the standard and test specimens are used as a means of comparing the theoretical hydrogen content of the standard with thatof the sample, the result being expressed as the hydr
16、ogen content (on a mass % basis) of the sample.3.2 To ensure an accurate measure of the absolute hydrogen content of the reference standard and sample, it is necessary toensure that the measured hydrogen integrator counts are always directly proportional to the absolute hydrogen content of thestanda
17、rd and sample.3.3 Undercounting of the reference standard with respect to the sample is avoided in Test Methods B and C by dilution of thestandard with a relaxation reagent solution. Undercounting of highly viscous or solid test samples is avoided by dissolving thesample in a non-hydrogen containing
18、 solvent, which ensures that all of the weighed sample is in a fluid and homogeneous solutionat the time of measurement.An elevated sample temperature at the time of measurement also ensures a homogeneous liquid-phasesample.4. Significance and Use4.1 The hydrogen content represents a fundamental qua
19、lity of a petroleum product that has been correlated with many of theperformance characteristics of that product.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 hydrogen content o
20、n a range of petroleum products.5. ApparatusNOTE 1This test method has been written around the Newport Analyzer Mark IIIF or its replacement version, the Newport 4000 (Oxford AnalyticalInstruments, Ltd., Oxford, England), and the details of the test method are to be read in conjunction with the manu
21、facturers handbook. These instrumentshave demonstrated statistically indistinguishable performance in these standard test methods and in Test Method D3701. Any similar instrument isacceptable, provided that the new instrument is adequately correlated and proved to be statistically similar. As of the
22、 mid-1990s, however, the Newport4000 instrument is no longer being manufactured by the vendor. No newer models are currently being manufactured as replacements for the Newport4000 instrument.5.1 Nuclear Magnetic Resonance Spectrometer:5.1.1 Alow-resolution, continuous wave instrument capable of meas
23、uring a nuclear magnetic resonance signal due to hydrogenatoms 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-frequen
24、cy level andaudio-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 elevatedtemperature (50C).(50 C).5.2 Conditioning BlockA block of aluminum alloy d
25、rilled with holes of sufficient size to accommodate the test cells with themean height of the sample being at least 20 mm 20 mm below the top of the conditioning block, capable of holding the sampleat the given test temperature (see Fig. 1).5.3 Test CellsNessler-type tubes of approximately 100-mL100
26、 mL capacity with a nominal external diameter of 34 mm34 mm and a nominal internal diameter of 31 mm 31 mm marked at a distance of 51 mm 51 mm above the bottom of the tubeby a ring around the circumference. The variation between the internal diameters of the test cells used for the sample and refere
27、ncematerial should not be greater than 60.5 mm.60.5 mm.NOTE 2To avoid potential difficulties with tightness when the test cell is introduced into the magnet coil, users are cautioned to avoid test cells thathave nominal external diameters that are greater than 34.2 mm.34.2 mm.5.4 Polytetrafluoroethy
28、lene (PTFE) Plugs, for closing the test cells and made from pure PTFE.5.5 Insertion RodA metal rod with a threaded end used for inserting and removing the PTFE plugs from the test cells (seeFig. 1).5.6 Analytical BalanceA top pan-type balance, capable of weighing the test cells in an upright positio
29、n to an accuracy of atleast 0.001 g.0.001 g.5.7 Beakers, 150 mL and 50 mL 150 mL and 50 mL with pour spouts.5.8 Glass Stirring Rod, approximately 250-mm250 mm length.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is i
30、ntended that allreagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, wheresuch specifications are available.3 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently highpurity to permit its use
31、without lessening the accuracy of the determination.3 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed bythe American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd.
32、, Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.D4808 1726.2 Reference Standardn-Dodecane . Standardn-Dodecane. (WarningFlammable.)6.3 Relaxation Reagent Solution, prepared from ferric acetylacetonate (Fe(C5 H
33、7 O2)3 MW = 353.16, reagent grade)Preparea fresh 0.02 M Fe(C5 H7 O2)3 solution by dissolving 1.77 g 1.77 g of Fe(C5 H7 O2)3 in 250 mL 250 mL TCE. If any of the Fe(C5H7 O2) remains undissolved, filter the solution, and use the filtrate in subsequent steps.6.4 Tetrachloroethylene (TCE). (WarningCancer
34、-suspect agent.)7. Sampling7.1 Take a homogeneous sample in accordance with Practice D4057 or D4177. Mix the sample prior to taking a representativealiquot as the test specimen. Middle distillates, gas oils, and residue can require heating to facilitate mixing to obtain ahomogeneous test specimen, a
35、s described in 8.2.2.2 and 8.3.2.8. Preparation of Test Specimen and Standard8.1 Test Method ALight Distillates8.1.1 Take a clean and dry test cell and PTFE plug, and weigh them together to the nearest 0.001 g 0.001 g and record theweight. Add 30 6 1 mL 30 mL 6 1 mL of the reference standard or test
36、 specimen to the tube, taking extreme care to preventsplashing the liquid above the line inscribed on the tube. Use a pipet for this operation.8.1.2 Using the insertion rod, push the PTFE plug into the tube until it is about 3 cm 3 cm above the liquid surface, being carefulto keep the tube upright.
37、A gentle twisting or rocking of the plug as it is inserted usually aids the escape of air from the test celland ensures that the lip of the PTFE plug is turned up around the entire circumference. Take care to ensure that this is so, sincea plug that is not properly inserted allows sample evaporation
38、 and gives rise to erroneous results.NOTE 3If difficulties are encountered in the insertion of the PTFE plug, this operation is facilitated by inserting a length of thin (less than0.2-mm0.2 mm diameter) and clean copper wire down the inside surface of the test cell until it is approximately 4 cm 4 c
39、m from the graduation mark,and then pushing the PTFE plug down past the wire which is then removed.8.1.3 Unscrew the insertion rod carefully and remove without disturbing the plug and without contacting the liquid with theunder surface of the plug.FIG. 1 Conditioning Block and Insertion RodD4808 173
40、8.1.4 Weigh the test cell containing the test specimen or standard and plug. Record this mass as MS or MR, respectively, to thenearest 0.001 g.0.001 g.8.1.5 Place the test cell in the sample conditioning block to equilibrate.8.1.6 Use procedures 8.1.1 through 8.1.5 to prepare both the reference and
41、sample test cells.8.2 Test Method BMiddle Distillates, Gas Oils8.2.1 Reference Standard Preparation:8.2.1.1 Take a clean and dry test cell with PTFE plug and a 150-mL150 mL beaker with glass rod. Weigh the test cell with plugand beaker with glass rod to the nearest 0.001 g 0.001 g and record as tare
42、 masses.8.2.1.2 Add 20 g 20 g of the reference standard, n-dodecane, to the beaker. Record this mass to the nearest 0.001 g 0.001 g asSM.8.2.1.3 To the beaker add 8.6 g 8.6 g TCE and 4.7 g 4.7 g of relaxation reagent solution, as described in 6.3, consisting of TCEand Fe(C5 H7 O2)3 (40 % dilution of
43、 reference standard with 1 mg 1 mg relaxation reagent/mL). Mix thoroughly using the glassstirring rod.NOTE 4Burets can also be used to aid the addition of TCE and relaxation reagent solutions.8.2.1.4 Transfer this solution from the beaker to the test cell, using the glass rod to prevent splashing th
44、e liquid above the lineinscribed on the test cell. Fill the test cell to the prescribed level, just below this mark.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 and plug. Record the mass of the reference solution to the nearest0.001 g 0.001 g a
45、s M1.8.2.1.7 Weigh the beaker and glass rod containing the unused solution, and record the mass of the remaining solution to thenearest 0.001 g 0.001 g as M2.8.2.1.8 Place the test cell containing reference solution into the conditioning block to equilibrate.8.2.2 Test Specimen Preparation:8.2.2.1 T
46、ake a clean and dry test cell with PTFE plug and a 150-mL150 mL beaker with glass stirring rod. Weigh the test cellwith plug and the beaker with glass rod to the nearest mg, and record as tare masses.8.2.2.2 Add 20 g 20 g of the test specimen to the beaker. Record this mass to the nearest 0.001 g 0.
47、001 g as SM. All samplesshall be homogeneous prior to sampling. If the sample is viscous or contains waxy materials, heat the sample in its container toapproximately 60C60 C and mix with a high-speed shear mixer prior to sampling.8.2.2.3 To the beaker containing sample, add 13.3 g 13.3 g ofTCE (40 %
48、 dilution of the test sample withTCE). Mix the solutionthoroughly, using the glass rod.NOTE 5For some samples, it is necessary to heat and stir until the sample is completely homogeneous. Maintain the liquid level with additional TCEduring heating if necessary.8.2.2.4 Continue as in 8.2.1.4 through
49、8.2.1.8.8.3 Test Method CResidue8.3.1 Take a clean and dry test cell with PTFE plug, a 150-mL150 mLbeaker, and a glass rod. Weigh each of them to the nearest0.001 g, and record as tare weights.8.3.2 Add 15 g 15 g of reference standard or test specimen to the beaker. Record this mass to the nearest 0.001 g 0.001 g asSM. All samples shall be homogeneous prior to sampling. If the sample is viscous or contains waxy materials, heat the sample inits container to approximately 60C60 C and mix with a high-speed shear mixer prior to sampling.8.3.3 To t
