ASTM D6560-22

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: D6560 − 17 D6560 − 22
Designation: IP 143 ⁄01⁄21
Standard Test Method for
Determination of Asphaltenes (Heptane Insolubles) in Crude
1,2
Petroleum and Petroleum Products
This standard is issued under the fixed designation D6560; 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*
1.1 This test method covers a procedure for the determination of the heptane insoluble asphaltene content of gas oil, diesel fuel,
residual fuel oils, lubricating oil, bitumen, and crude petroleum that has been topped to an oil temperature of 260 °C (see A1.2.1.1).
1.2 The precision is applicable to values between 0.50 % m ⁄m and 30.0 % m ⁄m. Values outside this range may still be valid but
may not give the same precision values.
1.3 Oils containing additives may give erroneous results.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 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.
1.6 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:
D86 Test Method for Distillation of Petroleum Products and Liquid Fuels at Atmospheric Pressure
D1298 Test Method for Density, Relative Density, or API Gravity of Crude Petroleum and Liquid Petroleum Products by
Hydrometer Method
D4052 Test Method for Density, Relative Density, and API Gravity of Liquids by Digital Density Meter
This test method is under the jurisdiction of ASTM International Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility
of ASTM Subcommittee D02.14 on Stability, Cleanliness and Compatibility of Liquid Fuels. The technically equivalent standard as referenced is under the jurisdiction of
the Energy Institute Subcommittee SC-B-5.
Current edition approved Dec. 1, 2017June 1, 2022. Published March 2018July 2022. Originally approved in 2000. Last previous edition approved in 20122017 as
D6560 – 12.D6560 – 17. DOI: 10.1520/D6560-17.10.1520/D6560-22.
This standard is based on material published in the IP Standard methods for Analysis and Testing of Petroleum and Related Products and British Standard 2000 Parts,
copyright Energy Institute, 61 New Cavendish Street, London, W1M 8AR. Adapted with permission of Energy Institute.
This test method has been developed through the cooperative effort between ASTM and the Energy Institute, London. ASTM and IP standards were approved by ASTM
and EI technical committees as being technically equivalent but that does not imply both standards are identical.
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
D6560 − 22
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
2.2 Energy Institute Standard:
Specifications for IP Standard Thermometers
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this test method, refer to Terminology D4175.
3.1.2 asphaltenes, n—(rarely used in the singular) — in petroleum technology, represent an oil fraction that is soluble in a specified
aromatic solvent but separates upon addition of an excess of a specified paraffinic solvent.
3.1.2.1 Discussion—
In this test method, the aromatic solvent is hot toluene and the paraffinic solvent is heptane.
3.1.2.2 Discussion—
Historically, benzene was the aromatic solvent, but benzene is not typically used now for health reasons. The precision of this test
method when using toluene has been found to be the same as when using benzene.
4. Summary of Test Method
4.1 A test portion of the sample is mixed with heptane and the mixture heated under reflux, and the precipitated asphaltenes, waxy
substances, and inorganic material are collected on a filter paper. The waxy substances are removed by washing with hot heptane
in an extractor.
4.2 After removal of the waxy substances, the asphaltenes are separated from the inorganic material by dissolution in hot toluene,
the extraction solvent is evaporated, and the asphaltenes weighed.
5. Significance and Use
5.1 Asphaltenes are the organic molecules of highest molecular mass and carbon-hydrogen ratio normally occurring in crude
petroleum and petroleum products containing residual material. They may give problems during storage and handling if the
suspension of asphaltene molecules is disturbed through excess stress or incompatibility. They are also the last molecules in a
product to combust completely, and thus may be one indicator of black smoke propensity. Their composition normally includes
a disproportionately high quantity of the sulfur, nitrogen, and metals present in the crude petroleum or petroleum product.
6. Apparatus
6.1 General—Ground-glass joints from different sources may have one of two diameter to length ratios. For the purposes of this
test method, either is suitable, and for some applications, the diameter itself can be one of two. However, it is critical that the male
and female parts of each joint are from the same series to avoid recession or protuberance.
6.2 Condenser, with a coil or double surface, fitted with a 34/45 or 34/35 ground-glass joint at the bottom to fit the top of the
extractor. Minimum length is 300 mm.
6.3 Reflux Extractor, conforming to the dimensions given in Fig. 1. Tolerances are 61 mm on the height and outer diameter (OD)
of the extractor body and 60.5 mm on all other dimensions. The female ground-glass joint at the top shall match the male at the
bottom of the condenser, and the male ground-glass joint at the bottom shall match the female of the conical flask.
6.4 Conical Flasks, of borosilicate glass of appropriate capacity (see 11.2 and Table 1), with ground-glass joints to fit the bottom
of the extractor.
NOTE 1—Sizes 24/39, 24/29, 29/43, or 29/32 are suitable.
Available from Energy Institute, 61 New Cavendish St., London, WIM 8AR, UK.
D6560 − 22
FIG. 1 Extractor
TABLE 1 Test Portion Size, Flask, and Heptane Volumes
Estimated Asphaltene Test Portion
Content Size Flask Volume Heptane Volume
% m/m g mL mL
Less than 0.5 10 ± 2 1000 300 ± 60
0.5 to 2.0 8 ± 2 500 240 ± 60
Over 2.0 to 5.0 4 ± 1 250 120 ± 30
Over 5.0 to 10.0 2 ± 1 150 60 ± 15
Over 10.0 to 25.0 0.8 ± 0.2 100 25 to 30
Over 25.0 0.5 ± 0.2 100 25 ± 1
6.5 Stopper, of borosilicate glass of a size to fit the conical flask.
6.6 Evaporating Vessel, of borosilicate glass. Either a hemispherical dish of approximately 90 mm diameter, or another suitable
vessel used in conjunction with a rotovapor.
NOTE 2—A rotovapor in conjunction with a nitrogen atmosphere reduces the hazard of toluene evaporation (see 11.7).
6.7 Filter Funnel, of borosilicate glass, approximately 100 mm diameter.
6.8 Filter Papers, Whatman Grade 42, 110 mm or 125 mm diameter.
6.9 Analytical Balance, capable of weighing with an accuracy of 0.1 mg.
6.10 Forceps, of stainless steel, spade ended.
The sole source of supply of the filter papers known to the committee at this time is Whatman Int. Ltd., Maidstone, UK. If you are aware of alternative suppliers, please
provide this information to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which
you may attend.
D6560 − 22
6.11 Timing Device, electronic or manual, accurate to 1.0 s.
6.12 Oven, capable of maintaining a temperature from 100 °C to 110 °C.
6.13 Graduated Cylinders, of 50 mL and 100 mL capacity.
6.14 Stirring Rods, of glass or polytetrafluoroethylene (PTFE), 150 mm by 3 mm diameter.
6.15 Cooling Vessel, consisting of either a dessicator without desiccant, or another suitable tightly-stoppered vessel.
6.16 Mixer, high-speed, nonaerating.
7. Reagents
7.1 Toluene (methylbenzene) [C H CH ], analytical reagent or nitration grade.
6 5 3
7.2 Heptane [C H ], analytical reagent grade.
7 16
8. Sampling
8.1 Unless otherwise specified, take samples by the procedures described in Practice D4057 or D4177.
9. Test Portion Preparation
9.1 Test portions from the laboratory samples shall be drawn after thorough mixing and subdivision. Heat viscous samples of
residual fuels to a temperature that renders the sample liquid, but not above 80 °C, and homogenize, using the mixer (see 6.16)
as necessary.
9.2 Heat samples of penetration grade bitumens to a temperature not exceeding 120 °C, and stir well before taking an aliquot.
9.3 Samples of hard bitumens shall be ground to a powder before an aliquot is taken.
9.4 Samples of crude petroleum shall be prepared in accordance with the procedure described in the Annex A1, unless it is known
that the crude petroleum contains negligible quantities of material boiling below 80 °C.
10. Apparatus Preparation
10.1 Clean all glass flasks (see 6.4) and dishes (see 6.6) by a means that matches the cleanliness obtained by the use of a strongly
oxidizing agent, such as ammonium peroxydisulfate in concentrated sulfuric acid at approximately 8 g ⁄L, or sulfuric acid itself,
soaking for at least 12 h, followed by rinses in tap water, distilled water, and the acetone, using forceps only for handling. Strong
oxidizing acid cleaning solutions are highly corrosive and potentially hazardous in contact with organic materials.
10.2 For routine analysis, use a proprietary laboratory detergent to clean the glassware, followed by the rinses described in 10.1.
When the detergent cleaning no longer matches the cleanliness required based on visual appearance, use a strong oxidizing agent.
10.3 After rinsing, place the glassware in the oven (see 6.12) for 30 min, and cool in the cooling vessel (see 6.15) for 30 min before
weighing.
11. Procedure
11.1 Estimate the asphaltene content of the sample, or residue obtained from the procedure in Annex A1, and weigh the quantity,
to the nearest 1 mg for masses above 1 g and to the nearest 0.1 mg for masses of 1 g and below (see Table 1), into a flask (see
6.4) of appropriate capacity (see Table 1).
D6560 − 22
11.2 Add heptane (see 7.2) to the test portion in the flask at a ratio of 30 mL to each 1 g of sample if the expected asphaltene
content is below 25 % m ⁄m. For samples with an expected asphaltene content of above 25 % m ⁄m, a minimum heptane volume
of 25 mL shall be used (see Table 1).
11.3 Boil the mixture under reflux for 60 min 6 5 min. Remove the flask and contents at the end of this period, cool, close with
a stopper (see 6.5), and store in a dark cupboard for 90 min to 150 min, calculated from the time of removal from reflux.
11.4 Place the filter paper, folded as shown in Fig. 2 (so as to prevent loss of asphaltenes by creeping), in the filter funnel, using
forceps. Thereafter, handle the filter paper only with forceps. Without agitation, decant the liquid into the filter paper, and then
transfer the residue in the flask as completely as possible with successive quantities of hot heptane, using the stirring rod (see 6.14)
as necessary. Give the flask a final rinse with hot heptane, and pour the rinsings through the filter. Set the flask aside, without
washing, for use as specified in 11.6.
11.5 Remove the filter paper and contents from the funnel, and place in the reflux extractor (see 6.3). Using a flask different from
that used initially, reflux with heptane (see 7.2) at a rate of 2 drops ⁄s to 4 drops ⁄s from the end of the condenser for an ex
...