ASTM D611-82(1998)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 611 – 82 (Reapproved 1998) An American National Standard
Designation: 2/98
Standard Test Methods for
Aniline Point and Mixed Aniline Point of Petroleum Products
and Hydrocarbon Solvents
This standard is issued under the fixed designation D 611; 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 (e) indicates an editorial change since the last revision or reapproval.
These test methods were adopted as a joint ASTM-IP standard in 1964.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope D 1500 Test Method for ASTM Color of Petroleum Prod-
ucts (ASTM Color Scale)
1.1 These test methods cover the determination of the
D 2700 Test Method for Knock Characteristics of Motor
aniline point of petroleum products and hydrocarbon solvents.
and Aviation Fuels by the Motor Method
Method A is suitable for transparent samples with an initial
E 1 Specification for ASTM Thermometers
boiling point above room temperature and where the aniline
point is below the bubble point and above the solidification
3. Terminology
point of the aniline-sample mixture. Method B, a thin-film
3.1 Definitions:
method, is suitable for samples too dark for testing by Method
3.1.1 aniline point—the minimum equilibrium solution
A. Methods C and D are for samples that may vaporize
temperature for equal volumes of aniline and sample.
appreciably at the aniline point. Method D is particularly
3.1.2 mixed aniline point—the minimum equilibrium solu-
suitable where only small quantities of sample are available.
tion temperature of a mixture of two volumes of aniline, one
Method E describes a procedure using an automatic apparatus
volume of sample, and one volume of n-heptane of specified
suitable for the range covered by Methods A and B.
purity.
1.2 These test methods also cover the determination of the
mixed aniline point of petroleum products and hydrocarbon
4. Summary of Test Methods
solvents having aniline points below the temperature at which
4.1 Specified volumes of aniline and sample, or aniline and
aniline will crystallize from the aniline-sample mixture.
sample plus n-heptane, are placed in a tube and mixed
1.3 This standard does not purport to address all of the
mechanically. The mixture is heated at a controlled rate until
safety concerns, if any, associated with its use. It is the
the two phases become miscible. The mixture is then cooled at
responsibility of the user of this standard to establish appro-
a controlled rate and the temperature at which two phases
priate safety and health practices and determine the applica-
separate is recorded as the aniline point or mixed aniline point.
bility of regulatory limitations prior to use. Specific precau-
tionary statements are given in Sections 7.1 and 7.3.
5. Significance and Use
5.1 The aniline point (or mixed aniline point) is useful as an
2. Referenced Documents
aid in the characterization of pure hydrocarbons and in the
2.1 ASTM Standards:
analysis of hydrocarbon mixtures. Aromatic hydrocarbons
D 1015 Test Method for Freezing Points of High-Purity
2 exhibit the lowest, and paraffins the highest values. Cyclopar-
Hydrocarbons
affins and olefins exhibit values that lie between those for
D 1217 Test Method for Density and Relative Density
2 paraffins and aromatics. In homologous series the aniline
(Specific Gravity) of Liquids by Bingham Pycnometer
points increase with increasing molecular weight. Although it
D 1218 Test Method for Refractive Index and Refractive
2 occasionally is used in combination with other physical prop-
Dispersion of Hydrocarbon Liquids
erties in correlative methods for hydrocarbon analysis, the
aniline point is most often used to provide an estimate of the
These test methods are under the jurisdiction of ASTM Committee D-2 on
aromatic hydrocarbon content of mixtures.
Petroleum Products and Lubricantsand are the direct responsibility of D02.04on
Hydrocarbon Analysis.
Current edition approved Aug. 27, 1982. Published January 1983. Originally
published as D 611 – 41 T. Last previous edition D 611 – 77. Annual Book of ASTM Standards, Vol 05.04.
2 4
Annual Book of ASTM Standards, Vol 05.01. Annual Book of ASTM Standards, Vol 14.03.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D611
taken to avoid contamination from atmospheric moisture (Note 2). It is
6. Apparatus
believed that under these conditions the aniline will remain unchanged for
6.1 For details of the aniline point apparatus required for
a period exceeding 6 months.
each method see:
7.2 Calcium Sulfate, anhydrous.
Annex A1 for Method A
7.3 n-Heptane (Warning—See Note 7), conforming to the
Annex A2 for Method B
Annex A3 for Method C
requirements listed in Table 1.
Annex A4 for Method D
Annex A5 for Method E NOTE 7—Warning: Flammable. Harmful if inhaled. See Annex A6.1.
NOTE 1—Alternative apparatus may be used, such as the U-tube
8. Sample
method for dark oils, provided it has been shown to give results of the
same precision and accuracy as those described in the Annexes. 8.1 Dry the sample by shaking vigorously for 3 to 5 min
with about 10 volume % of a suitable drying agent such as
6.2 Heating and Cooling Bath—A suitable air bath, a
anhydrous calcium sulfate or anhydrous sodium sulfate. Re-
nonvolatile, transparent liquid bath, or an infrared lamp (250 to
duce the viscosity of viscous samples by warming to a
375 W), provided with means for controlling the rate of
temperature below that which would cause the loss of light
heating.
ends or the dehydration of the drying agent. Remove any
NOTE 2—Water should not be used as either a heating or cooling
suspended drying agent by use of a centrifuge or by filtration.
medium since aniline is hygroscopic and moist aniline will give erroneous
Heat samples containing separated wax until they are homo-
test results. For example, the aniline point of the n-heptane reagent as
geneous and keep heated during filtration or centrifugation to
measured with aniline containing 0.1 volume % water is approximately
ensure against separation of wax. When suspended water is
0.5°C (0.9°F) higher than that measured with dry aniline. If the aniline
visibly present and the sample material is known to dissolve
point is below the dew point of the atmosphere, pass a slow stream of dry
inert gas into the aniline point tube to blanket the aniline-sample mixture. less than 0.03 mass % of water, the use of a centrifuge for the
removal of suspended water is an acceptable procedure.
6.3 Thermometers, having the following ranges and con-
forming to the requirements of the designated ASTM or IP
9. Procedure for Aniline Point
specification:
9.1 The following methods, to be used as applicable, are
ASTM
covered as follows:
Range (Specification E 1) IP
9.1.1 Method A, described in detail in Annex A1, is appli-
−38 to + 42°C (−36.5 to + 107.5°F) 33C, 33F 20C
cable to clear samples or to samples not darker than No. 6.5
25 to 105°C (77 to 221°F) 34C, 34F 21C
90 to 170°C (194 to 338°F) 35C, 35F 59C ASTM color, as determined by Test Method D 1500, having
initial boiling points well above the expected aniline point.
6.4 Pipets, with capacities of 10 6 0.04 mL, 5 6 0.02 mL,
9.1.2 Method B, described in detail in Annex A2, is appli-
the latter equipped with a long, fine tip. Provide a rubber
cable to light-colored samples, moderately dark samples, and
suction bulb for use with pipets when measuring aniline.
to very dark samples. It is suitable for samples that are too dark
6.5 Balance—A laboratory balance sensitive to 0.01 g,
to be tested by Method A.
suitable for weighing the tube and sample when the sample
9.1.3 Method C, described in detail in Annex A3, is appli-
cannot be pipetted conveniently.
cable to clear samples or to samples not darker than No. 6.5
6.6 Safety Goggles.
ASTM color, as determined by Test Method D 1500, having
6.7 Plastic Gloves, impervious to aniline.
initial boiling points sufficiently low as to give incorrect aniline
point readings by Method A, for example, aviation gasoline.
7. Reagents
9.1.4 Method D, described in detail in Annex A4, is appli-
7.1 Aniline (Warning—See Note 3.) Dry chemically pure
cable to the same type of sample as Method C. It is particularly
aniline over potassium hydroxide pellets, decant, and distill
useful when only limited quantities of sample are available.
fresh on the day of use, discarding the first and last 10 %.
Aniline thus prepared when tested with n-heptane according to
Section 9 shall give an aniline point of 69.3 6 0.2°C (156.7 6
0.4°F) as determined from the average of two independent tests These requirements for n-heptane are identical, except for tetraethyl lead, with
those prescribed in the 1987 Annual Book of ASTM Standards, Vol 05.04.
having a difference of not more than 0.1°C (0.2°F).
NOTE 3—Warning: Aniline should not be pipetted directly by mouth
TABLE 1 Requirements for n-Heptane
because of its extreme toxicity. Aniline is also toxic by absorption through
ASTM
the skin even in very small quantities, and should be handled with great
Method
caution.
ASTM Motor Octane Number 0.0 6 0.2 D 2700
NOTE 4—For routine purposes the distillation process is not mandatory
Density at 20°C, g/mL 0.68380 6 0.00015 D 1217
provided the aniline meets the requirements of the test with n-heptane.
20°C
Refractive index, n 1.38770 6 0.00015 D 1218
D
NOTE 5—The aniline point of aniline and n-heptane determined with
Freezing point, °C −90.710 min D 1015
automatic apparatus (Method E) shall be 69.3 6 0.2°C (156.7°F 6 0.4°F) A
Distillation, 50 % recovered at 98.427 6 0.025
when corrected in accordance with the equation in Section A5.2.1
1.013 bar (760 mm Hg), °C
NOTE 6—As an alternative to distilling the aniline on the day of use, the Differential, 80 % recovered minus 0.020 max
20 % recovered, °C
aniline may be distilled as described in 7.1, collecting the distillate in
A
ampoules, sealing the ampoules under vacuum or dry nitrogen, and storing
For equipment and method used, see Journal of Research, National Institute of
in a cool dark place for future use. In either case, rigid precaution must be Standards and Technology, Vol 44, No. 3, 1950, pp. 309 and 310 (RP2079).
D611
9.1.5 Method E is applicable when using automatic appa- the normal and correct operation of the test method, exceed the
ratus in accordance with the instructions in Annex A5. following values only in one case in twenty:
Repeatability
10. Procedure for Mixed Aniline Point
Aniline point of:
10.1 This procedure is applicable to samples having aniline
Clear, light-colored samples 0.16°C (0.3°F)
A
points below the temperature at which aniline crystallizes from
Moderately dark to very dark samples 0.3°C (0.6°F)
Mixed aniline point of:
the mixture. Pipet 10 mL of aniline (Warning: See Note 3), 5
A
Clear, light-colored samples 0.16°C (0.3°F)
mL of sample, and 5 mL of n-heptane into a clean, dry
A
Moderately dark to very dark samples 0.3°C (0.6°F)
apparatus. Determine the aniline point of the mixture by
__________
A
Not determined from recent cooperative tests; however, the ratios with those
Method A or B as described in Annex A1 or Annex A2.
given in the 1953 version are believed to apply.
12.1.2 Reproducibility—The difference between two single
11. Report
and independent results, obtained by different operators, work-
11.1 If the range of three successive observations of the
ing in different laboratories on identical test material, would in
aniline point temperature is not greater than 0.1°C (0.2°F) for
the long run, in the normal and correct operation of the test
light-colored samples or 0.2°C (0.4°F) for dark samples, report
method, exceed the following values only in one case in
the average temperature of these observations, corrected for
twenty:
thermometer calibration errors, to the nearest 0.05°C (0.1°F) as
12.2 Bias—A statement of bias is now being developed by
the aniline point.
the subcommittee.
11.2 If such a range is not obtained after five observations,
Reproducibility
repeat the test using fresh quantities of aniline and sample in a
clean, dry apparatus, and if consecutive temperature observa-
Aniline point of:
tions show a progressive change, or if the range of observations Clear, light-colored samples 0.5°C (0.9°F)
A
Moderately dark to very dark samples 1.0°C (1.8°F)
is greater than the repeatability given in 12.1, report the method
Mixed aniline point of:
as being inapplicable. A
Clear, light-colored samples 0.7°C (1.3°F)
A
Moderately dark to very dark samples 1.0°C (1.8°F)
12. Precision and Bias __________
A
Not determined from recent cooperative tests; however, the ratios with those
12.1 The precision of these test methods as obtained by
given in the 1953 version are believed to apply.
statistical examination of interlaboratory test results is as
12.3 The precision of this test was not obtained in accor-
follows:
dance with Committee D-2 Research Report RR:D02-1007,
12.1.1 Repeatability—The difference between successive
“Manual on Determining Precision Data for ASTM Methods
test results (two average temperatures obtained in a series of
on Petroleum Products and Lubricants.”
observations as described in Section 11 obtained by the same
13. Keywords
operator with the same apparatus under constant operating
conditions on identical test material, would in the long run, in 13.1 aniline point; aromatics; mixed aniline point
ANNEXES
(Mandatory Information)
A1. METHOD A
A1.1 Apparatus alternative for the manual operation.
A1.1.1 The apparatus shown in Fig. A1.1 shall consist of the
A1.2 Procedure
following:
A1.1.1.1 Test Tube, approximately 25 mm in diameter and
A1.2.1 Clean and dry the apparatus. Pipet 10 mL of aniline
150 mm in length, made of heat-resistant glass. (Warning— see 7.1) and 10 mL of the dried sample (8.1) into
A1.1.1.2 Jacket, approximately 37 to 42 mm in diameter the test tube fitted with stirrer and thermometer. If the material
is too viscous for pipetting, weigh to the nearest 0.01 g a
and 175 mm in length, made of heat-resistant glass.
quantity of the sample corresponding to 10 mL at room
A1.1.1.3 Stirrer, manually operated, metal, approximately 2
temperature. Center the thermometer in the test tube so that the
mm in diameter (14 B&S gage) metal wire as shown in Fig.
immersion mark is at the liquid level, making sure that the
A1.1. A concentric ring shall be at the bottom, having a
thermometer bulb does not touch the side of the tube. Center
diameter of approximately 19 mm. The length of the stirrer to
the test tube in the jacket tube. Stir th
...