ASTM D890-98(2008)
(Test Method)Standard Test Method for Water in Liquid Naval Stores
Standard Test Method for Water in Liquid Naval Stores
SIGNIFICANCE AND USE
Many naval stores products contain water as a result of the processes used for their production. Typically refined products such as terpenes, pine oil, tall oil fatty acids, and distilled tall oil contain only traces of water, but crude tall oil might contain 0.5 to 2.5 % of water. Although the Karl Fischer and coulometric methods are most applicable to low levels of moisture, these can be and are used at higher levels. The azeotropic distillation method is generally used at higher levels.
SCOPE
1.1 These test methods cover the quantitative determination of dissolved or occluded water present in any proportion in liquid naval stores, such as turpentine, pinene, dipentene, pine oil, tall oil, and tall oil fatty acids. Three methods of moisture testing are included. The Karl Fisher titration method is the preferred method for testing tall oil, Test Methods D 803.
1.1.1 The Karl Fischer Titration method is based on the reaction between water and a complex reagent consisting of iodine, sulfur dioxide, pyridine, and methanol, whereby the iodine is converted to a colorless compound. The appearance of a persistent iodine color in the reaction mixture indicates the complete removal of free water by reaction with the reagent, and the endpoint may be measured colorimetrically. Automatic titrators find this endpoint by the restoration of a current strength when the resistance provided by the presence of water is eliminated. Amperometric automatic titrators find this endpoint by detecting the current flow that occurs once water is eliminated.
1.1.2 The coulometric titration method determines water content by electronic integration of a current sufficient to generate the precise amount of iodine from the required reagent to react with the water in the sample.
1.1.3 The azeotropic method utilizes the relatively low boiling point of water, as compared with other sample constituents, in a toluene or xylene matrix so that water is collected in a trap and measured.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 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 health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D890 − 98 (Reapproved 2008)
StandardTest Method for
Water in Liquid Naval Stores
This standard is issued under the fixed designation D890; 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 1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
1.1 These test methods cover the quantitative determination
responsibility of the user of this standard to establish appro-
of dissolved or occluded water present in any proportion in
priate safety and health practices and determine the applica-
liquid naval stores, such as turpentine, pinene, dipentene, pine
bility of regulatory limitations prior to use.
oil, tall oil, and tall oil fatty acids. Three methods of moisture
testing are included. The Karl Fisher titration method is the
2. Referenced Documents
preferred method for testing tall oil, Test Methods D803.
2.1 ASTM Standards:
1.1.1 The Karl Fischer Titration method is based on the
2 D803 Test Methods for Testing Tall Oil
reaction between water and a complex reagent consisting of
D1364 Test Method for Water in Volatile Solvents (Karl
iodine, sulfur dioxide, pyridine, and methanol, whereby the
Fischer Reagent Titration Method)
iodine is converted to a colorless compound. The appearance
of a persistent iodine color in the reaction mixture indicates the
3. Significance and Use
complete removal of free water by reaction with the reagent,
3.1 Many naval stores products contain water as a result of
and the endpoint may be measured colorimetrically.Automatic
the processes used for their production. Typically refined
titrators find this endpoint by the restoration of a current
products such as terpenes, pine oil, tall oil fatty acids, and
strength when the resistance provided by the presence of water
distilled tall oil contain only traces of water, but crude tall oil
is eliminated. Amperometric automatic titrators find this end-
might contain 0.5 to 2.5 % of water.Although the Karl Fischer
point by detecting the current flow that occurs once water is
and coulometric methods are most applicable to low levels of
eliminated.
moisture, these can be and are used at higher levels. The
1.1.2 The coulometric titration method determines water
azeotropic distillation method is generally used at higher
content by electronic integration of a current sufficient to
levels.
generatethepreciseamountofiodinefromtherequiredreagent
to react with the water in the sample.
1.1.3 The azeotropic method utilizes the relatively low
Moisture By Karl Fischer Titration
boiling point of water, as compared with other sample
(Preferred method)
constituents, in a toluene or xylene matrix so that water is
collected in a trap and measured. 4. Apparatus
4.1 Titration Vessel, preferably closed, with stirring
1.2 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this capabilities,
standard.
4.2 Buret, capable of being read at 0.1 mL divisions, or
automatic buret, or
This test method is under the jurisdiction of ASTM Committee D01 on Paint 4.3 Automatic Karl Fischer titrator.
and Related Coatings, Materials, andApplications and is the direct responsibility of
4.4 Balance, capable of weighing to the nearest 0.0001 g.
Subcommittee D01.34 on Naval Stores.
Current edition approved June 1, 2008. Published June 2008. Originally
5. Reagents
approved in 1946. Last previous edition approved in 2003 as D890 - 98 (2003).
DOI: 10.1520/D0890-98R08.
5.1 Karl Fischer Reagent, or Other Suitable Reagent, such
This procedure has been adapted from the method of Karl Fischer published in
as Pyridine-free Adaptations of Karl Fischer Reagent . Re-
Zeitschrift für Angewandte Chemie, Vol 48, 1935, p. 395; Chemical Abstracts,Vol
29, 1935 p. 6532; as modified by Smith, Bryant, and Mitchell, Journal , Am.
agents vary in strength (titer). This test method is written
Chemical Soc., Vol. 61, 1939, p. 2407; and further modified by Axel Johansson,
Svensk Papperstidning , Vol 50, No. 11B, 1947, p. 124; see also Publication 19 of
the Swedish Wood Research Institute, Wood Chemistry and Paper Technique For referenced ASTM standards, visit the ASTM website, www.astm.org, or
(Stockholm) (1947). Karl Fischer reagent is available from various laboratory contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
supplies. Pyridine-free adaptations of the Karl Fischer reagent are available Standards volume information, refer to the standard’s Document Summary page on
commercially. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D890 − 98 (Reapproved 2008)
assuming a titer of 5 mg water/mL reagent. Recommended practical to measure the precision for moisture content of
additions of water in this test method may need to be adjusted Naval Stores products, since these test methods are applicable
depending on the titer of the reagent. to many of these products that vary widely in purity, and the
precision would vary with the purity of each product.
5.2 Methanol—ACS grade.
Moisture By Coulometric Titration
6. Standardization of Iodine Reagent
10. Apparatus
6.1 Add methanol to the titration vessel, and titrate with
reagent until the lemon-yellow color just changes to a red-
10.1 Coulometric Karl Fischer Titrator.
brown color, or, if an automatic titrator is used, until the
10.2 Sample Vials, 8-mL or 4-dram
readings indicate no free water present. The titration vessel is
10.3 Medicine Dropper.
now ready for titrating, and is considered conditioned.
10.4 Disposable Plastic Syringes , 1-cc with 16, 18 or 20
6.2 Add a drop of water, weighed to the nearest 0.0001 g, to
gage needles.
the titration vessel by use of a transfer pipet, or a weighing
pipet, weighing the pipet before and after the addition. Each
10.5 Syringe, 10 µL
drop will weigh approximately 0.03 g and will require roughly
11. Reagents
6 mL of titrant having a titer of 5 mg/mL. Alternatively, a
25-µL, or other volume syringe may be used to introduce exact
11.1 See 5.1.
volumes.
12. Instrument Preparation
6.3 Titrate with reagent until the lemon-yellow color just
12.1 Prepare and calibrate the instrument according to the
changes to a red-brown color, or, if an automatic titrator is
manufacturer’s operating instructions. This generally includes:
used, until the readings indicate no free water present. Record
12.1.1 Clean and assemble the titration chamber.
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