ASTM D1744-92
(Test Method)Standard Test Method for Determination of Water in Liquid Petroleum Products by Karl Fischer Reagent (Withdrawn 2000)
Standard Test Method for Determination of Water in Liquid Petroleum Products by Karl Fischer Reagent (Withdrawn 2000)
SCOPE
1.1 This test method covers the determination of water in the concentration from 50 to 1000 mg/kg in liquid petroleum products.
1.2 Values stated in SI units are to be regarded as the standard. Inch-pound units are provided for information only.
1.3 This standard does not purport to address all of the safety problems, 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.> For specific precautionary statements see Notes 1 through 5.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
An American National Standard
Designation:D1744–92
Standard Test Method for
Determination of Water in Liquid Petroleum Products by
Karl Fischer Reagent
This standard is issued under the fixed designation D 1744; 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 (ϵ) indicates an editorial change since the last revision or reapproval.
This method has been adopted for use by government agencies to replace Method 3253 of Federal Test Method Standard No. 791b.
1. Scope 6. Apparatus
1.1 This test method covers the determination of water in 6.1 Assemble the apparatus as described in the Annex A1.
the concentration from 50 to 1000 mg/kg in liquid petroleum
7. Reagents and Materials
products.
7.1 Purity of Reagents—Reagent grade chemicals shall be
1.2 Values stated in SI units are to be regarded as the
standard. Inch-pound units are provided for information only. used in all tests. Unless otherwise indicated, it is intended that
all reagents shall conform to the specifications of the Commit-
1.3 This standard does not purport to address all of the
safety problems, if any, associated with its use. It is the tee onAnalytical Reagents of theAmerican Chemical Society,
where such specifications are available. Other grades can be
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- used, provided it is first ascertained that the reagent is of
sufficiently high purity to permit its use without lessening the
bility of regulatory limitations prior to use. For specific
precautionary statements see Note 1 through Note 5. accuracy of the determination.
7.2 Purity of Water—Unless otherwise indicated, references
2. Referenced Documents
to water shall be understood to mean distilled water or water of
2.1 ASTM Standards: equal purity. The solvents used must have low-water content,
D 4057 Practice for Manual Sampling of Petroleum and for example, less than 500 mg/kg mass.
2 5
Petroleum Products 7.3 Karl Fischer Reagent, Solution, Stock (Note 1) — For
each litre of solution, dissolve 85 6 1 g of iodine in 270 6 2
3. Summary of Test Method
mL of pyridine in a dry, glass-stoppered bottle. Add 670 6 2
3.1 The material to be analyzed is titrated with standard mL of methanol (99.9 %) (Note 2). Cool the mixture in an ice
Karl Fischer reagent to an electrometric end point.
bath to below 3.9°C. Bubble gaseous sulfur dioxide (SO )
(Note 3) through concentrated sulfuric acid (H SO , rel dens
2 4
4. Significance and Use
1.84)(Note4)intothecooledmixture.Continuetheadditionof
4.1 Knowledge of the water content of petroleum products
SO until the volume is increased 50 6 1 mL. Alternatively,
canbeusefultopredictqualityandperformancecharacteristics
add50 61mLoffreshlydrawnliquidSO insmallincrements
of the product.
to the precooled mixture in an ice bath. Mix well and set aside
for at least 12 h before using.
5. Interferences
NOTE 1—Warning: Toxic.
5.1 Free alkali, oxidizing and reducing agents, mercaptans,
NOTE 2—If 99.9 % methanol is not commercially available, it can be
certain basic nitrogenous substances, or other materials that
prepared by dissolving 24 g of magnesium metal turnings in 200 mL of
react with iodine, interfere. One part per million of sulfur as
methanol. Caution, the reaction is vigorous. When the reaction is
mercaptan causes an error in the titration, equivalent to complete, add 3 L of methanol. Reflux for 5 h and distill directly into the
approximately 0.2 mg/kg of water.
Any apparatus that will give equal or better precision is acceptable.
Reagent Chemicals, American Chemical Society Specifications, American
This method is under the jurisdiction of ASTM Committee D-2 on Petroleum Chemical Society, Washington, DC. For suggestions on the testing of reagents not
ProductsandLubricantsandisthedirectresponsibilityofSubcommitteeD02.02.0B listed by the American Chemical Society, see Analar Standards for Laboratory
on Sediment and Water. Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Current edition approved March 15, 1992. Published May 1992. Originally and National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,
published as D 1744 – 60 T. Last previous edition D 1744 – 83. MD.
2 5
Annual Book of ASTM Standards, Vol 05.02. Commercially prepared Karl Fischer Reagent may be used.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
D1744–92
container in which the 99.9 % methanol is to be kept. Vent the system
9.1.6 Dip the spatula into the solvent to ensure the removal
through a drying tube during the distillation.
of any adhering tartrate (Note 2). Stopper the flask and titrate
NOTE 3—Precaution: Follow standard safety precautions for handling
to the end point as described in 9.1.1.
toxic gases.
NOTE 6—To facilitate transferal of the tartrate to vessels having
NOTE 4—Warning: Poison. Corrosive. Strong oxidizer. Contact with
constricted openings or narrow necks, a spatula with the tip bent at a right
organic material can cause fire. Can be fatal if swallowed. Liquid and
angle to the handle is satisfactory.
vapor can cause severe burns. Harmful if inhaled. Contact with water
liberates large amounts of heat. Spillage can cause fire.
9.1.7 Determine the total water content of the sodium
tartrate dihydrate by drying a preweighed sample to a constant
7.4 Karl Fischer Reagent, Dilute Solution—Adjust the
mass in an oven at 150 6 5°C.
strength of the stock solution to a water equivalence of 2 to 3
9.1.8 Calculate the water equivalence of the Karl Fischer
mg of water per mL by dilution with pyridine.
reagent as follows:
7.5 Sample Solvent—Mix 1 volume of methanol (Note 3)
with 3 volumes of chloroform (Note 5). F 5 ~A 3 B!/100T (2)
NOTE 5—Warning: Can be fatal if swallowed. Harmful if inhaled. Can
where:
produce toxic vapors if burned.
F = the water equivalence of Karl Fischer reagent, mg/
mL,
8. Sampling
A = milligrams of sodium tartrate dihydrate used,
8.1 Take samples in accordance with the instructions in B = percentage of water in the sodium tartrate dihydrate,
Practice D 4057D 4057. and
T = millilitres of reagent required for titration of the water
in the sodium tartrate dihydrate.
9. Standardization of Karl Fischer Reagent
9.1 The dilute Karl Fischer reagent should be standardized
10. Procedure
at least daily in accordance with either 9.1.1 to 9.1.3 or 9.1.4 to
10.1 Add 50 mL of solvent to the titration flask and titrate
9.1.8.
with standardized Karl Fischer reagent to the end point as
9.1.1 Add 50 mL of the sample solvent to a clean, dry
described in 9.1.1. It is important to stopper the sample inlet
titration flask. Insert the stopper and adjust the magnetic stirrer
tube as quickly as possible to prevent absorption of moisture
to give a smooth stirring action. Turn on the indicating circuit
from the atmosphere.
and adjust the potentiometer to give a reference point with
10.2 Obtain a hydrometer reading on the material to be
approximately 1 µA of current flowing. Add Karl Fischer
tested and convert degrees API to relative d
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