ASTM E203-08
Standard Test Method for Water Using Volumetric Karl Fischer Titration

Standard No.

ASTM E203-08

Release Date

2008

Published By

American Society for Testing and Materials (ASTM)

Status

Be replaced

Replace By

ASTM E203-16

Latest

ASTM E203-24

Scope

Titration techniques using KF reagent are one of the most widely used for the determination of water.

Although the volumetric KF titration can determine low levels of water, it is generally accepted that coulometric KF titrations (see Test Method E 1064) are more accurate for routine determination of very low levels of water. As a general rule, if samples routinely contain water concentrations of 500 mg/kg or less, the coulometric technique should be considered.

Applications can be subdivided into two sections: (1) organic and inorganic compounds, in which water may be determined directly, and (2) compounds, in which water cannot be determined directly, but in which interferences may be eliminated by suitable chemical reactions or modifications of the procedure. Further discussion of interferences is included in Section 5 and Appendix X2.

Water can be determined directly in the presence of the following types of compounds:

Organic Compounds
Acetals	Ethers
Acids (Note 1)	Halides
Acyl halides	Hydrocarbons (saturated and unsaturated)
Alcohols	Ketones, stable (Note 4)
Aldehydes, stable (Note 2)	Nitriles
Amides	Orthoesters
Amines, weak (Note 3)	Peroxides (hydro, dialkyl)
Anhydrides	Sulfides
Disulfides	Thiocyanates
Esters	Thioesters
Inorganic Compounds
Acids (Note 5)	Cupric oxide
Acid oxides (Note 6)	Desiccants
Aluminum oxides	Hydrazine sulfate
Anhydrides	Salts of organic and inorganic acids (Note 6)
Barium dioxide
Calcium carbonate

Note 18212;Some acids, such as formic, acetic, and adipic acid, are slowly esterified. For high accuracy with pyridine-based reagents, use 30 to 50 % pyridine in methanol as the solvent. When using pyridine-free reagents, commercially available buffer solutions can be added to the sample prior to titration. With formic acid, it may be necessary to use methanol-free solvents and titrants (1).

Note 28212;Examples of stable aldehydes are formaldehyde, sugars, chloral, etc. Formaldehyde polymers contain water as methylol groups. This combined water is not titrated. Addition of an excess of NaOCH₃ in methanol permits release and titration of this combined water, after approximate neutralization of excess base with acetic acid (see Note 9).

Note 38212;Weak amines are consid.........

ASTM E203-08 Referenced Document

• ASTM D1123 Standard Test Methods for Water in Engine Coolant Concentrate by the Karl Fischer Reagent Method
• ASTM D1152 Standard Specification for Methanol (Methyl Alcohol)
• ASTM D1193 Standard Specification for Reagent Water
• ASTM D1348 Standard Test Methods for Moisture in Cellulose
• ASTM D1364 Standard Test Method for Water in Volatile Solvents (Karl Fischer Reagent Titration Method)
• ASTM D1533 Standard Test Method for Water in Insulating Liquids by Coulometric Karl Fischer Titration*， 2024-04-19 Update
• ASTM D1568 Standard Test Methods for Sampling and Chemical Analysis of Alkylbenzene Sulfonates
• ASTM D1631 Standard Test Method for Water in Phenol and Related Materials by the Iodine Reagent Method
• ASTM D2072 
• ASTM D2575 
• ASTM D3277 Standard Test Methods for Moisture Content of Oil-Impregnated Cellulosic Insulation
• ASTM D3401 Standard Test Methods for Water in Halogenated Organic Solvents and Their Admixtures
• ASTM D4017 Standard Test Method for Water in Paints and Paint Materials by Karl Fischer Method
• ASTM D4377 Standard Test Method for Water in Crude Oils by Potentiometric Karl Fischer Titration
• ASTM D4672 Standard Test Method for Polyurethane Raw Materials: Determination of Water Content of Polyols
• ASTM D4928 Standard Test Method for Water in Crude Oils by Coulometric Karl Fischer Titration
• ASTM D5460 Standard Test Method for Rubber Compounding Materials-Water in Rubber Additives
• ASTM D5530 Standard Test Method for Total Moisture of Hazardous Waste Fuel by Karl Fischer Titrimetry
• ASTM D6304 Standard Test Method for Determination of Water in Petroleum Products, Lubricating Oils, and Additives by Coulometric Karl Fischer Titration
• ASTM D789 Standard Test Methods for Determination of Relative Viscosity and Moisture Content of Polyamide (PA)
• ASTM D803 Standard Test Methods for Testing Tall Oil
• ASTM D890 Standard Test Method for Water in Liquid Naval Stores
• ASTM E1064 Standard Test Method for Water in Organic Liquids by Coulometric Karl Fischer Titration
• ASTM E180 Standard Practice for Determining the Precision of ASTM Methods for Analysis and Testing of Industrial and Specialty Chemicals

ASTM E203-08 history

• 2024 ASTM E203-24 Standard Test Method for Water Using Volumetric Karl Fischer Titration
• 2023 ASTM E203-23 Standard Test Method for Water Using Volumetric Karl Fischer Titration
• 2016 ASTM E203-16 Standard Test Method for Water Using Volumetric Karl Fischer Titration
• 2008 ASTM E203-08 Standard Test Method for Water Using Volumetric Karl Fischer Titration
• 2001 ASTM E203-01 Standard Test Method for Water Using Volumetric Karl Fischer Titration
• 2001 ASTM E203-96 Standard Test Method for Water Using Volumetric Karl Fischer Titration