This Standard specifies the general method of the Karl Fischer method and electrometric method for the determination of free water or water of crystallization.
This Standard is applicable to the determination of free water or water of crystallization in most solid or liquid chemical products, both organic and inorganic.
This Standard is not applicable to the water content determination of test samples which may react with the main components of Karl Fischer reagent and produce water, and the test samples which produce iodine or iodine oxide by reduction reaction.
Pretreatment measures are necessary in certain cases and these are specified in the appropriate national standards.
The visual method can be used when no electrometric apparatus is available; as a direct tritration, it is applicable only to colourless solutions. The electrometric method involves either a direct titration or a back-titration, which is more accurate no matter either of them is adopted, and for this reason the electrometric method is recommended.
2 Normative References
The following normative documents contain provisions which, through reference in this text, constitute provisions of this Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies.
GB/T 6682 Water for Analytical Laboratory Use — Specification and Test Methods (GB/T 6682-2008, ISO 3696:1987, MOD)
1 Scope
This Standard specifies the general method of the Karl Fischer method and electrometric method for the determination of free water or water of crystallization.
This Standard is applicable to the determination of free water or water of crystallization in most solid or liquid chemical products, both organic and inorganic.
This Standard is not applicable to the water content determination of test samples which may react with the main components of Karl Fischer reagent and produce water, and the test samples which produce iodine or iodine oxide by reduction reaction.
Pretreatment measures are necessary in certain cases and these are specified in the appropriate national standards.
The visual method can be used when no electrometric apparatus is available; as a direct tritration, it is applicable only to colourless solutions. The electrometric method involves either a direct titration or a back-titration, which is more accurate no matter either of them is adopted, and for this reason the electrometric method is recommended.
2 Normative References
The following normative documents contain provisions which, through reference in this text, constitute provisions of this Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies.
GB/T 6682 Water for Analytical Laboratory Use — Specification and Test Methods (GB/T 6682-2008, ISO 3696:1987, MOD)
