ASTM D1364 for Water in Volatile Solvents (Karl Fischer Reagent Titration Method)
1. Scope
1.1 This test method covers the determination of water in volatile solvents and chemical intermediates used in paint, varnish, lacquer, and related products.

1.2 This test method is not applicable in the presence of mercaptans, peroxides, or appreciable quantities of aldehydes or amines.

1.3 For purposes of determining conformance of an observed or a calculated value using this test method to relevant specifications, test result(s) shall be rounded off "to the nearest unit" in the last right-hand digit used in expressing the specification limit, in accordance with the rounding-off method of Practice E 29.

1.4 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.

1.5 For hazard information and guidance, see the supplier's Material Safety Data sheet.

2. Referenced Documents
2.1 ASTM Standards:
D1500 Test Method for ASTM Color of Petroleum Products (ASTM Color Scale)
E 29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications

3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 instrumental end point - that point in the titration when two small platinum electrodes, upon which a potential of 20 to 50 mV has been impressed, are depolarized by the addition of 0.05 mL of Karl Fischer reagent (6 mg of H2O per mL), causing a change of current flow of 10 to 20 µA that persists for at least 30 s.

NOTE 1 - This end point is sometimes incorrectly called the "dead stop" which is the reverse of the above.

3.1.2 color end point - During the titration, the solution first turns yellow, then later deepens towards the end of the titration; the end point is indicated by the change from yellow to orange-red which is quite sharp and easily repeated. The orange-red color must persist for at least 30 s in order to indicate an end point.

NOTE 2 - View the color by transmitted daylight or by transmitted light from an artificial daylight lamp, such as the one that complies with the specifications given in Test Method D1500.