ASTM D1123-99(2009)

1.1 These test methods cover the determination of the water present in new or unused glycol-based coolant concentrates using a manual (Test Method A) or an automatic (Test Method B) coulometric titrator procedure.

1.2 Many carbonyl compounds react slowly with the Fischer reagent, causing a fading end point and leading to high results. A modified Fischer reagent procedure is included that minimizes these undesirable and interfering reactions.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 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 hazards statements see Sections 8 and 16.
Significance and Use:

The total apparent water in engine coolant concentrate as determined by Karl Fischer titrations consists of the fol-
lowing: (1) water present in the original glycol base; (2) water added (for example, inhibitor solutions); (3) water of hydration of inhibitors (for example, Na ₂B₄O₇·5H₂O); ( 4) water formed in the chemical reaction between borate and ethylene glycol, producing boratediol condensate and water; and ( 5) quantitative interference by the reaction of the reagent with inhibitors such as tetraborate or sodium hydroxide.