Environmental Laboratory
Automatic Determination of the Hydroxyl Number According to ASTM E 1899-08 and DIN 53240-2
Feb 12 2010
Metrohm presents a fully automated titrimetric method for the determination of the hydroxyl number according to ASTM E 1899-08 and DIN 53240-2. The hydroxyl number is defined as the mg of KOH equivalent to the hydroxyl
content of 1 g of sample. The system used to carry out the test consists of: 814 USB Sample Processor, 905 Titrando, 800 Dosino, Solvotrode and the tiamo™ software.
The method suggested in ASTM E 1899-08 is based on the reaction of the primary and secondary hydroxyl groups with excess toluene-4-sulfonyl-isocyanate (TSI) to form an acidic carbamate. The latter can then be
titrated in a non-aqueous medium with the strong base tetrabutyl-ammonium hydroxide (TBAOH).
The method suggested in DIN 53240-2 is based on the catalyzed acetylation of the hydroxyl group. After hydrolysis of the intermediate, the remaining acetic acid is titrated in a non-aqueous medium with alcoholic KOH solution.
The two methods allow, for example, the determination of polyols and oxooils without any tedious and time consuming sample preparation and is therefore a big benefit for laboratories that have to analyse a great number of these samples per day.
Digital Edition
AET 28.2 April/May 2024
May 2024
Business News - Teledyne Marine expands with the acquisition of Valeport - Signal partners with gas analysis experts in Korea Air Monitoring - Continuous Fine Particulate Emission Monitor...
View all digital editions
Events
Jul 10 2024 Birmingham, UK
Jul 21 2024 Cape Town, South Africa
Australasian Waste & Recycling Expo
Jul 24 2024 Sydney, Australia
Jul 30 2024 Jakarta, Indonesia
China Energy Summit & Exhibition
Jul 31 2024 Beijing, China