| 摘要 |
In a titration compsn. contg. an amine, SO2 and I2, the amine is (a) an aliphatic opt. 1.2 or 3 O atom-contg. amine, (A), or (b) a 5- or 6-membered, opt. substd. heterocyclic cpd., (B), contg. at least 2 heteroatoms, at least 1 heteroatom being an N atom. Molar ratio (A): SO2 is 0.5:1 to 1.3:1, while molar ratio (B): SO2 is 10:1 to 0.5:1. The compsn. is used as a 2- or 1-component reagent for determining small water quantities in solids or liqs., e.g. inorganic salts, organic solvents, fats, oils, foods and pharmaceuticals, by the Karl Fischer method. The compsn. can also be used as electrolyte for coulometric water determination. The compsn. has high storage-stability, e.g. over 12 months, and even over 2 years on using (B), as a 2-component reagent, and 3 weeks, even 1 year on using (B), as a 1-component reagent. A high reaction velocity can be achieved. The titration end-point is clearly visible as a colour-change from colourless to brown. |
