| 摘要 |
An anhydrous composition for the detection of a substance in an aqueous fluid, comprising (A) a compound which reacts specifically with the substance to be detected, but only in an acidic medium, and (B) a solid addition product of a Friedel-Crafts salt (e.g. SnCl4, BCl3, BF3, AlCl3, FeCl3 or ZnCl2) and an organic Lewis base (e.g. an amine, amide, imide, urea, ether, cyclic ether or nitrile) which is hydrolysable by an aqueous fluid into a mineral acid which furnishes an acidic medium for the composition. The composition may also contain a neutral or weakly acidic salt to augment the buffering power of the acid formed by hydrolysis of (B). Colorimetric detection (i.e. quantitative, semi quantitative or qualitative analysis) of aqueous biological, industrial or other fluids employing reactions which only operate at an acidic pH. |
