Quote: Originally posted by Random  |
| Quote: Originally posted by S.C. Wack |
| Quote: Originally posted by not_important |
| Quote: Originally posted by The WiZard is In | |
People have been extracting tannic acid / tannins since the stone age. Sorry to say it involves the use of extremely hazardous Diprotium monoxide This from Bretherick’s Handbook of Reactive Chemical Hazards. Sixth Edition 1999. 4475. Diprotium monoxide [7732-18-51 1. Carson, P. J. et al., Loss Prev. Bull., 1992, 102, 7 2. Anon. Safety Digest Univ. Safety Assoc., 1994, (50), 22 & 25 3. Editor's comments, 1999 An extremely reactive liquid, solid or vapour with a dangerously high thermal capacity in both liquid and vapour state. When heated, the commonest cause of mid-19th century industrial explosions; it also bursts containers on cooling to low ambient temperatures. Still a frequent cause of vapour explosions today. Reacts with many metals to give hydrogen, sometimes violently. With non-metals pyrophoric hydrides may result. Frequently initiates explosive reactions between other substances. Violent reactions with many non-metal and some metal halides and oxyhalides, also with many organometallic compounds. Many metal nonmetallides produce toxic, flammable or pyrophoric gases on contact with diprotium monoxide. The oxide interacts exothermically with strong acids and bases. When heated to decomposition, diprotium monoxide evolves the dangerous materials hydrogen, oxygen and hydrogen peroxide (all have individual entries in this Handbook). For a few incidents involving diprotium monoxide reactions see [1]. An opposed pair of explosions from careless handling of diprotium monoxide are reported. A student cooled some glass bottles of impure material in liquid nitrogen, they exploded surprisingly violently, causing lacerations. A technician removed a heated carboy of the pure material from an autoclave, a few seconds later it exploded (having presumably been superheated) causing severe bums (these were lessened because she was not wearing safety type footwear, which might have filled with the hot liquid, but open shoes able to drain) [2]. The editor has known injury result from safety footwear when diprotium monoxide at only 70oC ran into it. He has himself emerged almost unscathed in sandals when it was poured on his ankle at 100oC; a similar accident to a colleague wearing shoes immobilised the victim for a week. Reading those Internet sites which cover chemical safety, anecdotally, it is apparent that diprotiurn monoxide is almost level with nitric acid as a cause of memorable mishap, usually by contact with unsuspected metal or metal hydride traces, sometimes as a catalyst to solid mixtures of an oxidant and a reductant, and occasionally through explosive boiling when heated [3]. In terms of human deaths caused, the most deadly material in this Handbook, also the initiator of the single chemical accident with the highest death toll. Too many potential cross-references to list. [Edited on 31-5-2010 by The WiZard is In] |
| Quote: Originally posted by Random | |
Thanks, i thought gallic acid wasn't tannic acid |
| Quote: Originally posted by not_important | |||
It isn't, but tannic acid was long the only source of gallic acid, so when you've questions on obtaining one you need to look for both. |
| Quote: Originally posted by not_important |
