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Tetramethylammonium hydroxide (TMAH or TMAOH) is a quaternary ammonium salt with the molecular formula N(CH3)4+ OH−.
T 1478 (OTTO) Tetramethylammonium hydroxide 1M solution in methanol Cas 75-59-2 - used for computer silicon wafer surface brighteners and as a cleaning agent. It is also involved in the purification of some metallic elements.