Barium hydroxide, it absorbs very little CO in aqueous solutions and is therefore insensitive to atmospheric fluctuations. This property is used in calibrating pH equipment. Volatile barium compounds burn with a green to pale green flame, which is an efficient test to detect a barium compound. The color results from spectral lines at 455.4, 493.4, 553.6, and 611.1 nm. Organobarium compounds are a growing field of knowledge: recently discovered are dialkylbariums and alkylhalobariums. Barium found in the Earth's crust is a mixture of seven primordial nuclides, barium-130, 132, and 134 through 138. Barium-130 undergoes very slow radioactive decay to xenon-130 by
Barium perchlorate employing gases under pressure, as the water must be removed from the air prior to the reaction taking place. Barium perchlorate is also used for the determination of small concentrations (down to 10 ppm, with an accuracy of +/- 1 ppm) of sulfate. In order for the titration to be successful, a high concentration of a nonaqueous solvent, such as ethyl alcohol, 2-propanol, or methanol, must be present. Thorin is typically used as the indicator. Barium perchlorate Barium perchlorate is a powerful oxidizing agent, with the formula Ba(ClO). It is used in the pyrotechnic industry. Barium perchlorate decomposes at 505