Abstract: A process of purifying titanium tetrachloride by first refluxing titanium tetrachloride (TiCl4) with copper powder, rendering the impurities of vanadium, niobium and antimony nonvolatile, and then in a single step fractionally distilling the refluxed mixture to effectively and substantially reduce any arsenic, tin, niobium and vanadium in the titanium tetrachloride.

Abstract: The method measures hydrogen sulfide concentrations in hydride gases in a sealed vessel. The sealed vessel has a gas inlet to receive a stream of hydride gas, a gas outlet to remove the stream of hydride gas and a metal acetate substrate. The stream of hydride gas contains a concentration of hydrogen sulfide gas. Introducing the stream of hydride gas through the gas inlet contacts the acetate substrate with the stream of hydride gas. Reacting the hydrogen sulfide gas contained in the stream of hydride gas with the acetate substrate modifies optical properties of the acetate substrate. Then measuring the optical properties of the acetate substrate determines the concentration of the hydrogen sulfide gas contained in the stream of hydride gas.