Colorimetric indicator for aliphatic hydrocarbon vapour - contg. chromium, chromate or di:chromate, phosphoric acid and perchloric acid on carrier

摘要

Colorimetric indicator for determining aliphatic hydrocarbon (I) consists of a reagent mixt. based on a Cr-VI cpd., i.e. CrO3 or alkali metal (di)chromate, a pentavalent phosphoric acid and HClO4 on an inert porous carrier. Pref. the reagent mixt. also contains I2. The amts. used are ca. 0.15-0.6 g CrO3, 16-34 ml 85% H2PO4, 1-15 ml 70% HClO4 and 0-0.04 g I2; and ca. 20-35 ml reagent/100 g SiO2 gel carrier. USE/ADVANTAGE - The indicator is for use in a (I) gas detector. It is esp. useful for detecting leaks in transport or storage tanks for volatile (I) e.g. JP-10 rocket fuel. It can be used over long periods. When exposed to an atmos. contg (I), the colour changes from orange-yellow to green and then brown.