Investigation of the thermal degradation of bi-tertiary butyl-peroxide in the capillary column of a gas Chromatograph

Abstract

Reactions in gas-chromatographic packed columns have been reported by many authors [1-4] . However, as a rule, these experiments have been carried out during the run of the substance through the column. Therefore, reliable results for peak areas are hardly achievable because of broadening and overlapping of the peaks. During experiments using the gas chromatograph as an instrument to carry out physicochemical measurements we found a method for the investigation of thermal decomposition reactions in a capillary column. This is exemplified by the gas phase degradation of di-tertiary butylperoxide (DBP) to give ethane and acetone. A Hewlett-Packard gas chromatograph Mod. 5880 A with an automatic sampler was modified by putting additional magnetic valves into the carrier gas gauge system so that it was possible to stop the gas flow through the capillary column for an exactly defined time period. When the carrier gas flow was stopped, the temperature of the oven was raised and kept constant at a higher level. After the heating period the oven was cooled down and the carrier gas flow was switched on again. The decomposition products and the undegraded DBP were separated on the column and detected by a flame ionisation detector as sharp peaks. The entire prcedure was automated so that it can be run outside the daily working hours, such as overnight.