Investigation of a dual filter sampling method for gaseous and particulate fluoride.

A two stage filter method designed to separate gaseous and particulate fluoride utilizing an alkaline treated filter to trap gaseous fluoride and post sampling heat treatment of the filters to promote desorption of gaseous fluoride from particulate phase was compared to standard impinger methods for the collection of hydrogen fluoride. Results indicate a high degree of comparability between the two methods. Initial studies involving the recovery of HF from dusted filters by heat treatment suggest recovery rates may vary directly with the amount of HF sampled for a given dust load.