Separation and Analysis of Dust in Lung Tissue

A coordinated procedure has been developed for the separation and subsequent x-ray diffraction analysis of dust in lung tissue. The tissue, preserved in 10% formalin, is dried at 110° C and then defatted with an azeotropic mixture of methyl alcohol and chloroform. Organic matter is destroyed by digestion on a hot plate with 30% hydrogen peroxide in the presence of an antifoaming agent. The dust, with or without added internal standard, is dispersed ultrasonically with the aid of a wetting agent and mounted for x-ray diffraction analysis by filtration of die suspension through a membrane filter disc. The method is applicable as a standard, routine technique to the analysis of relatively small specimens of lung tissue submitted for confirmation of pathologic findings.