Analytic aspects of the chemical behaviour of 8-hydroxyquinoline (oxine)

As a result of the study of the chemical behaviour of some metallo-oxinates it is shown that : 1. A fluorescence test can be used to detect the presence of calcium, magnesium and aluminium in paper. The test is made by spotting the paper or its ash with a solution of oxine and examining tlie spot in the ultraviolet light. 2. A test for a fluoridc can be based on the inability of a qualitative filter paper which has been exposed to hydrogen fluoride to form fluorescent oxinate by spotting with oxine. 3. A test for a cyanide can be based on the liberation of oxine from coppcr(II)oxinate and the detection of the oxine by the formation of fluorescent aluminium oxinate. 4. Some non-fluorescent oxinates are able to quench the fluorescence of aluminium oxinate dissolved in chloroform. 5. The oxinates of aluminium, gallium, and iron(III) have a remarkable resistance to the action of 3N hydrochloric acid, whereas all other oxinates dissolve immediately. An explanation for this behaviour is proposed.