“…The alumina3 for thin-layer chromatography was processed according to the method of Malaiyandi et a/. (9) with plates activated at 120" instead of 14.5". Aqueous hydrochloric acid, 6 N ; aqueous sodium nitrite solution, 1 .O % ; aqueous ammonium sulfamate solution, 5.0 %; Bratton-Marshall reagent (aqueous N-( 1-naphthy1)ethylenediamine dihydrochloride), 0.1 %.…”