Dynamic Microscopic Extraction of Europium(III) with 2-Thenoyltrifluoroacetone Observed as Random Fluorescence Flashes at Dodecane–Water Interface

Many random circular flashes of Eu(III) fluorescence (8–23 (mu)m in diameter) appeared at the interface in the extraction of Eu(III) with 2-thenoyltrifluoroacetone (Htta) into dodecane, when a Eu3+ aqueous solution was added after pre-distribution of Htta in the aqueous phase. The flash was caused by the interfacial reaction between a pre-generated micro-aggregate of Eu(tta)2+ in the aqueous phase and excess Htta in the dodecane phase. The interfacial reaction produced more fluorescent Eu(tta)3, which diffused away into the dodecane phase.