Study of the fluorescence system thulium–bis(1′-phenyl-3′-methyl-5′-pyrazol-4′-one) hexanedione–cetyltrimethylammonium bromide and its analytical application

Abstract

The fluorescence system thulium–bis(1′-phenyl-3′-methyl-5′-pyrazol-4′-one)hexanedione–cetyltrimethylammonium bromide (Tm–BPMPHD–CTMAB) was studied. It was found that in aqueous solution Tm³⁺ could form an ion association complex with BPMPHD and CTMAB that could emit the intrinsic fluorescence of Tm³⁺. CTMAB could enhance the fluorescence intensity 25-fold. Based on the ion association system, a rapid, simple and sensitive method was developed for the determination of trace amounts of Tm³⁺ in samples containing rare earth elements. The composition of the ion association complex was determined to be 1:2:1 (Tm:BPMPHD:CTMAB).