Determination of Tb(III) in aqueous solution by fluorescence spectrometry

형광분광법에 의한 수용액 중의 Tb(III) 정량

Methods to determine terbium(III) ion in aqueous solution by measuring the enhanced fluorescence intensity of terbium(III)-terephthalic acid(TPA) complex ion have been studied. The optimum analytical conditions for pH, excitation wavelength and concentration of TPA were found to be 6.0, 260nm and $4.0{\times}10^{-4}M$, respectively. The fluorescence intensity of the terbium(III) complex ion was further increased with addition of trioctylphosphine oxide (TOPO). In this case Triton X-100 was used to dissolve TOPO in aqueous solution. When TOPO was used, the optimum analytical conditions for pH, excitation wavelength, and concentrations of TPA, TOPO and Triton X-100 were found to be 4.5, 285nm. $4.0{\times}10^{-4}M$, $5.0{\times}10^{-5}M$, and 0.05%, respectively. Under the optimum experimental conditions, calibration curve for Tb(III) was linear over the range from $4.0{\times}10^{-8}M$ to $4.0{\times}10^{-5}M$ and the detection limit was $4.0{\times}10^{-8}M$. When TOPO was used, the concentration range of linear response, and the detection limit were $4.0{\times}10^{-9}M$ to $2.0{\times}10^{-6}M$, and $4.0{\times}10^{-9}M$, respectively. Effects of interferences from various cations for the determination of terbium(III) ion were also investigated.

형광광도법을 이용하여 수용액에서의 terbium(III) 이온을 terbium(III)-terephthalic acid(TPA) 착이온의 형광세기를 측정함으로써 정량하는 방법에 대하여 연구하였다. 들뜸파장, pH, TPA의 농도에 대한 최적 분석조건은 각각 260nm, 6.0, $4.0{\times}10^{-4}M$이었다. Trioctylphosphine(TOPO)을 Triton X-100에 용해시켜 이 용액을 첨가시켰을 때 형광세기가 현저히 증가함을 관찰하였으며, 이 경우의 최적 분석조건은 들뜸파장, pH, TPA의 농도, TOPO의 농도, Triton X-100의 농도에 대하여 각각 285nm, 4.5, $4.0{\times}10^{-4}M$, $5.0{\times}10^{-5}M$, 0.05%였다. Terbium 이온 검정곡선의 직선 감응범위와 검출한계는 TOPO를 첨가하지 않았을 경우에는 각각 $4.0{\times}10^{-8}M{\sim}4.0{\times}10^{-5}M$, $4.0{\times}10^{-8}M$이었고, TOPO를 첨가하였을 경우에는 각각 $4.0{\times}10^{-9}M{\sim}2.0{\times}10^{-6}M$, $4.0{\times}10^{-9}M$이었다. Terbium(III) 이온을 본 방법으로 정량할 때의 방해이온 효과에 대하여 조사하였다.