磺基水杨酸的荧光光谱与荧光量子产率

报道了磺基水杨酸 (SSA)的荧光光谱和荧光量子产率。在 pH <2时 ,SSA无荧光 ,随pH升高 ,SSA荧光增强 ,在 pH 5～ 10 5之间 ,SSA有稳定的强荧光 ,最大发射波长为 4 0 2nm ,激发波长为 2 12 ,2 38和2 97nm。在 pH >13的强碱性条件下 ,SSA转变为另一种荧光型体 ,最大激发波长 2 6 1nm ,最大发射波长390nm。SSA浓度较高时 ,荧光激发光谱发生变化 ,但发射光谱不变。在近中性条件下 ,SSA稀溶液的荧光强度与浓度之间存在良好的线性关系 ,线性范围为 5～ 2 5 0ng·mL- 1 ,检测下限为 5ng·mL- 1 。以硫酸奎宁为参比 ,测量了SSA在不同波长下的荧光量子产率 ,在最大激发波长 2 97nm处的荧光量子产率为 0 5 4。

Fluorescence Spectra and Fluorescence Quantum Yield of Sulfosalicylic Acid

Fluorescence spectra and fluorescence quantum yield of sulfosalicylic acid (SSA) have been studied. Under the condition of pH<2, SSA has no fluorescence. With the increase in pH value, fluorescence intensity of SSA increases. In the range of pH 5-10.5, SSA gives a strong and steady fluorescence with a maximum emission wavelength at 402 nm and excitation wavelengths at 212, 238 and 297 nm, respectively. In strong alkaline solutions with pH>13, SSA exists as another fluorescence species with a maximum excitation wavelength at 261 nm and a maximum emission wavelength at 390 nm. The excitation spectrum of SSA changes when its concentration is relatively higher, but the emission spectrum remains unchanged. There is an excellent linear relationship between fluorescence intensity and the concentration of SSA under neutral condition. The linear range is 5-250 ng x mL(-1), and the detection limit is 5 ng x mL(-1). Using quinine bisulphate as a reference, fluorescence quantum yields of SSA at different wavelengths were measured. At the maximum excitation wavelength 297 nm, fluorescence quantum yield of SSA is 0.54.