在pH=5.00的HAc-NaAc介质中,铽(Ⅲ)与甲苯磺酸妥舒沙星发生络合,产生稀土敏化荧光现象,使铽(Ⅲ)的λem=545nm处荧光增强最为显著,当适量叶酸加入时,铽(Ⅲ)的荧光强度明显下降,以此建立了简单、快速、灵敏的测定叶酸的荧光分析方法。叶酸溶液在7.3×10-5—5.6×10-8mol/L浓度范围内符合线性关系,方法检出限为8.1×10-9mol/L。该法用于叶酸片剂中叶酸含量的测定,其回收率为98.4%—102.9%。 Terbium (Ⅲ) complexed with tosufloxacin tosylate in the HAc-NaAc medium at pH = 5.00, resulting in the rare earth sensitized fluorescence that maximized the fluorescence at λem = 545 nm of terbium (III) The fluorescence intensity of terbium (Ⅲ) decreased obviously when the appropriate folic acid was added, so a simple, rapid and sensitive method for the determination of folic acid was established. The concentration of folic acid in the concentration range of 7.3 × 10-5-5.6 × 10-8mol / L fitted a linear relationship with the detection limit of 8.1 × 10-9mol / L. The method for the determination of folic acid tablets folic acid content, the recovery was 98.4% -102.9%.