A novel fluorescent chelating ligand, 2,4-[bis-(2-hydroxy-3-methoxybenzylidene)]-dihydrazinoquinazoline (HBQZ), was synthesized, and the fluorescence characteristics of its complex with metal ions were investigated. Among the 36 different metal ions tested in this study, it was found that HBQZ emits intense fluorescence at 506 nm with an excitation wavelength of 414 nm in the presence of Zn2+. The fluorescence intensity was almost constant in the pH range 3.5—10.5. Complexes of other metal ions with HBQZ did not show fluorescence, and the detection limit of Zn2+ was approximately 250 nM (16 ppb). The proposed method was applied to the validation test of a bioactive compound containing Zn2+ in its structure—an antibacterial and antifungal reagent, zinc pyrithione (ZnPT). In order to effectively release Zn2+ from ZnPT, a pretreatment procedure involving heating with H3PO4 at 100 °C for 60 min was adopted. Under these conditions, a linear calibration curve was obtained in the ZnPT concentration range of 0.79—15.7 μM (0.25—5.0 ppm); the correlation coefficient and the relative standard deviation were 0.996 and within 3.1% (n=5), respectively.
合成了一种新型荧光螯合
配体--2,4-[双-(2-羟基-3-甲氧基亚苄基)]-二
肼基
喹唑啉(HBQZ),并研究了其与
金属离子配合物的荧光特性。研究发现,在 36 种不同的
金属离子中,当 Zn2+ 存在时,HBQZ 在激发波长为 414 nm 的 506 nm 处发出强烈的荧光。在 pH 值为 3.5-10.5 的范围内,荧光强度几乎保持不变。其他
金属离子与 HBQZ 的络合物不显示荧光,Zn2+ 的检测限约为 250 n
M(16 ppb)。该方法被应用于一种结构中含有 Zn2+ 的
生物活性化合物--抗菌抗真菌试剂
吡啶硫酮锌(Zn
PT)的验证测试。为了有效释放 Zn
PT 中的 Zn2+,采用了一种预处理程序,即在 100 °C 下用 H3PO4 加热 60 分钟。在此条件下,在 Zn
PT 浓度范围 0.79-15.7 μ
M(0.25-5.0 ppm)内获得了线性校准曲线;相关系数和相对标准偏差分别为 0.996 和 3.1% 以内(n=5)。