一种基于Fe-化学传感器为基础评判鞣酸铁墨水字迹形成时间的方法

为探索利用化学传感器对鞣酸铁墨水字迹色痕形成时间的精确分析,构建了以Fe-化学传感器为基础判定鞣酸铁墨水字迹色痕形成时间的识别模型,即采用邻菲啰啉识别Fe^(2+)的质量浓度和磺基水杨酸识别Fe^(3+)的质量浓度。研究结果表明,在1年之内,鞣酸铁墨水字迹色痕提取液中,Fe^(2+)的质量浓度随着时间的推移呈现逐渐减少的趋势,鞣酸铁墨水字迹色痕提取液中,Fe^(3+)的质量浓度随着时间的推移呈现逐渐升高的趋势;超过1年之后,提取液中Fe^(2+)、Fe^(3+)质量浓度都呈现减少的趋势,这种变化规律归属于被空气中氧气的氧化和载体中纸张的吸附作用力引起的变化规律。该方法可成功地检测不同年代的样本中鞣酸铁墨水字迹色痕的形成时间,通过与同期样品进行双重比对检验的方式判断鞣酸铁墨迹色痕的形成时间。最后,依据不同年代的样本测试数据,拟合出鞣酸铁墨水中Fe^(2+)、Fe^(3+)与时间的变化规律,并在真实的样本中得到了验证。

A reversible fluorescent chemosensor for Fe^(3+) and H_2PO_4^- with “on-off-on” switching in aqueous media

To realize highly selective relay recognition of Fe3＋ and H2PO4^- ions, a simple benzimidazole-based fluorescent chemosensor （L） was designed and synthesized. Sensor L displays rapid, highly selective, and sensitive recognition to Fe^3＋ in H2O/DMSO （1：1, v/v） solutions. The in stitu-generated L-Fe^3＋ complex solution exhibits a fast response and high selectivity toward dihydrogen phosphate anion via the Fe^3＋ displacement approach. The detection limits of sensor L to Fe^3＋ and L-Fe^3＋complex to H2PO4 anion were estimated to be 1.0 × 10^-9 mol/L. Notably, the sensor was retrievable to indicate dihydrogen phosphate an- ions with Fe^3＋, and HePO4 , in turn, increased. This successive recognition feature of sensor L makes it a potential utility for Fe^3＋ and H2PO4 anion detection in aqueous media.