Synthesis Of Several Metal Ion Fluorescent Probes And Their Applications In Herbal

As a treasure of our country,traditional Chinese medicine has a unique role in preventing and curing diseases.In recent years,with the rapid development of Chinese medicine,the demand for herbal medicine is increasing,and its quality has also attracted people’s attention.Among them,the pollution of harmful metal ions has become an important factor affecting the quality of herbal medicines.Therefore,the rapid and simple analysis of harmful metal ions in herbal medicines has become a research hotspot for inspectors.In this paper,three types of organic small molecule fluorescent probes were designed and synthesized,and were used for the detection of harmful metal ions in herbal medicine.The specific research contents are as follows:1.Preparation of fluorescent probe TAA-S and its recognition and detection of Hg²⁺.N-（1,1’-biphenyl-4-yl）-9,9-dimethyl-9H-fluoren-2-amine and p-chlorob-enzaldehyde coupled to obtain triarylamine derivatives,the thioacetal protection reaction was carried out to prepare the triarylamine fluorescent probe TAA-S.In the mixed system of ACN/HEPES（v:v=9:1,pH=7.4）,the probe promoted the deprotection of thioacetal through Hg²⁺,and realized the specific"turn-off"detection of Hg²⁺.Experiments show that the probe had the advantages of short response time,good ion selectivity,and strong resistance to interf erence from other metal ions in the Hg²⁺detection process.At the same time,the detection limit was as low as 1.57×10^-8mol/L,which could achieve trace amounts of Hg²⁺detection.The method was applied to the detection of Hg²⁺in herbal medicine,and it was found that the recovery rate of the experimental addition was within97.0%～104.3%,and the relative standard deviation was belo w 2.7%,and a good detection effect was obtained.2.The preparation of fluorescent probe CA-H and its recognition and detection of Cu²⁺or Ni²⁺.A Schiff base fluorescent probe CA-H was designed and synthesized from 7-（diethylamino）coumarin-3-formaldehyde and methyl hydrazine carboxylate.The probe had cyan fluorescence in methanol solution.After recognizing Cu²⁺or Ni²⁺,the fluorescence of probe CA-H was quenched quickly,which could realize the"turn-off"naked eye detection of Cu²⁺or Ni²⁺.The detection limits of the probe for Cu²⁺and Ni²⁺were 1.70×10^-8mol/L,2.30×10^-8 mol/L.The recovery test of Cu²⁺in herbal medicine showed that the experimental recovery rate was between 95.6%～100.5%and98.6%～103.8%,the relative standard deviation was below 3%.The recovery test of Cu²⁺in herbal medicine showed that the experimental recovery rate was between 95.6%～100.5%and the relative standard deviation was below 3%.The probe could be used for the trace detection of Cu²⁺in herbal medicine.3.Preparation of fluorescent probe NA-M and its recognition of Al³⁺and F^-.The prepared 6-amino-m-cresol diazonium salt aqueous solution was added dropwise to the methanol solution of 1-naphthol to obtain an azo structure fluorescent probe NA-M through the occurrence of electrophilic substitution reaction.In the Me OH/HEPES（v:v=9:1,p H=7.4）solution,the probe was rapidly complexed with Al³⁺to achieve"turn-on"detection of Al³⁺,with a detection limit of 8.4×10^-7mol/L.The detection results of added scalar Al³⁺in herbal medicine showed that the experimental recovery rate was between 97.0%～101.6%and the relative standard deviation was below 1.8%,which indicated that this method could measure the harmful metal Al³⁺in herbal medicine.In addition,the probe NA-M+Al³⁺system could realize the"turn off"detection of F^-based on the strong complexation ability of Al³⁺with F^-,The detection process had the characteristics of good ion selectivity and strong anti-anion interference.At the same time,the detection limit of F^-was 9.5×10^-7mol/L.and the probe has good performance in reproducible and reproducible use.The probe NA-M synthesized in this paper could simultaneously detect Al³⁺and F^-in series.In this paper,mercury,copper,nickel and aluminum fluorescent probes were designed based on the chemical characteristics of harmful metals.The probes and intermediate compounds synthesized in this paper were characterized by ¹H NMR,¹³C NMR,IR and HRMS.The qualitative and quantitative analysis of harmful metal ions was carried out by using fluorescent probe technology,and the meth od was applied to the detection of harmful metal content in Chinese herbal medicine,which has a certain significance in the field of harmful metal analysis and detection.