Reactive Conjugated Polymer Fluorescence Probes: Synthesis And Detection Of Fluorine Ions In Tea

As an important tea producing country,China enjoys a good fame in the whole world.It is worth noting that tea tree is a kind of plant with a large amount of fluorine,and tea is the main organ to accumulate fluorine.Water-soluable fluorine in tea can be dissolved in tea soup and absorbed by human body.However,if the human body ingests excessive fluorine,it will cause fluorosis,so it is very important for human health to accurately realize the content of fluorine in tea.Fluorescence probe has been widely used in fluoride detection due to its good sensitivity,strong selectivity and convenient operation.Firstly,two novel polymer probes(PBTPV-OSi and PBTFE-OSi)were synthesized by Heck coupling and Sonogashira coupling reactions,the structures of the related polymers and monomers were characterized by 1H NMR spectra,then the sensing properties of two polymer probes for fluorine ions were studied by UV-vis and fluorescence emission spectroscopy.The results show that no matter the fluorine ions come from organic or inorganic sources,PBTPV-OSi and PBTFE-OSi are new polymer materials with highly selectivity for F-,but compared with other factors such as quenching constants and Stokes shifts,the sensing performance of PBTPV-OSi is better than PBTFE-OSi.Three kinds of tea(Yunnan black tea,Maojian tea and jasmine tea)as raw materials,water as the soaking solvent,Alizarin complexant spectrophotometry was used as the standard method to measure the fluorine content in the tea,and the content of fluorine in tea was measured by spectrophotometry and fluorescence probe respectively,then practicability and accuracy of the fluorescence probe method were verified.Finally,the extraction conditions of Yunnan black tea with the highest fluorine content were optimized by single factor experiment and orthogonal experiment.The optimum temperature is 80?,the solid-liquid ratio is 1:38,and the dunking time is 80 minutes.