Electrospinning Nanofiber Solid-phase Micro-extraction Of Charged Compounds In Water

With the continuous development of industrialization,the discharge of heavy metal ions and metal oxygenated acid roots causes serious pollution to the water environment.However,due to the complex environment and low ion concentration,it is difficult to conduct direct sample injection analysis.Therefore,it is extremely important to find a fast,efficient and sensitive heavy metal detection and analysis method.In view of its advantages of simple operation,high enrichment ratio and high determination efficiency,SPME has a broad application prospect in environmental analysis.In this paper,the mixed charged materials containing metallic elements were taken as an example.The modified electrostatically spun nanofiber membrane was used to conduct the electro-assisted solid-phase microextraction(EA-SPME).to enrich metal ions in water.The mixed system was measured by UV-Vis spectrophotometry and quantitatively analyzed by using the PLS model.Firstly,modified polyvinylidene fluoride 2-acrylamide-2-methyl propane sulfonate(PVDF-AMPS)nanofiber membranes were prepared by electrospinning method.The effects of the voltage,the use of modified substances and the voltage,time and elution conditions during the electrostatic spinning process on the extraction efficiency were investigated.The extraction performance of the nanofiber membrane was evaluated by using the method of ultraviolet detection combined with the PLS model analysis.The results showed that the enrichment multiple of PVDF-AMPS nanofiber membrane for Cu2+,Ni2+ and Co2+ mixed metal ions was more than 20 times.Secondly,the PVDF-AMPS nanofiber membrane and PVDF-dodecylamine modified nanofiber membrane were used for the electro-assisted solid phase microextraction of trace metal oxygenated anion mixture in water.The extraction effect of the membrane was enhanced by optimizing the elution solution,pH value,extraction voltage,extraction time and other parameters.The results showed that the linear correlation coefficients of,MnO4-?CrO42-and V2O5-were all greater than 0.99,RMSECV were 1.7837,1.9850 and 1.1941,respectively,and the enrichment multiple of PVDF-AMPS electrostatic spinning nanofiber membrane for electro-assisted solid-phase microextraction could reach more than 19 times.To sum up,the effect of PVDF-AMPS electrostatic spinning nanofiber membrane on the adsorption of cations and anions in water by electro-assisted solid-phase microextraction is outstanding,which confirms the modification effect of AMPS on PVDF electrostatic spinning nanofiber membrane.Among them,the combination of ultraviolet visible spectrophotometry and stoichiometry for the detection of mixed substances is simple and effective,and the model error is small,which can be widely used for the detection of trace charged substances in water.