Study On The Pretreatment Of Neonicotinoid Insecticides With Porous Polymers With β-CD As Skeleton

Purposes:Neonicotinoids(NNIDs)are a new class of insecticides,which are widely used due to their wide range of action,convenient application,and low toxicity to non-target organisms.However,recent studies have found that NNIDs exist in the environment for a long time,which will cause chronic damage to insects,aquatic organisms,and humans,and affect ecological safety.Therefore,it is of great significance to develop a sensitive and accurate analytical method to detect trace NNIDs in the environment for the protection of the environment and human health.This study intends to synthesize Porous β-CD-containing polymers(P-CDP)withβ-cyclodextrin(β-CD)and tetrafluoroterephthalonitrile(TF),and used the polymer to realize the specific adsorption and pretreatment research of a variety of NNIDs in water samples,and combined with ultra-high performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS)for the qualitative and quantitative analysis of NNIDs.Method:After learning and improving the synthesis method of P-CDP in the literature,using β-CD and TF as raw materials,P-CDP was successfully synthesized through a simple constant temperature bath method.The Dispersive solid-phase extraction(DSPE)method was established on the basis of P-CDP,and the vortex extraction time,desorption solvent,vortex desorption time,p H and ionic strength in the DSPE process were optimized,and The parameters of UPLC-MS/MS were optimized to obtain the best conditions of the instrument.Scanning electron microscope was used to observe the form of P-CDP,and the reaction mechanism ofβ-CD and TF to synthesize P-CDP was explored by infrared spectroscopy.And use it for actual sample detection.Result:A light yellow powder P-CDP was successfully synthesized using the mixed solvent method.Vortex extraction for 5 min,desorption solvent is acetonitrile,vortex desorption for 2 min,p H value is 7,and no NaCl is the best condition.Under the best experimental conditions,the five NNIDs have good linearity in the range of1～200μg/L(r>0.99),the limit of detection(LOD,S/N=3)and the limit of quantitation(LOQ,S/N=10)is low,reaching 0.11～0.57 μg/L and 0.37～1.90 μg/L,the recovery rate is 74.58%～119.06%,and it can be reused more than three times.Using the two-way ANOVA to compare the new method constructed with the traditional solid phase extraction(SPE)detection results,there was no statistical difference(P>0.05).Conclusion:P-CDP has excellent adsorption capacity for a variety of NNIDs.The method is simple,stable,and inexpensive,and has satisfactory recovery and reusability for NNIDs.It can be used for rapid separation and detection of NNIDs in various water samples.