Solid-phase Microextraction Fibers Based Conjugated Microporous Polymers For Detection Of Trace Organic Pollutants In Water Samples

Trace organic pollutants can exist in the environment for a long time.It can be enriched through the food chain and cause serious harm to human health and the environment.Persistent organic pollutants are natural or synthetic organic pollutants,Because of the low levels of persistent organic pollutants in the environment and human body,it is difficult to detect them.Basically POPs contain hardly degradable benzene rings or chlorine substituents,POPs are characterized by their hard-to-degrade and strong toxicity,which increases the difficulty of targeted degradation.Therefore,deepening the basic research on POPs and completely eliminating its long-term harm to humans has become a worldwide focus.In this study,conjugated microporous polymers?PPc-CMPs?and covalent organic frameworks?Tppa-1?were successfully prepared.They were used as new solid phase microextraction coatings.Corresponding characterization of the two materials,and optimization of the factors affecting the extraction effect,Compare with commercially available materials and explore possible adsorption mechanisms.Finally,this method was validated in several actual water samples,proving a new method for solid phase microextraction,The main results of this paper are as follows:PPc-CMPs was synthesized according to the previous method.In brief,a mixture of TBB?50 mg,0.127 mmol?and BDBA?63.1 mg,0.381 mmol?in DMF?12 mL?was added to another mixture of an aqueous solution of K2CO3(1.0 mol L^-1,1.0 mL)and Pd?PPh₃?₄?12.0mg,10.4 mmol?.The mixture was purged with argon and stirred at 90°C for 20 h.The precipitate was filtered,washed with water and methanol to remove any unreacted monomers or catalyst residues,and dried at 70°C for several hours.Finally,PPc-CMPs as a gray solid was obtained.The material was used as a solid phase microextraction coating adsorbent and GC-MS/MS was used to detect trace amounts of phenols in drinking water.The experimental conditions,including extraction conditions?ionic strength,sample pH,extraction temperature,and time?and desorption conditions?desorption temperature and time?,were investigated and optimized in details to obtain high extraction efficiency.The linearity range of the phenols was 0.1¹000 ng^-1,with the correlation coefficient?r?ranging from 0.9907 to 0.9984.The limits of detection?LOD??S/N?3?and limits of quantification?LOQs??S/N?10?were0.02-0.05 and 0.06⁰.15 ng L^-1 for the five phenols,To assess its potential commercial value,the developed PPc-CMPs-coated fiber was compared with 85 mm PA fiber.good repeatability?2.47⁸.07%,n=5?and reproducibility 6.31⁹.22%,n=3)were achieved.The two fibers were used to extract 1.0 mgL-1 phenols in water samples under optimal conditions.the PPc-CMPs-coated fiber achieved higher extraction efficiencies than PA fiber for the five phenols.This method is applied to the analysis of actual water samples.The result is also satisfactory.The syntheses of TpPa-1 and TpPa-2 were carried out by the Schiff-base reactions of Tp?63 mg,0.3 mmol?with Pa-1?48 mg,0.45 mmol?and Pa-2?61 mg,0.45 mmol?,respectively,in the presence of 3 M acetic acid?0.5 m L?using 1:1 mesitylene/dioxane?3 mL?as the solvent.Ultrasound for 10 min to obtain a homogenous mixture,Nitrogen was fed for 30 min.Finally,the reactor was heated in an oven at 120°C.for 3 days.The red reaction pellet was centrifuged to give a red solid which was washed with dry acetone?5⁶ times?.The solid was placed in an oven at 80°C for 24 hours to obtain a deep red powder.Then,TpPa-1 as a gray solid was obtained.The material was used as a solid phase microextraction coating adsorbent and GC-MS/MS was used to detect trace amounts of PBDEs in drinking water.The experimental conditions,including extraction conditions?ionic strength,sample pH,extraction temperature,and time?and desorption conditions?desorption temperature and time?,were investigated and optimized in details to obtain high extraction efficiency.Under the optimized conditions,low detection limits(0.00057⁰.0019 ng L^-1),awide linear range(0.001¹00 ng L^-1),good repeatability?4.86⁹.33%,n=5?and reproducibility?5.73⁹.85%%,n=3?were achieved.The spiked recoveries(5,10,and 50 ng L^-1)of the three real environmental water samples were 66.8%-¹10.8%.The results show that TpPa-1 is a new type of coating for solid-phase microextraction,.TpPa-1 shows a good application prospect in the analysis of water samples of polybrominated diphenyl ethers.