磁性复合材料的制备及其在水中多氯联苯测定中的应用OA

A magnetic composite material,NiFe2O4/SiO2@PDA,was synthesized by coating the surface of a magnetic material with polydopamine(PDA).A method for the rapid determination of 18 PCBs in water using magnetic solid-phase extraction coupled with gas chromatography-mass spectrometry(MSPE-GC-MS)was established.NiFe2O4/SiO2@PDA extractant(0.05 g)was added to water(15 mL;the pH of the sample was adjusted to 3.0),and a surrogate standard solution(1.0 μL)was added.The mixture was extracted by vortexing for 1.5 min,separated with a magnet,and the supernatant was decanted.Subsequently,1.0 mL of V(dichloromethane)∶V(acetone)=1∶1 was added,followed by vortex desorption for 2 min and a second separation with a magnet.The solution was transferred to a chromatographic vial and injected into a gas chromatography-mass spectrometer for determination.The method validation results were as follows:the method detection limits(MDLs)for the 18 PCBs ranged from 30 to 100 ng/L,with correlation coefficients(r)≥0.9995.Spiked recovery tests were performed on actual wastewater samples at two concentrations(3.33 and 13.3 μg/L).The spiked recoveries ranged from 91.8％to 105％and 92.8％to 105％,respectively,with relative standard deviations(RSDs)of 1.7％～4.4％and 1.6％～3.9％(n=6).After six repeated extractions using the magnetic composite material,the recoveries of the target analytes remained in the range of 93.1％～103％.This method is simple,rapid,accurate,recyclable,and can be applied to the determination of 18 PCBs in water.