QuEChERS-超高效液相色谱-串联质谱分析鱼中13种全氟及多氟烷基化合物

Determination of 13 perfluorinated and polyfluoroalkyl substances in fishes by QuEChERS⁃ultra⁃high performance liquid chromatography⁃tandem mass spectrometry

全氟及多氟烷基化合物(PFASs)广泛存在于全球环境水体中,鱼类等水产品的摄入可能是人类接触PFASs的重要来源,因此亟需建立鱼类产品中PFASs的高效、准确分析技术。本研究以磁性纳米材料为净化吸附剂,基于QuEChERS方法,建立了鱼类产品中13种PFASs的超高效液相色谱-串联质谱(UHPLC-MS/MS)分析方法。实验分别考察了萃取溶剂类型、净化吸附剂(Fe_( 3)O_( 4)-TiO_( 2)和N-丙基乙二胺(PSA))用量对PFASs回收率的影响,确定了最佳样品前处理条件。采用Luna Omega C18色谱柱(100 mm×2.1 mm,1.6μm)进行分离,利用电喷雾电离(ESI)源,在多反应监测(MRM)模式下采集质谱数据,内标法定量。在优化的实验条件下,13种PFASs在0.01~50μg/L内具有良好的线性关系,相关系数(R)≥0.9973,检出限为0.001~0.023μg/L,定量限为0.003~0.078μg/L。在低、中、高3个加标水平(0.5、10、100μg/kg)下,13种PFASs的加标回收率为78.1%~118%,日内精密度为0.2%~11.1%,日间精密度为0.8%~8.7%。将该方法应用于实际样品分析,所有鱼样品中均有PFASs检出,分别为全氟辛酸、全氟辛基磺酸、全氟十一烷酸、全氟十二烷酸和全氟十三烷酸,各自的检出总含量为0.327~1.728μg/kg。本方法前处理过程简单且灵敏度高,适用于鱼类产品中PFASs的分析。

Perfluorinated and polyfluoroalkyl substances(PFASs)are compounds characterized by at least one perfluorinated carbon atom in an alkyl chain linked to side-chain groups.Owing to their unique chemical properties,these compounds are widely used in industrial production and daily life.However,owing to anthropogenic activities,sewage discharge,surface runoff,and atmospheric deposition,PFASs have gradually infiltrated the environment and aquatic resources.With their gradual accumulation in environmental waters,PFASs have been detected in fishes and several fish-feeding species,suggesting that they are bioconcentrated and even amplified in aquatic organisms.PFASs exhibit high intestinal absorption efficiencies,and they bioaccumulate at higher trophic levels in the food chain.They can be bioconcentrated in the human body via food(e.g.,fish)and thus threaten human health.Therefore,establishing an efficient analytical technique for use in analyzing PFASs in typical fish samples and providing technical support for the safety regulation and risk assessment of fish products is necessary.In this study,by combining solvent extraction and magnetic dispersion-solid phase extraction(d-SPE),an improved QuEChERS method with ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)was developed for the determination of 13 PFASs in fish samples.Fe_( 3)O_( 4)-TiO_( 2) can be used as an ideal adsorbent in the removal of sample matrix interference and a separation medium for the rapid encapsulation of other solids to be isolated from the solution.Based on the matrix characteristics of the fish products and structural properties of the target PFASs,Fe_( 3)O_( 4)-TiO_( 2)and N-propyl ethylenediamine(PSA)were employed as adsorbents in dispersive purification.The internal standard method was used in the quantitative analyses of the PFASs.To optimize the sample pretreatment conditions of analyzing PFASs,the selection of the extraction solvent and amounts of Fe_( 3)O_( 4)-TiO_( 2)and PSA were optimized.Several PFASs contain acidic groups that are non-dissociated in acidic environments,thus favoring their entry into the organic phase.In addition,acidified acetonitrile can denature and precipitate the proteins within the sample matrix,facilitating their removal.Finally,2%formic acid acetonitrile was used as the extraction solvent,and 20 mg Fe_( 3)O_( 4)-TiO_( 2),20 mg PSA and 120 mg anhydrous MgSO 4 were used as purification adsorbents.Under the optimized conditions,the developed method exhibited an excellent linearity(R≥0.9973)in the range of 0.01-50μg/L,and the limits of detection(LODs)and quantification(LOQs)ranged from 0.001-0.023 and 0.003-0.078μg/L,respectively.The recoveries of the 13 PFASs at low,medium,and high spiked levels(0.5,10,and 100μg/kg)were 78.1%-118%,with the intra-and inter-day precisions of 0.2%-11.1%and 0.8%-8.7%,respectively.This method was applied in analyzing real samples,and PFASs including perfluorooctanesulfonic acid,perfluorooctanoic acid,perfluoroundecanoic acid,perfluorododecanoic acid,and perfluorotridecanoic acid,were detected in all 11 samples evaluated.This method is simple,sensitive,and suitable for use in analyzing PFASs in fish samples.