Zarejousheghani Mashaalah, Fiedler Petra, Möder Monika, Borsdorf Helko
UFZ-Helmholtz Centre for Environmental Research, Department Monitoring and Exploration Technologies, Permoserstraße 15, D-04318 Leipzig, Germany.
UFZ-Helmholtz Centre for Environmental Research, Department Monitoring and Exploration Technologies, Permoserstraße 15, D-04318 Leipzig, Germany.
Talanta. 2014 Nov;129:132-8. doi: 10.1016/j.talanta.2014.05.034. Epub 2014 May 24.
A novel approach for the selective extraction of organic target compounds from water samples has been developed using a mixed-bed solid phase extraction (mixed-bed SPE) technique. The molecularly imprinted polymer (MIP) particles are embedded in a network of silica gel to form a stable uniform porous bed. The capabilities of this method are demonstrated using atrazine as a model compound. In comparison to conventional molecularly imprinted-solid phase extraction (MISPE), the proposed mixed-bed MISPE method in combination with gas chromatography-mass spectrometry (GC-MS) analysis enables more reproducible and efficient extraction performance. After optimization of operational parameters (polymerization conditions, bed matrix ingredients, polymer to silica gel ratio, pH of the sample solution, breakthrough volume plus washing and elution conditions), improved LODs (1.34 µg L(-1) in comparison to 2.25 µg L(-1) obtained using MISPE) and limits of quantification (4.5 µg L(-1) for mixed-bed MISPE and 7.5 µg L(-1) for MISPE) were observed for the analysis of atrazine. Furthermore, the relative standard deviations (RSDs) for atrazine at concentrations between 5 and 200 µg L(-1) ranged between 1.8% and 6.3% compared to MISPE (3.5-12.1%). Additionally, the column-to-column reproducibility for the mixed-bed MISPE was significantly improved to 16.1%, compared with 53% that was observed for MISPE. Due to the reduced bed-mass sorbent and at optimized conditions, the total amount of organic solvents required for conditioning, washing and elution steps reduced from more than 25 mL for conventional MISPE to less than 2 mL for mixed-bed MISPE. Besides reduced organic solvent consumption, total sample preparation time of the mixed-bed MISPE method relative to the conventional MISPE was reduced from more than 20 min to less than 10 min. The amount of organic solvent required for complete elution diminished from 3 mL (conventional MISPE) to less than 0.4 mL with the mixed-bed technique shows its inherent potential for online operation with an analytical instrument. In order to evaluate the selectivity and matrix effects of the developed mixed-bed MISPE method, it was applied as an extraction technique for atrazine from environmental wastewater and river water samples.
已开发出一种使用混合床固相萃取(mixed - bed SPE)技术从水样中选择性萃取有机目标化合物的新方法。分子印迹聚合物(MIP)颗粒嵌入硅胶网络中,形成稳定均匀的多孔床。以莠去津作为模型化合物证明了该方法的性能。与传统的分子印迹固相萃取(MISPE)相比,所提出的混合床MISPE方法与气相色谱 - 质谱联用(GC - MS)分析相结合,能够实现更具重现性和高效的萃取性能。在优化操作参数(聚合条件、床基质成分、聚合物与硅胶比例、样品溶液pH值、穿透体积以及洗涤和洗脱条件)后,分析莠去津时观察到检测限得到改善(混合床MISPE为1.34 μg L⁻¹,而MISPE为2.25 μg L⁻¹)以及定量限(混合床MISPE为4.5 μg L⁻¹,MISPE为7.5 μg L⁻¹)。此外,与MISPE(3.5 - 12.1%)相比,莠去津浓度在5至200 μg L⁻¹之间时的相对标准偏差(RSD)在1.8%至6.3%之间。另外,混合床MISPE的柱间重现性显著提高至16.1%,而MISPE为53%。由于床质量吸附剂减少且在优化条件下,用于调节、洗涤和洗脱步骤所需的有机溶剂总量从传统MISPE的超过25 mL减少至混合床MISPE的不到2 mL。除了减少有机溶剂消耗外,混合床MISPE方法相对于传统MISPE的总样品制备时间从超过20分钟减少至不到10分钟。完全洗脱所需的有机溶剂用量从3 mL(传统MISPE)减少至不到0.4 mL,混合床技术显示出其与分析仪器在线操作的内在潜力。为了评估所开发的混合床MISPE方法的选择性和基质效应,将其用作从环境废水和河水样品中萃取莠去津的萃取技术。