State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; School of Environmental Studies, China University of Geosciences, Wuhan 430074, China.
State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
J Chromatogr A. 2018 Sep 21;1568:29-37. doi: 10.1016/j.chroma.2018.07.026. Epub 2018 Jul 5.
Accurate analysis of polycyclic aromatic hydrocarbons (PAHs) in soils remains a challenge due to the complexity of sample matrices. In this paper, phenyl-modified magnetic mesoporous silica (FeO@mSiO-Ph-PTSA) was synthesized with p-toluenesulfonic acid (PTSA) as the catalyst and used as a selective adsorbent for the clean-up of PAHs extracted from soils. The material prepared without PTSA as the catalyst (FeO@mSiO-Ph) was synthesized for comparison. The synthesized materials were first systematically characterized and evaluated. It was found that the grafting amount of the phenyl group onto FeO@mSiO-Ph-PTSA was higher than that onto FeO@mSiO-Ph. The extraction efficiency obtained by extracting PAHs from the extracted soil matrix solution demonstrated that FeO@mSiO-Ph-PTSA possessed a much higher extraction efficiency than that of FeO@mSiO-Ph, which can be attributed to the greater amount of phenyl groups grafted on FeO@mSiO in the presence of the PTSA catalyst. Moreover, contrast experiments showed that FeO@mSiO-Ph-PTSA displayed higher selectivity towards PAHs than towards n-alkanes and that the π-π interaction played a key role in the adsorption process. In the presence of the soil extract matrix, the parameters affecting the extraction efficiency of FeO@mSiO-Ph-PTSA for PAHs were optimized. Under the optimal conditions, coupled with pressurized liquid extraction and gas chromatograph-mass spectrometer, the proposed method for the determination of PAHs in soils was linear in the range of 5-500 ng g, and the correlation coefficients (R) ranged between 0.9994 and 0.9999. The limits of detection (LODs) and limits of quantification (LOQs), which were based on signal-to-noise ratios of 3 and 10, respectively, were in the range of 0.07-0.41 ng g and 0.24-1.37 ng g. The developed method displayed a better clean-up effect than that for silica gel column method, and the matrix effect markedly decreased compared to that of the uncleaned condition. Finally, the developed method was successfully applied for the detection of PAHs in environmental soils, and the data were consistent with the results obtained by the silica gel column method. The analytical results were also consistent with those for the real environment.
由于土壤样品基质的复杂性，准确分析多环芳烃（PAHs）仍然是一个挑战。本文合成了以对甲苯磺酸（PTSA）为催化剂的苯基修饰磁性介孔硅（FeO@mSiO-Ph-PTSA），并将其作为一种选择性吸附剂，用于从土壤中提取 PAHs 的净化。还合成了没有 PTSA 作为催化剂的材料（FeO@mSiO-Ph）作为对比。首先对合成材料进行了系统的表征和评价。结果发现，苯基接枝到 FeO@mSiO-Ph-PTSA 上的接枝量高于接枝到 FeO@mSiO-Ph 上的接枝量。从提取的土壤基质溶液中提取 PAHs 的实验结果表明，FeO@mSiO-Ph-PTSA 具有比 FeO@mSiO-Ph 更高的提取效率，这归因于 PTSA 催化剂存在时，在 FeO@mSiO 上接枝的苯基数量更多。此外，对比实验表明，FeO@mSiO-Ph-PTSA 对 PAHs 的选择性高于正构烷烃，π-π 相互作用在吸附过程中起关键作用。在存在土壤提取基质的情况下，优化了影响 FeO@mSiO-Ph-PTSA 对 PAHs 萃取效率的参数。在最佳条件下，结合加压液体萃取和气相色谱-质谱联用，该方法用于测定土壤中的 PAHs 呈线性关系，范围为 5-500ng g，相关系数（R）在 0.9994 到 0.9999 之间。基于信噪比 3 和 10，检测限（LOD）和定量限（LOQ）分别为 0.07-0.41ng g 和 0.24-1.37ng g。与硅胶柱法相比，该方法具有更好的净化效果，与未净化条件相比，基质效应明显降低。最后，该方法成功应用于环境土壤中 PAHs 的检测，得到的数据与硅胶柱法的结果一致。分析结果与实际环境的结果也一致。
