镍钛合金纤维基体表面纳米多孔复合氧化物的可控生长及其对多环芳烃的选择性固相微萃取

Controllable Growth of Nanoporous Metal Oxide Composites on Nickel-Titanium Alloy Fibers for Selective Solid-Phase Microextraction of Polycyclic Aromatic Hydrocarbons

采用水热氧化法制备镍钛合金(Ni Ti)固相微萃取纤维。实验结果表明,在80℃的H2O2溶液中,直接氧化Ni Ti纤维基体可在其表面原位生长纳米多孔氧化镍/氧化钛复合涂层,其中氧化镍含量显著高于氧化钛含量。与高效液相色谱-紫外检测器(HPLC-UV)检测技术联用,考察了所制备Ni Ti纤维对典型芳香族化合物的萃取性能。结果表明,富Ni复合氧化物涂层对多环芳烃(PAHs)表现出良好的萃取选择性。在优化实验条件下,方法的线性范围为0.1~400.0 ng/m L,相关系数大于0.999,PAHs的检出限为0.026~0.056 ng/m L。对于50 ng/m L加标水样,单支Ni Ti纤维日内和日间测量的相对标准偏差(RSDs)分别为4.8%~6.2%和5.4%~6.5%(n=5),使用5支不同批纤维测量的RSDs为6.4%~8.4%。本方法适用于环境水样中PAHs的富集和测定,相对回收率为89.9%~108.5%,RSDs<8.1%。而且,Ni Ti纤维机械强度高,化学稳定性好,制备过程精密可控。

Hydrothermal oxidation was used to prepare a nickel-titanium alloy（ Ni Ti） solid-phase microextraction fiber. The experimental results demonstrated that a nanoporous Ni Ti oxide composite coating was in situ grown on the surface of Ni Ti substrate by direct oxidation in aqueous H2 O2 solution at 80℃. The resulting composite oxide coating included more nickel and less titanium. The prepared Ni Ti fiber with Ni-rich oxide coating was used to extract typical aromatic compounds coupled with HPLC-UV and exhibited good extraction selectivity for polycyclic aromatic hydrocarbons（ PAHs）. The key factors affecting extraction efficiency of PAHs were examined. Under the optimized conditions,the calibration curves were linear in the range from 0. 05 to 500 ng/m L with correlation coefficients ≥ 0. 999,and the limits of detection were0.026-0.056 ng/m L. Furthermore, the relative standard deviations（ RSDs） for intra-day and inter-day repeatability of the single fiber varied from 4.8% to 6.2% and from 5.4% to 6.5% for five replicates of PAHs at the spiking level of 50 ng/m L,respectively. The RSDs for the fiber-to-fiber reproducibility of five fibers prepared in different batches ranged from 6.4% to 8.4%. This method was suitable for selective enrichment and detection of target PAHs in environmental water samples with relative recoveries of 87.4%-108.2% and RSDs8.1%. Moreover,this novel Ni Ti fiber was mechanically strong and chemically stable,and its preparation was precisely controllable.