N-doped carbon nanotubes-reinforced hollow fiber solid-phase microextraction coupled with high performance liquid chromatography for the determination of phytohormones in tomatoes.
N-doped carbon nanotubes-reinforced hollow fiber solid-phase microextraction coupled with high performance liquid chromatography for the determination of phytohormones in tomatoes.
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DOI：
10.1016/j.talanta.2018.03.063
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发表时间：
2018-08
期刊：
影响因子：
6.1
通讯作者：
Xiaofei Han;Juan Chen;Yan-ping Shi
中科院分区：
文献类型：
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作者：
Xiaofei Han;Juan Chen;Yan-ping Shi
开发了一种氮掺杂碳纳米管增强中空纤维固相微萃取（N-掺杂CNTs-HF-SPME）方法，用于测定番茄中痕量的两种萘衍生植物激素：1-萘乙酸（NAA）和2-萘氧基乙酸（2-NOA）。将氮掺杂碳纳米管在表面活性剂的帮助下分散在超纯水中，然后通过毛细管力和超声处理将其固定到中空纤维的孔中。将所得 N 掺杂 CNTs-HF 用 1-辛醇润湿，随后浸入番茄样品中，在磁力搅拌下提取目标分析物，然后通过超声处理用甲醇解吸，然后进行色谱分析。与碳纳米管相比，氮掺杂碳纳米管由于氮原子的掺杂，表面亲水性得到提高，并形成均匀的分散体，从而大大简化了制备工艺，减少了材料的浪费。此外，由于引入了路易斯碱性氮，N掺杂CNTs-HF对NAA和2-NOA表现出更有效的萃取性能。值得一提的是，由于HF的净化功能，微萃取前无需任何复杂的样品预处理程序。为了达到最高的萃取效率，对重要的微萃取参数进行了彻底的研究和优化，包括表面活性剂溶液中氮掺杂碳纳米管的长度和浓度水平、萃取时间、解吸条件（例如溶剂的类型和体积）、pH值、搅拌速率和供体相的体积。在最佳条件下，该方法显示 NAA 和 2-NOA 的富集倍数为 165 倍和 123 倍，纤维间重复性和批次间重现性良好，线性良好，相关系数高于 0.9990，检测和定量限较低（ngg−1 水平），三个加标水平的回收率令人满意，在 83.10-108.32% 范围内。该方法结合了氮掺杂碳纳米管优异的吸附性能和HF的净化功能，是一种简单、绿色、高效且经济的富集方法，用于测定番茄中痕量NAA和2-NOA。
A N-doped carbon nanotubes-reinforced hollow fiber solid-phase microextraction (N-doped CNTs-HF-SPME) method was developed for determination of two naphthalene-derived phytohormones, 1-naphthalene acetic acid (NAA) and 2-naphthoxyacetic acid (2-NOA), at trace levels in tomatoes. N-doped CNTs were dispersed in ultrapure water with the assistance of surfactant, and then immobilized into the pores of hollow fiber by capillary forces and sonification. The resultant N-doped CNTs-HF was wetted with 1-octanol, subsequently immersed into the tomato samples to extract the target analytes under a magnetic stirring, and then desorbed with methanol by sonication prior to chromatographic analysis. Compared with CNTs, the surface hydrophilicity of N-doped CNTs was improved owing to the doping of nitrogen atoms, and a uniform dispersion was formed, thus greatly simplifying the preparation process and reducing waste of materials. In addition, N-doped CNTs-HF exhibits a more effective extraction performance for NAA and 2-NOA on account of the introduction of Lewis-basic nitrogen. It is worth to mention that owing to the clean-up function of HF, there are not any complicated sample pretreatment procedures prior to the microextraction. To achieve the highest extraction efficiency, important microextraction parameters including the length and the concentration level of N-doped CNTs in surfactant solution, extraction time, desorption conditions such as the type and volume of solvents, pH value, stirring rate and volume of the donor phase were thoroughly investigated and optimized. Under the optimal conditions, the method showed 165- and 123-fold enrichment factors of NAA and 2-NOA, good inter-fiber repeatability and batch-to-batch reproducibility, good linearity with correlation coefficients higher than 0.9990, low limits of detection and quantification (at ng g−1levels), and satisfactory recoveries in the range of 83.10–108.32% at three spiked levels. The proposed method taking advantages of both excellent adsorption performance of N-doped CNTs and the clean-up function of HF, was a simple, green, efficient and cost-effective enrichment procedure for the determination of trace NAA and 2-NOA in tomatoes.