Thermogravimetry-mass spectrometry for carbon nanotube detection in complex mixtures.
Thermogravimetry-mass spectrometry for carbon nanotube detection in complex mixtures.
复制标题
用于复杂混合物中碳纳米管检测的热重-质谱法。
DOI：
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发表时间：
2012
影响因子：
11.4
通讯作者：
P. Gschwend
中科院分区：
文献类型：
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作者：
D. Plata;C. Reddy;P. Gschwend
尽管碳纳米管 (CNT) 行业不断发展，但目前还没有成熟的分析方法来检测或量化环境基质中的 CNT。鉴于碳纳米管具有相对较高的热稳定性，我们研究了使用热技术来分离和量化单壁碳纳米管（SWCNT）。测试材料包括十种商业单壁碳纳米管、代表性生物大分子（牛血清白蛋白和甲基纤维素）、烟灰、天然海岸沉积物和单壁碳纳米管修正沉积物。不同的单壁碳纳米管表现出广泛不同的降解温度，热分析方法可能需要单壁碳纳米管类型的特定参数。为了提高定量能力，通过质谱法监测逸出的气体。单壁碳纳米管产生的诊断离子比率反映了其高碳含量和低氢氧含量。目前的检测限约为每个样品 4 μg(SWCNT)（例如，100 μg(SWCNT) g(-1)（沉积物）和 40 mg 样品），由与仪器非气密设计相关的干扰离子控制。尽管未来的修改可能会改善这一限制，但当前的方法足以在处理单壁碳纳米管的实验室和工业场所量化单壁碳纳米管。此外，该方法有望区分偶然（例如烟灰）和工程（例如单壁碳纳米管）纳米粒子，这是当前最先进的技术不可能实现的。
In spite of the growth of the carbon nanotube (CNT) industry, there are no established analytical methods with which to detect or quantify CNTs in environmental matrices. Given that CNTs have relatively high thermal stabilities, we investigated the use of thermal techniques to isolate and quantify single wall carbon nanotubes (SWCNTs). Test materials included ten types of commercial SWCNTs, representative biological macromolecules (bovine serum albumin and methylcellulose), soot, natural coastal sediments, and SWCNT-amended sediments. Different SWCNTs exhibited widely diverse degradation temperatures, and thermal analytical methods may require SWCNT-type specific parameters. To improve quantification capabilities, evolved gases were monitored by mass spectrometry. SWCNTs produced diagnostic ion ratios reflective of their high carbon and low hydrogen and oxygen contents. Current detection limits are roughly 4 μg(SWCNT) per sample (e.g., 100 μg(SWCNT) g(-1)(sediment) and 40 mg sample), controlled by interfering ions associated with the instrument's non-airtight design. Although future modifications could improve this limitation, the current method is sufficient for quantifying SWCNTs in laboratories and industrial sites where SWCNTs are handled. Furthermore, the method shows promise to distinguish between incidental (e.g., soot) and engineered (e.g., SWCNTs) nanoparticles, which is not possible with current state-of-the-art techniques.