Research Institute for Environmental Management Technology, National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan.
Talanta. 2011 May 15;84(3):802-8. doi: 10.1016/j.talanta.2011.02.017. Epub 2011 Feb 19.
This paper describes a method for determination of multiwall carbon nanotubes (MWCNTs) in rat lungs after intratracheal instillation exposure. The MWCNTs were quantitatively decomposed to CO(2) by combustive oxidation and were then determined by non-dispersive infrared analysis. Samples were pretreated by acid digestion, muffle ashing and in situ preheating to remove interferences due to coexisting biological carbon from the lung tissue sample, while preserving the MWCNTs as in its their original form. The preservation was confirmed by transmission electron microscopic observation of the pretreated samples of exposed lung tissues and by the fact that the recoveries of MWCNTs spiked to the lung tissues were close to 100%. The detection limit for MWCNTs obtained by the proposed method was 0.30 μg and the repeatability as expressed by the relative standard deviation was 5.6% (n=4). The method was sufficiently sensitive and precise to apply to real samples of rat lung to investigate the in vivo persistence of intratracheally instilled MWCNTs. To our knowledge, this is the first report of this type of sample pretreatment and direct determination of pristine MWCNTs without modification or tagging. Conventional indirect methods use tagging with other compounds or metal impurities in the CNTs for detection, and the detachment of these tags can increase uncertainties in the determination of the CNTs. The tags can also change how the CNTs persist in vivo, which can lead to an incorrect understanding of the persistence of pristine CNTs in vivo.
本文描述了一种测定气管内滴注染毒后大鼠肺内多壁碳纳米管（MWCNTs）的方法。MWCNTs 通过燃烧氧化定量分解为 CO(2)，然后通过非分散红外分析进行测定。样品通过酸消解、马弗炉灰化和原位预热预处理，以去除肺组织样品中由于共存生物碳而产生的干扰，同时将 MWCNTs 以其原始形式保留下来。通过对暴露肺组织预处理样品的透射电子显微镜观察以及向肺组织中添加的 MWCNTs 的回收率接近 100%这一事实，证实了 MWCNTs 的保留。该方法测定 MWCNTs 的检测限为 0.30 μg，重复性（相对标准偏差）为 5.6%（n=4）。该方法足够灵敏和精确，可应用于大鼠肺的实际样品中，以研究气管内滴注的 MWCNTs 在体内的持久性。据我们所知，这是首次报道这种类型的样品预处理和未经修饰或标记的原始 MWCNTs 的直接测定。传统的间接方法使用 CNTs 中的其他化合物或金属杂质进行标记检测，这些标记的脱落会增加 CNTs 测定的不确定性。标记物还可以改变 CNTs 在体内的持久性，从而导致对体内原始 CNTs 持久性的不正确理解。
