Computer controlled multi-walled carbon nanotube inhalation exposure system
Computer controlled multi-walled carbon nanotube inhalation exposure system
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DOI：
10.1080/08958370802712713
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发表时间：
2009-10-01
影响因子：
2.1
通讯作者：
Frazer, Dave
中科院分区：
文献类型：
--
作者：
McKinney, Walter;Chen, Bean;Frazer, Dave
吸入暴露系统是确定吸入毒物在各种暴露条件下的剂量-反应关系的必要工具。该项目的目标是开发一种自动化计算机控制系统，使小型实验室动物暴露于精确浓度的空气中多壁碳纳米管（MWCNT）。研制了一种气溶胶发生器，它能够从散装材料中悬浮可吸入部分的多壁碳纳米管。发生器的输出用于将小型实验室动物暴露于恒定的气溶胶浓度，浓度高达12 mg/m（3）。测量递送到暴露室的MWCNT气溶胶的颗粒分布和形态，并与先前从生产MWCNT的设施内的空气中采集的样品进行比较。比较显示，MWCNT发生器产生的颗粒在尺寸和形状上与工作环境中发现的颗粒相似。吸入暴露系统结合了气流控制器、颗粒监测器、数据采集设备和具有自动反馈控制的定制软件，以实现恒定和可重复的暴露室温度、相对湿度、压力、气溶胶浓度和粒度分布。自动控制算法能够将平均气溶胶浓度保持在选定目标值的0.1 mg/m3以内，并且在吸入暴露开始期间，可以在不到10分钟内达到目标值的95%。该系统的主要优点之一是，一旦选定了曝光参数，在曝光期间所需的操作员干预量最小。
Inhalation exposure systems are necessary tools for determining the dose-response relationship of inhaled toxicants under a variety of exposure conditions. The objective of this project was to develop an automated computer controlled system to expose small laboratory animals to precise concentrations of airborne multi-walled carbon nanotubes (MWCNT). An aerosol generator was developed which was capable of suspending a respirable fraction of multi-walled carbon nanotubes from bulk material. The output of the generator was used to expose small laboratory animals to constant aerosol concentrations up to 12 mg/m(3). Particle distribution and morphology of the MWCNT aerosol delivered to the exposure chamber were measured and compared to samples previously taken from air inside a facility that produces MWCNT. The comparison showed the MWCNT generator was producing particles similar in size and shape to those found in a work environment. The inhalation exposure system combined air flow controllers, particle monitors, data acquisition devices, and custom software with automatic feedback control to achieve constant and repeatable exposure chamber temperature, relative humidity, pressure, aerosol concentration, and particle size distribution. The automatic control algorithm was capable of maintaining the mean aerosol concentration to within 0.1 mg/m(3) of the selected target value, and it could reach 95% of the target value in less than 10 minutes during the start-up of an inhalation exposure. One of the major advantages of this system was that once the exposure parameters were selected, a minimum amount of operator intervention was required over the exposure period.