利用太赫兹时域光谱(THz—TDs)技术在室温下分别对石棉、滑石粉及其混合物进行了光谱测量,获得了它们在0.2THz~1.5THz波段的吸收谱和折射率谱。结果表明滑石粉在太赫兹波段存在明显的特征吸收峰,可以作为其在太赫兹波段的指纹特征用于物质识别;另外,混合物中石棉含量越高,吸收系数越大。采用偏最小二乘方法对滑石粉中石棉的含量进行了定量分析,结果表明滑石粉中的石棉含量与太赫兹吸收系数具有较高的相关性,相关系数为0.98,均方根误差为2.05%,检出限到达2.0%。
Absorption spectra of asbestos in talc was measured in the range of 0.2 THz -1.5 THz using terahertz time-domain spectroscopy (THz-TDS) system at room temperature, and the refractive index and absorption spectrum were obtained as well. Experimental results indicated that talc had distinct absorption features in the THz region, which can be used as fingerprint for the molecular recognition. The partial least squares (PLS) regression was taken to analyze the content of asbestos in talc. The results showed that the higher the asbestos content was, the larger the absorption coefficient. The research after the PLS regression analysis showed that there was good relativity (correlation coefficient 0.98) between THz absorption coefficient and the content of asbestos in talcu, while the root mean square error was 2.05 %; and the detection limit of asbestos content in mixtures can be less than 2.0 %.