小麦粉中掺杂滑石粉的太赫兹光谱检测

利用太赫兹时域光谱(THz-TDS)技术在室温下分别对小麦粉、滑石粉及其混合物进行了光谱测量,获得了它们在0.2～1.5 THz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,混合物中滑石粉含量越高,吸收系数越小.采用偏最小二乘(PLS)方法对小麦粉中滑石粉的含量进行了定量分析,结果表明小麦粉中的滑石粉含量与太赫兹吸收系数具有较高的相关性,相关系数为0.993 9,均方根误差为1.48％,检出限优于2.0％.

The detection of talc in wheat powder based on terahertz time-domain spectroscopy

The terahertz spectra of wheat, talc powder and their compounds were measured in 0.2-1.5THz using terahertz time-domain spectroscopy (THz-TDS) system at room temperature, and the refractive index and absorption spectrum were calculated as well. Experimental results indicate that talcum powder had distinct absorption features in the THz region, which can be used as fingerprint for the material recognition; in addition, the higher concentration of talcum powder, the smaller the absorption coefficient in the compounds. The partial least squares (PLS) regression was taken to analyze the concentration of talcum in wheat powder, correlation coefficient as high as 0.9939 between the concentration of talcum and absorption coefficient is demonstrated, the root mean square error is 1.48%, and the detection limit of talcum powder concentration in mixtures is 2.0%.