摘要
利用太赫兹时域光谱（terahertz time—domain spectroscopy，THz—TDS）技术对偶氮甲酰胺（小麦粉添加剂）、小麦粉及两者混合物进行测试，获得其在0．20～2．00THz波段的吸收谱与折射率谱。结果显示，偶氮甲酰胺在1．93THz处存在1个明显的特征吸收峰，可用于物质识别。此外，随着混合物中偶氮甲酰胺含量的减少，样品的吸收系数逐渐上升，折射率逐渐下降。通过偏最小二乘法（partial least squares，PLS）对小麦粉中偶氮甲酰胺的含量进行定量分析。结果表明，混合物中偶氮甲酰胺含量与吸收系数、折射率都有良好的线性关系，其中基于吸收系数PLS模型相关系数可达到0．9999，标准误差为O．06％．检出极限可达0．11％，最大绝对偏差小于0．19％。
The characteristics of azodiformamide, flour and their mixtures have been investigated within 0.20 - 2.00 THz region with THz- TDS technology in the paper. The refractive index and absorption spectrum have been established finally. The results showed that there was a distinct absorption feature of azodiformamide at approximate 1.93 THz, which could be used to perform material recognition. Absorption coefficient of mixtures increased with the fewer azodiformamide in mixture, while the refractive index decreased gradually. The content of azodiformamide in flour was quantitatively analyzed by the Partial Least Squares （PLS） regression. The results showed that there was a fine linear relationship between the contents of azodiformamide in the mixture, parameters of absorption coefficient and refractive index. The correlation factor produced from PLS model based on absorption coefficient was 0. 999 9 ; the standard error was 0.06%, detection limit of azodiformamide concentration was 0.11% and the maximum absolute deviation error was less than 0.19%.
出处
《中国粮油学报》
EI
CAS
CSCD
北大核心
2016年第1期107-111,共5页
Journal of the Chinese Cereals and Oils Association
基金
国家自然科学基金(21205110)
浙江省留学人员择优资助(C00152)
关键词
偶氮甲酰胺
定量分析
太赫兹时域光谱
偏最小二乘法
squaresazodicarbonamide, quantitative analysis, terahertz time- domain spectroscopy, partial least squares
