增白剂中吊白块含量的太赫兹光谱定性与定量检测

利用太赫兹时域光谱(THz-TDS)技术在室温下分别对吊白块(甲醛次硫酸氢钠)、增白剂(过氧化苯甲酰)及其混合物进行了光谱测量,获得了在0.2~1.5 THz波段的吸收谱和折射率谱。结果表明增白剂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,混合物中吊白块含量越高,吸收系数越小,折射率越大。采用偏最小二乘(PLS)方法对增白剂中掺杂吊白块的含量进行了定量分析,结果表明增白剂中的吊白块含量与太赫兹吸收系数具有较高的相关性,相关系数为0.999 8,均方根误差(RMSE)为1.21%,检出限优于2.0%。研究表明THz-TDS技术可以用于食品领域中快速、无损检测增白剂中严禁使用的吊白块。

The qualitative and quantitative detection of sodium formaldehyde sulfoxylate in benzoyl peroxide based on terahertz time-domainspectroscopy

In this study, the absorption spectra of sodium formaldehyde sulfoxylate in benzoyl peroxide was 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 obtained as well. Experimental results indicate that benzoyl peroxide had distinct absorption features in the THz region. The partial least squares (PLS) regression was taken to analyze the content of sodium formaldehyde sulfoxylate in benzoyl peroxide. The results after the PLS regression analysis showed that the root mean square error was 1.21%, and the detection limit of talcum powder content in mixtures was less than 2.0%. This research indicated that the THz-TDS technique can rapidly and non-destructively detect the forbidden used sodium formaldehyde sulfoxylate in benzoyl peroxide in food fields.