紫外分光光度法测定烤烟挥发油溶液浓度

Determination of the concentration of flue-cured tobacco volatile oils by UV-spectrophotography

为建立利用紫外分光光度法测定烤烟挥发油溶液浓度方法,先用同时蒸馏萃取方法得到烤烟挥发油,再用二氯甲烷将其稀释成梯度溶液,紫外分光光度扫描,并确定工作波长,以此建立烤烟挥发油浓度与其紫外吸光度间的线性回归方程。结果表明,烤烟挥发油的紫外光吸收带在225~245 nm,239 nm最适合作为测定烤烟叶挥发油溶液浓度的工作波长,线性回归方程为y=0.2501 x+0.0393,R2=0.9993,且有很好吸光度重复性(RSD<0.5%);所得线性工作曲线的LOD为0.153 g/L,LOQ为0.464 g/L。

To determining the concentration of volatile oils solution extracted from flue-cured tobacco leaves,a method based on UV spectrophotometry was researched.Volatile oils were extracted by simultaneous distillation and diluted with dicholormethane to pre⁃pare a set of gradient solutions.Each solution was scanned by UV spectrophotomet.The best working wavelength was selected to estab⁃lish linear regression equation between the concentration of volatile oil and its ultraviolet absorbance.Results showed that the volatile oils had a large absorption spectrum between 225~245 nm.The best analysis wavelength was 239 nm,the linear relationship was y=0.2501x+0.0393,R2=0.9993.Its relative error of was less than 0.5%,the limit of detection(LOD)and the limit of quantifica⁃tion(LOQ)of the working curve were 0.153 g/L and 0.464 g/L separately.