烟样水分质量分数对其常规化学成分近红外测定的影响

Effect of water content on the determination of routine chemical components in tobacco by near-infrared spectroscopy

在连续改变样品水分质量分数的条件下,采集了烟样的近红外吸收光谱,并用预测模型测定了它们的总糖、总氮和烟碱质量分数.结果表明,烟样水分质量分数的升高使其在近红外区域的光谱吸收明显增大,直接影响以上化学成分的测定结果.烟样水分质量分数大于10%时,以上几种常规化学成分的测定误差随样品含水量的降低而减小,而当样品水分质量分数小于10%时,样品水分差异引起的总糖、总氮和烟碱测定的误差可忽略不计.

NIR spectra were collected under the condition of continuous altering the water content in tobacco leave samples. The total sugar, nitrogen and nicotine were determined by using corresponding NIR qualitative predictive methods. Results showed that the absorbance of NIR was obviously increased with the increase of water content in tobacco samples, which affected the prediction of chemical compositions. The predictive errors decreased with the increasing of water content in sample when the water content was higher than 10%. The predictive errors of total sugar, nitrogen an nicotine caused by the differences in sample water contents could be neglected when the water content was less than 10%.