采用近红外光谱技术对白酒中甲醇超标进行快速无损检测可行性研究。设计实验配制掺杂不同体积分数甲醇的白酒样本,采集波数4000-5200cm-1透射光谱,采用偏最小二乘法在4360-4460cm-1 范围构建甲醇含量分析模型,实现甲醇体积分数大于0.1%(质量浓度0.0791g/100mL)样本的快速无损识别。实验数据表明模型相关系数R=0.9998,交叉验证均方根误差RESEC=0.062539,甲醇体积分数的预测精度达到0.1%(质量浓度0.0791g/100mL)。近红外光谱技术可以作为一种快速无损检测方案实现甲醇超标的劣质白酒(假酒)的市场筛查。
Near-infrared spectroscopy was used to establish a fast and nondestructive method for determining excess methanol in liquor. A model in the range of 4360--4460 cm-1 that allows the rapid and nondestructive identification of methanol concentrations exceeding 0.1% (0.0791 g/100 mL) was developed using partial least square (PLS) regression based on the acquired transmission spectra in the range of 4000-5200 cm-1 of experimental liquor samples adulterated with different concentrations of methanol. The developed model showed a correlation coefficient of 0.999, a RESEC value of 0.062 and a prediction precision of 0.1%. Therefore, near-infrared spectroscopy can be used for market screening of adulterated commercial liquors as a fast and nondestructive detection technique.