采用漫反射近红外光谱方法测定聚乙烯醇(简称PVA)的醇解度与挥发分含量。 从PVA生产线选取120个样品, 分别用容量法与恒重法测量样品的醇解度与挥发分含量。 用光栅扫描近红外光谱仪采集样品光谱, 光谱范围1 000～1 800 nm。 样品光谱用卷积平滑、 卷积求导、 均值中心化与正交信号校正方法进行预处理后, 与样品的醇解度与挥发分含量, 采用PLS1定量校正方法建立近红外分析模型。 醇解度与挥发分含量模型的校正相关系数RC分别为0.976和0.981, 校正标准偏差SEC分别为0.176和0.197, 验证相关系数RP分别为0.967和0.969, 验证标准偏差SEP分别为0.202和0.193。 方法具有速度快, 操作方便的特点, 分析结果满足PVA生产过程醇解度与挥发分含量的检测要求。

A new method using reflection NIR technology was developed to determine the alcoholysis degree and volatile matter of Poly-vinyl alcohol (PVA). 120 samples were used in this research. NIR spectra of the sample were scanned by the spectrometer from 1 000 to 1 800 nm. The alcoholysis degree and volatile matter were determined by the national standard method of volumetric and gravimetric method respectivily. Partial least squares (PLS1) was used to establish the quantitative correction model of alcoholysis degree and volatile matter of PVA. The corrected relationship(RC) of alcoholysis degree and volatile matter was 0.976 and 0.981 respectively. The corrected standard deviation(SEC) was 0.176 and 0.197. The predicted relationship(RP) was 0.967 and 0.969. The predicted deviation(SEP) was 0.202 and 0.193. The test for actual samples showed that the NIR method was fitted for the requirement of PVA analysis.