无机盐对乙醇-水体系LF-NMR弛豫特性的影响及主成分分析

Effect of Inorganic Salt on Relaxation Characteristics of Ethanol- Water System Analyzed by PCA

该文研究了不同浓度（0~9%）的Na Cl,Mg SO4或Na OH对乙醇-水体系LF-NMR弛豫特性的影响,并应用主成分分析（PCA）对样品的弛豫特性进行了分析。研究表明：无机盐种类和浓度会对水及乙醇-水体系的LF-NMR弛豫特性产生影响。无机盐-水二元体系仅存在1个弛豫峰,且弛豫时间：Mg SO4〉Na OH〉Na Cl。而无机盐-乙醇-水三元体系则存在2个弛豫峰,Na Cl/Na OH-乙醇-水体系的弛豫峰分别位于200~330 ms和1 300~1 600 ms处;而Mg SO4-乙醇-水体系则位于约250~335 ms和1 620~1 707 ms处。不同种类无机盐、水和乙醇-水体系间的LF-NMR弛豫特性差异均可在PCA得分图上有效反映,且随着无机盐浓度的增加,各浓度梯度在主成分得分图中亦呈规律性分布。说明基于样品的LF-NMR弛豫特性,结合主成分分析法可快速分析无机盐对水/乙醇-水的缔合特性。

Different concentrations（ 0- 9%） of inorganic salts, such as Na Cl, Mg SO4,Na OH,were added into the ethanol- water system,and principal component analysis（ PCA） was used to analyze the LF- NMR（ T2） relaxation characteristics of the samples. The results indicated that the type and concentration of the inorganic salts could change the relaxation characteristics of the ethanol- water system. For the inorganic salt- water system,there was only one relaxation peak,and the relaxation time followed the order like this,Mg SO4 Na OH Na Cl. When the inorganic salt was added into the water- ethanol system,two relaxation peaks appeared on the map,and the relaxation peaks of Na Cl / Na OH- ethanol- water system appeared at 200- 330 ms and 1 300- 1 600 ms,while that of Mg SO4- ethanol- water system located about 250- 335 ms and 1 620- 1 707 ms. After principal component analysis on the LF- NMR data,good differentiations among inorganic salt,water system and ethanol- water system could be found. And the distribution of samples moved regularly on the principal component scores with the increase of concentration. Therefore,the LF- NMR relaxation characteristics could be used to reflect the interaction of inorganic salt in water and ethanol- water systems with the aid of PCA.