气相色谱法测定马来松香组分的研究

METHOD FOR QUANTITATIVE DETERMINATION OF COMPONENTS IN MALEIC MODIFIED ROSIN BY GAS CHROMATOGRAPHY

本研究建立了一套理想的利用气相色谱快速分析马来松香组分含量的方法。结果表明,在OV-101玻璃色谱柱上,马来松香样品采用重氮甲烷在非质子介质中酯化,所得到的加合物甲酯的色谱峰为单峰。经GC-MS分析发现,该加合物甲酯的分子离子峰为414,系左旋海松酸甲酯马来酐加合物,只有游离羧基被酯化,酸酐环保留。在程序升温操作条件下,游离树脂酸部分各组分的色谱峰基本上得到完全分开。当以去氢枞酸甲酯峰为参比峰(f_M=1.000)、采用校正面积归一化法进行定量分析时,加合物组分的相对摩尔校正因子在其浓度为0～0.75(mol/L)的范围内保持不变,其f_M值为0.8315,相应的重量校正因子为1.096。分析方法的精确度较高,测量值的相对偏差为±0.6％左右。本方法可用于跟踪分析松香马来化反应过程中各组分随反应时间的变化,也可用于直接分析马来松香样品中各组分的含量。

The method lor quantitative determination of components in maleic modified rosin (MMR) by temperature programmed OC has been established. The results showed that,after the sample of MMR was esterified by azimethylene in non-proton solvent (ethyl acetate) ,the methyl ester of maleopinaric acid (MPA) gave a single peak on the OV-101 glass chromatographic column (3mm X 2m). It was found that the peak of molecular ion of methyl ester of MPA was 414 (an adduct of methyl levopimarate and maleic anhydride-only the free-carboxyl group was esterified,and the cycle of anhydride remained in fact) by GC/MS. Under the conditions of temperature programming,the peaks of rosin acids (as methyl esters) in MMR on OC were separated completely. When taking the peak of methyl dehydroabietate as control (fM= 1. 000) and the method of normalization is used for quantitative determination,the relative mole correction factor (fM) of methyl ester of MPA keeps constant (0. 8315) ,within the concentration range from 0 to 0. 75 mol/L of MPA. This method,which is of higher precision and lower relative error (about @@0. 6%) an be used for tracing the component changes during the process of the maleinization of rosin and analyzing the components of MMR directly.