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

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.