Rapid method for determination of dehydro abietic acid in gum rosin and disproportionate rosin by proton nuclear magnetic resonance spectroscopy

摘要: In present work a simple, direct and rapid method developed based on proton nuclear magnetic resonance spectroscopy for the quantitative determination of dehydroabietic acid in gum rosin and disproportionated rosins and validated. This method can also be applied to the determination of other acids of gum rosins like abietic acid, pimaric acid isopimaric acid, palustric acid, neo abietic acid, levopimaric acid, tetrahydro abietic acid, dihydro abietic acid. Dehydroabietic acid has been estimated using aromatic proton while vinyl propton was used for estimation of other acids in gum rosins. Analysis of rosin acid methyl ester derivative in disproportionated rosins was also carried out by gas chromatography-mass spectroscopy to identify peak of dehydro abeitic acid along with abeitic acid based on their mass fragmentation pattern and quantified using gas chromatography with flame ionization detector. Good correlation was observed between the results of gas chromatography with flame ionization detector with newly developed nuclear magnetic resonance method.