Development of NMR and Raman spectroscopic methods for the determination of the degree of substitution of maleate in modified starches

In this paper we report the application of NMR spectroscopy and Raman spect roscopy to determine the degree of maleate substitution in maleinated starc hes. Five kinds of maleinated starches were investigated and calibration se ts were constructed to derive linear regression equations that may be used to predict the degree of maleate substitution for starch samples with unkno wn amounts of chemical modification. The calibration sets reported have ver y high linearity (r > 0.99) for both the NMR and Raman methods. The NMR and Raman;calibration sets allow fast and nondestructive measurement of the de gree of maleate substitution for different starches with little need of sam ple preparation.