A new method for determination of hydroperoxides in cellulose

Abstract.

A new chromatographic method for determination of hydroperoxides in cellulose is described, whereby the sample is dispersed in phosphate buffer solution (pH 7) of FeCl₃, EDTA and the hydroxyl radical scavenger, N,N'–(5–nitro,1,3-phenylene)bisglutaramide. The reaction time, concentration of reagents and chromatographic conditions for subsequent separation and quantification of hydroxylated products are optimised. The limit of detection is 0.14 µmol L^–1 H₂O₂ which corresponds to 2.1 µmol hydroperoxides per kg of cellulose (mass of sample: 0.4 g). It was shown that in the concentration range of H₂O₂ up to 15 µmol L^–1 the method gives linear response and that adsorption of reaction products on fibres is negligible. For cellulose samples, this corresponds to a linear range of 2.1–225 µmol of hydroperoxides per kg. Due to possible side reactions of hydroxyl radicals in the suspension of analyte, it is recommended that the standard addition technique is used. In purified cotton cellulose, the steady state concentration of hydroperoxides at room conditions was found to be 15.1±1.5 µmol kg^–1.