hrvatski

Spektrofotometrijska analiza lignina bukovine

The structural complexity of lignin has continually chalenged the ingenuity of researchers to develop suitable methods for its characterization prior to and following a wide variety of chemical, biological and physical treatmens. Increasingly wide ranging, in-depth investigations on the structure and reactivity of lignin exposed the inadequcy of many of the methods currently in use and underscored the ever-continuing need to develop new methods capable of solving the unique analitical problems associated with lignin. One notable example of the headway being made in reching this objective are methods based on the usefullness of sophisticated instrumentation like UV- and IR-spectrophotometric used in this work.Goals of investigation, which are elaborated and optained in this work, give their share to knowledge and utilization of lignin as component of group chemical wood compound, as the product or nusproduct in chemical wood technology. The most important factor that stipulated further use is the chemical structure, becouse of which the goals of this work is to investigate the chemical structure of common beech.Analyse and research of native (Brauns) lignin, according to Brauns method, valuable dates have been obtained, like value of accessory matter exctracted with dietil-ether as solvent and value of native lignin contents and it has been confirmed efficiency of modified isolation method for native lignin in hardwoods, especialy for commom beech (modification method by Sertić and Antonović).Using results of UV-spectrophotometry on native lignin in common beech as well as results of apsorbance, on 281 nm wavelenght, we can concluded that the lower average value have samples from Pleternica (Abs = 1.4030) and the highest value have samples from Sljeme (Abs = 1.7091). This results suggest that the ordinary concentration of native lignin in wood samples for common beech are the lowest in Pleternica, but highest in Sljeme. The ideal method of lignin isolation has not yet been discovered, considerate the hypothesis is that the absorption for the structure of native lignin in live tree are even higher.Based on FTIR-spectrophotometry analysis of native lignin for beech on all locations, the most significant peaks on specifical wavelenght of its IR-spectar (16 peaks) have been determented, and give them assigments, as preposition to spectrophotometric analysis of native lignin and lignin generally, which is very important for determination of native lignin in unknown samples.

Obična bukva (Fagus sylvatica L.); nativni (Brauns-ov) lignin; UV-spektrofotometrijska analiza; FTIR-spektrofotometrijska analiza

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