Optimisation of focused microwave digestion of proteinaceous binders prior to gas chromatography

The aim of the present study is to accelerate the acid-digestion step needed for the study of proteinaceous binding media by gas chromatography. The optimisation of the digestion step was carried out using full and half-fractioned factorial designs. The evaluation of the precision of the proposed digestion method and its comparison with the method considered as the reference showed the high irreproducibility of the derivatisation reaction needed for the analysis of the amino acids by gas chromatography. Although the optimal digestion time was found to be 90 min, the differences between different irradiation times were statistically non-significant, so an extremely high reduction on the analysis time is achieved.