| Abstract: | The X-RF method for the determination of the total glucosinolate content in rapeseed is a comparatively new method, which is, due to its striking features in precision and speed, becoming the most favoured method for glucosinolate analyses within the European Community. This contribution presents a first systematic study on sources of variations in analytical results obtained with the X-RF method. Sample born sources of variations (immaturity, contaminations with weeds and fungi, inhomogeneity) primary cause deviations of the results obtained by chemical reference or control methods. One of the most striking problems is the immaturity of seeds which leads to systematically lower glucosinolate values by chemical methods so that the results obtained by the X-RF method appear to high. Compared to this possible error, variations caused by mistakes during preparation and measurement are of less importance. However, the knowledge of these factors may give helpful hints when deviations to results of other analytical methods want to be explained and to optimize the routine work in order to avoid systematic errors in the analytical procedure. |
