Vergleich der fluorimetrischen und der Blauzahl-Methode für die Bestimmung des a -Aminostickstoffs in Aluminiumsulfatfiltraten von Zuckerrüben

In this study the results obtained by application of a fluorimetric method for the determination of the a -amino nitrogen content in sugar beet from filtrates clarified with aluminium sulfate were analyzed. A comparison was made between the usually applied “blue number” method (Stanek-Pavlas), modified by Kubadinow and Wieninger, and the fluorimetric method using the OPT reagent introduced by Burba and Georgi. For calibrations L-(+)glutamine, L-(-)-asparagine and g -aminobutyric acid were tested. A statistically very significant correlation between the two methods for a -amino nitrogen was found. For the OPT reagent preparation, borate buffer made in laboratory can be used as a substitute for the buffer made by a commercial manufacturer. The results were more reliable if the calibration solutions and the filtrates, before measurements, are diluted in a ratio of 1:50.