DETERMINATION OF TOTAL NITROGEN IN BARLEY, MALT AND BEER BY KJELDAHL PROCEDURES AND THE DUMAS COMBUSTION METHOD - COLLABORATIVE TRIAL

A method relying on the Dumas Combustion Principle for the determinati on of total nitrogen in barley, malt and beer has been collaboratively tested by the Analysis Committee of the Institute of Brewing. ''Kjeld ahl'' procedures were used for comparison. The Committee approved the adoption of the Dumas procedure as the reference method for barley and malt. Precision values were independent of total nitrogen content for barley and malt, over the range 1.17 to 1.71 %m/m and 1.45 to 2.03 %m /m (as is) respectively. Repeatability (r95) and reproducibility (R95) values were 0.030 and 0.070 respectively for barley and 0.036 and 0.0 65 respectively, for malt, over the given ranges. Slightly higher valu es were obtained for total nitrogen by the Dumas method, compared with those given by Kjeldahl procedures.