Process and {TAIL ~ catalyst} for determining {HEAD ~ nitrogen} in a sample according to the Kjeldahl principle 
Process and { TAIL ~ catalyst } for determining { HEAD ~ nitrogen } in a sample according to the Kjeldahl principle
OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH