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