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