“…Other methods involve the use of NH3-electrode (45), sodium salicylate ( 46), or chloramine-T (47). Jurecek et al (48,49) determined nitrogen in triazens and indazolinones by digestion with chromic acid; this reagent was also used for biological materials (50). Faust et al (51) described isotope-dilution analysis of nitrogen with the automated N-15 analyzer; it required that nitrogen in the sample be present as easily hydrolyzable amino groups.…”