While many drugs and metabolites contain nitrogen, harnessing their diagnostic N-15 NMR signature for their characterization is underutilized because of inherent detection difficulties. Here, we demonstrate how precise ultralow field signal amplification by reversible exchange (+/- 0.2 mG) in conjunction parahydrogen and an iridium precatalyst of the form IrCl(COD)-(NHC) with the coligand d(9)-benzylamine allows the naturally abundant N-15 NMR signatures of pyridine, pyrazine, metronidazole, and acetonitrile to be readily detected at 9.4 T in single NMR observations through >50% N-15 polarization levels. These signals allow for rapid and precise reagent quantification via a response that varies linearly over the 2-70 mM concentration range.