Rare nitrogen molecule could improve water quality testing

Researchers at UCD and UCLA have shown that the rare 15N15N isotopologue in dissolved nitrogen acts as a natural fingerprint of microbial nitrogen conversion. The method, published in Science, could help estimate how much nitrogen is removed from water as gas and improve groundwater monitoring.

• The rare 15N15N isotopologue is more abundant in air than random pairing would predict
• Microbes produce N2 with nearly random isotope pairing, reducing the excess of heavy pairs
• Measurements were made using UCLA's Panorama mass spectrometer
• The technique could reveal how much nitrate is removed from groundwater before reaching rivers