Nitrate converted easily to a simple gas is detected by the Solvita SLAN probe in recent lab tests, eliminating fussy interference from chloride.

Solvita announced quantitative recovery of nitrate nitrogen via a one-step chemistry conversion, using a Solvtia SLAN probe, “a small feat of basic chemistry” says inventor Brinton.  The Solvita SLAN test normally detects ammonia, ammonium and amines released when soil is treated with an alkaline extract. “Its important for soil fertility assessment” says Brinton, “since accumulation of soil organic nitrogen is a fundamental hallmark of biological soil fertility”. The discovery of simultaneous detection of nitrate by a Solvita probe came about as a result of a collaboration with Kansas State University’s Dr. Ignatio Ciampitti, in his breakthrough N-fixation research on soybeans. There, researchers seek to isolate amino-N and nitrates from ureides formed in the early stages of N-fixation, a procedure that could help farmers and plant breeders significantly select on, and improve, N-fixation efficiencies in soils and plants. Recollecting his early grad school work to include ammonia and nitrates in combined analyses, Brinton suggested a metal catalyst to convert NO3 directly to ammonia in the routine 4-24hr Solvita test period, thereby achieving quantitative recovery of NO3 by the SLAN probe. As a disassociated gas, the bothersome ion interferences plaguing soil labs using auto-analyzers for NO3 are eliminated. Preliminary trials show the new test can reach down to about 10 ppm nitrate-N in ammonia form and up to 500 ppm. “We imagine combining these as a simple fertility-N test for any soil extract, also for plant tissues”, protocols under development.  Woods End Labs will introduce the test as a technical bulletin for labs which already possess Solvita equipment, a cost-effective procedure requiring no new equipment.