Determination of nitrogen-15 at sub-microgram levels of nitrogen using automated continuous-flow isotope ratio mass spectrometry
Abstract
Recent developments in continuous-flow isotope ratio mass spectrometry have considerably enhanced the ability to make rapid and precise measurements of the stable isotope 15N. Although the amounts of nitrogen required for precise analyses have been reduced considerably, the levels required remain a limitation for many applications. A simple manipulation of the use of commercially available equipment is described that allows the simultaneous determination of nitrogen and 15N at levels as low as 10 nmol of total nitrogen.