METHOD FOR SIMULTANEOUSLY DETERMINING NITROGEN AND OXYGEN ISOTOPIC COMPOSITION OF NATURAL NITRATE AND NITROGEN AND OXYGEN ISOTOPIC COMPOSITION OF NATURAL NITRITE

摘要

Provided is a method for simultaneously determining nitrogen and oxygen isotopic composition of natural nitrate and nitrogen and oxygen isotopic composition of natural nitrite, comprising: quantitatively converting nitrate and nitrite into corresponding organic esters and nitro compounds, and then using gas chromatography/pyrolysis/gas chromatography/isotope ratio mass spectrometry combined technique to simultaneously determine δ¹⁸O and δ¹⁵N of nitrate and those of nitrite. The method for simultaneously determining nitrogen and oxygen isotopic composition of natural nitrate and nitrogen and oxygen isotopic composition of natural nitrite requires a small amount of sample, and does not cause loss, obtaining, exchange, and fractionation of nitrogen and oxygen.