Proficiency Testing of ¹⁵N Abundance Determination by Interlaboratory Comparisons

We have taken part in inter laboratory comparisons of total N and ¹⁵N abundance determination proficiency testing organized by FAO/IAEA. It was proven that our laboratory analytic results of three plant samples are identical with reference results in two comparisons. Our results of total N and ¹⁵N abundance are absolutely perfect and accurate. This EQA plan should be useful in defining our laboratory testing proficiency and testing level in inter laboratory.