О точности определения изотопного состава легких элементов
The performance of isotope ratio mass spectrometry systems (GC-C-IRMS, EA-IRMS, TC/EA-IRMS, DI-IRMS) with respect to dependence of δ13 C, δ15 N, δ18 O values on the amount of sample was presented. Various amounts of gas, liquid and solid samples were used for introducing to the mass spectrometry systems. The main reasons of non-linear dependence of measured isotope ratios on decreasing sample amounts appeared to be the presence of water in the ion source, imperfect optimization of ion source, and scattering of ions by molecules of gas-contaminants.
