Isotope monitoring is a research area that involves the analysis and tracking of isotopic compositions in various substances, typically in the fields of geology, environmental science, and biological sciences. Isotopes are variants of elements that have the same number of protons but different numbers of neutrons, leading to differences in their atomic mass. By studying the ratios of isotopes in a sample, researchers can gain valuable information about processes such as nutrient cycling, pollution sources, and climate change. Isotope monitoring often involves techniques such as mass spectrometry and stable isotope analysis to study these isotopic compositions.