Isotopic ratios refer to the abundance of different isotopes of an element in a sample, typically measured using mass spectrometry. These ratios can provide valuable information about the source, history, and processes involved in the formation of a material or substance. Isotopic ratios are commonly used in fields such as geology, archaeology, environmental science, and forensics to trace the origin of materials, study past climates, and investigate biological processes. By comparing isotopic ratios in samples, researchers can gain insights into the processes that have shaped our planet and its inhabitants over time.