What is the main focus of a mass spectrometer in evidence analysis?

A mass spectrometer primarily focuses on finding the relative abundances of atomic masses in a sample. This analytical technique works by ionizing chemical species and sorting the ions based on their mass-to-charge ratio. Each ion can be associated with a specific atomic mass, allowing scientists to identify the composition of a sample and its isotopic variations. By analyzing this data, forensic scientists can gain insight into the molecular structure and composition of the materials being examined, which is crucial for various applications in evidence analysis, including identifying substances or determining their sources.

The other choices present alternative analytical processes that do not align with the primary function of a mass spectrometer. For example, determining the color of materials, measuring the volume of gases, or assessing pH levels involve different methodologies and equipment, which are not the focus of mass spectrometry. The ability of a mass spectrometer to separate and quantify ions makes it an invaluable tool in forensic analysis for establishing material identities.