Mass spectrometer device

Mass spectrometer, an instrument that identifies molecules by mass-to-charge ratio, used in chemistry, biology, and medicine.

About this subject

A mass spectrometer is an analytical instrument that measures the mass-to-charge ratio of ions to identify and quantify molecules. The basic principle involves three steps: ionization of the sample, separation of ions by their mass-to-charge ratio in an analyzer, and detection. Different ionization techniques, such as electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI), allow analysis from small molecules to whole proteins. Common analyzers include quadrupole, time-of-flight (TOF), and ion trap, each with specific advantages in resolution and mass range. Mass spectrometers are essential tools in organic chemistry, biochemistry, and medicine. In proteomics, they enable identification of thousands of proteins in a biological sample. In clinical diagnostics, they are used to detect disease biomarkers and monitor therapeutic drugs. In environmental science, they help quantify pollutants in water and air. The development of the mass spectrometer began with J.J. Thomson in the early 20th century, who built the first mass spectrograph. Since then, technology has evolved tremendously, with modern instruments achieving mass accuracy of parts per million and sensitivity to detect attomoles of analyte. Tandem mass spectrometry (MS/MS) allows fragmentation of selected ions to obtain detailed structural information, being fundamental for the elucidation of unknown compound structures.

Frequently Asked Questions

How does a mass spectrometer work?

It works by ionizing the sample (converting molecules into ions), separating those ions by their mass-to-charge ratio in an analyzer (such as quadrupole or time-of-flight), and detecting them. The result is a mass spectrum showing the relative abundance of each ion.

What are the main types of mass spectrometers?

The main types are based on the analyzer: quadrupole (simple and robust), time-of-flight (TOF, high resolution), ion trap (tandem analysis), magnetic sector (high precision), and Orbitrap (ultra-high resolution). Each is suited for different applications.

What is a mass spectrometer used for in medicine?

In medicine, it is used for diagnosing metabolic diseases, therapeutic drug monitoring, identifying cancer biomarkers, and analyzing proteins in biological fluids. Techniques like MALDI-TOF are common for identifying bacteria in infections.