Quadrupole (single) [Mass Spectrometry]

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Glossary

WHAT IT IS

Single Quadrupole Mass Spectrometry is a core mass spectrometry technique used for detecting and quantifying chemical compounds based on their mass-to-charge ratio (m/z). uses a single set of four rods (a quadrupole) to filter ions based on their mass-to-charge ratio, providing fast and reliable mass detection

HOW IT WORKS

The sample is introduced into the system through a suitable ionization source. Once ionized, the ions are directed into the quadrupole analyzer, which consists of four parallel rods arranged symmetrically.

A combination of radio frequency (RF) and direct current (DC) voltages is applied to the rods. These voltages create an oscillating electric field that stabilizes the path of ions with a specific m/z. Ions that do not meet the stability criteria are filtered out.

By systematically changing the RF and DC voltages, the quadrupole allows ions of different m/z to pass through one at a time to the detector, which generates a mass spectrum representing the compounds in the sample.

ADVANTAGES

Fast and Efficient Scanning: Capable of rapidly scanning a full m/z range, supporting real-time analysis and quick data acquisition.

Reliable Quantification: Delivers linear and reproducible responses across a wide concentration range, suitable for regulatory and routine testing.

Cost-Effective: One of the most affordable mass spectrometry options, ideal for high-throughput laboratories.

Simple Operation and Maintenance: User-friendly software, straightforward calibration, and minimal routine maintenance requirements.

Robust and Durable: Withstands demanding workflows and delivers consistent results with basic infrastructure.

CHALLENGES AND LIMITATIONS

Unit Mass Resolution: Can only distinguish between ions that differ by 1 atomic mass unit (e.g., m/z 100 vs. 101), limiting its ability to resolve isobaric species.

No Structural Elucidation: Cannot provide detailed fragmentation data for structural analysis.

Limited Specificity in Complex Matrices: Overlapping peaks and matrix interference can reduce confidence in identification compared to high-resolution or MS/MS instruments.

Lower Sensitivity for Trace-Level Compounds: While suitable for most routine applications, may not detect ultra-low concentrations as effectively as more advanced systems.