LC-MS System Combines Three Mass Analyzers

The Thermo Scientific Orbitrap Fusion Tribrid liquid chromatography-mass spectrometry (LC-MS) system combines its three mass analyzers—quadrupole, Orbitrap, and linear ion trap—in a novel “Tribrid” architecture that offers depth of analysis of complex biological samples. One way the Orbitrap Fusion system can address throughput challenges is through tandem mass tags (TMT). This technique enables mass spectrometers to determine relative quantification of proteins in multiple samples simultaneously. The Orbitrap Fusion instrument increases depth and quality of data compared to previous tools to make TMT results far better. The new platform takes advantage of MS³ selectivity to improve quantitative accuracy, and can collect twice as many MS³ scans per unit time, at significantly greater sensitivity than was previously possible. New TMT reagents are also available from Thermo Fisher, allowing comprehensive, simultaneous analysis of up to 10 samples.

At the heart of the Orbitrap Fusion LC-MS is a configuration of three different mass analyzers that work together to raise analytical performance to new levels and enable completely new experimental methods:

• A quadrupole for precursor selection at isolation widths down to 0.4 amu for sensitivity and selectivity;
• An ultra-high-field Orbitrap offering resolution in excess of 450,000 and scan rates up to 15 Hz for selectivity and speed of analysis;
• An ion routing multipole followed by dual-pressure linear ion trap providing MSn HCD, CID and ETD fragmentations and fast, sensitive mass analysis with scan rates of up to 20 Hz. Synchronous precursor selection enhances the instrument’s signal-to-noise ratio.

This Tribrid configuration enables users to positively identify larger numbers of low-abundance proteins faster than previously possible with existing commercial instruments. Its unique architecture enables simultaneous precursor isolation, fragmentation, and data acquisition in both the Orbitrap and linear ion trap mass analyzers.

The ability to choose between fragmentation modes at any stage of MSⁿ analysis with detection by the Orbitrap or linear ion trap analyzer makes possible a range of novel experiments to achieve a new level of structural information from metabolites, glycans, posttranslational modifications, and sequence polymorphisms.

In typical metabolomics experiments, scientists frequently encounter unknowns along with target compounds. To identify the unknowns, the sample must be rerun on an LC-linear ion trap instrument to obtain MSⁿ data. But it is difficult to match chromatography retention time on the second run, introducing substantial uncertainty. With its three mass analyzer configuration, however, the new Orbitrap Fusion Tribrid LC-MS addresses this problem, offering users the ability to transform many small molecule experiments by conclusively identifying unknowns as they are encountered.

Thermo Fisher Scientific Inc., 800-678-5599, www.thermofisher.com