Pegasus HRT GC and GCxGC-TOFMS
Redefining High-Resolution Analysis
Never miss another clue with the Pegasus HRT high-resolution GC-TOFMS (gas chromatography time-of-flight mass spectrometry) platform. The HRT delivers <1 ppm mass accuracy and resolving power upwards of 50,000 without sacrifices to sensitivity, acquisition speed, or spectral fidelity. Exceptional mass accuracy and soft ionization capabilities enable accurate formula determination for elucidating the identity of unknown analytes.
For the most complex mixtures, pair the HRT with LECO’s QuadJet thermal modulator for enhanced separation power and identification accuracy. The HRT empowers deeper insights for environmental studies, petroleum characterization, metabolic profiling, and much more.
Why Choose the Pegasus HRT Series?

Ultra-High Resolution for Confident Identification
Folded Flight Path (FFP) time-of-flight (TOF) technology delivers resolving power over 50,000 to easily isolate analyte signals from matrix.

Superb Mass Accuracy Improves Identifications
Routinely achieve sub-ppm mass accuracy for confident molecular formula calculations.

Capture Everything in One Run
Acquire full-spectrum data at speeds up to 200 spectra per second, ideal for GCxGC coupling and complex, non-target analyses.

Innovative, Flexible Ionization Source
The HRT comes standard with the Multi-Mode Source (MMS)—select Electron Impact (EI), Positive Chemical Ionization (CI), or Negative Chemical Ionization (NCI) with the click of a button.
Instrument Applications
Core Analyses
Featured Application Notes
PFAS and Environmental Pollutants in Household Dust
PFAS and Environmental Pollutants in Household Dust
Characterizing Extractables from Dental Bite Guards with GC-TOFMS
Characterizing Extractables from Dental Bite Guards with GC-TOFMS
Analysis of Polychlorinated Paraffins using GCxGC-HRTOFMS
Analysis of Polychlorinated Paraffins using GCxGC-HRTOFMS
Identifying Disinfection Byproducts in Treated Water
Identifying Disinfection Byproducts in Treated Water
Identification of Components of Polymer Extracts by Gas Chromatography with EI and CI High Resolution Time-of-Flight Mass Spectrometry
Identification of Components of Polymer Extracts by Gas Chromatography with EI and CI High Resolution Time-of-Flight Mass Spectrometry
Discovery of Environmental Pollutants at an Electronic Waste Recycling Facility by Pegasus GC-HRT 4D
Discovery of Environmental Pollutants at an Electronic Waste Recycling Facility by Pegasus GC-HRT 4D
How it works
The LECO Pegasus HRT is a gas chromatography–mass spectrometry (GC‑MS) system designed for the analysis of complex organic mixtures. It combines gas chromatography for chemical separation with high‑resolution time‑of‑flight mass spectrometry (HR‑TOFMS) for compound detection and identification. The system is commonly paired with comprehensive two‑dimensional gas chromatography (GCxGC) to increase separation capacity for samples containing many co‑eluting components.
After chromatographic separation, analytes enter the mass spectrometer ion source, where they are typically ionized by electron ionization (EI). Soft ionization techniques like Chemical Ionization (CI) and Negative Chemical Ionization (NCI) can also be used to preserve molecular ions for improved elemental composition determination. With LECO’s Multi-Mode Source (MMS) for the HRT, analysts can switch between the three ionization modes with a simple software toggle.
The resulting ions are accelerated into a time‑of‑flight analyzer, where they are separated based on their mass‑to‑charge ratio by measuring the time required to travel a fixed distance. LECO’s unique Encoded Frequency Pushing (EFP) maximizes TOF duty cycle, instrument sensitivity, and spectral quality.
The Pegasus HRT employs the Folded Flight Path (FFP), which transmits ions for either 20 or 40 meters before reaching the detector, depending on the acquisition mode selected. Use of an ultra-long flight path ensures reliable detection of all ions that is not sensitive to atmospheric conditions or sample concentration.
Ions are detected by a fast detector, and the resulting signals are deconvoluted into accurate‑mass spectra across the full mass range for every chromatographic peak. Because the system collects full spectral data without mass filtering, both known and unknown compounds can be evaluated post‑analysis without re‑running samples.
Multi-Mode Source
The LECO Multi-Mode Source (MMS) is a versatile ionization platform designed to streamline complex characterization by integrating multiple ionization techniques into a single, high-performance source. It allows users to switch seamlessly between Electron Ionization (EI), Positive Chemical Ionization (PCI), and Electron Capture Negative Ionization (ECNI) via simple software commands. This eliminates the need for manual hardware changes, ensuring perfect retention time alignment across different modes and providing the high mass accuracy required for both molecular and fragment ions in a single workflow.


Folded Flight Path
LECO’s patented Folded Flight Path (FFP) maximizes resolving power and mass accuracy while maintaining a compact instrument footprint. By extending the effective ion flight length through a folded geometry, the system achieves high resolution and precise mass measurements without sacrificing stability or speed. This design minimizes spatial requirements while enhancing separation of closely spaced mass peaks, supporting confident identification of compounds even in highly complex or trace‑level analyses.
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Ensure reliable instrument performance with extensive support, training, and maintenance services. Need tailored support for your mass spectrometers? Our experts are standing by.
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