Pegasus 4D-C Comprehensive Two-Dimensional Gas Chromatography with Time-of-Flight Mass Spectrometer


Automated Peak Find

LECO’s patented Automated Peak Find and True Signal Deconvolution algorithms serve as a foundation for identifying a sample's true chemical content.

True Signal Deconvolution

A mass spectrum for each analyte is automatically extracted free of interferences from the system background, matrix background, and coeluting analytes using True Signal Deconvolution


Developed side-by-side experts in the field, Pegasus® 4D GCxGC TOFMS delivers a comprehensive technological solution.  From complex omic applications, routine quantification of flavour fragrance samples to forensic profiling or drinking and waste water analysis, the Pegasus 4D provides incomparable GCxGC performance.  Thermally isolated and independently controlled, the dual stage-quad jet modulator and secondary oven are mounted inside the primary GC oven.  All aspects of the LECO Pegasus 4D GCxGC TOFMS are completely integrated, fully automated and entirely driven by LECO’s exclusive ChromaTOF software.  Powerful whilst easy-to-use ChromaTOF maximises chromatographic optimisation, providing a significant increase in efficiency and productivity.  Pegasus 4D offers an unrivalled gold standard in GCxGC technology: one instrument, one software, your only GCxGC solution.

Benefits of LECO Pegasus 4D GCxGC TOFMS:

  • Reduce operation costs by omitting the need for LN2 using the LECO Consumable Free GCxGC solutions
  • Lower detection limits by benefiting from the Cryo-focusing effect of dual stage quad jet modulation when using any LECO GCxGC solutions unlike the disadvantages seen in flow modulation
  • Reduce sample run times by increased Peak Capacity and working faster with TOFMS high speed detection rates
  • Easily characterise your complex samples by visualising all chemical groups within a sample due to the benefit of structured chromatograms based on chemical classes that are only achievable using a dual stage quad jet GCxGC separation and ChromaTOF Classification tools.
  • Increase information gleaned from a single injection by taking advantage of the increased peak capacity offered by LECO GCxGC strategies
  • Increased sensitivity as all the sample is delivered to the detector, without the need of splitting flow rates to enter the Mass Spectrometer
  • Optimise and save precious 1st dimension separation efforts by using Variable Modulation Times (VMT) which counteracts over modulation of heavy boilers and improves analyte detectability over the entire chromatographic area
  • Simplified operation and data processing by using ChromaTOF GCxGC single software solution that negates the need for lengthy data export followed by data processing and interpretation strategies using several 3rd party software tools.
  • Matrix problems are easily overcome – TSD® readily resolves coelutions in GCxGC
  • Reduce the burden of sample preparation as dirty samples are no problem for the uniquely designed open ion source design which never needs cleaning
  • Robust & proven technology – minimal maintenance and endorsed by users globally
  • Efficiency in the laboratory – high throughput readily & routinely achieved


Only the Pegasus TOFMS, with continuous full-range mass spectral acquisition rates up to 500 spectra/sec written to disc, offers MS data with sufficient data density to address the requirements of any GCxGC separation.  Spectral quality at these high acquisition rates is maintained in the Pegasus TOFMS as seen in Figure 5.  Two-dimensional gas chromatography (GCxGC) occurs by the repetitive re-injection of all effluent from one chromatographic column into a second column of orthogonal phase.  LECO GCxGC systems accomplish this with a dual-stage, quad-jet thermal modulator positioned between the two columns.  The cycle of refocusing and re-injection is matched in time to eluting compounds from the second GC column, resulting in separation of compounds across a plane, rather than just along a line.

Features and Benefits :

Features Benefits
Continuous full-range mass acquisition rate up to 500 spectra/second written to disc Ability to define the narrowest of GC peaks Full-range mass spectral data for True Signal Deconvolution Accurate identification of unknown and targeted compounds in complex samples Ability to review archived data for new compounds outside the scope of the initial analysis
Full-range mass sensitivity Accomplish in one run what other mass spectrometers require multiple runs to achieve
Linear dynamic range of 4 orders of magnitude or more Analyze and quantitate real-life samples of varying concentrations in matrix
Robust Never-Clean ion source No laboratory down-time associated with source cleaning Proven reliability Higher productivity
ChromaTOF software Scripting for GCxGC Classifications for GCxGC Variable Modulation Times for GCxGC optimisation Statistical Compare for GCxGC Reference Compare True Signal Deconvolution – no data export required Quantification & Screening strategies with custom reports
Integrated control from ChromaTOF software Total system automation for maximum productivity


LECO’s versatile instrumentation can be used to perform a wide range of applications. Please find below a selection of application notes for the most popular applications. Contact our sales and application specialists for more details.

New! Differentiation of Fresh and Oxidized Wine Samples with HS-SPME, GC-TOFMS, and GC×GC-TOFMS

Pegasus HT and Pegasus 4D systems were used to differentiate two wine samples namely one fresh and one oxidized by the presence of oxygen inside the bottle. Thanks to the increased peak capacity and sensitivity offered by the coupling of a secondary column on the GCXGC system, it was possible to assign correctly the components formed during the oxidation process. Furthermore, LECO’s Deconvolution tool allowed the correct identification of the components well resolved or masked from the sample matrix. Ref. 203-821-514Learn more...

Chemical Analysis of Polymer Microbeads in Toothpaste by TD- and Py-GC×GC-TOFMS

This application note focuses on the direct analysis of a brand-name toothpaste containing polyethylene to determine the additives or inactive ingredients by consecutive thermal techniques coupled to a LECO Pegasus 4D for comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS).Learn more...

Crude Oil Fingerprinting

Light Crude Oil Fingerprinting from Six Different Global Regions Using GCxGC-TOFMS with Structural Classifications to Compare Functional Group Differences Learn more...

FAME in Jet Fuels

Analysis of Fatty Acid Methyl Esters (FAMEs) traces in Jet Fuel by GC-TOFMS Learn more...

Environmental, Water, Waste water

Utilization of GCxGC-TOFMS as a Broad Spectrum Analysis for Endocrine-Disrupting Compounds in Urban and Rural Watersheds Learn more...

Fast Aroma Profiling

Aroma Profile of Pet Food by GC-TOFMS and GCxGC-TOFMSLearn more...

Classifications, Hydrocarbon, Excel, Sumif

The Use of GCxGC-TOFMS and Classifications for the Quantitative Determination of Different Compound Classes in Complex Isoparrafinic Hydrocarbon SamplesLearn more...

Aromas, Variable Modulation, Headspace SPME

Analysis of Sagebrush Aromas by Headspace SPME-GCxGC-TOFMS and Utilization of Variable Modulation in the Second Dimension SeparationLearn more...

Metabolomics, Healthy and Disease

Metabolomics GCxGC-TOFMS Analysis Comparison of Healthy and Disease States in Zucker Rat PlasmaLearn more...


Headspace SPME-GCxGC-TOFMS of Sagebrush with Variable ModulationLearn more...

Light Crude Oil

GCxGC-TOFMS of Light Crude Oil Optimized with Variable Modulation & Structured Chromatographic ClassificationsLearn more...


Analysis of Kerosene by GCxGC-TOFMS with Variable Modulation & ClassificationsLearn more...

Pesticides, Consumable-Free Modulator

Analysis of Pesticides by GCxGC-TOFMS Using a Consumable-Free ModulatorLearn more...

Options & models


Various options are available for this product. Contact our sales and application specialists to select the right configuration for your application.
Online diagnostic LECO's convenient remote diagnosis via Internet


Each instrument can be configured to meet your individual lab needs. Contact our sales and application specialists to select the right configuration for your application.
Pegasus 4D GCxGC TOFMS The Pegasus® 4D GCxGC TOFMS system including ChromaTOF® software
Pegasus 4D CF GCxGC TOFMS The Pegasus® CF 4D GCxGC TOFMS system including ChromaTOF® software