• Integrated control of all GC, modulator, TOFMS, and auto sampler system components  
• Comprehensive GCxGC capabilities  
• Comprehensive quantitative analysis of target analytes  
• Qualitative analysis with Automated Peak Find and True Signal Deconvolution® algorithms  

What is GCxGC?  

Comprehensive two-dimensional gas chromatography (GCxGC) is the answer for complete analysis and characterization of complex samples. As opposed to heart-cutting, GCxGC passes all effluent from the primary column through the secondary column, whereby maximizing sample resolution throughout the entire analysis. Heart-cutting can only accomplish this in a narrow, pre-determined time window. Hundreds-to-thousands of individual heart-cutting analyses would be required to accomplish what LECO's GCxGC delivers to you in one analysis.  

GCxGC adds a second dimension of chromatographic resolution to the sample analysis. This is accomplished by using two orthogonal separation phases (such as non-polar and polar) within a single analysis. The use of these two separation mechanisms expands the chromatographic plane—thus creating additional peak capacity in which peaks can be resolved.  

LECO’s GCxGC Thermal Modulator is the key to the enhancement of chromatographic resolution obtained by the Pegasus 4D system. The modulator, placed between the two columns, consists of a robust quad-jet system that creates two distinct trapping zones that ensure all of the effluent from the first column is properly focused prior to thermal release into the second column. A secondary oven is used for optimization of the second dimension separation.  

The GCxGC Advantage  

The demands of complex samples (such as the petroleum sample shown in Figure 2) quickly   overwhelm traditional GCMS analysis techniques.  

LECO provides the solution for complex sample analysis with the Pegasus 4D, the pre-eminent MS detector for Comprehensive Two-Dimensional GC (GCxGC). The High-Definition sample resolving capabilities of the Pegasus 4D, and the data processing features of ChromaTOF software offer every laboratory the ability to characterize and quantify even the most challenging samples.  

• Spectral collection rates up to 500 full-range mass spectra/second (500 Hz)—the Pegasus is the only MS detector capable of true Comprehensive multi-dimensional chromatography.  
• Cryo-focusing prior to release on secondary column provides up to a ten fold increase in analyte detectability.  
• True Signal Deconvolution —no other MS manufacturer in the world can match LECO’s   deconvolution experience and success.  
• Automated Peak Find  
• Wide dynamic range (4 orders of magnitude)  
• Maintenance-free ion source (no cleaning required)  
• A robust quad-jet, dual stage Thermal Modulator  
• Secondary oven for enhanced selectivity  

TOFMS—A Must-Have for GCxGC  

As part of the cryo-focusing process in the GCxGC modulator, analyte bands that elute from the first column are significantly sharpened prior to being released into the second column. As a result, peaks ranging from 50 to 200 milliseconds wide are produced (Figure 5). These narrow peak widths require a detection system that is capable of   collecting data at rates of 100 Hz or more in order to adequately characterize the shape of the chromatographic peak.  

Only the Pegasus TOFMS, with continuous full-range mass spectral acquisition rates at up to 500 Hz, 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.