GCxGC-ECD/FID | Comprehensive Two-Dimensional Gas Chromatography | LECO

QuadJet™ SD
Comprehensive Two-Dimensional Gas Chromatography


LECO's QuadJet™ SD is the ideal solution for samples which arrive in your lab. By combining the sensitivity of Flame Ionization Detection (FID) with the increased chromatographic resolution of comprehensive two-dimensional gas chromatography (GCxGC), the QuadJet SD delivers a better measure of the actual components of your sample than a straight GC analysis. No other system available on the market can deliver the same reduction in noise and error as the QuadJet SD.
 

 

Features

  • Enhanced separating power for complex sample analysis
  • Easy-to-use ChromaTOF®-based software provides acquisition processing and reporting funtionality within a single package
  • Classification software feature simplifies component identification
  • Available Cryogen-free modulator eliminates the need for LN2 dewars 

When performing GC-FID analysis, most laboratories quantify compounds using the area of the FID signal. Real world samples are rarely clean and straightforward. For example, a diesel sample can have thousands of different compounds in a single injection. The more compounds in a sample, the higher the chance of coelution; this coelution will increase the FID signal, thus creating a high bias error in the measurement. With GCxGC performing two separate chromatographic separations in one experiment, the accuracy of the FID measurement is maintained.

Due to the orthogonal nature of the separation mechanism in GCxGC, coeluting compounds are easily pulled apart in a single run. True GCxGC instruments, such as the LECO QuadJet SD, improve upon simply running the same sample through two different columns by incorporating a modulation device. Peaks eluting from the primary column are quantitatively segmented into smaller sections prior to release onto the second column. This segmenting, along with the cryo-focusing of the modulator, can deliver peak widths as narrow as 50 ms to the second column.

Thermal Modulation

There is no better-performing modulator for GCxGC than thermal modulation, and not even other thermal modulators can match up to the ruggedness, reliability, and performance of LECO's GCxGC modulator. With LECO's QuadJet SD, modulation is accomplished via a dual-stage, quad-jet thermal modulator positioned between the two columns. LECO's thermal modulator allows for on-column cryo-focusing within the GCxGC system, providing increased peak detectability and increased separation of coeluting compounds for an order-of-magnitude increase in signal-to-noise.

LECO's Consumable-Free Modulator (which does not utilize Liquid Nitrogen) is an available option, saving time and money without sacrificing performance when modulating moderately volatile compounds.

LECO's QuadJet SD is designed to give you the upper hand in laboratory productivity. Its ease-of-use and industry's best secondary oven for the secondary column allows for improved analytical results. When you take the step to the next dimension in gas chromatography, make sure you're taking the step that will let you see what you've been missing.

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QuadJet™ SD Details

GC×GC ECD/FID

  • Models
    1. QuadJet™ SD with LN2 Cooled Thermal Modulator

    1. QuadJet™ SD with Consumable-Free Modulator

Wednesday, 02 December 2020 15:43

ChromaTOF® | Identification Grading System | LECO

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ChromaTOF® IGS | Identification Grading System | LECO

ChromaTOF® Identification Grading System


Bring the Power of Accurate Mass and Confidence to your Identification Problems

LECO's Identification Grading System (IGS) eases data review by allowing users to quickly see, justify, have confidence in, and report on which chemicals are in a particular sample. This in turn allows a user to make confident decisions on what to do next.

Start Knowing What is in Your Sample

The IGS uses all the available chemical information generated from the Pegasus® GC-HRT+ 4D to add confidence to your unknown unknown identification process.

The IGS gives a grade to a particular identification based on 4 criteria:

  1. Presence and accurate mass of a molecular ion
  2. Presence and good correlation of a spectral similarity score from a curated library
  3. Accurate masses of sensible potential formulae of fragmented ions corresponding to a spectral library hit
  4. Matching retention index from the library hit

The higher the value of the grade, the more confident you can be in your identification.

The true power of identification can only be realized with the combined power of GCxGC and high resolution time-of-flight mass spectrometry (TOFMS).

  • GCxGC separates coeluting species and gives cleaner mass spectra than other techniques.
  • TOFMS enables unskewed mass spectra across a chromatographic peak even across very narrow second dimensional peak; which, when combined with deconvolution, yields the highest quality spectra that you can generate.

Born out of the United States of America Environmental Protection Agency (EPA)’s Non-Targeted Analysis Collaborative Trial (ENTACT), the IGS is LECO’s solution to the time-intensive process of data review.

Take for example the unfiltered deconvolution results from a GCxGC-TOFMS analysis of a sample from the EPA's ENTACT project (below, left). By applying the IGS filter, we can quickly view only the most confident indentifications. This simplification is dramatic and enables you to immediately begin investigating the "unknown unknowns," as indicated by the arrows in the diagram image on the right.

ChromaTOF IGS Sample Example

Left: Initial HRD (n=4800). Right: IGS > 2 (n=245)

Of the known compounds entered into the sample from this particular example (which was provided to LECO as a blind sample), IGS identified approximately 80% of the known peaks. The combination of GCxGC and high resolution TOF was proven to be necessary for this confidence. Read "Identifying Small Molecules via High Resolution Mass Spectrometry" for more information.

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