LECO Paradigm Reverse Fill-Flush modulator and Shift flow splitter

Paradigm Flow Modulator and Shift Flow Splitter
Improve GC peak capacity without sacrificing accuracy

Greatly expand chromatographic peak capacity across entire volatility ranges with the Paradigm Reverse Fill-Flush (RFF) Modulator. Reverse fill-flush modulators deliver comprehensive two-dimensional gas chromatography separation by filling a fixed volume sample loop with primary column effluent, before rapidly flushing the contents out of the sample loop and onto an orthogonal secondary stationary phase. Complete transfer of analytes between the respective stationary phases (comprehensive GCxGC) ensures excellent method repeatability and quantitation.

  • Cryogen-Free modulation for GCxGC-FID or simultaneous TOFMS/FID acquisition when paired with the Shift flow splitter
  • Unique backpressure-controlled loop filling which permits method flexibility without the hassle of restrictor or bleedline changes
  • Column and loop fittings are readily accessible with standard wrench

ChromaTOF Makes Modulation Simple

Paradigm does away with complicated offline flow calculators. The integrated ChromaTOF software features a simple user interface that automatically performs the necessary calculations for users. The resulting methods are guaranteed to feature complete analyte transfer, excellent peak shapes, and excellent chromatographic resolution.

ChromaTOF software screenshot demonstrating integrated modulation issue identification

ChromaTOF Software identifies method calculation improvements for RFF modulation

A Shift Forward in Chromatographic Analyses

The Shift flow splitter is simple in design and appearance, but Shift’s novel splitting mechanism delivers long-sought functionality for complex sample characterization. Unlike traditional splitters, Shift maintains a constant split ratio between the MS and FID throughout the GC oven program. The result is unparalleled quantitative accuracy with minimal internal standardization required, greatly simplifying analyte and group-type quantitation for GC and GCxGC analyses.

Shift GCxGC Flow Splitter

Close-up on the Shift Flow Splitter installed in a GC oven


  • Novel chromatography splitter featuring two channels of pressure assistance
  • Designed to work with the high flow rates needed for RFF modulation (approximately 20 mL/min)
  • Maintains constant split ratio between MS and FID throughout an entire run, even during oven temperature ramps

Software-optimized Detector Performance

ChromaTOF automatically optimizes the flow rate directed to the TOFMS and FID for proper peak shapes and balanced sensitivity.

ChromaTOF software screenshot demonstrating integrated flow split calculations

ChromaTOF Software automatically optimizes flow rates

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