Modifier Stream Elution for Trap Column Analyte Refocusing

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Solution Overview

Problem

In near-supercritical or supercritical fluid chromatography, focusing analytes onto an analytical column after elution from a trap column is challenging due to the high diffusivity of analytes in the mobile phase, leading to breakthrough peak profiles, as the mobile phase with sufficient solvating strength for elution from the trap column is too strong for proper retention on the secondary dimension analytical column.

Innovation Solution

A method and system involving a valve-configured chromatographic separation system that modulates a flowstream to a trap column for analyte retention, followed by a flow of a modifier to elute analytes from the trap column, and then merges a compressible fluid-based solvent with the elution to generate a diluted flow that refocuses analytes at the head of a CFC column, reducing elution strength and improving peak sharpness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a mobile phase with sufficient solvating strength is used to elute analytes from the trap column, then analyte elution is achieved, but the mobile phase is too strong to enable proper retention and refocusing of analytes on the secondary dimension analytical column

Engineering Contradiction:

Improvesolvating strengthVSAvoidanalyte retention

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The mobile phase delivery is segmented into two distinct streams: a trap column elution stream with high solvating strength for analyte release, and a CFC solvent stream for dilution. This segmentation allows each stream to perform its specific function optimally without compromise

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The CFC solvent acts as an intermediary substance that mediates between the strong elution mobile phase and the analytical column requirements. By introducing this intermediate dilution step, the system transitions from high-strength elution conditions to appropriate retention conditions on the analytical column

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If a strong mobile phase is used for trap column elution, then analyte release is effective, but analyte refocusing on the analytical column fails due to high diffusivity

Engineering Contradiction:

Improveelution efficiencyVSAvoidpeak sharpness

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The system dynamically changes mobile phase parameters (composition, flow rate, strength) at different stages: high-strength parameters during trap column elution for productivity, then dilution with CFC solvent to adjust parameters for optimal peak sharpness and refocusing on the analytical column

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach effectively refocuses analytes on the secondary chromatographic column, resulting in sharper chromatographic peaks and improved chromatographic efficiency by controlling the elution strength, addressing the challenge of breakthrough peak profiles in supercritical fluid chromatography.

Implementation Method 1

modulating a portion of a flowstream to a trap column to thereby retain at least one analyte from the flowstream on the trap column

Methodology Applied

Scientific EffectAdsorption: Adsorption

Implementation Method 2

The trap column often has different retentivity than the secondary analytical column

Methodology Applied

Scientific EffectPartition:

Implementation Method 3

A flow of a modifier is provided through the trap column to thereby generate an elution comprising the at least one analyte

Methodology Applied

Scientific EffectCompetition for binding sites:

Implementation Method 4

A flow of a compressible fluid based chromatography (CFC) solvent is merged with the elution from the trap column to generate a diluted elution

Methodology Applied

Scientific EffectDilution:

Implementation Method 5

the diluted elution is provided to a CFC column wherein the at least one analyte is focused at a head of the CFC column

Methodology Applied

Scientific EffectBand focusing:

Implementation Method 6

focusing an analyte of interest onto an analytical column after elution from a trap column can be challenging due to the high diffusivity of analytes in the mobile phase flow

Methodology Applied

Scientific EffectDiffusion: Diffusion

Data Source

PatentUS10823712B2Modifier stream elution of trap column for multidimensional compressible fluid-based chromatography

Publication Date: 2020.11.03 WATERS TECHNOLOGY CORP

AI summary

A method of performing a chromatographic separation includes modulating a portion of a flowstream to a trap column to retain at least one analyte from the flowstream on the trap column. A flow of a modifier is provided through the trap column to generate an elution comprising the at least one analyte. A flow of a compressible fluid-based chromatography (CFC) mobile phase or CFC solvent is merged with the elution from the trap column to generate a diluted elution. Carbon dioxide may be used as the CFC solvent or as a component of the CFC mobile phase. The diluted elution is provided to a CFC column where at least one analyte is focused at a head of the CFC column. Examples of a flowstream that may be used include an eluent from a chromatography column or a fluid flow from an extraction system.