Single Stage Flow Modulator for Comprehensive Chromatography

Solution Overview

Problem

Conventional two-dimensional gas chromatography modulators are complex, require cryogenic materials, or suffer from limitations such as temperature restrictions and contamination risks, making them unsuitable for efficient comprehensive analysis of complex chemical mixtures.

Innovation Solution

A single-stage flow modulator using a Deans switch and solenoid valve to direct a portion of the primary column effluent to a secondary column, allowing continuous modulation and flexible operation without the need for cryogenic materials or complex fluid couplings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a thermal two-stage modulator is used to cool and concentrate the effluent, then the chromatographic peak concentration is improved, but the device complexity and manufacturing difficulty increase significantly

Engineering Contradiction:

Improvechromatographic peak concentrationVSAvoidmodulator design complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent removes the cryogenic cooling stage from the modulator design, extracting only the essential flow switching function. This eliminates the need for complex thermal management systems while maintaining the core capability of transferring effluent between columns.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the thermal/mechanical cooling system with a purely flow-based modulation approach using solenoid valves. This substitution eliminates the need for cryogenic materials and complex thermal management while achieving efficient peak transfer through flow control.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If a flow-switching two-stage modulator is used to avoid cryogenic materials, then the ease of operation is improved, but the device complexity increases due to complex fluid couplings

Engineering Contradiction:

Improveoperation without cryogenic materialsVSAvoidfluid coupling complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent divides the flow modulation function into separate solenoid valves positioned at different locations in the system. This segmentation allows each valve to handle specific flow paths independently, simplifying the overall fluid coupling design while maintaining flexible flow control capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediate flow path configuration that allows effluent to be diverted to either the secondary column or detector without requiring complex direct coupling. This intermediary approach simplifies the fluid connections while maintaining operational flexibility.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If a diaphragm valve is used for effluent transfer, then the ease of manufacture is improved, but the temperature range is restricted to below 250 degrees Celsius

Engineering Contradiction:

Improvevalve fabrication simplicityVSAvoidmaximum operating temperature

Core Design Contradiction:

Ease of manufactureVSTemperature

Solution Approach 1:

The patent uses solenoid valves with simple, replaceable components that can be manufactured at low cost and replaced if needed. These valves are designed for ease of manufacture and replacement rather than long-term durability at extreme temperatures, achieving a practical balance between manufacturing simplicity and operational requirements.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

4Ease of manufacture

If mechanical valves are used for effluent transfer, then the ease of manufacture is improved, but contamination risks increase due to sample contact with valve materials

Engineering Contradiction:

Improvevalve construction simplicityVSAvoidsample contamination

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the sample from the valve body interior, allowing it to flow through external tubing rather than passing through the valve mechanism. This eliminates contact between the sample and potential contamination sources in the valve while maintaining the simplicity of mechanical flow control.

Inventive Principle:

Principle #2Taking out (Extraction)

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

Enables efficient comprehensive two-dimensional gas chromatography with simplified design and operation, allowing for flexible column configurations and reduced contamination risks, while maintaining high analysis precision and resolution.

Implementation Method 1

A single stage flow modulator for performing comprehensive chromatography comprises a first chromatographic column, a valve fluidically coupled to at least two fluid conduits, wherein when in a first position, the valve directs a control flow to direct an output of the first chromatographic column to a first detector, and wherein when in a second position, the valve directs a control flow to direct a portion of an output of the first chromatographic column to a second chromatographic column

Methodology Applied

Scientific EffectSolenoid actuation: Solenoid

Data Source

PatentUS7383718B2Single stage flow modulator for performing comprehensive chromatography

Publication Date: 2008.06.10 AGILENT TECHNOLOGIES INC

AI summary

A single stage flow modulator for performing comprehensive chromatography comprises a first chromatographic column, a valve fluidically coupled to at least two fluid conduits, wherein when in a first position, the valve directs a control flow to direct an output of the first chromatographic column to a first detector, and wherein when in a second position, the valve directs a control flow to direct a portion of an output of the first chromatographic column to a second chromatographic column, wherein the portion of the output of the first chromatographic column directed to the second chromatographic column is continuously modulated throughout a sample run.