Parallel Liquid Chromatograph Scheduling to Avoid Solvent Substitution

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Solution Overview

Problem

Conventional automatic analyzers with parallel liquid chromatograph flow passages face issues of reduced throughput and increased solvent consumption due to solvent substitution, which are not effectively addressed by existing solutions that require additional space and mechanisms for reordering samples.

Innovation Solution

A control method that determines the use of specific analysis flow passages with time lags for different solvents, optimizing the analysis schedule to minimize solvent substitution by comparing solvent types and selecting flow passages that avoid the need for solvent replacement, thereby maintaining throughput and reducing solvent consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If solvent substitution is performed to change solvent composition between successive separation processes, then the analyzer can perform different types of separation processes, but throughput drops and solvent consumption increases

Engineering Contradiction:
Improveability to perform different types of separation processesVSAvoidthroughput
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The control unit predicts future solvent substitution needs in advance and schedules analysis in a manner that prevents solvent substitution. By looking ahead at the analysis schedule and identifying when solvent substitution would be required, the system proactively arranges analyses to use the same solvent continuously, thereby maintaining high throughput while still enabling different separation processes through strategic planning

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the analysis schedule based on real-time information about solvent usage patterns. Rather than using a fixed schedule, the control unit continuously monitors which solvents are being used and reorders analyses on the fly to group those requiring the same solvent together, allowing the system to adaptively maximize throughput while accommodating diverse separation process requirements

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If solvent substitution is performed to change solvent composition between successive separation processes, then the analyzer can perform different types of separation processes, but solvent consumption amount increases

Engineering Contradiction:
Improveability to perform different types of separation processesVSAvoidsolvent consumption amount
Core Design Contradiction:
Adaptability or versatilityVSLoss of substance

Solution Approach 1:

The control unit predicts future solvent substitution needs in advance and schedules analysis to avoid such substitutions. By identifying solvent usage patterns ahead of time and arranging analyses to maintain continuous use of the same solvent, the system eliminates unnecessary solvent disposal and replacement, thereby reducing overall solvent consumption while still supporting diverse separation processes

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Instead of discarding and replacing solvent when changing separation process types, the system recovers and continues using the existing solvent by strategically scheduling analyses. This approach transforms what would normally be waste (solvent that needs replacement) into a reusable resource, significantly reducing solvent consumption while maintaining the ability to perform different separation processes

Inventive Principle:
Principle #34Discarding and recovering

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

The method effectively prevents throughput reduction and solvent waste by strategically scheduling analyses to avoid solvent substitution, enhancing operational efficiency and cost-effectiveness in automatic analyzers with parallel chromatograph flow passages.

Implementation Method 1

a chromatograph is an analyzer that makes a sample pass through a separation column filled with a stationary phase together with a mobile phase (solvent), to separate the component as the object of analysis through interaction between the component of the sample and the stationary phase and mobile phase

Methodology Applied
Scientific EffectChromatography: Chromatography

Data Source

PatentEP4306964B1Control method for automated analysis device
Publication Date: 2025.10.08 HITACHI HIGH TECH CORP
  • EP4306964B1 patent drawingFigure 1
  • EP4306964B1 patent drawingFigure 2
  • EP4306964B1 patent drawingFigure 3

AI summary

[Problem] To provide a control method of avoiding drop of a throughput by solvent substitution and of avoiding increase of a solvent consumption amount in a control method for an automatic analyzer including a liquid chromatograph that includes plural analysis flow passages arranged to be parallel to each other. [Solution] Which one of plural analysis flow passages 105 to 107 is to be used is determined in introducing plural separation processes using solvents whose kind is different from each other with a time lag relative to one another, and a solvent used in a next separation process executed at timing after starting the plural separation processes determined to be introduced with a time lag relative to one another and each of the solvents used in the plural separation processes determined to be introduced with a time lag relative to one another are compared. Whether or not a solvent substitution process is required for the analysis flow passages 105 to 107 used in the plural separation processes is determined, an analysis flow passage used in the next separation process out of the plural analysis flow passages 105 to 107 is determined according to the determination, and an analysis schedule is prepared.