LC-MS Oxidation Analysis Using Cholesteryl Ester Peroxides

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Solution Overview

Problem

Current methods for evaluating the quality of stored samples, particularly in lipidomics, lack the ability to quantitatively assess the degree of oxidation, which is crucial for accurate analysis and interpretation of biological samples.

Innovation Solution

The proposed method involves using liquid chromatography/mass spectrometry (LC/MS) to detect cholesteryl ester and cholesteryl ester peroxide ions in samples, allowing for the analysis of the sample's oxidation level based on the intensity ratio of these ions, thereby quantitatively evaluating the sample's quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional mass spectrometry methods are used for sample quality evaluation, then general lipid quantification can be performed, but quantitative assessment of oxidation degree is not achievable

Engineering Contradiction:
Improveoxidation degree quantificationVSAvoidoxidation state information
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent segments the analysis by separating cholesteryl ester detection from cholesteryl ester peroxide detection. This is achieved by using different mass-to-charge ratio detection settings in the mass spectrometer, allowing independent quantification of each component. The segmentation enables specific measurement of oxidation products without interference from non-oxidized lipids, thereby achieving precise oxidation degree assessment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses cholesteryl ester peroxide as an intermediary marker to indicate the oxidation state of the sample. By detecting and quantifying this specific peroxide form, the system indirectly measures the overall oxidation degree without needing to detect all possible oxidation products. This intermediary approach simplifies the measurement while providing reliable oxidation state information.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If general lipid analysis is performed without specific oxidation markers, then overall lipid composition can be determined, but sample quality assessment based on oxidation is lost

Engineering Contradiction:
Improvesample quality evaluationVSAvoidanalysis method complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates multiple functions into a single mass spectrometry analysis workflow. The same instrument and basic methodology used for general lipid quantification are extended to simultaneously detect cholesteryl ester and cholesteryl ester peroxide. This multi-functionality allows both composition analysis and quality assessment to be performed without requiring separate specialized equipment or complex additional procedures.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent utilizes changes in mass-to-charge ratio parameters to differentiate between cholesteryl ester and cholesteryl ester peroxide. By adjusting the detection parameters of the mass spectrometer to target specific mass differences corresponding to the peroxide functional group, the system can selectively quantify oxidation products using the existing instrument capabilities, avoiding the need for complex additional analytical steps.

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 enables precise and quantitative evaluation of the sample's oxidation state, enhancing the accuracy of lipidomics analysis and sample quality assessment.

Implementation Method 1

performing mass spectrometry of the sample S subjected to liquid chromatography to detect a non-peroxide ion corresponding to cholesteryl ester and a peroxide ion corresponding to cholesteryl ester peroxide

Methodology Applied
Scientific EffectIonization: Ionisation

Implementation Method 2

subjecting a sample S to liquid chromatography; performing mass spectrometry of the sample S subjected to liquid chromatography

Methodology Applied
Scientific EffectChromatography: Chromatography

Data Source

PatentEP3805750B1Analysis method and analytical device
Publication Date: 2025.01.08 SHIMADZU CORP
  • EP3805750B1 patent drawingFigure 1
  • EP3805750B1 patent drawingFigure 2
  • EP3805750B1 patent drawingFigure 3

AI summary

An analysis method includes: subjecting a sample to liquid chromatography; performing first mass spectrometry of the sample subjected to the liquid chromatography to detect a first ion corresponding to cholesteryl ester and a second ion corresponding to cholesteryl ester peroxide; and analyzing a degree of oxidation of the sample based on a ratio between an intensity of the detected first ion and an intensity of the detected second ion.