MALDI Specimen Preparation Using Dissolvable Pellet Cups

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Solution Overview

Problem

Current methods for preparing specimens of water insoluble materials for MALDI mass spectrometry face challenges in achieving homogeneous mixing and uniform thickness, leading to poor reproducibility and difficulty in obtaining quantitative analysis using commercial MALDI-TOF MS equipment.

Innovation Solution

A method involving mixing a water insoluble material with a matrix and a volatile solvent, followed by filling a pellet cup and pressing it to create a specimen with uniform thickness, which is then dissolved to produce a homogeneous specimen for MALDI mass spectrometry, allowing for reproducible spectra and quantitative analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If water insoluble materials are mixed with matrix using conventional methods (pestles, mortars, ball mills), then homogeneity of the sample is attempted to be ensured, but large variation in homogeneity occurs depending on skill and static electricity issues arise

Engineering Contradiction:

Improvehomogeneity of sampleVSAvoidreproducibility of MALDI spectrum

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

A conductive material (intermediary) is introduced between the water insoluble material particles to facilitate homogeneous mixing and eliminate static electricity issues. The conductive material acts as a mediator that enables reliable mixing without skill-dependent variation

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The electrical conductivity parameter of the mixing system is changed by adding conductive material, which fundamentally alters the mixing behavior and eliminates static electricity problems that plague conventional mixing methods

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If specimen is pressed in pellet form by mixing matrix and insoluble material, then specimen is obtained, but thickness of the specimen cannot be controlled

Engineering Contradiction:

Improvespecimen preparationVSAvoidthickness uniformity

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The mechanical pressing system is replaced with a dissolution-based system. Instead of mechanically controlling thickness through pressing force, the system uses the dissolution of a water-soluble support structure to automatically form uniform thickness specimens

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The water-soluble support structure undergoes a phase transition from solid to dissolved state, which automatically releases the specimen with controlled thickness. This phase change mechanism replaces mechanical thickness control

Inventive Principle:

Principle #36Phase transitions

3Ease of manufacture

If CS technique (compressed-sample technique) is used with hole in plate, then specimen is formed, but electric field is not uniformly formed resulting in different peak m/z at center and edge

Engineering Contradiction:

Improvespecimen formationVSAvoidpeak m/z consistency

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The hole in the plate (which causes electric field distortion) is completely removed from the system. The specimen is formed without any cavity or hole, eliminating the source of electric field non-uniformity that causes m/z variations

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The specimen formation process is segmented into two independent steps: first forming the specimen with uniform thickness using the dissolution method, then placing it on the plate without requiring holes for insertion, thereby separating the thickness control function from the mounting function

Inventive Principle:

Principle #1Segmentation

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 results in a reproducible MALDI spectrum with small thickness variations, enabling effective quantitative analysis of water insoluble materials using commercial MALDI-TOF MS equipment, with improved homogeneity and reduced static electricity issues.

Implementation Method 1

adding a volatile solvent to disperse the water insoluble material and the matrix until the volatile solvent is evaporated

Methodology Applied

Scientific EffectEvaporation: Evaporation

Implementation Method 2

dissolving the pellet cup with water to obtain a specimen of water insoluble material

Methodology Applied

Scientific EffectDissolution: Solvation

Data Source

PatentUS11282684B2Method for producing test pieces of water-insoluble material for MALDI mass spectrometry and method for quantitative analysis of water-insoluble material using MALDI mass spectrometry

Publication Date: 2022.03.22 LG CHEM LTD

AI summary

The present invention relates to a method for producing test pieces in which the thickness of the samples of homogeneous water-insoluble material is uniform, and to a method for quantitative analysis of water-insoluble material by analyzing such test pieces using MALDI mass spectrometry. Specifically, the test pieces can be produced by: adding a volatile solvent to a mixture of water-insoluble material and matrix; placing, in a pellet cup made of water-soluble material, and pressing, with even pressure, the sample obtained by mixing the mixture of water-insoluble material and matrix until the solvent has evaporated; and melting the pellet cup with water.