Thin-Layer Phthalate Screening With UV and Color Reagent

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Solution Overview

Problem

Existing methods struggle to accurately and efficiently detect the presence of restricted phthalates in resin and rubber materials used in electrical products, particularly butyl benzyl phthalate, due to overlapping Rf values with other compounds in thin-layer chromatography and ultraviolet light analysis.

Innovation Solution

A two-step analysis method involving thin-layer chromatography followed by ultraviolet light irradiation and a color reagent is employed to differentiate and accurately detect the presence of restricted phthalates, specifically butyl benzyl phthalate, using acetonitrile as the extraction and developing solvent and reversed-phase chromatography.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single analysis method is used to detect phthalates, then the analysis process is simple, but the detection accuracy is insufficient leading to false positives

Engineering Contradiction:

Improvedetection accuracyVSAvoidanalysis process complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The analysis method is divided into two distinct analysis steps: first analysis using ultraviolet light irradiation and second analysis using color reagent application. This segmentation allows each analysis to target specific phthalate characteristics, with the first analysis detecting phthalates with aromatic rings and the second analysis detecting butyl benzyl phthalate specifically, thereby improving overall detection accuracy while maintaining procedural simplicity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The method changes detection parameters by using different detection mechanisms in sequence: ultraviolet light absorption for initial screening followed by color reagent reaction for confirmation. This parameter change approach enables differentiation between various phthalate types and eliminates false positives without requiring complex analytical instruments

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If expensive analytical devices are used, then detection accuracy improves, but cost and accessibility decrease

Engineering Contradiction:

Improvedetection accuracyVSAvoidcost-effectiveness

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The method replaces expensive, complex analytical instruments with simple, inexpensive reagents and equipment. The use of ultraviolet light sources and color reagents that can be easily prepared and applied allows for accurate phthalate detection without requiring costly gas chromatographs or mass spectrometers, making the method cost-effective and accessible for routine screening

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

Complex mechanical and electronic analytical systems are replaced with optical and chemical detection methods. Instead of using sophisticated instruments for separation and detection, the method employs ultraviolet light irradiation and color reagent reactions that can be performed with simple equipment, achieving comparable accuracy at lower cost

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 method enhances the accuracy of detecting restricted phthalates, ensuring compliance with RoHS regulations by minimizing false positives and providing a simpler, cost-effective primary screening process.

Implementation Method 1

a first analysis detecting a presence or absence of phthalates in a sample by irradiating ultraviolet light on a plate

Methodology Applied

Scientific EffectUltraviolet light absorption: Absorption (EM radiation)

Implementation Method 2

a second analysis detecting a presence or absence of butyl benzyl phthalate in the sample by supplying a color reagent to the plate

Methodology Applied

Scientific EffectColor reagent reaction:

Implementation Method 3

the sample being developed on the plate by thin-layer chromatography

Methodology Applied

Scientific EffectChromatography: Chromatography

Data Source

PatentUS12523639B2Analysis method

Publication Date: 2026.01.13 KK TOSHIBA

AI summary

According to one embodiment, an analysis method includes a first analysis and a second analysis. The first analysis detects a presence or absence of phthalates in a sample by irradiating ultraviolet light on a plate. The sample is developed on the plate by thin-layer chromatography. The second analysis detects a presence or absence of butyl benzyl phthalate in the sample by supplying a color reagent to the plate on which the sample is developed.