Steroid Quantitative Charge Tags for LC-MS Analysis
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Solution Overview
Problem
Current methods for global steroid analysis in biological samples face challenges due to the diversity of steroids, lack of strong chromophores or ionized functional groups, and scarcity of quantitative standards, limiting the effectiveness of mass spectrometry techniques like GC-MS and LC-MS.
Innovation Solution
The use of quantitative charge tags based on Girard P and Girard T reagents, which allow for the labeling and detection of steroids with and without ketone groups, enabling simultaneous analysis in LC-MS through differential or isobaric mass tagging, facilitating the differentiation and quantification of various steroids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GC-MS is used for steroid analysis, then volatility and detection capability are improved, but steroid sulphates and cholesterol esters cannot be analyzed due to lack of volatility
Solution Approach 1:
The patent applies parameter changes by derivatizing steroids with Girard P or Girard T reagents, which chemically modify the steroid molecules to introduce charged groups. This transformation changes the physical and chemical parameters of the analytes, enabling them to be detected by mass spectrometry without requiring volatility, thus resolving the limitation of GC-MS for non-volatile steroid derivatives.
2Adaptability or versatility
If LC-MS is used for steroid analysis, then analysis of non-volatile steroids is enabled, but sensitivity to neutral steroids is reduced and fragment-ion spectra are uninformative
Solution Approach 1:
The patent uses Girard P and Girard T reagents as intermediary substances that react with steroid ketone groups to form charged derivatives. These reagents act as mediators that bridge the gap between neutral steroids and the ionization requirements of mass spectrometry, enhancing sensitivity and providing informative fragment-ion spectra while maintaining the ability to analyze non-volatile steroids.
3Measurement precision
If isotope dilution mass spectrometry with stable-isotope labelled standards is used, then quantification accuracy is improved, but the method becomes impractical for global steroid analysis
Solution Approach 1:
The patent applies universality by developing a single derivatization protocol using Girard P or Girard T reagents that can be applied to multiple different steroid analytes simultaneously. This universal approach eliminates the need for separate stable-isotope labelled standards for each individual steroid, reducing method complexity while maintaining quantification accuracy through the use of common internal standards.
4Measurement precision
If multiple separate analyses are performed for different steroid types, then detection specificity is improved, but analysis time and instrument usage increase
Solution Approach 1:
The patent merges the analysis of different steroid types into a single LC-MS run by using a universal derivatization protocol. All steroid analytes are derivatized with the same reagent system, allowing them to be analyzed simultaneously in one injection, thereby maintaining detection specificity while dramatically improving analysis throughput and reducing instrument usage.
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 the quantitative detection of multiple steroids in a single LC-MS run, improving throughput and reducing instrument time, while maintaining sensitivity and specificity, even in complex mixtures like plasma samples.
Implementation Method 1
The use of quantitative charge tags based on Girard P and Girard T reagents, which allow for the labeling and detection of steroids with and without ketone groups
Implementation Method 2
enabling simultaneous analysis in LC-MS through differential or isobaric mass tagging
Implementation Method 3
enabling simultaneous analysis in LC-MS through differential or isobaric mass tagging
Data Source
Figure 1A~1C
Figure 1D~1E
Figure 2A
AI summary
The invention relates to a kit and methods for quantitative detection of steroids in a sample. The kit comprises quantitative charge tags and an oxidising agent.