LC-MS/MS Ascorbic Acid Measurement Using In-Source Fragmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for analytical techniques to accurately measure biomarkers such as ascorbic acid for clinical diagnosis, as vitamin C deficiency can lead to severe health issues and its concentration is inversely associated with various diseases.
Innovation Solution
A method and system using tandem mass spectrometry to generate fragment and product ions from ascorbic acid, involving in-source fragmentation and chromatographic separation, allowing for the detection and quantification of ascorbic acid in biological samples through mass spectrometry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current analytical techniques are used to measure ascorbic acid, then the measurement process is simpler, but the measurement precision and detection sensitivity are insufficient
Solution Approach 1:
The patent applies segmentation by dividing the ascorbic acid molecule into fragment ions through in-source fragmentation. The intact ascorbic acid ion is broken into characteristic fragment ions (m/z 115, 87, 59) that can be detected with high precision by the mass spectrometer, thereby improving measurement precision while managing system complexity through intelligent molecular breakdown
Solution Approach 2:
The patent uses an intermediary approach by introducing a declustering potential field as a mediator between the ion source and mass analyzer. This electric field intermediary enables controlled in-source fragmentation, allowing the system to achieve both high detection sensitivity and acceptable device complexity by mediating the fragmentation process rather than requiring complex external fragmentation equipment
2Reliability
If in-source fragmentation is applied to generate fragment ions, then the detection sensitivity is improved, but the device complexity increases
Solution Approach 1:
The patent applies self-service by enabling the ion source itself to perform fragmentation through the application of declustering potential. The system uses its existing components (ion source, electric field generation capability) to achieve fragmentation without requiring separate, complex fragmentation equipment, thereby improving detection reliability while minimizing increases in device complexity
Solution Approach 2:
The patent employs parameter changes by adjusting the declustering potential parameter to control the fragmentation process. By optimizing this electrical parameter, the system achieves reliable fragment ion generation for detection, improving detection reliability through parameter optimization rather than through complex hardware modifications
3Measurement precision
If chromatographic separation is performed before mass spectrometry, then the measurement precision is improved, but the analysis time increases
Solution Approach 1:
The patent applies partial action by performing chromatographic separation only to the extent necessary to isolate ascorbic acid from major interfering substances, rather than achieving complete separation of all sample components. This partial separation approach maintains sufficient measurement precision for clinical diagnosis while reducing the time penalty associated with exhaustive chromatographic analysis
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
Enables precise determination of ascorbic acid levels in the range of 0.05 mg/dL to 5 mg/dL, facilitating clinical diagnosis and monitoring of vitamin C status to prevent deficiency-related health issues.
Implementation Method 1
generating a fragment ion from the ascorbic acid of with a mass to charge ratio (m/z) of about 115 by in-source fragmentation
Implementation Method 2
During in-source fragmentation, a voltage can be applied to an orifice plate as ions travel from the source into the mass analyzer
Implementation Method 3
chromatographically separating the ascorbic acid from other components in the sample
Data Source
AI summary
Disclosed are methods and systems using liquid chromatography/tandem mass spectrometry (LC-MS/MS and 2D-LC-MS/MS) for the analysis of ascorbic acid in biological samples.