Single-Pump 2D LC-MS/MS for Continuous-Flow Analysis
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Solution Overview
Problem
Existing 2D LC-MS/MS methods require two separate solvent systems and pump systems, making them complex, costly, and impractical for many laboratories, while also leading to sample loss and reduced reproducibility due to solvent exchange processes.
Innovation Solution
A novel 2D LC-MS/MS method using a single solvent system for both dimensions, with a diverting valve to switch solvent flow between columns, eliminating the need for a second pump system and solvent exchange, allowing continuous flow and simplified setup.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional online 2D LC-MS/MS methodology is used with two separate pump systems and multiple-port diverting valve, then separation of analytes from matrix contaminants is achieved, but device complexity and cost increase significantly
Solution Approach 1:
The patent combines two separate LC pump systems into a single pump system that controls both the first dimension (normal phase) and second dimension (reverse phase) columns. This merging reduces device complexity and cost while maintaining the orthogonal separation capabilities that eliminate matrix contaminants like phospholipids, proteins, and nucleotides.
Solution Approach 2:
A single pump system is designed to perform multiple functions: it generates mobile phase for the normal phase column, controls solvent exchange to the reverse phase column, and maintains flow through the second dimension column. This multi-functionality eliminates the need for dedicated pump systems for each dimension while preserving analytical performance.
2Adaptability or versatility
If solvent exchange process is used between SPE and 1D LC-MS/MS, then solvent system compatibility is achieved, but sample loss and reduced reproducibility occur
Solution Approach 1:
The patent implements continuous flow throughout the entire analytical process from sample injection through both chromatographic dimensions to detection. The single pump system maintains uninterrupted mobile phase flow, eliminating the discontinuous solvent exchange steps that cause sample loss and variability. Analytes continuously traverse the normal phase column, transfer to the reverse phase column, and elute to the mass spectrometer without interruption.
3Reliability
If SPE cartridges are used for sample cleanup, then matrix contaminants are eliminated, but process time and cost increase
Solution Approach 1:
The normal phase column in the first dimension performs preliminary separation of matrix contaminants from analytes of interest. Phospholipids, proteins, and nucleotides are retained on the normal phase column while analytes elute and are transferred to the reverse phase column. This preliminary action eliminates the need for separate SPE cartridge cleanup steps, reducing both time and cost.
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
Reduces equipment costs, simplifies method development, enhances reproducibility, and allows 2D LC-MS/MS analyses in standard laboratories, improving flexibility and reducing sample turnaround time.
Implementation Method 1
The first column, often made with hydrophilic resin (normal phase chromatography), is used to eliminate major matrix contaminants
Implementation Method 2
The second column can be made of hydrophobic resin (reverse phase chromatography) and further resolves analytes of interest from other interfering molecules
Data Source
AI summary
The present invention relates to a novel analytical method for detecting one or more analytes in a source sample by continuous flow 2D LC-MS/MS using a single LC system.