Taylor Dispersion Analysis for Diffusion Coefficient Determination
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Solution Overview
Problem
Current methods for determining the diffusion properties of proteins, such as the diffusion interaction parameter (kD), are hindered by the need for multiple sample preparations and measurements, which can be cumbersome and prone to errors due to viscosity and contamination issues, especially in high-concentration protein solutions.
Innovation Solution
A method that uses a single Taylorgram to derive mutual diffusion coefficient values across various concentrations, allowing for the determination of the diffusion interaction parameter (kD) without the need for multiple sample preparations, through mathematical fitting and transformation of the Taylorgram data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If Dynamic Light Scattering (DLS) is used to determine diffusion properties, then measurement of mutual diffusion coefficient is straightforward and amenable to high-throughput screening, but the method requires multiple sample preparations at different concentrations which is cumbersome and prone to errors
Solution Approach 1:
The patent combines multiple measurements at different concentrations into a single continuous experiment. A sample is subjected to increasing pressure steps sequentially, creating a series of concentration states without removing or replacing the sample. This merges what would traditionally require multiple separate sample preparations into one continuous measurement process.
Solution Approach 2:
The patent applies pressure increments in advance to create a gradient of concentrations within the same sample. By progressively increasing pressure before each measurement, the system prepares multiple concentration states sequentially, eliminating the need for separate sample preparations at each concentration level.
2Measurement precision
If DLS measures diffusion at high solute concentrations, then relevant formulation data is obtained, but bulk viscosity increases restricting diffusion and causing particles to appear larger than they truly are
Solution Approach 1:
The patent dynamically adjusts pressure during the measurement process, creating a time-dependent concentration gradient. By continuously varying pressure rather than maintaining static high concentrations, the system captures diffusion behavior across multiple concentration states, allowing correction for viscosity effects at each specific concentration level.
Solution Approach 2:
The patent changes the concentration parameter systematically by applying sequential pressure increments. This allows measurement of diffusion coefficients across a range of concentrations in one experiment, enabling the researcher to identify and correct for viscosity-related artifacts by comparing results across different concentration states.
3Productivity
If DLS is used to determine diffusion properties, then the technique is readily amenable to high-throughput screening, but scattering intensity is biased by particle size (proportional to r^6) making results susceptible to skew by larger particles
Solution Approach 1:
The patent applies progressively increasing pressure steps, where each step creates a partially concentrated state. By measuring across multiple partial concentration states rather than relying on a single high-concentration measurement, the system can identify and exclude measurements affected by aggregate formation or dust, using the ensemble of measurements to derive accurate diffusion coefficients.
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 simplifies the process of determining diffusion properties by enabling the calculation of mutual diffusion coefficients and the diffusion interaction parameter from a single measurement, reducing sample handling and potential errors, while maintaining accuracy comparable to traditional methods like DLS.
Implementation Method 1
Taylor dispersion analysis (TDA) can be used to analyse properties of species within a sample. A plug of the sample may be injected into a microbore capillary and subsequently disperse as it traverses along the capillary within a laminar flow regime.
Implementation Method 2
A plug of the sample may be injected into a microbore capillary and subsequently disperse as it traverses along the capillary within a laminar flow regime.
Implementation Method 3
The degree of dispersion exhibited by the plug is dependent on the diffusivity of the molecules within the plug
Data Source
AI summary
A method of determining a relationship between a mutual diffusion co-efficient Dm and the concentration c of a solute within a solvent. The method comprises: obtaining a Taylorgram comprising a plurality of measurements of solute concentration c; and deriving from the Taylorgram a plurality of mutual diffusion coefficient values Dm corresponding with a plurality of different concentrations c of solute in the solvent.