Preparative Liquid Chromatograph Delay Volume Estimation
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Solution Overview
Problem
Preparative liquid chromatograph systems face challenges in accurately determining delay volume and time due to estimation errors and the need for additional detectors, leading to inaccurate separation of target components in chromatograms, and increased production costs.
Innovation Solution
A preparative liquid chromatograph system that includes a preparative separation execution controller, an individual LC execution controller, a peak data calculator, and a calculation processor to estimate delay data using peak data from standard samples, eliminating the need for additional detectors and considering inner volumes of flow channels and valves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a detector is added to measure delay time accurately, then measurement precision of delay volume is improved, but device complexity and production cost increase
Solution Approach 1:
The patent makes the existing detector serve dual functions: both detecting the target component in the eluate for preparative separation and measuring the delay time by detecting a known component in a standard sample. This eliminates the need for a separate dedicated detector, reducing device complexity and production cost while maintaining measurement precision.
Solution Approach 2:
The system uses its own existing detector and standard sample to self-determine the delay volume and delay time without requiring external measurement devices. The detector automatically measures the delay characteristics by analyzing the retention time of a known component in a standard sample, making the system self-calibrating.
2Device complexity
If delay volume is estimated based on flow channel dimensions, then device complexity is reduced, but measurement precision of delay volume deteriorates
Solution Approach 1:
The patent replaces the mechanical/geometric estimation method (calculating delay volume from flow channel inner diameter and length) with a chromatographic measurement method. The delay volume is determined by measuring the retention time of a known component in a standard sample and calculating the volume based on actual flow conditions, achieving high accuracy without complex structural modifications.
3Measurement precision
If delay volume is calculated using retention time difference between two detectors, then measurement precision is improved, but device complexity increases due to additional detector
Solution Approach 1:
The patent makes the single existing detector perform multiple functions: detecting target components during preparative separation and measuring delay time by analyzing a standard sample. This eliminates the need for a second detector while maintaining the ability to accurately determine delay characteristics through retention time measurement.
4Device complexity
If user inputs delay volume manually, then device complexity is reduced, but manufacturing precision of separation process deteriorates due to human error
Solution Approach 1:
The system automatically determines the delay volume by analyzing the retention time of a known component in a standard sample, eliminating the need for manual user input. The controller automatically calculates the delay volume based on the measured retention time and flow rate, removing human error from the process while maintaining simplicity in operation.
Solution Approach 2:
The system uses feedback from the detector signal of a known component in a standard sample to automatically adjust and determine the delay volume. The controller receives the detection signal, calculates the retention time, and uses this feedback to establish the accurate delay volume for subsequent preparative separations.
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 system achieves high accuracy in determining delay volume and time, ensuring precise separation and collection of target components while reducing production costs by utilizing existing detectors for LC analysis.
Implementation Method 1
A preparative liquid chromatograph system detects a sample component in an eluate when the eluate passes through a detector such as an ultraviolet-visible light absorption detector
Implementation Method 2
an LC unit including a column for isolating a component in a sample and a detector for detecting the component in an eluate from the column
Data Source
AI summary
A sample is introduced from an injector unit into a mobile phase. One target component is separated into a plurality of vials by a fraction collector. Next, a sampler sequentially suctions the eluate from the plurality of the vials and performs an LC analysis on each of the eluate portions, thereby producing a chromatogram. A peak detector calculates the peak area corresponding to the amount of the target component in each chromatogram. A delay estimator extracts the peak area in the fraction having the maximum peak area and the peak areas in the previous and succeeding fractions on the time axis of the foregoing fraction. Then, the delay estimator estimates a delay volume from a detector to the tip end of the dispenser nozzle based on data such as the peak areas, the flow rate of the liquid fed from the pump, positions of the vials, and the position of the peak of the target component in the chromatogram detected by the detector, and stores the delay volume. Upon preparative separation of a desired component, a delay time is calculated based on the delay volume and the flow rate and the timing for the preparative separation is controlled based on the delay time.