OPI-MS Calibration Flow Control to Prevent Liquid Overflow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Mass spectrometers require frequent calibration, especially high-resolution ones like time-of-flight (TOF) models, to maintain accuracy and resolution, but existing methods can disrupt the aspiration force and flow rate, leading to inefficiencies and potential overflows during calibration.
Innovation Solution
A calibration system with a fluidic junction and pumps for introducing calibration and transport liquids into a mass spectrometer's open port interface (OPI), controlled by a controller to manage flow rates and prevent overflows, using a transport liquid to mix with a calibration standard for ionization and analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If calibration liquid is introduced into the mass spectrometer for frequent calibration, then mass accuracy and resolution are maintained, but liquid overflow occurs at the liquid/air interface of the OPI
Solution Approach 1:
The system dynamically adjusts the transport liquid flow rate based on operational conditions. During calibration events, the controller reduces the transport liquid flow rate to accommodate the additional calibration liquid being introduced, preventing overflow while maintaining calibration accuracy. This dynamic flow rate adjustment allows frequent calibration without the harmful overflow effect.
Solution Approach 2:
The system monitors liquid flow conditions and adjusts transport liquid flow rate in response to calibration events. The controller detects when calibration liquid is being introduced and provides feedback to modify the transport liquid pump operation, ensuring the total liquid flow remains within safe limits and preventing overflow at the OPI liquid/air interface.
2Productivity
If transport liquid flow rate is increased for efficient sample transport, then sample introduction efficiency is improved, but calibration liquid mixing and uniform liquid surface conditions are compromised
Solution Approach 1:
The transport liquid flow rate is dynamically adjusted based on operational mode. During calibration, the flow rate is reduced to allow proper mixing with calibration liquid and maintain uniform liquid surface conditions. During normal sample analysis, the flow rate is increased to maximize sample introduction efficiency. This dynamic adjustment resolves the contradiction between productivity and composition stability.
3Measurement precision
If calibration is performed frequently for high resolution mass spectrometers, then analytical quality is maintained, but aspiration force and flow rate are disrupted
Solution Approach 1:
The system performs preliminary action by reducing the transport liquid flow rate before calibration liquid is introduced. This prevents disruption to the aspiration force by ensuring the total liquid load remains manageable throughout the calibration process. The flow rate adjustment is prepared in advance, allowing frequent calibration events without compromising analytical quality or disrupting the aspiration force.
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 ensures precise calibration by adjusting flow rates to prevent overflows and maintain uniform liquid surface conditions, allowing for effective tuning of mass spectrometers while minimizing disruptions to the aspiration force and flow rates, thereby improving analytical performance.
Implementation Method 1
A first pump can be operably coupled to the first reservoir for causing flow of the calibration liquid from that reservoir to the first inlet
Implementation Method 2
a second pump that is operably coupled to the second reservoir for causing a flow of the transport liquid from the second reservoir to the second inlet for introduction into the fluidic junction
Implementation Method 3
the controller can adjust the pumping speed of any of the first and the second pump so as to inhibit an overflow of a mixture of the calibration liquid and the transport liquid at the liquid/air interface of the OPI
Implementation Method 4
a fluidic junction having a first inlet in fluid communication with a first reservoir... and a second inlet in fluid communication with a second reservoir... such that any of the calibration liquid and the transport liquid can exit the fluidic junction via said outlet
Data Source
AI summary
In one aspect, a calibration system for use in a mass spectrometer having an open port interface (OPI) for receiving a sample for mass analysis is disclosed, which includes a fluidic junction having a first inlet in fluid communication with a first reservoir, which is configured for storing a calibration liquid, and a second inlet in fluid communication with a second reservoir, which is configured for storing a transport liquid. The fluidic junction can further include an outlet in fluid communication with the first and second inlets such that any of the calibration liquid and the transport liquid can exit the fluidic junction via said outlet.