Ion Source Analyte Accumulation for Sensitive Hazard Detection
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Solution Overview
Problem
Conventional ionization sources for mass and/or ion mobility spectrometers dilute analyte concentration due to continuous gas flow during sample heating, reducing detection sensitivity for hazardous materials like explosives and chemical warfare agents.
Innovation Solution
A method where analytes are accumulated for a period before being passed to an ionization region, allowing for increased concentration and improved sensitivity through controlled valve operations and gas flow management in a thermal desorption oven system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If continuous gas flow is used during sample heating, then the ionization process can proceed continuously, but the analyte concentration is diluted and detection sensitivity is reduced
Solution Approach 1:
The system performs preliminary accumulation of analyte in the heating region before ionization. The valve sequence controls gas flow to trap and accumulate analyte molecules in the heating region during a first time period, then transfers the accumulated analyte to the ionization region in a second time period. This preliminary accumulation action increases analyte concentration before ionization, thereby improving detection sensitivity without requiring continuous high-flow gas during the entire process.
2Productivity
If gas flow rate is increased to maintain continuous ionization, then ionization can proceed without interruption, but analyte concentration decreases
Solution Approach 1:
The system employs periodic valve switching to create distinct accumulation and transfer phases. During the accumulation phase, valves are positioned to trap analyte in the heating region with minimal gas flow. During the transfer phase, valves switch to deliver the accumulated analyte to the ionization region. This periodic action allows the system to maintain ionization continuity through scheduled transfer events while achieving high analyte concentration during the accumulation phase, thus resolving the contradiction between productivity and quantity.
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
Enhances detection sensitivity by concentrating analytes before ionization, leading to more intense and focused signal profiles for better detection of low-level hazardous materials.
Implementation Method 1
a sample to be analysed is heated so that analyte (e.g. gas phase analyte molecules) is released from the sample
Data Source
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AI summary
A method of ionisation is disclosed in which a sample is heated such that analyte is released from the sample. Analyte released from the sample is accumulated, and then the accumulated analyte is passed to an ionisation region where the analyte is ionised.