Related Experiment Video
Updated: Jul 31, 2025
07:57
Quantitative Detection of Trace Explosive Vapors by Programmed Temperature Desorption Gas Chromatography-Electron Capture Detector
Published on: July 25, 2014
20.0K
A MEMS-enabled portable gas chromatography injection system for trace analysis
Nipun Thamatam1, Jeonghyeon Ahn2, Mustahsin Chowdhury1
1VT MEMS Lab, The Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, United States.
Analytica Chimica Acta
|May 5, 2023
Summary
Portable sampling of volatile organic compounds (VOCs) is enhanced by a new micro-preconcentrator (μPC) autosampler. This system integrates easily with gas chromatography, enabling faster and more sensitive detection of trace-level compounds.
Area of Science:
- Environmental Science
- Analytical Chemistry
- Chemical Engineering
Background:
- Growing concerns in environmental monitoring, public health, and diagnostics necessitate portable methods for trace volatile organic compound (VOC) analysis.
- Microelectromechanical systems (MEMS)-based micropreconcentrators (μPCs) offer reduced size, weight, and power for flexible sampling.
- Commercial adoption of μPCs is limited by the lack of integrated thermal desorption units (TDUs) for gas chromatography (GC) systems.
Purpose of the Study:
- To develop and demonstrate a versatile μPC-based autosampler-injection unit for seamless integration with traditional, portable, and micro-GC systems.
- To introduce a novel modular interfacing architecture (FEMI) for easy connection and disconnection of μPCs.
- To evaluate the performance of the developed autosampler prototype in detecting trace-level VOCs.
Main Methods:
- Designed and fabricated a μPC-based autosampler-injection unit (FEMI-AS) utilizing 3D-printed cartridges and a modular FEMI interface.
- Integrated the FEMI-AS prototype with a GC system equipped with a flame ionization detector (GC-FID).
- Tested the system's performance using synthetic gas samples and ambient air, comparing results with sorbent tube sampling and TD-GC-MS.
Main Results:
- The FEMI-AS prototype (9.5 cm × 10 cm × 20 cm, ≈500 g) achieved sharp injection plugs (≈240 ms).
- Demonstrated detection of analytes at <15 ppb within 20 s and <100 ppt within 20 min sampling times.
- Successfully identified over 30 trace-level compounds in ambient air samples.
Conclusions:
- The developed FEMI architecture and FEMI-AS prototype significantly enhance the usability and integration of μPCs.
- This advancement accelerates the commercial adoption of μPC technology for diverse environmental and health monitoring applications.
- The system offers a versatile and efficient solution for rapid, on-site characterization of trace VOCs.
Keywords:
Fluidic connectionsGas chromatographyMicropreconcentratorPortable thermal desorption unitTrace analysisVolatile organic compoundsMore Related Videos
Related Concept Videos
01:08Gas Chromatography: Sample Injection Systems
473
In gas chromatography, the sample is introduced as a vapor plug into the carrier gas stream for high efficiency and resolution. A microsyringe injects the sample solution into a heated sample port, vaporizing it and mixing it with the carrier gas. This process is important to ensure the sample is properly prepared for analysis. Thermally sensitive samples can be injected directly into the column and volatilized by slowly increasing the column temperature.
Two primary injection methods are used...
Two primary injection methods are used...
473
01:14Gas Chromatography–Mass Spectrometry (GC–MS)
4.4K
Gas chromatography–mass spectrometry (GC–MS) is the combination of analytical techniques of gas chromatography and mass spectrometry in a single instrument for analyzing a mixture of compounds. The gas chromatograph separates the compounds in the mixture, and the mass spectrometer analyzes each compound separately to determine the molecular masses and molecular structures.
A gas chromatograph consists of a long, narrow capillary column with a polysiloxane coating on the inner wall....
A gas chromatograph consists of a long, narrow capillary column with a polysiloxane coating on the inner wall....
4.4K
01:19Gas Chromatography: Types of Detectors-II
439
In gas chromatography, different detectors are employed to meet specific analytical needs. These detectors are often categorized based on their detection mechanisms and the types of compounds they are best suited to analyze. Thermal Conductivity Detectors (TCD), Flame Ionization Detectors (FID), and Electron Capture Detectors (ECD) represent common categories, each with unique operating principles and applications. However, beyond these, several other detectors are designed for more specialized...
439
01:13Gas Chromatography: Overview of Detectors
653
Detectors in gas chromatography (GC) help identify and quantify the components of a mixture by translating chemical properties into measurable signals, which are displayed on a chromatogram. Detectors can be categorized into two main types: destructive and non-destructive.
A non-destructive detector allows a sample to be analyzed without altering or consuming it, meaning the sample can be collected after detection for further analysis. Examples include thermal conductivity detectors and...
A non-destructive detector allows a sample to be analyzed without altering or consuming it, meaning the sample can be collected after detection for further analysis. Examples include thermal conductivity detectors and...
653
01:21Gas Chromatography: Types of Detectors-I
503
There are different types of detectors used in gas chromatography, each with its own specific properties that make it suitable for detecting certain types of analytes. The most commonly used detectors in GC are thermal conductivity detector (TCD), flame ionization detector (FID), and electron capture detector (ECD).
TCD is the earliest and most widely used detector that operates by measuring the changes in the thermal conductivity of the carrier gas. When a sample compound enters the detector,...
TCD is the earliest and most widely used detector that operates by measuring the changes in the thermal conductivity of the carrier gas. When a sample compound enters the detector,...
503
01:21Mass Spectrometry: Complex Analysis
840
Mass spectrometry is an important technique for the identification of pure compounds. However, it has some limitations for the analysis of complex mixtures, often due to excessive fragmentation making the spectrum too complicated to decipher. Mass spectrometry can be combined with suitable separation methods in sequence, forming hyphenated methods, which are useful in the analysis of complex mixtures.
GC–MS is a powerful hyphenated method commonly used in forensics and environmental...
GC–MS is a powerful hyphenated method commonly used in forensics and environmental...
840