Multisensory Gas Chromatography for Field Analysis of Complex Gaseous Mixtures

Vladimir Dobrokhotov,Alexander Larin

doi:10.3390/chemengineering3010013

Vladimir Dobrokhotov, Alexander Larin

Open Access

https://doi.org/10.3390/chemengineering3010013

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Journal: ChemEngineering	Publication Date: Feb 2, 2019
Citations: 11	License type: CC BY 4.0

Affiliation: Western Kentucky University

Abstract

A novel approach to analysis of complex gaseous mixtures is presented. The approach is based on the utilization of a compact gas chromatograph in combination with an array of highly integrated and selective metal oxide (MOX) sensors. Thanks to the implementation of a multisensory detector, the device collects multiple chromatograms in a single run. The sensors in the integrated MEMS platform are very distinct in their catalytic properties. Hence, the time separation by chromatographic column is complemented by catalytic separation by a multisensory detector. Furthermore, the device can perform the analysis in a broad range of concentrations, from ppb to hundreds of ppm. Low ppb and even sub-ppb levels of detection for some analytes were achieved. As a part of this effort, nanocomposite gas sensors were synthesized for selective detection of hydrogen sulfide, mercaptans, alcohols, ketones, and heavy hydrocarbons.

Highlights

The detection and analysis of gases and vapors is an important part of the modern world, where gas sensing technology is becoming increasingly important for various aspects of our lives
The ability of the instrument to analyze complex mixes containing light and heavy compounds on a single compact gas chromatography (GC) column at constant temperature is one of the key advantages that separates our technology from similar products
For a portable natural gas analyzer, the ability to analyze sulfur-based gaseous compounds and BTEX at the same time is of great importance

Summary

Introduction

The detection and analysis of gases and vapors is an important part of the modern world, where gas sensing technology is becoming increasingly important for various aspects of our lives. A variety of gas analysis techniques and gas detectors are regularly used to improve safety and establish more precise product quality control and process control [1,2] Some industrial sectors such as the food/medicine, automotive, heavy industry, environmental, security, and home appliances sectors have utilized gas analysis for a wide range of applications [3,4,5,6]. Real-time field monitoring using a conventional GC with standard sensors (FID, PID, etc.) has a lot of fundamental barriers and limitations due to its bulky size, heavy weight, special carrier gases requirement, and high maintenance. Conventional gas chromatography utilizes an approach of analyzing a total signal coming from the FID or PID detector These types of detectors are non-selective and respond to a wide variety of analytes. A detailed chemical analysis of a complex blend using a single compact GC column requires a more advanced analytical technique than conventional separation via retention time only. The detector’s short response and recovery time, together with ultra-high sensitivity, allowed us to obtain high-resolution chromatograms for analytes of interest from light (hydrogen sulfide, carbon monoxide) to heavy (O-Xylene) in a short time interval of 12.5 min on a single compact GC column

Experiment

Findings

Discussion