In-Line Detection with Microfluidic Bulk Acoustic Wave Resonator Gas Sensor for Gas Chromatography.

Jizhou Hu,Hemi Qu,Wei Pang,Xuexin Duan

doi:10.3390/s21206800

Abstract

A microfluidic film bulk acoustic wave resonator gas sensor (mFBAR) adapted specifically as an in-line detector in gas chromatography was described. This miniaturized vapor sensor was a non-destructive detector with very low dead volume (0.02 μL). It was prepared by enclosing the resonator in a microfluidic channel on a chip with dimensions of only 15 mm × 15 mm × 1 mm. The device with polymer coating showed satisfactory performance in the detection of organophosphorus compound, demonstrating a very low detection limit (a dozen parts per billion) with relatively short response time (about fifteen seconds) toward the simulant of chemical warfare agent, dimethyl methylphosphonate. The in-line detection of the mFBAR sensor with FID was constructed and employed to directly measure the concentration profile on the solid surface by the mFBAR with the controlled concentration profile in the mobile phase at the same time. The difference of peak-maximum position between mobile phase and solid phase could be a convenient indicator to measure mass transfer rate. With the response of the mFBAR and FID obtained in one injection, an injection mass-independent parameter can be calculated and used to identify the analyte of interest.

Highlights

Gas chromatography (GC) is the pillar technology for gas-phase analysis in a variety of applications including environmental science, clinic diagnosis, petroleum production, etc. [1,2,3,4]
Recent studies demonstrated that a combination of gas sensors with GC technology was promising to produce small-size and low-consumption instruments with good analytical accuracy
In comparison with conventional GC detectors, the detectors based on micro gas sensors have the apparent advantage of a small footprint and are potential candidates for the in-line detection

Summary

Introduction

Gas chromatography (GC) is the pillar technology for gas-phase analysis in a variety of applications including environmental science, clinic diagnosis, petroleum production, etc. [1,2,3,4]. While the conventional detectors, such as thermal conductivity detectors (TCDs) [5] and flame ionization detectors (FIDs) [6], are generally installed at the terminal end, in-line detectors (or on-column detectors) could be configured in the capillary line, demonstrating a high flexibility in a serial combination with other detectors to provide multichannel detection with complementary information [7,8]. Recent studies demonstrated that a combination of gas sensors with GC technology was promising to produce small-size and low-consumption instruments with good analytical accuracy. In comparison with conventional GC detectors, the detectors based on micro gas sensors have the apparent advantage of a small footprint and are potential candidates for the in-line detection. Micro gas sensors, sealed in a microfluidic channel, could be conveniently employed for in-line detection with other types of detectors in a serial form [15,22]

Objectives

Methods

Results