Acoustic methods of detection in gas chromatography

Abstract

Review Acoustic methods of detection in gas chromatographyA brief review of the use of acoustic detection methods in GC is presented. While a number of methods (some quite similar) have been developed for use as gas-phase sensors in various applications, this article focuses specifically on those techniques that have been used to detect analytes following their separation by GC. Overall, a number of "active" acoustic methods (which measure analytes through their interaction with a controlled external acoustic wave source) were reportedly used as GC detectors. These include ultrasonic, thickness shear mode, surface acoustic wave (SAW), and flexural plate wave methods. Conversely, "passive" acoustic methods (those that produce an acoustic signal through some chemical reaction with the analyte) have also been used as GC detectors. These include photoacoustic and acoustic flame methods of detection. Of the two major classifications, reports of active methods are far more prevalent. In particular, the usage of SAW techniques with GC is an area of research that has seen accelerated growth in recent years.

Towards new analyses of aroma and volatiles to understand sensory perception of olive oil

“…Solutions can come from designing new architectures for the sensor chamber, the substitution of current capillary columns by micromachine columns and MOS sensors by SAW sensors that show a faster desorption time. Although the use of SAW sensors as chromatographic detectors has been already explored 27, the robustness and reproducibility of the production process of these devices still need to be improved 28.…”

Response Mechanism for Surface Acoustic Wave Gas Sensors Based on Surface-Adsorption

“…In many areas, such as environmental monitoring, food security, explosive detection, there is a strong need for sensors which have a wide detecting range to monitor volatile organic or semi-volatile organic compounds (VOCs or SVOCs) [10–12]. To satisfy the demand, another kind of SAW sensor [13–17] was reported, in which a gas separation apparatus such as a gas chromatography (GC) column is set in front of the detector to separate and identify the tested multi-component gas. A multi-component gas can be separated and identified by their characteristic retention time in the GC column; thus SAW-GC sensors are available to detect VOCs and SVOCs in a wide range.…”

Analysis of Surface Acoustic Wave Propagation Velocity in Biological Function-Oriented Odor Sensor

“…Electrochemical methods, optical methods, and acoustic techniques are used in biological function-oriented odor sensors [1]. Among these methods, acoustic techniques have lately received considerable attention for odor sensor systems because of their high sensitivity, rapid detection, and safety [2][3][4]. Surface acoustic wave (SAW) devices, in which Rayleigh waves propagate, have also been studied for biological function-oriented odor sensors [5].…”