Design of an ultrasonic piezoelectric injection port for analysis of thermally unstable compounds using corona discharge ion mobility spectrometry

Abstract

This paper reports on a novel ultrasonic injection port designed and constructed to analyze thermally unstable chemical compounds using corona discharge ion mobility spectrometry (CD-IMS). In order to achieve the highest possible efficiency with the device, some parameters such as the solvent type, carrier gas flow rate and sample volume were exhaustively investigated. Through a comparative study conducted, it was revealed that unlike the thermal desorption system, the proposed ultrasonic injection port could easily be used for the analysis of some thermally unstable compounds such as carbaryl, propoxur and vitamin B1, by means of CD-IMS. To evaluate the potential of the device, carbaryl, extracted from different samples by dispersive liquid-liquid microextraction technique, was quantitatively analyzed. The CD-IMS-based results brought forth the detection limit of 0.03 mg L−1, and dynamic range of 0.1–10.0 mg L−1 with the determination coefficient of 0.9981. The relative standard deviations for one day and three consecutive days were 4 and 6%, respectively. Further, the spiked samples of agricultural wastewater, underground water, and tomato analyzed culminated in the recovery values of 83%, 98% and 82%, respectively. The satisfactory results proved an acceptable capability of the sample introduction system, to be conveniently used for routine analysis of thermally unstable compound, without any tedious derivatization.