Univariate and multivariate DMS calibration for a single analyte

Andrzej Szczurek,Żaneta Zajiczek,Monika Maciejewska,B Kaźmierczak,M Kutyłowska,P Jadwiszczak,U Miller

doi:10.1051/e3sconf/201910000078

Abstract

Differential mobility spectrometry (DMS) is a promising measurement technique. It is used in the detection of chemical warfare agents, explosives, drugs, and volatile organic compounds. The measurement principle is based on separation of gas-phase ions according to their differential mobility in alternating low and high electric fields. The DMS measurement result is a two dimensional spectrum of ion current displayed as a function of separation voltage and compensation voltage. The DMS spectral peaks, in terms of their height, location and width, are affected by gas sample composition, separation field and the gas flow rate. In this work, there is presented the calibration procedure which utilises the univariate and multivariate approach to differential ion mobility spectrum. We demonstrated the possibility of a successful retrieval of quantitative information using partial least squares regression as well as univariate linear regression. However, the multivariate approach outperformed the univariate one in terms of the quality of the model and the concentration prediction accuracy.

Highlights

Differential mobility spectrometry (DMS) is one of the most promising measurement techniques [1, 2]
We proposed that the independent variables in partial least squares (PLS) model are ion currents associated with all compensation voltages CV and the defined separation voltage
In this work we focussed on the DMS spectrum as a source of quantitative information about the analyte

Summary

Introduction

Differential mobility spectrometry (DMS) is one of the most promising measurement techniques [1, 2]. A lot of experimental data concerning a rapidly growing number and variety of its applications had been published and discussed. The measurement principle of this technique is based on separation and characterization of gas-phase ions [1]. When ions move through a gas under the influence of an electric field, the combination of acceleration due to the field and deceleration due to collisions with gas molecules affects their movement. DMS separates ions based on their differential mobility in alternating low and high electric fields. The differential mobility of an ion depends on a number of properties, including the mass, shape, centre of mass, dipole moment, effects of clustering between ions and neutral gas molecules during separation

Methods

Results

Conclusion