Open Journal of Physical Chemistry, 2013, 3, 170-176 Published Online November 2013 (http://www.scirp.org/journal/ojpc) http://dx.doi.org/10.4236/ojpc.2013.34021 Open Access OJPC Effect of Temperature on Separation of Sarin (GB) Ions in Differential Mobility Spectrometry Mirosław Maziejuk, Michał Ceremuga, Monika Szyposzyńska * , Tomasz Sikora Wojskowy Instytut Chemii i Radiometrii, Warszawa, Poland Email: * m.szyposzynska@wichir.waw.pl Received June 10, 2013; revised July 8, 2013; accepted July 16, 2013 Copyright © 2013 Mirosław Maziejuk et al. This is an open access article distributed under the Creative Commons Attribution Li- cense, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT Different environmental conditions in which, equipment based on differential ion mobility spectrometry must operate, forced designers and engineers to analyze the impact of, among other things, external factors on their performance and efficiency. These devices, thanks to the DMS technology, can identify and characterize the ions contained in the gase- ous state. However, many areas of this technique remain undiscovered, which should be examined in more detail. One such aspect is the influence of the temperature of gaseous medium, containing tested analyte. The research presented in this article shows why temperature is an important factor on the distribution of generated peaks. The results are shown for different spectra generated carrier gas temperatures (50˚C - 80˚C) in which ions were toxic warfare agents. Based on those graphs, it can be stated that increase of the temperature allows for better separation of the peaks from the back- ground. Because of the similar ion mobility of the analyte and background ions for high and low electric field, DMS device can send false alarms, due to the poor interpretations of passing a signal to them. So to be able to accurately as- sess the level of risk due to the presence of substances BST in air, the test medium was added to isobutanol and isopro- panol additives. They help better analyze and separate measured ions. Keywords: DMS; Spectrometry; Ion Mobility 1. Introduction Current knowledge of the DMS method has been de- scribed in various publications, however, this article will present the basic phenomena that took part in the exami- nations. Method of differential ion spectrometry has been recognized as a powerful tool for the separation and characterization of ions present in the gas phase. Ion mo- bility spectrometry (IMS) is now one of the best tech- niques for chemical warfare agent’s detection [1-4] espe- cially differential mobility spectrometry (DMS) [5-10]. In the past, DMS was called field asymmetric waveform ion mobility spectrometry (FAIMS) [11,12]. DMS is a special method used in ion separation based on differ- ence in ion mobility in high and low electric field under atmospheric pressure [13]. Relation between mobility of ions and electric field may be described by Equation (1):     0 1 K EN K EN         (1) where: K—ion mobility, cm 2 /V·s, ectric field strength, V/cm, 2 ·s], of Townsend, [T ion tra E—el K 0 —reduced mobility [cm /V E/N—electric field expressed in units , −17 2 d] (1 Td = 1·10 V·cm ), α(E/N)—function characterized by mobility field. Mobility of the ions depends on mass and charge of the ion and flow rate of carrier gas. The schema of nsfer in the DMS chamber is presented in the Figure 1. Under alternating electric field applied to the electrodes, some of the ions in the chamber are intercepted. Chang- ing values of compensated electric field, it may be used as specific ion filter [14,15]. Stability and repeatability of spectra obtained by DMS have a great meaning in chemical analysis. Pressure and temperature of carrier gas have an influence on the ion mobility and peak shifts on the spectra. The main goal of this work was investigation of influence of temperature on the resolution and separation of the ions chemical warfare agents on the example of sarin (GB). * Corresponding author.