Identification of volatile organic compounds by retention times and ion mobility spectra

Abstract

Retention times are determined and ion mobility spectra are recorded for reference substances belonging to the homologous series of saturated aldehydes, ketones, and alcohols with a nonbranched chain containing from two to nine carbon atoms. For aldehydes, ketones, and alcohols, the retention times grow exponentially with the number of carbon atoms in the analyte. The retention times decrease exponentially with increasing separation temperature. The dependences of the reduced mobilities of two peaks in the ion ograms of aldehydes, ketones, and alcohols with drift in air at 330 K on the number of carbon atoms in the analyte molecules with a saturated nonbranched chain are obtained. In the range of molecular weights stud ied, normalized mobilities linearly decrease with increasing number of carbon atoms in the analyte, which is consistent with the published data. For substances with equal numbers of carbon atoms and a nonbranched chain, mobility decreases in the order ketone > aldehyde > alcohol.

Structure of aldehyde cluster ions in the gas phase, according to data from ion mobility spectrometry and ab initio calculations

“…However, the above works are of an applied character and do not deal with questions of the structure of the formed ions. Considering homological series [20][21][22], which allows us to find correlations between the molecular weight and ionic mobility of organic compounds in the gas phase, is useful. In this work, the structure of ions of the monomers and dimers formed by aldehydes in the gas phase is investigated by means of ion mobility spectrometry in combination with ab initio quantum chemical calculations.…”

The Composition and Distribution of Volatile Organic Compounds in Sediments of the East Taijinar Salt Lake in Northern Qinghai-Tibet Plateau

“…The most evident difference among the three samples was the presence of a siloxane substance, which was numbered as 14, 31-32, and 38-39 (shown in the red frame and the yellow dotted frame of Figure 4). However, most of these substances did not originate from the sample itself; instead, they existed in the stationary phases of the chromatographic column (Levin and Lantsuzskaya, 2014) and could not be avoided when testing. Moreover, the reagent used for boron extraction from the East Taijinar salt lake brine was 2-ethyl-1-hexanol (Gao et al, 2010), which was identified during the analysis.…”

Ion Mobility Spectrometry Towards Environmental Volatile Organic Compounds Identification and Quantification: a Comparative Overview over Infrared Spectroscopy

“…Acetone, being one of the most common VOCs in room air, was identified in several independent studies [10,24,75,79,80,[106][107][108]. Similarly, ethanol is also a very common analyte, being identified in [10,[79][80][81]106]. Among all the addressed works underlying this review, hexanal is the most common analyte to be identified [10,24,75,79,105,106,108,109].…”

“…The VOCs can be measured from pure samples, a mixture of distinct analytes, or even from a VOCemitting solid or liquid sample. For instance, to identify VOCs by their respective retention time obtained in ion mobility spectrometry measurements, pure samples of each analyte were used by Levin et al to create headspace which was then injected into a GC-IMS device [79]. Yokoshiki et al, in their turn, prepared a ternary mixture of VOCs for quantification purposes.…”

“…In general and independent of the type of procedures, all the addressed works provide a list of the identified or analyzed VOCs. Acetone, being one of the most common VOCs in room air, was identified in several independent studies [10,24,75,79,80,[106][107][108]. Similarly, ethanol is also a very common analyte, being identified in [10,[79][80][81]106].…”