A novel quantitation approach for maximizing detectable targets for offensive/volatile odorants with diverse functional groups by thermal desorption-gas chromatography-mass spectrometry.

Ki-Hyun Kim,Yong-Hyun Kim

doi:10.1038/srep29248

Abstract

A multitude of analytical systems are needed to analyze diverse odorants with various functionalities. In this study, an experimental method was developed to assess the maximum covering range of odorants using a single experimental setup consisting of a thermal desorber-gas chromatography-mass spectrometry system. To this end, a total of 20 offensive odorants (aldehyde, ketone, ester, alcohol, aromatic, sulfide, amine, and carboxyl) were selected and tested by a single system. The analytical results of standards and environmental samples were evaluated in a number of respects. In the analysis of the standards, all targets were quantified via Carbopack (C + B + X) tube sampling while operating the thermal desorber at −25 °C. The method detection limits of 18 targets (exception of 2 out of the 20 targets: acetaldehyde and methanethiol) were excellent (mean 0.04 ± 0.03 ppb) in terms of their odor threshold values (74.7 ± 140 ~ 624 ± 1,729 ppb). The analysis of organic fertilizer plant samples at a pig farm (slurry treatment facility, compost facility, and ambient air) confirmed the presence of 18 odorants from 0.03 ppb (dimethyldisulfide, ambient sample) to 522 ppb (methyl ethyl ketone, slurry treatment facility). As such, our method allowed simultaneous quantitation of most key odorants with sufficient reliability and sensitivity.

Highlights

Relative to grab-sampling approaches[5]
In order to carry out reliable quantitation of diverse malodors in air, the combined application of several types of analytical methods and systems is needed due to the complexities involved in the analysis
A single analytical system based on the sorbent tube (ST)/thermal desorber (TD)-gas chromatography (GC)-mass spectrometry (MS) system was developed to simultaneously analyze a maximum number of odorants

Summary

Introduction

Relative to grab-sampling approaches[5]. in the case of sulfur or nitrogen compounds, specific detectors that are best-suited to detect each target should be used to gain maximum reliability[6,7]. A GC-mass spectrometry (MS)-based analytical method has been developed to cover a maximum range of odorants with a single analytical system. This system is based on sorbent tube (ST) sampling with the aid of a thermal desorber (TD) technique. To this end, the maximum number of the designated odorants with diverse functionalities and related physicochemical properties were simultaneously collected in the same manner with a ST by considering all of the relevant quality assurance (QA) procedures. To obtain optimal recovery of each target odorant, appropriate TD conditions and MS methodologies were controlled and developed

Methods

Results

Conclusion