Development of Time-Weighted Average Sampling of Odorous Volatile Organic Compounds in Air with Solid-Phase Microextraction Fiber Housed inside a GC Glass Liner: Proof of Concept

Madina Tursumbayeva; Jacek A Koziel; Devin L Maurer; Bulat Kenessov; Somchai Rice

doi:10.3390/molecules24030406

Development of Time-Weighted Average Sampling of Odorous Volatile Organic Compounds in Air with Solid-Phase Microextraction Fiber Housed inside a GC Glass Liner: Proof of Concept

Molecules. 2019 Jan 23;24(3):406. doi: 10.3390/molecules24030406.

Authors

Madina Tursumbayeva^{1

2}, Jacek A Koziel³, Devin L Maurer⁴, Bulat Kenessov⁵, Somchai Rice⁶

Affiliations

¹ Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA 50011, USA. madina@iastate.edu.
² Department of Meteorology and Hydrology, Al-Farabi Kazakh National University, Almaty 050040, Kazakhstan. madina@iastate.edu.
³ Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA 50011, USA. koziel@iastate.edu.
⁴ Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA 50011, USA. dmaurer@iastate.edu.
⁵ Center of Physical Chemical Methods of Research and Analysis, Al-Farabi Kazakh National University, Almaty 050012, Kazakhstan. bkenesov@cfhma.kz.
⁶ Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA 50011, USA. somchai@iastate.edu.

Abstract

Finding farm-proven, robust sampling technologies for measurement of odorous volatile organic compounds (VOCs) and evaluating the mitigation of nuisance emissions continues to be a challenge. The objective of this research was to develop a new method for quantification of odorous VOCs in air using time-weighted average (TWA) sampling. The main goal was to transform a fragile lab-based technology (i.e., solid-phase microextraction, SPME) into a rugged sampler that can be deployed for longer periods in remote locations. The developed method addresses the need to improve conventional TWA SPME that suffers from the influence of the metallic SPME needle on the sampling process. We eliminated exposure to metallic parts and replaced them with a glass tube to facilitate diffusion from odorous air onto an exposed SPME fiber. A standard gas chromatography (GC) liner recommended for SPME injections was adopted for this purpose. Acetic acid, a common odorous VOC, was selected as a model compound to prove the concept. GC with mass spectrometry (GC⁻MS) was used for air analysis. An SPME fiber exposed inside a glass liner followed the Fick's law of diffusion model. There was a linear relationship between extraction time and mass extracted up to 12 h (R² > 0.99) and the inverse of retraction depth (1/Z) (R² > 0.99). The amount of VOC adsorbed via the TWA SPME using a GC glass liner to protect the SPME was reproducible. The limit of detection (LOD, signal-to-noise ratio (S/N) = 3) and limit of quantification (LOQ, S/N = 5) were 10 and 18 µg·m^-3 (4.3 and 7.2 ppbV), respectively. There was no apparent difference relative to glass liner conditioning, offering a practical simplification for use in the field. The new method related well to field conditions when comparing it to the conventional method based on sorbent tubes. This research shows that an SPME fiber exposed inside a glass liner can be a promising, practical, simple approach for field applications to quantify odorous VOCs.

Keywords: GC–MS; SPME; TWA SPME; VOCs; air monitoring; air quality; environmental analysis; odor; on-site sampling; retracted SPME.

MeSH terms

Dietary Fiber
Environmental Monitoring*
Gas Chromatography-Mass Spectrometry
Odorants / analysis*
Solid Phase Microextraction
Specimen Handling
Volatile Organic Compounds / chemistry*

Substances

Dietary Fiber
Volatile Organic Compounds

Grants and funding

IOW05556/Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa