Key Odorants from Pig Production Based on Improved Measurements of Odor Threshold Values Combining Olfactometry and Proton-Transfer-Reaction Mass Spectrometry (PTR-MS).

Michael Hansen,Anders Adamsen,Pernille Kasper,Anders Feilberg

doi:10.3390/s18030788

Michael Hansen, Anders Adamsen + Show 2 more

Open Access

https://doi.org/10.3390/s18030788

Copy DOI

Abstract

Analytical measurements of odorants in combination with odor threshold values is an alternative to sensory measurements that can be used to evaluate abatement technologies for pig production facilities. The purpose of the present study was to estimate odor threshold values for key odorants found in pig house air. A new method was applied where an olfactometer was used to dilute the sample air and the concentrations of odorants presented to the panelists at the dilutions steps were measured by proton-transfer-reaction mass spectrometry (PTR-MS). The results demonstrate that the odor threshold values of acetic acid, butanoic acid, and 4-methylphenol are considerably lower than reported previously, whereas the values of hydrogen sulfide, methanethiol and dimethylsulfide were comparable. Consequently, acetic acid, butanoic acid, and 4-methyl-phenol will have a larger influence on odor from pig production facilities than previously assumed. The results highlight the necessity for directly measuring exposure concentrations when determining odor threshold values.

Highlights

Odor from agricultural facilities measured by a chemical method has often been suggested as an alternative to the olfactometric method [1], which is based on dilution-to-threshold with human panelists
A new method combining an olfactometer and a proton-transfer-reaction mass spectrometry (PTR-MS) was applied for Discussion measuring odorand threshold values for odorants normally found in pig house air
Undiluted samples measuringdilution odor threshold values for odorants found in pig house

Summary

Introduction

Odor from agricultural facilities measured by a chemical method has often been suggested as an alternative to the olfactometric method [1], which is based on dilution-to-threshold with human panelists. The odor activity value is calculated as the gas-phase concentrations divided by the odor threshold values. The odorant contributions are assumed to be additive and the calculated odor concentration is denoted “Sum of odor activity values” (SOAV). This approach gave a reasonable relationship with the odor concentration measured by olfactometry the absolute odor concentration was underestimated [16].

Objectives

Methods

Results

Conclusion