Comparison of Water Pretreatment Devices for the Measurement of Polar Odorous Compounds

Joo-Yeon Lee,Shin-Young Park,Trieu-Vuong Dinh,In-Young Choi,Dong-June Kim,Jo-Chun Kim,Ji-Won Ahn,Yoo-Jin Jung

doi:10.3390/app9194045

Abstract

A major problem of measuring polar compounds in the air is water vapor. Therefore, it is important to use a water pretreatment device prior to sampling and analysis. However, many studies have reported the occurrence of many problems following the application of an existing water pretreatment device. Accordingly, the performance of a Desolvator-K that was developed by the authors and two commercial coolers were investigated and compared in this study. Water vapor removal efficiency, recovery rate, and reproducibility of polar odorous compounds (i.e., methyl ethyl ketone (MEK), isobutyl alcohol (i-BuAl), methyl isobutyl ketone (MIBK), butyl acetate (BuAc), styrene) in air were taken into account. It was found that the Desolvator-K, the Cooler-G, and the Cooler-K showed 91.6%, 67.2%, and 62.1% water vapor removal efficiency, respectively, at the relative humidity of 90%. In terms of recovery rate, after water vapor removal devices, the Desolvator-K, the Cooler-G, and the Cooler-K revealed average recoveries of 96.6–103%, 81–101%, and 88.6–100%, respectively. Reproducibility of odorous compounds under all conditions of the Desolvator-K, the Cooler-G, and the Cooler-K were 5.94%, 31.2%, and 8.14% of relative standard deviation (RSD), respectively. Therefore, it is suggested that the Desolvator-K should be established as a water pretreatment device for the MEK, i-BuAl, MIBK, and BuAc compounds in the air.

Highlights

A water pretreatment device is an apparatus that can remove only water vapor presented in sample gas in order to improve accurate and reliable sampling and analysis
We evaluated the performance of the manufactured Desolvator-K as a water pretreatment device
The target compounds were MEK, i-BuAl, MIBK, and BuAc, which were the polar odorous compounds of volatile organic compound (VOC) in air, and styrene was used as a simple comparison compound

Summary

Introduction

A water pretreatment device is an apparatus that can remove only water vapor presented in sample gas in order to improve accurate and reliable sampling and analysis. Interference and loss of analytes occur when samples containing water vapor are taken from the atmosphere [1]. The measuring instruments could be damaged by the remaining water vapor. Water vapor taken with a sample gas could disturb the adsorption capacity of adsorbents, destabilize the baseline of the chromatograph, cause column damage, and change the retention times of sample compounds [2]. It might clog the transfer line of the instrument or reduce the sensitivity of the measurement process [3]. The filament condition could be changed during the operation of a mass spectrometer (MS), which results in response variation [4]

Methods

Results

Conclusion