Development of a Combined Real Time Monitoring and Integration Analysis System for Volatile Organic Compounds (VOCs)

Atsushi Mizukoshi,Akihiro Yamasaki,Yukio Yanagisawa,Kentaro Oka,Atsushi Iizuka,Miyuki Noguchi,Yasuo Inoue

doi:10.3390/ijerph7124100

Abstract

A combined integration analysis and real time monitoring (Peak Capture System) system was developed for volatile organic compounds (VOCs). Individual integration analysis and real time monitoring can be used to qualitatively and quantitatively analyze VOCs in the atmosphere and in indoor environments and determine the variation in total VOC (TVOC) concentration with time, respectively. In the Peak Capture System, real time monitoring was used to predict future elevations in the TVOC concentration (peak), and this was used an indicator of when to collect (capture) ambient air samples for integration analysis. This enabled qualitative and quantitative analysis of VOCs when the TVOC concentration was high. We developed an algorithm to predict variation in the TVOC concentration, and constructed an automatic system to initiate air sampling for integration analysis. With the system, auto-sampling and analysis of VOCs in a conventional house were conducted. In comparison with background concentrations, the results of peak analysis enabled identification of compounds whose concentration rose. This also enabled an evaluation of possible VOC emission sources.

Highlights

Volatile organic compounds (VOCs) are organic compounds with large vapor pressures, and include aldehydes, ketones, and other light hydrocarbons
VOCs are collected into a sorbent tube with an air pump, and analyzed using methods such as gas chromatography/mass spectrometry (GC/MS), gas chromatography/flame ionization detection (GC/FID), or high performance liquid chromatography (HPLC)
We optimized the three parameters in the algorithm using 22 data sets of total VOC (TVOC) concentrations measured over 24 h in conventional Japanese houses

Summary

Introduction

Volatile organic compounds (VOCs) are organic compounds with large vapor pressures, and include aldehydes, ketones, and other light hydrocarbons. VOCs are collected into a sorbent tube with an air pump, and analyzed using methods such as gas chromatography/mass spectrometry (GC/MS), gas chromatography/flame ionization detection (GC/FID), or high performance liquid chromatography (HPLC) This provides qualitative and quantitative information on each VOC in the collected air sample. Proton transfer reaction-mass spectrometry (PTR/MS) has drawn great deal of attention for the purpose These techniques allow immediate and continuous monitoring of the variation in TVOC concentration with time. Real time monitoring was used to predict future elevation in TVOC concentration (peak) This was used as an indicator of when to collect (capture) air samples for integration analysis. We applied the system to auto-sampling and analysis of VOCs in a conventional house This system will be effective in cases of intermittent air pollution from unknown emission sources

Physical Setup of the PCS

Peak Prediction Algorithm

Integration Analysis

Optimization of the Elevation Prediction Algorithm

B: Elevations predicted with the algorithm

Application of the PCS with Optimized Algorithm to Indoor Air Measurements

Background

Conclusions