Diffusive Uptake Rates of Volatile Organic Compounds on Standard ATD Tubes for Environmental and Workplace Applications

Chunrong Jia,Xianqiang Fu

doi:10.3390/environments4040087

Abstract

Passive sampling for airborne volatile organic compounds (VOCs) has gained popularity; however, diffusive uptake rates (URs) have been experimentally determined for only a small subset of VOCs. This study aims to develop empirical models that can interpolate effective URs (UReff) for a wide range of VOCs. The modelling was based on the standard automated thermal desorption (ATD) tubes packed with Tenax TA and targeted the sampling efficiency (α), defined as the ratio between the ideal UR (URideal) and UReff. Available experimentally determined URs were compiled from literature. Method detection limits were determined on a thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS) system. The 8-h UReff can be modeled with retention volumes or boiling points (BPs) and the biases were within ±20%. The α for 7-day UReff can be estimated by the model: α = 0.3626 Ln(BP) − 1.2324. The 8-h and 7-day UReff values were then compiled for 75 VOCs commonly encountered in the environmental and occupational settings. The TD analytical method showed high precision, linearity and sensitivity, suitable for measuring indoor and outdoor VOCs. The approach and data presented here are anticipated to ease passive monitoring of VOCs for the general users.

Highlights

Volatile organic compound (VOC) contamination represents a health concern in indoor, outdoor and occupational environments [1,2]
If direct Vg values were unavailable, 8h-UReff values were modeled using boiling points (BPs) and the modeled values were within ±20% of the measured
8h-UReff values estimated by Equations (4) and (5) applied to ketones and α-pinene

Summary

Introduction

Volatile organic compound (VOC) contamination represents a health concern in indoor, outdoor and occupational environments [1,2]. Current exposure and risk assessment of VOCs requires representative exposure measurements, which are achieved by large sample sizes and frequent and long-term sampling [3]. Sample sizes of several hundred are common in large survey studies, e.g., Relationship of Indoor, Outdoor and Personal Air (RIOPA) study [5], National Health and Nutrition Examination Surveys (NAHANES) [6] and urban air toxics studies [7]. There is a critical need for simple, low-cost and reliable VOC measurement methods to realistically evaluate public health risks and regulation compliance. Passive sampling is a widely used sampling technique for determining time-weighted average concentrations of airborne VOCs [8,9].

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Discussion

Conclusion