Comparative Analysis Of Air Sampling Strategies For VOC Monitoring

Air Monitoring, Methods, and Technology
Oral Presentation

Presented by C. Widdowson
Prepared by H. Calder1, P. Arya2, K. Piduru1
1 - Markes International, 1000B Central Park, Western Avenue, Bridgend, (State/Province), CF31 3RT, United Kingdom
2 - Agilent Technologies India, Plot No. CP-11, Sector – 8, IMT, Manesar, Haryana, Gurgaon 122 051, India


Contact Information: [email protected]; 01443230935

ABSTRACT

Human exposure to VOCs, such as benzene, is a major public health concern. Many VOCs have been associated with wide ranging adverse health effects and exposure can occur anywhere: outside, the workplace and in the home. In this study we compare different sorbent based methodologies for sampling VOCs in air and assess which techniques provide the most comprehensive overview of the air quality and determine how advanced software tools can more easily help analysts process the large amounts of information generated in studies like this.

Four separate sampling sites in India which may have unique VOC profiles (roadside, next to a gas station, industrial area, residential area) were chosen for the sampling study and a range of diffusive and active samplers were installed at each site. Diffusive sampling has the advantage of not requiring any external equipment or power to take the sample and can easily be applied to remote locations or used for extended time periods. Active sampling using a pump is often a more sensitive technique where large air volumes can be collected to enhance sensitivity of the analysis allowing for pg/L concentrations of compounds in air to be quantified.

Once the samples were collected they were returned to the lab for analysis by Thermal Desorption (TD) - Gas Chromatography (GC) - Mass Spectrometry (MS). TD is a solvent free technique which preconcentrates analytes prior to automated injection into the GC-MS. Samples were analysed in scan mode to enable qualification of unknowns whilst still being able to quantitate target species. The data files were then run through Unknowns Analysis. This presentation will discuss the respective benefits of each sampler and whether there were any distinct benefits when applied to the different locations.