Ph.D Thesis

Ph.D StudentBelostotsky Inessa
SubjectMonitoring of Contaminants in Air with High Flow Rate
On-Line System
DepartmentDepartment of Chemistry
Supervisors PROF. Israel Schechter
PROF. Stuart Licht


Sampling and in situ measurement of hazardous chemical species in ambient air are important components of modern analytical environmental chemistry. Our objective was to promote an on-line method for monitoring trace contaminants in air.

The methods for ambient detection of airborne traces of heavy metals and polycyclic aromatic hydrocarbons (PAHs) were developed, in which the hydrodynamic approach to sampling and pre-concentration stages was combined with highly sensitive detection schemes. In the case of metallic traces, Square Wave Anodic Stripping Voltammetry (SW ASV) detection was applied. The pre-concentrated PAHs were detected using Multi-Photon Ionization Fast Conductivity (MPI-FC) detection facility and fluorimetric measurements. A straightforward mathematical treatment was shown to reliably assist in modeling and optimizing the performance of the system.  The approach was successfully tested with environmental samples.

A continuous sampler, utilizing liquid for both aerosol accumulation and entrapment, is a promising tool for direct on-line monitoring of heavy metals and PAHs traces. However, wet sampling based analysis cannot provide information about the original aerosol, i.e. size distribution and particle shape. This information was achieved by means of a polymer film sensor (PFS). The analysis was based on direct fluorescence and Fourier Transform Spectral Imaging Microscopy (FT SIM) measurements of PAH aerosol and vapor entrapped by a polymeric film. The capabilities of PFS for detection of both mono-component and simple PAH mixtures were studied.

The proposed method provides morphological information about the PAH aerosol, quantification of air contamination by PAH (both gaseous and particulate matter) and allows for direct on-site analysis of fluorescent organic pollutants.