AIR PARTICULATE RESEARCH CAPABILITY AT THE NEW ZEALAND ION BEAM ANALYSIS FACILITY USING PIXE AND IBA TECHNIQUES

Abstract

PIXE and Ion Beam Analysis are one of the few techniques that can be used to identify the elemental composition of air particulates without destroying the filter sample. They are key tools for identifying the sources and determining the relative contribution of biogenic and anthropogenic sources of air particulate matter pollution in our environment. Over the last 8 years, specialised equipment has been designed and built at the New Zealand Ion Beam Analysis facility in Lower Hutt for semi automated analysis of air filters. The equipment and experimental techniques have been refined to improve sensitivities for many of the elements in the periodic table. At GNS, sensitivities have recently been further improved by using two X-ray detectors simultaneously with different amounts of X-ray filtering and collimation. The average limit of detection is improved from 66 ng/cm² (typical for a setup using a single detector) to 35 ng/cm² using two detectors simultaneously. The New Zealand Ion Beam Analysis facility now routinely analyses air particulate matter collected on filters from several locations around New Zealand. In this paper, results of air particulate studies from several locations in the Wellington region are presented.