Speciation of Elements in the Environment by Laser Microprobe Mass Analysis (LAMMA)

Abstract

The laser microprobe mass analyser (LAMMA) is being used in our laboratory for the mass spectral identification of inorganic substances. Examples are given showing the characteristic ion species obtained for some of the authentic salts studied namely those of sodium nitrate, potassium chloride and sodium sujphate. The ions observed seem to be formed by decomposition of the parent molecules followed by ion-molecule interactions. The knowledge acquired from this study has been applied to the elucidation of the mass spectra of environmental samples. The examples given show that the speciation of elements in the environment by LAMMA is possible. However, at the present state of the art due to the irreproducibility of the laser energy and the inhomogeneity of the samples a quantitative approach is impossible.

Key Words:

• Mass spectrometry
• laser desorption
• air particulate matter
• speciation.