FTIR aids understanding of soil organic matter

摘要

Soil chemistry aims to characterise the contents of soils to understand their ability to promote plant growth and to act as vectors for environmental contaminants. There has been a shift to the latter in recent years. Soil analysis is undertaken as a matter of routine when assessing construction sites for contamination, for agricultural soil management and improvement, and to study the effects of invasive plant and animal species on soil matter. The major component of soil is the inorganic mineral matter which comprises about 40-45% of its bulk; the remainder is air and water and a small fraction of soil organic matter (SOM). The organic component is a mixture of various living, dead, and decaying organic materials, along with a stable part known as humus . FTIR is one of several techniques, along with Raman and LIBS, which offers a rapid and multi-parameter measurement of soils to replace the slower (albeit direct) methods of digestion and titration. Though it is naturally suited to the study of organic matter, the mineral content of some soils also contributes to the signals found in the mid-infrared region, and careful subtractions are often required to ensure that the measured spectra are indicative of organic matter only. This is an ongoing area of research.