Development of preparation methods for carbon13/carbon12 analysis of soil and plant samples using optical breath test analyzers

Until recently, the only reliable way of doing (12)C-(13)C analysis was using a mass spectrometer. For many developing countries, the high initial cost and running costs of a mass spectrometer precluded the purchase of such an instrument. Recent developments in optical systems have provided a robust, low-cost option for undertaking (13)C analysis. Although these machines were initially developed for breath testing for Helicobacter pylori, they have an enormous potential as a research tool for soil science. The relatively low cost of the equipment at US$15,000-25,000 is within the research budgets of most institutes or universities. The simplicity of the mechanisms and optical nature mean that the equipment requires relatively low maintenance and minimal training. (13)C may be used to study numerous areas including: organic matter turnover, shifts in delta (13)C from C4 to C3 vegetation, organic matter residence times, determination of sources of stable organic matter, delta (13)C differences in drought and salt tolerant isolines, root turnover, soil respiration, the breakdown of different pesticides in the soil, soil respiration as an indicator of soil quality and mineralization. The data presented will describe the preparation methods of soil and plant materials for analysis using the breath test analyzer. These will include testing the system at natural abundance level and for enriched samples.