ANYL 135 |
| The exact determination of the Ti/Zr ratio in soils is very important for the reliable study of the uniformity of parent geological material between soil horizons which is the basis for evaluating any change of soil properties during pedogenesis or caused by soil mangagement. Additionally, the identification of lithologic discontinuities or differences in parent materials is a prerequisite for distinguishing soil properties of pedological origin from those of geological origin. When uniformity of parent material of a profile is established, changes in chemical, physical and mineralogical properties of soils along profiles can be attributed to pedogenic processes, and quantitative pedological studies on soils may be conducted. Comparing the ratios of the concentration of two resistant minerals between horizons is the most common method of assessing the uniformity of parent material. If elements are present exclusively in certain resistant minerals, such as Ti in rutile and Zr in zircon, the ratios of the elemental concentrations can also be used for identifying lithological breaks. For exact determination of the Ti/Zr ratio, both elements must be recovered quantitatively from the soil matrix which is difficult, in particular for Zr. Sample digestion can be carried out by fusion with either Na2B4O7, Na2CO3 or (NH4)2SO4. However, large amounts of reagents are needed and the system is prone to contamination. Additionally, due to the high salt content of the fusion solution, determination of Ti and Zr by ICP spectrometry is severely hampered. X-ray fluorescence, which can be used alternatively, suffers from matrix interferences and a lower sensitivity compared to ICP spectrometry. We will present a method that allows both the fast and reliable determination of Ti and Zr in soil samples based on high-pressure microwave-assisted digestion and element-specific detection by ICP-OES down to 0.5 mg/kg for both Ti and Zr, respectively. |
|
General Posters
7:00 PM-9:00 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Analytical Chemistry |