TY - JOUR
T1 - Contrast agents for soil investigation with X-ray computed tomography
AU - Van Loo, Denis
AU - Bouckaert, Liesbeth
AU - Leroux, Olivier
AU - Pauwels, Elin
AU - Dierick, Manuel
AU - Van Hoorebeke, Luc
AU - Cnudde, Veerle
AU - De Neve, Stefaan
AU - Sleutel, Steven
PY - 2014/1/1
Y1 - 2014/1/1
N2 - The majority of microbial mediated soil processes depend on availability of organic matter (OM), water and air. Because of its ability to visualize the 3D architecture of soil non-destructively, X-ray computed tomography (CT) is becoming a widespread tool for studying soil pore network structure. However, phase determination of pore space, soil OM, soil mineral matter (MM) and water is often limited even with the latest technological and software advances, allowing high resolution and better quality imaging. Contrast agents commonly used in histology enable enhancement of X-ray attenuation of targeted structures or compounds. Here we report on the first systematic investigation of the use of such X-ray contrast agents for soil research. An evaluation procedure as well as a method to apply the agents to soil samples was developed and applied on reference soil samples. The effectiveness and selectivity of the contrast agents was evaluated for soil organic matter (SOM), MM and water. Several products were found to selectively increase the attenuation of water or SOM. The four agents with the best OM-staining capabilities (phosphomolybdenic acid (PMA), silver nitrate, lead nitrate and lead acetate) were further tested on an OM-MM mixture and all showed an increased of the SOM attenuation coefficient above the MM values.
AB - The majority of microbial mediated soil processes depend on availability of organic matter (OM), water and air. Because of its ability to visualize the 3D architecture of soil non-destructively, X-ray computed tomography (CT) is becoming a widespread tool for studying soil pore network structure. However, phase determination of pore space, soil OM, soil mineral matter (MM) and water is often limited even with the latest technological and software advances, allowing high resolution and better quality imaging. Contrast agents commonly used in histology enable enhancement of X-ray attenuation of targeted structures or compounds. Here we report on the first systematic investigation of the use of such X-ray contrast agents for soil research. An evaluation procedure as well as a method to apply the agents to soil samples was developed and applied on reference soil samples. The effectiveness and selectivity of the contrast agents was evaluated for soil organic matter (SOM), MM and water. Several products were found to selectively increase the attenuation of water or SOM. The four agents with the best OM-staining capabilities (phosphomolybdenic acid (PMA), silver nitrate, lead nitrate and lead acetate) were further tested on an OM-MM mixture and all showed an increased of the SOM attenuation coefficient above the MM values.
KW - Soil organic matter
KW - Staining
KW - X-ray computed tomography
UR - http://www.scopus.com/inward/record.url?scp=84884723500&partnerID=8YFLogxK
U2 - 10.1016/j.geoderma.2013.08.036
DO - 10.1016/j.geoderma.2013.08.036
M3 - Article
AN - SCOPUS:84884723500
SN - 0016-7061
VL - 213
SP - 485
EP - 491
JO - Geoderma
JF - Geoderma
ER -