I have soil columns containing isotope enriched gases (N2O, CO2) in the soil profile. This soil column is going to be wetted up, resulting in a moving water front containing dissolved gases. I want to take small discrete samples of the water from the wetting front without causing major disruption to it or the dissolved gases. This rules out suction sampling devices I think. One idea is to bury small, concave vessels in the soil column that should passively collect water and could be immediately siphoned off to exetainers. Any ideas would be greatly appreciated. Tim Clough. xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Dr Tim Clough, Research Scientist, Soil, Plant and Ecological Sciences Division, Soil and Physical Sciences Group, P O Box 84, Lincoln University, Canterbury, New Zealand. Phone: (64) (3) 325 2811 Fax: (64) (3) 325 3607