| method | Pore water is sampled directly from sediment using rhizon soil moisture samplers (artificial root). The sampler is connected to a standard syringe using luer-lock fittings and PVC tubing. Evacuating the syringe by drawing the piston is sufficient to withdraw filtered porewater from marine sediments. |
| setup | 
|
| sampling rate | approx. 2 mL / 20 min for a 50 mm length sampler in marine sediment with the setup as above. Samlple flow rate may be enhanced by using greater filter length and better vacuum. |
| pore size | 0.1 µm mean (0.2 µm max.) |
| filter dimensions | diameter 2.5 mm x 50 mm length, other sizes and materials available |
| filter material | microporous tube (0.1 µm pore width) supported by a glassfiberepoxy (SS316), nylon or stainless steel wire. (titanium wire on special request) |
| dead volume | less than 0.5 mL |
| advantages | direct
pore water sampling. no extra filtering needed since the sampler has a 0.1µm pore width. no wet sediment has to be sampled and squeezed or centrifuged. only a small hole in the sediment is left after sampling. pore water sampling is even possible through liner caps or through liner wall of closed cores by drilling a 2.5mm hole and pushing the Rhizon sampler in. |
| 50 mm Rhizon sampler connected to standard 2 mL syringe |  |
| pore water yield (approx. 0.5 mL) after 5 minutes. Vacuum is kept by distance piece attached to syringe piston |  |
pore water sampling from closed plastic liner with water saturated marine sediment by drilling 3.8mm holes and gently inserting rhizon pore water samplers. sampling with needles and 10 mL plain vacuum tubes (right) or F-F luer adapter (blue) and standard syringe that holds vacuum by keeping plunger in place with wooden spacer |
|
| pore
water sampling from the open core (gravity corer) 5 cm Rhizon CSS with female luer adapter connected to a 10 mL disposable syringe. The vacuum is kept by a wooden spacer that holds the plunger |
 |
| tipps | For
the application above we use a special flat tip version of the Rhizones(
Rhizon CSS - Core Solution
Sampler), where tip diameter = porous tubing diamter, so the
contact between sediment and sampler is very smooth in soft sediments.
If sediment is stiff a hole has to be prepared before insertion
in order to protect the microporous tube from breaking (i.e. knitting
needle of appropiate diameter).
For all Rhizons
add "F" to the order number if you want a female luer
connector (for directly connecting syringe) instead of the standard
male connector
(for connecting needle and vacutube |
| manufacturer | Frits
Meijboom |
| also available from | Eijkelkamp Agriresearch (www.eijkelkamp.com) |
| references | F.W.Meijboom
and M.van Nordwijk (1992): Rhizon Soil Solution Samplers
as artificial roots. In: L. Kutschera et. al (Eds.): Root Ecology
and its practical Application.- Proc 3rd ISSR Symp., 2.-6. Sep 1991,
Wien Austria; pp 793-795. |
