Van Walt Ltd - Monitoring Your Needs 1 Soil Sampling Coring equipment to sample soil on volatiles Traditional method: –Closed stainless steel tubes with filler blocks that avoid head space and evaporation for soil with volatiles located deeper than 0.5m –Additionally sample tube is wrapped in aluminium foil and cooled –Preferably horizontal transportation, to avoid higher concentrations at one side of the tube

Van Walt Ltd - Monitoring Your Needs 2 Soil Sampling Methanol or sodiumthiosulphate method –Details can be found in US- EPA 5035A-2002 (both methods) or applicable ISO standards as ISO and ISO18512 –Decontaminate the corer

Van Walt Ltd - Monitoring Your Needs 3 Soil Sampling –Push or hammer the soil corer into the larger sample. –Overfill the corer –Push a second time if the soil is very sticky (like here in Haslemere)

Van Walt Ltd - Monitoring Your Needs 4 Soil Sampling –Use plunger to push the 16ml of soil in the jar with 25 grams methanol or sodiumthiosulphate. To allow the lab to express the concentrations found as based on dry weight a black capped coring ring should be sent with the methanol stored samples –Or wrap chemical analysis sticker around capped sample and store sample in a cool location or freeze. - Extraction is done in the laboratory

Van Walt Ltd - Monitoring Your Needs 5 Soil Sampling –In the laboratory the methanol or sodiumthiosulphate will be analysed for volatiles. –A criticism: there are much better extraction liquids for volatiles. Use the “freeze method” –Be aware of safety risks: Methanol is highly flammable and toxic for humans. Chemicals in the field !?