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AS3000

Pre-treatment according to Dutch regulations
In environmental laboratories many solid samples are being analysed. Main examples are soil, building material and waste samples. Especially for soil samples it is often assumed that no special pre-treatment is necessary as the samples are assumed to be homogeneous enough.

Sample pre-treatment is an indispensable part of the whole analytical procedure for soil, waste and building material samples. A significant decrease in measurement uncertainty is achieved. The procedure has no effect on the mean concentration of the compounds.

The accredited procedure developed by ALcontrol is fast and efficient, making all express services still possible, providing the sample received can be taken into analysis. Indeed drying (at 40 ºC) and sieving over 2 mm are first required, at least an extra day is added to the whole procedure.

Pre-treatment procedure at ALcontrol
The pre-treatment procedure at ALcontrol is in conformity with Dutch regulations. For soil as well as for other solid materials the whole sample is taken. No sieving is carried out unless it is especially required for the concerning project. Only “artefacts” (particles not belonging to soil like glass, metallic parts) are taken out by hand picking. For organic semi volatile compounds the sample has to be ground under cryogenic conditions. For volatile compounds (volatile aromatic and halogenated compounds and Cyanide) sub-samples are directly taken without further pre-treatment.

ALcontrol has developed a grinding device with which the sample pre-treatment for organic and inorganic parameters can be combined in 1 step. The grinding is carried out under cryogenic conditions in order to avoid losses of especially organic compounds. An important characteristic of the procedure used by ALcontrol is that it can be carried out very fast. By that all usual express services (overnight, 24 hr) are still possible, which would not have been the case if samples would have been required to be dried before sample pre-treatment.