WORKING PARTY ON HARMONIZATION OF QUALITY ASSURANCE
Title: Assessment of uncertainty associated with soil sampling
in agricultural, semi-natural, urban and contaminated environments (SOILSAMP)
Remarks: Coordinated by the Italian National Environmental Protection
Agency (Agenzia Nazionale per la Protezione dell'Ambiente, ANPA)
Completion Date: 2005 - Project completed
The main objective of the project is to establish quantification
of uncertainty components connected to the most widely used methodologies
for soil sampling in agricultural, semi-natural, urban and contaminated
A lot of effort has been invested in recent years by various international
organizations and bodies in the harmonization and preparation of guidance
documents on proper quantification of uncertainty in chemical measurements.
All these was/is done with the aim to achieve better international comparability
between results produced by testing or calibration laboratories.
However, the uncertainty associated with field sampling is normally
left out from the uncertainty quantification process and has not been
satisfactorily covered yet in any of the existing guidance documents.
The SOILSAMP project is to fill this gap in the field of soil analysis.
The validation of the different sampling procedures will be performed
with a collaborative approach. All the participants will contribute
directly to the elaboration of the technical reports, evaluating the
work outcomes and discussing the technical doucments needed.
A first meeting of the Expert Advisory Group took place in Udine, Italy
between Dec. 18 and 19, 2000. 22 participants from 5 countries and 3
international organizations attended the meeting.
The meeting objectives were:
- Presentation and selection of the test areas with reference to agricultural
soils and semi-natural soils for the intercomparison.
- Characterization of the reference sampling.
- Definition and quantification of the uncertainty in reference sampling
(identification of uncertainty sources).
- Uncertainty acceptable for reference sampling (acceptance criteria).
- Selection of the sampling strategy for the reference sampling.
- Selection of sampling techniques (devices) for agricultural and
- Definition of elements to be considered for sampling procedures/protocols.
- Discussion of the nomenclature (terminology) to be used in the project.
- To define further steps in the project.
The following soil parameters and their uncertainties will be investigated:
texture (stones and gravel), sand, silt, clay, pH, carbonate, organic
carbon, total nitrogen, available P, K, Ca, Mg, Fe, Mn, Cd, Cr, Hg,
Ni, Cu and Zn. Instrumental neutron activation analysis (INAA), a non-destructive
technique with a low matrix effect for most of the analytes, was selected
as a method of choice for actual trace element determinations.
It is worth mentioning that soil as a matrix is only one example where
the gap on uncertainty assessment in sampling exists. Taking into account
a large number of sample/analyte combinations, e.g. soil/trace elements,
soil/radionuclides, soil/organic contaminants, etc., there is still
a lot of research opportunities and room for improvement.
All documents, transparencies and other material used during the meeting
are available upon request. Meetings of the Expert Advisory Groups are
planned to take place twice per year.
A second meeting was organised by the Environmental Protection Agency,
Rome, Italy between June 11 and 12, 2002. 17 participants from five
countries and three international organisations attended the meeting.
The main purpose of this meeting was to review the present status of
the project, to evaluate results obtained so far, and to select a new
sampling site for the intercomparison exercise in contaminated environment.
The experimental activities carried out from July 2001 to July 2002
All results were extensively discussed and it was confirmed that the
agricultural site selected (Pozzuolo del Friuli) is suitable as a reference
site for testing the soil sampling equipment. From the technical point
of view, the first phase of the project is now concluded.
Beside technical findings, one additional result of this project is
a compilation of existing and some new terms related to soil sampling
and associated uncertainty. It is planned to publish this compilation
as IUPAC recommendations within the next half of the year. Although
the assessment of uncertainty associated with the soil sampling in agricultural
areas represents only a part of the complete project, the results obtained
are extensive and very informative. For this reason it was concluded
to publish a report on this part as a separate document. It will be
published in Italian and English language.
The second part of the project will now start with the assessment of
sampling uncertainty in contaminated areas. For this purpose a highly
contaminated site was selected in Scarlino (Grosseto, Italy.) Next meeting
of the Expert Advisory Group is planned for the first quarter 2003.
July 2003 - A draft is submitted to public
review for comment until 30 November 2003
> see provisional
> Nov 2004 report update (pdf
file - 12KB)
Project completed - IUPAC Recommendations published in Pure
77(5), 827-841, 2005
Last update: 9 May 2005