terrestic proficiency test of soil

International Soil-analytical Exchange Programme - ISE

Proficiency tests

Participation is open to all laboratories.


Test programme Soil
Number of rounds 4 per year
Number of samples 4 per round
Sample size 100 g
Origin Natural source
Exercise name ISE

General Information

  • The sample types/matrices are chosen to represent the materials which you normally analyse. There is no spiking or use of artificial samples.
  • The soil samples are dried at max. 40°C, milled and sieved to <0.5 mm.
  • The homogeneity of each batch of samples is tested on a selection of parameters.
  • The dried soil samples are stable over a number of years when stored at room temperature.
  • You analyze the test materials according to your normal validated methods and procedures for those elements and parameters you are interested in.
  • Your results are processed at WEPAL-QUASIMEME and published every three months under confidential code names.
  • The reports contain all data, statistical evaluation including Z-score plots and method information about the method used.
  • The reports are available within three weeks after the submission deadline.
  • New determinands can be added on request.

Determinands and analysis

Major and Trace Elements

Determinand group

  • Real totals (inorganic composition) (Major and trace elements)
  • Acid extractable (So-called totals) (Major and trace elements)
  • Aqua Regia (ISO 11466) (Major and trace elements)
  • Digestion with conc. HNO3 + conc. HCl + H2O2 (UNEP-UN/EC 91075A)
  • Mehlich-3 (Major and trace elements)

Click here for more detailed information about the determinands and the scope of accreditation.

Soil Characteristics

Determinand group

  • Soil characteristics (Particle size distribution, pH, inorganic and organic C, conductivity)

Click here for more detailed information about the determinand and the scope of accreditation.

Nutrients (several extractions)

Determinand group

  • Extraction with 0.01M CaCl2 1:10 (Available nutrients)
  • Extraction with 1M KCl 1:10 (w/v)
  • Extraction with 0.01M CaCl2 - 0.005M DTPA 1:10 (w/v) (Micro nutrients)
  • Phosphorus and related analysis

Click here for more detailed information about the determinands and the scope of accreditation.

Extractable determinands

Determinand group

  • Extraction with boiling 2M HNO3 (Available trace metals)
  • Extraction with 0.1M NaNO3 (Available trace metals)
  • Extraction with dilute nitric acid (0.43 Mol/l) ISO 17586
  • Extraction with 1M HCl (Polish standard)
  • Extraction with Ca-lactate (VDLUFA, Germany)
  • Fluoride (Swiss standard procedure)
  • UK Soil Methods
  • Water soluble 1:10 (w/v) (EN-12457-4)
  • Water soluble 1:10 (w/v) (Neth standard VPR C85-06)

Click here for more detailed information about the determinands and the scope of accreditation.

Exchangeable cations

Determinand group

  • Act. CEC using cobaltihexamine (AFNOR NFX 31 130)
  • Act. CEC using 0.01M BaCl2 (ISO 11260)
  • Act. CEC using 0.1M BaCl2 (UNEP-UN/EC 91065A)
  • Pot. CEC using 1M NH4-acetate at pH=7
  • Pot. CEC using 1M or 0.1M BaCl2-TEA at pH=8.1 (ISO 13536 OR BZE)
  • Pot. CEC using 1M NH4Cl (BZE)

Click here for more detailed information about the determinands and the scope of accreditation.

Others and Experimental

Determinand group

  • Other determinations (Moisture content, CN detn, stable isotope ratios, additional extractions)

Click here for more detailed information about the determinand and the scope of accreditation.

Webshop

Samples of previous proficiency tests are sold as reference materials. Available materials can be selected and ordered in our webshop. Participants of our proficiency tests are entitled to a discount.