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 one month 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)
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Soil Characteristics
Determinand group
- Soil characteristics (Particle size distribution, pH, inorganic and organic C, conductivity)
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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
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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)
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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)
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Others and Experimental
Determinand group
- Other determinations (Moisture content, CN detn, stable isotope ratios, additional extractions)
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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.