International Plant-analytical Exchange - IPE
Proficiency tests
Participation is open to all laboratories.
| Test programme | Plant |
| Number of rounds | 4 per year |
| Number of samples | 4 per round |
| Sample size | 20 g |
| Origin | Natural source |
| Exercise name | IPE |
General Information
- The sample types/matrices are chosen to represent the materials which you normally analyse.
- The plant samples are dried at max. 70°C and milled and sieved to <0.5 mm.
- The homogeneity of each batch of samples is tested on a selection of parameters.
- The dried plant samples are stored at -20°C and are stable over a number of years.
- 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.
- Your 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
- Inorganic Chemical Composition (Nutrients, major and trace elments)
- Real totals (Elements including silicates)
- Acid extractabel inorganic composition (so-called totals) (Elements excluding silicates)
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Nutricional values
Determinand group
- Nutricional values
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Other determinations
Determinand group
- Isotopes
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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.