Overview
ISO 664:2008 - "Oilseeds - Reduction of laboratory sample to test sample" specifies the standardized procedure for obtaining a representative test sample from a laboratory sample of oilseeds. The standard ensures uniform, traceable sample preparation for subsequent analyses (e.g., oil content, moisture, impurities, acidity, NMR). It covers handling on receipt, separation of large impurities, homogenization, division to a prescribed minimum mass, sealing and storage of the test sample.
Key topics and requirements
- Scope and purpose: Defines how to reduce a laboratory sample to a test sample representative of the original lot for analytical testing.
- Initial handling: Check seals and container condition on receipt; store samples away from heat and extreme humidity until preparation.
- Separation of impurities: Remove large impurities (those that cannot be mixed uniformly) before homogenization. Note: some contracts require analysis of the sample including impurities, or of the cleaned seed.
- Homogenization and division: Mix remaining seed to uniformity, then divide using an appropriate dividing apparatus (e.g., quartering apparatus, conical divider, multiple‑slot divider) until the minimum mass specified in the standard is obtained.
- Minimum test sample masses: Table 1 gives minimum masses by seed size/category and type of analysis. Minimum masses range from small‑seed analyses (around 20 g) to larger requirements (up to 1 000 g) depending on the seed species and test.
- Packaging and storage: Place test sample in a dry, clean, hermetically closable container, label and store securely away from heat and humidity. Perform analyses within intervals compatible with sample stability.
- Referenced methods: ISO 658 is cited for determination of content of impurities and for procedures when analysis of purified seed is required.
Applications and users
Who uses ISO 664:2008:
- Analytical laboratories performing seed and oilseed testing (quality, composition, contaminants).
- Trade and commodity inspection bodies ensuring contractual compliance for oilseed shipments.
- Seed testing organizations and regulatory authorities responsible for certification and official testing.
- Food processing and oil extraction companies that require reliable test sampling for quality control and specification compliance.
Practical benefits:
- Produces representative, reproducible test samples for accurate test results.
- Reduces sampling bias and legal disputes in trade by standardizing sample reduction.
- Supports consistent workflow for lab sample preparation and chain of custody.
Related standards
- ISO 658 - Oilseeds - Determination of content of impurities (normative reference).
- ISO 5507 - Nomenclature for oilseeds, vegetable oils and fats (referenced for species names).
- ISTA nomenclature lists (used for stabilized plant names).
Keywords: ISO 664:2008, oilseeds sample reduction, test sample preparation, seed testing, dividing apparatus, sample homogenization, laboratory sample handling.
