Test Overview
A Purity Analysis determines the composition of a seed lot by separating a representative portion of the sample into:
- Pure Seed
- Other Crop Seed
- Weed Seed
- Inert Matter
Results are reported as the percentage by weight of each component and may be used to provide purity information required for seed labeling.
Test Details
The submitted sample is thoroughly mixed and divided to obtain a representative working sample for analysis.
The weight of the working sample is specified by the AOSA Rules for Testing Seeds and is based on approximately 2,500 seeds of the species being tested. The working sample is separated into Pure Seed, Other Crop Seed, Weed Seed, and Inert Matter, and each component is weighed to determine its percentage of the sample.
Sample Requirements
Minimum submitted sample size varies by species. The submitted sample must be larger than the working sample used for the Purity Analysis so that a representative portion can be obtained for testing.
See How Much Seed Should I Send? for minimum sample-size guidance.