LABORATORY ACCREDITATION FOR THE AFPC

1. Submit a written plan to the AFPC Check Sample & Accreditation Committee (See Elements of a Quality Assurance Manual) for the parameters to be under the QA Plan for your laboratory. Example: Nitrogen and Available Phosphates may be the only analyses requested for Laboratory Accreditation.
2. The Laboratory must participate in a check sample program such as AFPC Fertilizer Check Sample, AFPC Phosphate Rock Check Program or Magruder Check Sample Check Program for at least one year.

a. Results from the Check Program must meet the following requirements:

1. 11/12 Check Samples must be within two (2) standard deviations for the parameters requested in your accreditation for each check sample.
2. Previous data from 1984-1993 listed:

NOTE: The above data was complied for the years 1984-1993. New data complied between 1994 and 1999 shows an improvement in the standard deviation for P2O5 from 0.22% to 0.19% and for nitrogen from 0.12% to 0.11% by members of the Association of Florida Phosphate Chemists. The standard deviation for P2O5 for all participants in the Check Sample was 0.33% and the standard deviation for nitrogen for all participants was 0.14%. Standard deviations for GTSP results are higher than DAP and MAP. Current data standard deviations have detoriated for phosphate and potash in all check sample programs including both the AFPC Fertilizer and Magruder Check Samples on high concentrate samples such as DAP and MAP. Typical one standard deviations currently is 0.50% from the 0.33% previously.

3. An on site inspection by the Committee to verify equipment, procedures and elements in the QA Plan will be conducted.