1. Manufacture, Homogeneity & Stability of PT samples SPEX CertiPrep/Protocol Analytical 203 Norcross Ave, Metuchen, NJ 08840 vsivakumar@SPEXCSP.Com

2. Studies Offered • Waste Water (WP) • Drinking Water (WS) • DMRQA Chem • DMRQA WET • Microbiology (WS) • Microbiology (WP)

3. Overview • Manufacture • Analysis • Assigned value • Homogeneity • Stability • Reporting

4. Sample Design • Follow EPA (NERL Ci0045) Criteria And NELAC Documents • Provide Labs Equal Challenge • Use Random Numbers to Select Concentrations within Range • Follow Historical Design Guidelines • Basis for Separation of Analytes • Stability • Spectral and chemical influences • Regression Equations from Historical Data • Rules for Number of Analytes Required to be Present

5. Manufacture • Raw materials from certified source • Analysis for impurities in the raw material • Assay for analyte content • Weigh out compound • Dissolve • Add matrix reagent • Dilute to volume • Flame seal in pre-cleaned glass ampules

6. Verification Analysis • Manufacture as per design • Verification Analysis • NIST RULE: • Quality Check: • Prepared Value is within + 1/3 of acceptance limit to a maximum of + 10% of the Prepared Value

7. Verification Analysis NELAC RULE: Mean of the verification analysis shall be within 1.5 standard deviation as calculated for Laboratory acceptance.

8. Method Repeatability NIST RULE: Method Repeatability expressed as standard deviation shall be within 1/6 acceptance limits as calculated for the laboratories ( to a maximum of 5% of the prepared value).

9. Method Repeatability • NELAC RULE • Repeatability limit is 0.5 sd

10. Homogeneity • Done prior to sample shipment • To establish all samples distributed to the laboratories have the same assigned value for every parameter to be evaluated. • Done on final packaged samples • Samples are selected randomly • Number of samples depend on the total number of ampules • Samples are picked from the beginning, middle and end of the packaging run

11. Homogeneity • Samples may be considered homogenous if • Sx < 0.25C When there is no apparent visual trend.

13. UNCERTAINTY Associated With Preparation • Purity Of Raw Material • Weighing • Make Up To Volume

14. Stability Absolute difference between the mean of the homogeneity verification value (X)and stability verification value should be |X – Y| < 0.2C or Stability value is within 1/3 acceptance limits given for the laboratories

15. Stability

16. Reports • Final assigned values • Study Statistics • Review of the Study for pass/fail rate • Study Summary • Study Discussion • Study data • Individual Laboratory Reports