Presentation is loading. Please wait.

Presentation is loading. Please wait.

NEW YORK STATE DEPT. OF HEALTH WADSWORTH CENTER ENVIRONMENTAL LABORATORY APPROVAL PROGRAM PROFICIENCY TESTING.

Similar presentations


Presentation on theme: "NEW YORK STATE DEPT. OF HEALTH WADSWORTH CENTER ENVIRONMENTAL LABORATORY APPROVAL PROGRAM PROFICIENCY TESTING."— Presentation transcript:

1

2 NEW YORK STATE DEPT. OF HEALTH WADSWORTH CENTER ENVIRONMENTAL LABORATORY APPROVAL PROGRAM PROFICIENCY TESTING

3 HISTORY 1985 NYS ELAP established, with PT as an integral part Program expanded to include full-volume solid waste samples Current Status All analytes offered for accreditation by NY ELAP are proficiency tested if they are on the NELAC PT FOT list (except CN in SW) Restricted to Potable and Non-Potable Water. All WS and WP analytes tested + many more

4 ANALYTES OFFERED TWICE YEARLY POTABLE WATER: 137 (Asbestos by TEM is available to laboratories that are not NY ELAP accredited) NON-POTABLE WATER: 173 WATER BACTERIOLOGY: 4 AIR: 4

5 STATISTICAL TECHNIQUES FOR SAMPLE VERIFICATION 1. Verification of Prepared Value 5 samples for each parameter are analyzed in duplicate Mean and standard deviation calculated Prepared value verified if mean and standard deviation are within prescribed limits [NIST Handbook , June 1999, (h)(5)]

6 STATISTICAL TECHNIQUES FOR SAMPLE VERIFICATION 2. Verification of Homogeneity 1 sample is collected at the beginning, ¼, ½, ¾, and finish of each prep. run Each sample is analyzed in duplicate One-tailed ANOVA applied: between sample set and within sample variances are compared [NELAC Chapter 2, B.3.2]

7 STATISTICAL TECHNIQUES FOR SAMPLE VERIFICATION 3. Verification of Stability After the close of the study, 5 samples for each parameter are analyzed Stability verified if mean is within prescribed limits of pre-distribution prepared value [NELAC Chapter 2, B.5]

8 STATISTICAL TREATMENT OF PT DATA All scoring conforms with NELAC requirements: Regression equations Fixed acceptance limits Statistical evaluation of study data

9 REPORTING Report forms contain the following information: Matrix Analyte Name Concentration Units Sample id Method Result Mean/Target Warning Limits (+/- 2 sd) Acceptance Limits Score (Satisfactory or Unsatisfactory) X labs passed out of Y reported results

10 ADDITIONAL INFORMATION AVAILABLE TO ALL LABS AND ACCREDITING AUTHORITIES Summary data: Matrix Analyte Name Concentration Units Sample id Target Reported limits Robust Mean Standard Deviation Median Number of labs passing/ Number of labs failing Histogram of no. of labs vs. result reported


Download ppt "NEW YORK STATE DEPT. OF HEALTH WADSWORTH CENTER ENVIRONMENTAL LABORATORY APPROVAL PROGRAM PROFICIENCY TESTING."

Similar presentations


Ads by Google