Keys to Improved PT results on Waste Water Microbiology Samples Waters Corporation 1

Transcription

1 Keys to Improved PT results on Waste Water Microbiology Samples 2013 Waters Corporation 1

2 Moderator: Tanya Rahn Account Representative ERA A Waters Company Presenter: Mike Blades Product Line Manager Organics, Radiochemistry Microbiology ERA A Waters Company 2013 Waters Corporation 2

3 About ERA Founded in 1977 Golden, Colorado More than 7,000 laboratories More than 80 countries 2013 Waters Corporation 3

4 About ERA Matrices: Waste water Drinking water Soils Air & emissions Microbiology Radiochemistry Custom standards 2013 Waters Corporation 4

5 Definitions Proficiency Testing Certified Reference Material 2013 Waters Corporation 5

6 Mike Blades Product Line Manager Organics, Radiochemistry and Microbiology ERA A Waters Company 2013 Waters Corporation 6

7 Agenda NELAC Criteria Calculating PT Limits using NELAC Criteria Sample Design and Intended Use Keys to Improved Results Questions 2013 Waters Corporation 7

8 NELAC Criteria NELAC Defines Target Analytes, Manufacturing Range, Acceptance Criteria and PTRLs Microbiology CFU/100 ml CFU/100 ml Total Coliform, MF 8 20 to 2400 Log transform; ±3 SD Fecal Coliform, MF 8 20 to 2400 Log transform; ±3 SD E.coli, MF 8 20 to 2400 Log transform; ±3 SD Enterococci, MF 8 20 to 1000 Log transform; ±3 SD 2 MPN/100 ml MPN/100 ml Total Coliform, MPN 9 20 to 2400 Log transform; ±3 SD Fecal Coliform, MPN 9 20 to 2400 Log transform; ±3 SD E.coli, MPN 9 20 to 2400 Log transform; ±3 SD Enterococci, MPN 9 20 to 1000 Log transform; ±3 SD 2 *NELAC PT for Accreditation :: Fields of Proficiency Testing (FoPT) Non-Potable Water (NPW) 2013 Waters Corporation 8

9 Frequency Calculating Limits Log Transform mean±3sd Each of the 8 analytes are evaluated individually as separate data sets for each study. Data reported by participants is first Log Transformed. Mean and standard deviation is then calculated. Results are evaluated and then reported as the whole number WP109 Fecal MF Frequency Curve Data Measured Value (CFU/100 ml) Non-Log Data Log Transform Data 2013 Waters Corporation 9

10 Sample Design and Intended Use ERA Certified Reference Material and Proficiency Testing Samples are delivered as Lyophilized pellets in Glass vial. Phosphate buffered rehydration fluid is provided for each sample. Manufactured to have Assigned values in range of CFU/100mL and MPN/100 ml Shipped at ambient temperature by 2 nd day service. Lyophilized pellets stored at 4±2ºC upon receipt. Store Phosphate buffer at room temperature. Expiration date is 3 years from manufacture date. This product is intended to be used as a proficiency test sample or quality control check of the entire analytical process for the analytes/matrix included in the standard Waters Corporation 10

11 Keys to Improved Results General Quality Control Sterility Checks o Does the procedure produce clean results Positive Controls o Does the procedure produce expected positive reaction Negative Controls o Does the procedure produce expected negative reaction Method Evaluation/Validation o Does the procedure produce expected quantitative result Hydration of Pellet o Do not deviate from instructions Culture Media o Quality of culture media is critical Dilution and Rinse water o ph conditions are critical Thermometers o Temperature is critical 2013 Waters Corporation 11

12 Key to Improved Results Method Specific Issues Membrane Filtration Methods Membrane Filtration Results o TNTC can not be evaluated Proper Dilution Schemes o It s a wide range Filter Paper o Not all filters are created equal Media Broth for Broth and Pad o How much media does your pad hold? Application of Filter o Make sure every organism gets media 2013 Waters Corporation 12

13 Keys to Improved Results Method Specific Issues Multiple Tube Fermentation Methods Multiple Fermentation Results o value will be evaluated as that value Dilution scheme o Covering the manufacturing range Degassing Broth o Avoid false positive Broth concentration o Use the appropriate media strength 2013 Waters Corporation 13

14 Keys to Improved Results Method Specific Issues Enzyme Substrate Multi-Well Methods Results Interpretation o Is it really an 18 or 24 hour test? Quanti-Tray (51 well) o Are you covering the range? Quanti-Tray 2000 (97 well) o The range is covered Comparators o If available use them Quanti-Tray Fecal Addendum o Temperature sensitive 2013 Waters Corporation 14

15 Contact ERA :00 am 6:00 pm Mon-Thu (MT) 6:00 am 5:00 pm Fri (MT) Waters Corporation 15