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Effects of Aging on Surface Inertness and Analyte Recoveries in SUMMA Passivated and Fused Silica Lined Canisters

Effects of Aging on Surface Inertness and Analyte Recoveries in SUMMA Passivated and Fused Silica Lined Canisters. Test Canisters from 4 Manufacturers for the Relative Aging Effects of Repeated Sampling on TO14 Standard Recoveries Repeat Test After Exposure to 1% Ozone for 8 hours

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Effects of Aging on Surface Inertness and Analyte Recoveries in SUMMA Passivated and Fused Silica Lined Canisters

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  1. Effects of Aging on Surface Inertness and Analyte Recoveries in SUMMA Passivated and Fused Silica Lined Canisters

  2. Test Canisters from 4 Manufacturers for the Relative Aging Effects of Repeated Sampling on TO14 Standard Recoveries Repeat Test After Exposure to 1% Ozone for 8 hours Test Aged Canisters using a Spectra Gas TO15 Mixture Objectives

  3. Canisters in Study • 4 Manufactures - 2 SUMMA, 2 Fused Silica Lined • 2 Cans from Each Manufacturer • SUMMA cans labeled S1 - S4 • Fused Silica Lined Canisters Labeled FS1-FS4

  4. Silonite Coated 6L Canisters

  5. Improves Recovery of Reactive Compounds Increases Range of Compounds Amenable to Canister Sampling and Analysis Compounds Containing: Sulfur Nitrogen Oxygen SiloniteTM Coating of Canisters

  6. 40 Day Formaldehyde Stability in Silonite Coated MiniCan Analysis of Cylinder - 9 December 1999 2.52 ppm 2.65 ppm 2.54 ppm Analysis of Mini Canister #1086 - 10 December 1999 2.56 ppm 2.44 ppm Analysis of Mini Canister #1087 - 10 December 1999 2.57 ppm 2.56 ppm Let time pass.... Analysis of Mini Canister #1086 - 20 January 2000 2.46 ppm 2.53 ppm Analysis of Mini Canister #1087 - 20 January 2000 2.37 ppm 2.47 ppm Data Courtesy of Dr. Daniel Riemer, NCAR

  7. 10 PPB TO14 Std 1-Day TO14 Stability Test @ 10PPB 5 PSIG Holding Time - 1 Day New Silonite Canister Used SUMMA Canister

  8. Clean up Test Blank Test After 100 PPB TO14 Exposure New Silonite Canister Used SUMMA Canister

  9. Canister Study • Test all Canisters at the Beginning of Study • Fill Canister with 10 PPB TO14 Mix • Equilibrate 1 Day and Analyze • Clean All 8 Canisters Together (3 cycles at 100 C) • Fill Canisters with Ambient Air using Glass Filtered Grab Sampler • Wait 1 Day, then Repeat Cleaning • Perform Operation 30 Times

  10. 8 Canister Cleaning System

  11. Glass Filtered Grab Sampling

  12. Standard Introduction and Analysis

  13. 7100 3-Stage Preconcentrator • Automates the GC analysis of gas phase samples • Complete heating of sample flow path. Easily accessed for trap and tubing replacement • Multiple trapping stages allow matrix to be eliminated before GC injection 7100 Preconcentrator

  14. 7100 Preconcentration and Matrix Management MFC PUMP 3-Stage Preconcentration N2, O2 H20, CO2 Helium Carrier Helium To GC Focuser Glass Beads Tenax Sample Headspace Internal Standard Calibration Standard Sample Cryogen in

  15. Fast Injection and Proper Water Management Minimizes Tailing of Polar Compounds Column: HP1, 60m, 0.32mm ID, 1um film. Flow rate: 1.5 ccm Carrier: He

  16. New SILONITE Coated Canister Before Study Concentration - 10 PPB Pressure - 10 PSIG Volume - 400 CC Water Management - Microscale Purge and Trap Instrumentation 7100/5973 Column - DB1 Starting Temperature - 35 deg. C Scan - 30-185, 6 min, then 34-270 amu

  17. 10 PPB/10 PSIG TO14 , 1 Day Stability - SUMMAs S1 S3

  18. 10 PPB/10 PSIG TO14 , 1 Day Stability - FSL Cans FS 1 FS 3

  19. 10 PPB/-4 PSIG TO14 , 1 Day Stability - SUMMAs S1 S3

  20. 10 PPB/-4 PSIG TO14 , 1 Day Stability - FSL Cans FS 3 FS 1

  21. 10 PPB/-4 PSIG TO15 , 1 Day Stability - SUMMAs FS 1 FS 3

  22. 10 PPB/-4 PSIG TO14 , 1 Day Stability - FSL Cans FS 1 FS 3

  23. Possible Reasons for Poor Recoveries in Canisters • Coating or Surface Treatment was not Initially Inert • Welds have Active Surfaces • Contaminants have been Introduced • Particulates • Semi-Volatiles • Reaction Products • Dirt

  24. Pressurized Field Sampling • Causes Condensation of Water in transfer lines and Canisters • Water can Promote Polymerization Reactions • White Deposits Found in Bottom of Canisters which were Repeatedly Sampled to Positive Pressure in the Field • Not Required for Today’s Samplers / Analyzers

  25. Removing Heavy Contaminants from Canisters • Evacuate Canisters • Use Vacuum to Draw in 200 cc of DI Water • Heat to 60 deg. C for 8 Hours (or Overnight) • Pressurize Cans to 20 psig • Shake Canister Well, Invert, Blow out Water • Perform Normal Cycle Cleaning

  26. Both SUMMA and Fused Silica Lined Canisters Showed no Detectable Loss of Inertness after 30 Samplings of Ambient Air Although Individual Recoveries of TO15 Standard Varied, Both Canister Types Provided Good Recoveries of Spectra Gas TO15 Compounds Ozone Exposure did not Change Recoveries Canister Cleanliness is Extremely Important. Canisters Should be Checked Regularly for Analyte Recovery If Recoveries are Found to be Low, Enhanced Cleanup Techniques are Available to Remove Adsorbing / Absorbing Contaminants Conclusion

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