1. Noxious Gases Ref Peaks: An Alternative to Dual Inlet Bellows Paul Eby

2. Normal Conflo Ref Gas GC / EA Ref Gas He IRMS - Ref Gas is always flowing (0.2mL/min) - Not okay for noxious gases - CO, CH 3 Cl, SO 2 - Small quantities / expensive gases

3. Using the Bellows GC / EA - Consumption is very low (0.02 to 0.002mL/min) - Continuously flows - Noxious gas exits with the pump exhaust IRMS REF SAMPLE - Requires dual inlet

4. 37 Cl Measurements 1.Precipitate chloride out as AgCl by adding AgNO 3 2.Convert AgCl to CH 3 Cl gas by reacting with CH 3 I 3.Run by GC-IRMS 4.Measured as CH 3 Cl Problems Requires an extra cup to measure masses 50 and 52 Bellows needed for toxic CH 3 Cl (also expensive) $ $ $ $

5. Thermo Conflo IV Allows for 5 different reference gases, 2 at a time

6. Thermo Conflo IV Ref A Ref B Ref C IRMS Can we leave the ref gas off until a peak is needed? Does the gas need to reach a steady state by constantly flowing? How long does it take to reach a steady state? Can I test this before upgrading the IRMS?

7. Thermo Conflo IV in Isodat Extra columns added to the method using Configurator

8. Carbon Dioxide On/Off Test ave = -0.03 stdev = 0.02 ave = -0.01 stdev = 0.04

9. Carbon Dioxide On/Off Test

10. Methyl Chloride Trials 1.Upgrade the detectors 2.Add ventilation to the Conflo IV 3.Pump exhaust vented 4.Small bomb of CH 3 Cl

11. Methyl Chloride On/Off Test ave = 0.01 stdev = 0.01 ave = -0.02 stdev = 0.02

12. Methyl Chloride On/Off Test

14. Conclusions 1.ConFlo IV can be used to limit consumption of ref gas 2.Comparing to Bellows: Flow rate in Conflo IV 0.2mL/min Flow rate in bellows 0.02 - 0.002mL/min?