1. Atmospheric Monitoring
New emissions of forbidden ozone-depleting CFC-11 detected?
Christian Heusser und Franziska Jud

2. General: Chlorofluorocarbons
CCl3F
CCl2F2
CF2Cl-CFCl2
CH3CCl3
CCl4
Known as
CFC-11
CFC-12
CFC-113
Methyl chloroform
Tetrachlorocarbon
Lifetime (years) 52
102 93 5 26
Atmospheric Annual Mean Mole Fractions 2012 (ppt)
235.5
527.5
73.6
5.2
84.2
MW / Da
136
120
186
132
152
Cooling agents in fridges
Blowing agents in polyurethane foams
Non-toxic
Ozone depletion in the stratosphere
Greenhouse Gases
L.J. Carpenter and S. Reimann, Ozone-Depleting Substances (ODSs) and Other Gases of Interest to the Montreal Protocol, Chapter 1 in Scientific Assessment of Ozone Depletion: 2014, Global Ozone Research and Monitoring Project – Report No. 55, World Meteorological Organization, Geneva, 2014, p
M. J. Molina and F. S. Rowland, Nature, 1974, 249, 810
Christian Heusser und Franziska Jud

3. Montreal Protocol Signed in 1987, ratified by 197 countries
Europe / Northern America: phase-out of CFC production by 1996 (Non-Article 5 countries)
Developing countries: phase-out delayed until 1999 (Article 5 countries)
Complete phase-out of CFC production by 2010
United Nations Environmental Programme, Handbook for the Montreal Protocol on Substances that Deplete the Ozone layer, 12th edition, 2018
Christian Heusser und Franziska Jud

4. CFC-11: global background concentration
source: last accessed:
Christian Heusser und Franziska Jud

5. CFC-11: new emissions since 2012?
2002 – 2012: steady decrease of atmospheric CFC-11 by -2.1±0.3 ppt/yr
2015 – 2017: decrease of atmospheric CFC- 11 slowed to -1.0±0.2 ppt/yr
Reported production of CFC-11 is close to zero since 2006
Red lines: Northern hemisphere
Blue lines: Southern hemisphere
Grey lines: projections based on World Meteorological Organization scenarios
Montzka et al., Nature, 2018, 557, 413
Christian Heusser und Franziska Jud

6. Advanced Global Atmospheric Gases Experiment (AGAGE)
10 primary measurement stations around the world, 3 affiliate stations
Prinn et al., Earth Syst. Sci. Data, 2018, 10, 985
Christian Heusser und Franziska Jud

7. GC-multidetector system
Alternating measurement of standard and unknown sample every 20 mins (36 unknown samples per day)
3 GC systems: 2 ECD systems and 1 FID
ECD A: CFC-12, N2O, carrier gas: Ar/CH4, sample loop volume 2 mL)
ECD B: CFC-11, CFC-113, CH3CCl3, CCl4 (carrier gas: Ar/CH4, sample loop volume 4.5 mL)
FID (CH4, carrier gas N2, sample loop volume 10 mL)
Prinn et al., J. Geophys. Res., 2000, 105 (D14), 17751
Christian Heusser und Franziska Jud

8. GC-ECD A radioactive β-emitter (63Ni) produces a constant current
Analyte molecules with a high electron affinity (e.g. halocarbons) capture electrons and reduce the constant current
Identification of different CFCs by GC retention time
L.S. Ettre and P. J. T Morris, LCGC North America, 2007, 25, 164
Christian Heusser und Franziska Jud

9. GC-MS
Alternating measurements of standard and unknown samples every 60 mins (12 unknown samples per day)
Sampling:
sample volume: 2L
Preconcentration in a cryotrap at -165°C
Separation and detection on a quadrupole GC-MS with EI ionization
Sensitivity: 0.01 ppt (theoretical LOD), 0.1 ppt (practical LOD) for 2L air sample
Sample volume needed to detect an amount of 1 ppt of CFC-11 above the baseline: 0.2 L needed for an LOD of 1 ppt, 0.6 L needed for quantification
Prinn et al., Earth Syst. Sci. Data, 2018, 10, 985
Prinn et al., J. Geophys. Res., 2000, 105 (D14), 17751
last accessed:
Christian Heusser und Franziska Jud

10. GC-multidetector system and GC-MS
GC-MD
GC-MS (Medusa)
Detection
Electron Capture Detector (ECD)
Flame Ionization Detector (FID)
EI-quadrupole-MS
Limit of detection
2.5 pg (GC-ECD)
1 pg (total ion current)
20 fg (single ion monitoring)
Sample volume (air)
2 mL – 10 mL
2 L
Median precision (1σ)
0.08 % (Barbados, 2017)
0.09 % (Ny Alesund, 2017)
Analytes
CFC-11, CFC-12, CFC-113, CH3CCl3, CCl4, N2O, CH4 (FID)
Over 40 trace gases
Measurement data for median precision: (last accessed: )
Prinn et al., Earth Syst. Sci. Data, 2018, 10, 985
Prinn et al., J. Geophys. Res., 2000, 105 (D14), 17751
S. Sousa and S. Bialkowski, Analytica Chimica Acta, 2001, 433, 181
Christian Heusser und Franziska Jud

11. Remote sensing Measurements based on limb sounding
Scan molecule specific IR emission lines
Good vertical, but poor horizontal resolution
Low concentrations measurable since atmospheric ray path is long
Fischer et al., Atmos. Chem. Phys., 8, 2151–2188, 2008.
Christian Heusser und Franziska Jud

12. CFC-11 and East Asia
Increasing emissions for CFC-11 since measured
Faster releases from banks unlikely
Illegal production in east Asia suspected
Red lines: Northern hemisphere
Blue lines: Southern hemisphere
Grey lines: projections based on World Meteorological Organization scenarios
Christian Heusser und Franziska Jud

13. How to find the malefactor?
Compare with measurement data from other AGAGE sites
Sites closer to source will measure higher concentrations
Additional measurements
In country, close to factories
On country borders, if measurements not allowed by country
Satellite measurements
Problem: no CFC-11 measuring satellite currently available
Christian Heusser und Franziska Jud

14. EIA report on illegal CFC-11 production in China
Wide-spread illegal production, trade and use of CFC-11 in China
18 factories in east China listed that confirm using CFC-11 as blowing agent
Large estimated number of unrecorded cases suspected
EIA, Blowing It, 2018.
Christian Heusser und Franziska Jud

15. Situation in China Growing demand for affordable PU foam
Bayer, BASF sell expensive foams
CFC-11 popular as cheap and excellent blowing agent
~150 $/t cheaper than legal HCFC-141b
No severe penalties for law-offending behavior
Confiscation and fines up to 150‘000 $
Corrupt administration
Production shut down when check is runned
Various tricks to mask or hide use of CFC-11
EIA, Blowing It, 2018.
Christian Heusser und Franziska Jud

16. Comments on EIA report
Measurements only indicate emission/use but not production of CFC-11
Origin unknown and not necessarily located in China
Alternative sources for CFC-11 possible
Illegal production of CFC-12
Leakage of old stockpiles
Alan R. Katritzky et al.: Comprehensive Organic Functional Group Transformations. Elsevier, 1995.
Christian Heusser und Franziska Jud

17. Thank you for your attention!