1. Jean-Philippe Putaud, Fabrizia Cavalli
Investigations on measurement protocols for carbonaceous aerosols compounds
at JRC-Ispra (IES)
Jean-Philippe Putaud, Fabrizia Cavalli
European Commission, Joint Research Centre, Institute for Environment and Sustainability
EMEP TFMM
10 May. 06

2. Sampling artifacts -1 related to G/P equilibrium shifts
OC collection depends on face velocity
EC collection does not
Pressure drop induced volatilization from collected POC OR
Face velocity dependence of VOC adsorption
1990, Mc Dow and Huntzicker:
Sampling artifacts -1
related to G/P equilibrium shifts
EMEP TFMM
10 May. 06

3. Sampling artifacts -2 Negative artifacts can reach 80%
1993, Eatough et al.:
Negative artifacts can reach 80%
EMEP TFMM
10 May. 06

4. Sampling artifacts -3 Positive artifacts account for > 25%
1993, Turpin et al.:
Positive artifacts account for > 25%
EMEP TFMM
10 May. 06

5. obtained with cascade impactors vs filter samplers
Total Carbon in PM2.5
obtained with cascade impactors vs filter samplers
Sampling artifacts -4
2004, Ten Brink et al.:
Consistently lower concentrations of total carbon
with cascade-impactors vs. fiber filter samplers
EMEP TFMM
10 May. 06

6. Denuder (1): Teflon a. Eliminate positive artifacts denuder quartz
EMEP TFMM
10 May. 06

7. The C honey comb monolith denuder (R&P)
4 to 8 cm high, 4 cm diameter
carbon monolith multi-channel structure
residence time = 0.15 to 0.3 s at 20 LPM
efficiency = being tested
EMEP TFMM
10 May. 06

8. that otherwise would adsorb on the quartz front filter
Denuder (3):
MARCH 2006
Denuder efficiency:
on average, the C honey comb monolith denuder retains % of the VOCs (+ SVOCs)
that otherwise would adsorb on the quartz front filter
EMEP TFMM
10 May. 06

9. Denuder (4): …for a selected sample 200°C 300°C 450°C 650°C 650°C
EMEP TFMM
10 May. 06

10. Denuder (5): < 20% ≈50% Positive artefacts relevance
Positive artifact contribution is larger (up to ca. 50%) when particulate TC (PM2.5) concentrations are lower.
EMEP TFMM
10 May. 06

11. a. Eliminate positive artifacts denuder
Sorbent (1):
a. Eliminate positive artifacts denuder
b. Determine negative artifacts sorbent
EMEP TFMM
10 May. 06

12. Sorbent (2): Pre-fired quartz fiber filters (QFF)
SEPTEMBER 2005
No significant differences between back-up_1 and back-up_2
QFF efficiency recently tested: POOR
EMEP TFMM
10 May. 06

13. Sorbent (3): C-impregnated glass fiber filter (CIG)
Teflon
CIG_1
Sorbent (3): C-impregnated glass fiber filter (CIG)
EMEP TFMM
10 May. 06

14. The issue of blank levels is very critical
Sorbents (4):
Not only efficiency in trapping what is lost from the quartz filters is to be considered:
The issue of blank levels is very critical
Efficiency of denuder with respect to CIG filters
EMEP TFMM
10 May. 06

15. Sorbents (4): a. Eliminate positive artifacts denuder
b. Determine negative artifacts sorbent
c. Negative artifact evaluation suitable denuder
EMEP TFMM
10 May. 06

16. Denuder vs CIG filter (1):
MARCH 2006
Denuder efficiency / CIG filters:
on average, the C honey comb monolith denuder retains % of the VOCs (+ SVOCs)
that otherwise would adsorb on CIG filters
EMEP TFMM
10 May. 06

17. Denuder vs CIG filter (2):
…for a selected sample
200C
300C
200C C
EMEP TFMM
10 May. 06

18. Analytical procedure (1):
Carbonaceous particle conference round robin stage 2, unpublished
EC /TC
EMEP TFMM
10 May. 06

19. Analytical procedure (2):
Charring to be avoided or corrected
OC / EC split
EMEP TFMM
10 May. 06

20. Analytical procedure (3): properly calibrate the instrument
detect pure organics (and mixtures) as OC
and pure EC as EC
EMEP TFMM
10 May. 06

21. Analytical procedure (4):
Pk1
μgC cm-2
Pk2
Pk3
Pk4
Pyrol
EC1
EC2 OC EC TC
0.01
0.26
2.49
1.06
7.41
6.97
0.41
11.23
0.00
EMEP TFMM
10 May. 06

22. Analytical procedure (4):
Thermal Creation of EC-Only Test Samples form Atmospheric Aerosols
Carrier gas
Temperature (C)
Time (s) He 50
Purging online
He_1
600 60
He_2
800
300
Charring Minimization in Thermal Analysis of Aerosol Carbon
J. Z. Yu and Q. Li EC/OC workshop, Durango, CO March 2003
EMEP TFMM
10 May. 06

23. Analytical procedure (4):
TC μgC cm-2
TC_in He μgC cm-2
%TC_He
@ 650 C
8.78  0.74
0.22  0.21
2.5
@ 750 C
3.90  0.49
0.63  0.23 16
@ 850 C
5.86  0.59
1.24  0.26 21
EMEP TFMM
10 May. 06

24. Analytical procedure (5): properly calibrate the instrument
detect pure organics (and mixtures) as OC
and pure EC as EC
avoid or reduce the occurrence of charring during analysis
keep the amount of carbon as small as possible
volatilise as much as possible at low T
avoid peak overlap
correct for charring
EMEP TFMM
10 May. 06

25. Analytical procedure (6):
Seek agreement between optical and thermal methods ?
Neuhaeusel, France-Germany border, 2003
EMEP TFMM
10 May. 06

26. Solutions are being tested (seasonal dependent)
Conclusions:
Sampling train:
Solutions are being tested (seasonal dependent)
Positive preliminary results
To be tested in various environments (EUSAAR)
Analytical procedures
Strong arguments can be used to discriminate unacceptable methods
Consensus still to be found on a “standardised” method
EMEP TFMM
10 May. 06

27. Thanks
EMEP TFMM
10 May. 06

28. Analytical procedure (5):
EMEP TFMM
10 May. 06