3° Presentazione del Workshop Finale del Progetto IPA/BC-Monitor Il progetto IPA/BC-Monitor ha sviluppato un sistema innovativo, compatto e standalone, per la misura online di due componenti chiave del particolato atmosferico, IPA e BC. Sito web del progetto: www.ipabcmonitor.it

1. Attuali procedure analitiche per
l’analisi di inquinanti organici
prioritari nel particolato atmosferico
Maria Chiara Pietrogrande
27 Giugno 2018

2. IPABC 2
Analysis of PAHs in PM samples
16 polycyclic aromatic hydrocarbons classified by U.S. EPA as priority pollutants.
Analysis in ambient aerosol is a challenging task as:
 PM is a very complex mixture,
 PAHs are very toxic compounds present at trace level, i.e., 0.1-1 ng m-3,
 several interfering compounds may affect the PAH signals.
PM sampling Solvent extraction Solvent evaporation
Conventional multiresidue method for organics
Chromatographic
analysis

3. IPABC 3
Chromatographic analysis of PAHs
RP-HPLC
Fluorecence, MS detection
HRGC
FID, MS detection

4. IPABC 4
GC-MS analysis of PAHs in PM samples
Interferences from several volatile compounds, mainly hydrocarbons
PM sampling Solvent extraction Solvent evaporation
High selectivity is required for:
 GC separation,
 MS detection.

5. IPABC 5
GC columns for PAH separation
Conventional GC column: high bleeding
Poster D.L. et al., Anal Bioanal Chem, 2006, 386: 859-862.
Time evolution of GC stationary phases:
New GC-MS columns:
 low bleeding
 high isomer selectivity

6. IPABC 6
GC columns for PAH separation
most commonly used GC column:
5% diphenyl/95% dimethyl polysiloxane
LC50: Liquid crystalline phase designed
to separate isomeric forms of PAHs

7. IPABC 7
Conventional bench-top GC/MS methods:
Full Scan MS (20-300 m/z) :
• Sensibility: low detection limits: 0.1 - 1 ng ml-1
• Precision: RSD%≤11 %
• Accuracy: recovery: 79 -103 %
First fragmentation energy Second fragmentation energy
Precursor ion Product ions
Tandem MS/MS: higher selectivity
Sensibility: lower detection limits: 0.01 ng ml-1
MS detection in GC analysis of PAHs

8. IPABC 8
Solid Phase Extraction using
Molecular Imprinted Phase for 5-6 ring PAHs
PM sample clean-up is required to:
 reduce sample complexity,
 selectively elute PAHs enriched fractions.
PAH pre-separation

9. IPABC 9
PAH pre-separation: SPE
GC MS TIC chromatogram of PM2.5 extract purified on MIP SPE column using dichloromethane as an
elution solvent
m/z: 252 m/z: 278 m/z: 302
Drabova L. et al., Talanta, 2012, 100, 207–216.
PAHs recoveries: 85% and 97%
1-BbFA;
2-BkFA;
3-BjFA;
4-BaP;
5-DBahA;
6-IP;
7-BghiP;
8-DBalP;
9-DBaeP;
10-DBaiP;
11-DBahP

10. IPABC 10
Solid Phase Micro extraction:
solvent free procedure
Selective PAH adsorption
on the fiber
Fiber: Polyacrylate
PAH pre-separation: SPME

11. IPABC 11Costa Menezes H. et al. Journal of Chromatography A, 2011, 21, 3300-3305.
Fiber:
Polydimethylsiloxane
LOQ: 0.05–3.86 ng,
relative standard deviation: 8.3–25.4%,
Accuracy (5 mg SRM1649b urban dust): ±1ng,
PAHs recoveries: 85% and 97%
PAH pre-separation: SPME

12. IPABC 12Yu J.Z. et al., Anal. Bioanal. Chem., 2011, 401, 3125–3139.
Thermal desorption GC-MS

13. IPABC 13
Elorduy I. et al., Journal of Analytical Methods in Chemistry, 2018, ID 8734013
TD-GC/MS Validation in Comparison with Soxhlet-GC/MS:
Standard Reference Material: 1649b urban PM
 better recovery: mean of 97%,
 good precision: mean of 12%,
 accuracy: ±25%.
LOQ: mg m-3: 0.02-0.3
Short path thermal desorption GC-MS
multi-sorbent tube (Glass beads, Carbopack C, and Carbopack B) for collecting the airborne PAHs.
Li Y. et al., Journal of Chromatography A, 2017, 1497,127-134.
Thermal desorption GC-MS
LOQ: mg m-3: 0.04-0.6

14. IPABC 14
TOF-MS with software for peak deconvolution:
 acquisition range was m/z 35 to 500
 acquisition frequency of 25 spectra/sec
Orasche J. et al., Atmos. Chem. Phys., 2011, 11, 8977–8993.
Compared to solvent extraction: ± 20%
measured concentrations: more affected by sampling artefacts
Thermal desorption GC-TOFMS
LOQ: mg m-3: 0.004-0.2

15. IPABC 15
m/z:178+202+228+252+276+278
m/z: 126+158+180+196+230+258
m/z:57+117
Orasche J. et al., Atmos. Chem. Phys., 2011, 11, 8977–8993.
Thermal desorption GC-TOFMS

16. IPABC 16
Aerosol gas chromatograph- aerosol MS
Brent J.W. et al., Aerosol Science and Technology, 2014, 48, 358-370.
Thermal Desorption Aerosol Gas Chromatography: GC-TOFMS:
in-situ speciation of organic chemicals in ambient aerosol particles with hourly time resolution

17. IPABC 17
2D GC for PAH separations
Heartcut GC–GC: medium to complex samples with 100–200 analytes,
Comprehensive GC × GC : samples with high complexity

18. IPABC 18
2D GC for PAH separations

19. IPABC 19
2D GC for PAH separations
GC columns orthogonality:
1st D: 5% phenyl methylpolysiloxane phase,
2nd D: 50% phenyl methylpolysiloxane or phenyl liquid crystal polysiloxane (LC50).
Columns with a 50% phenyl phase or similar especially demonstrated improved separation
for isomeric PAHs of chrysene/triphenylene and benzo[b]fluoranthene/benzo[j]- fluoranthene
Lee J.L. et al., Atmospheric Environment, 2012, 55, 17-25

20. IPABC 20
Thermal desorption:TD-GCxGC-TOFMS
TD–GC×GC–MS/MS with a selected reaction monitoring mode.
High sensitivity: the instrumental detection limits:
0.03–0.3 pg (PAHs),
0.04–0.2 pg (oxygenated PAHs),
0.03–0.1 pg (nitrated PAHs),
0.01–0.08 pg (methylated PAHs).
one or two orders of magnitude greater than that of TD–GC–HRMS and TDGC×GC–QMS
Accuracy
certified standard reference materials (SRMs 1649a and 1650b, urban dust and diesel
exhaust particles)
Agreement within a the range 0.5–2.
Fushimi A. et al., Journal of Chromatography A, 1252 (2012) 164– 170
#significantly different
from the reference value

21. IPABC 21
2D-LC/2D-GC
Lim et al., Anal. Bioanal. Chem., 2017, 409, 5619–5629.
Automated clean-up, separation and detection of PAHs:
2D system combining:
• 2D-LC: sample clean-up and the fractionation of PAHs enriched samples,
• 2D-GC: PAHs analysis using heart-cut GC–GC,
• two triple-quadrupole mass spectrometer detectors
air and diesel exhaust
LC × LC orthogonality : clean-up and isolation of the PAH fraction of interest from complex
samples:
1 LC: C18 reversed phase : PAH separation according to the number of aromatic rings,
2 LC: Hypercarb porous graphitic carbon phase: selective separation of each PAH fraction
containing PAHs, e.g. isomers or alkyl substituents;
GC × GC orthogonality:
1. 5%phenyl: PAH separation according to the number of aromatic rings,
2. liquid crystal polysiloxane LC50 column: selective separation of isomers

22. IPABC 22
2D-LC/2D-GC 1 Phe-d10,
2 Phe,
3 Ant,
4 Flu,
5 Pyr-d10,
6 Pyr,
7B[a]A-d12,
8 B[a]A,
9 Chr,
10 B[b]F,
11 B[k]F,
12 B[e]P,
13 B[a]P-d12,
.
Two-dimensional GC/MS chromatogram obtained in SIM mode from urban dust (SRM 1649a):
a) first dimension, b) and second dimension
14 B[a]P,
15 Per,
16 I[1,2,3-cd]P,
17 DB[a,h]A, 1
8 B[ghi]p-d12,
19B[ghi]p,
20 Pic,
21 DB[a,e]P,
22 benzo[j]fluoranthene,
23 benzo[a]-
fluoranthene,
24 CPP,
25 triphenylene
Lim et al., Anal. Bioanal. Chem., 2017, 409, 5619–5629.

23. IPABC 23
Sensitivity: limit of detection: 10-200 pg,
Accuracy: ± 20% vs: NIST
2D-LC/2D-GC
Lim et al., Anal. Bioanal. Chem., 2017, 409, 5619–5629.

24. Thanks for your attention