Recent Developments in Catbonyl Sampling & Analysis · Recent developments in Carbonyl Sampling and...
Transcript of Recent Developments in Catbonyl Sampling & Analysis · Recent developments in Carbonyl Sampling and...
© 2012 Sigma-Aldrich Co. All rights reserved.
sigma-aldrich.com/analytical
Recent developments in Carbonyl Sampling and AnalysisFrank [email protected]
© 2012 Sigma-Aldrich Co. All rights reserved.
Sources of carbonyl compounds
Anthropogenic sources• Outdoor
– Industrial processes– Combustion of fossile fuels
– Car exhaust– Heating, energy
• Indoor– Release from fabrics e.g. carpets, wooden furniture,ceiling tiles– Smoking
Biogenic sources• Plants
2
© 2012 Sigma-Aldrich Co. All rights reserved.
Importance of monitoring carbonyls
Adverse effect on human health (acute and chronic) [1]• Eye and lung irritation• Formaldehyde is a suspected carcinogen• Photochemical smog [2]
• [1] Altshuller A. P., J Atmos Chem, 1978, 28: 594–598• [2] "What is Smog?", Canadian Council of Ministers of the Environment
3
© 2012 Sigma-Aldrich Co. All rights reserved.
First approach for carbonyl analysis: Impingers
Derivatizationreagent solution containing• 2,4-Dinitrophenylhydrazin (DNPH) [3]• 2,3,4,5,6-Pentafluorbenzylhydroxylamin (PFBHA)• 2-AminoethanthiolDetection by HPLC/UV or fluorescence
Disadvantages:• Quantitation (need to use in series, evaporated solvent)• Inconvenient• Not robust• Dealing with liquid solution in the field
4
[3] D. Grosjean, Environ. Sci. Technol. 16 (1982) 254
© 2012 Sigma-Aldrich Co. All rights reserved.
State of the Art: Coated Adsorbents
Derivatization Reagent• 2,4-Dinitrophenylhydrazine (DNPH)
• 5-Dimethylaminonaphtalenesulfonic acid hydrazine (Dansylhydrazine, DNSH)
• N-Methyl-2,4-dinitrophenylhydrazine (MDNPH) [4]• 2-(Hydroxymethyl)piperidine• 2,4,6-Trichlorophenylhydrazine• 2,3,4,5,6-Pentafluorobenzylhydroxylamine (PFBHA)
5
O2N
NO2
NH
NH2
CH3
S
O
O
NH
NH2
[4] A. Bueldt, U. Karst, Anal. Chem. 1997, 69, 3617-3622
© 2012 Sigma-Aldrich Co. All rights reserved.
DNPH Derivatization of Carbonyls [5,6]
NO2
O2N
NHNH2
R'
O
R
H+
-H2O
NO2
O2N
NHN
R'R
+
DNPH derivative(a hydrazone)• Stable• UV detection[5] C.F.H. Allen, J. Am. Chem. Soc. 52 (1930) 2955
[6] Beasley R. K. et al.; Anal. Chem., 1980, 52, 1110-1114
© 2012 Sigma-Aldrich Co. All rights reserved.
Isomerization Possible
Only non-symmetric carbonyl compounds (R ≠ R‘)Might occur by UV radiation or acidic catalysis [7]Usually only E isomer is observed
7
NO2
O2N
NHN
HCH3
NO2
O2N
NHN
CH3H
Z isomer E isomer[7] S. Uchiyama et al., J. Chromatog. A 996 (2003) 95-102
R'
O
R
© 2012 Sigma-Aldrich Co. All rights reserved.
Isomerization Possible
8
Instrument: Shimadzu HPLC/UVDet.: 360 nmCol.: Discovery RP-Amide C16,
250 x 4.6 mm, 5 µm Mob. Phase: acetonitrile/water. Gradient:Time (min) 0 5 25 40 60Acetonitrile (%) 40 40 58 70 70Flow-rate: 1.5 ml/minTemp: 40 °CInj. Volume: 20 ml
Sample A: Solution of the E isomers ofDNPH hydrazones of C1 - C10aldehydes (50 µmol/L)
Sample B: Solution of sample A after addition of phosphoric acid
[7] S. Uchiyama et al., J. Chromatog. A 996 (2003) 95-102
© 2012 Sigma-Aldrich Co. All rights reserved.
Potential Interferences
Ozone O3• Formation of several products [8,9]Nitrogen oxides NOX• React to 2,4-dinitrophenyl azide (may eliminate N2 and react further
to 5-nitrobenzofurazan 3-oxide under cyclization) [10]Coelution of by-products with the hydrazones possible• Dual-wavelength detection for peak purity from by-products [11]
• [8] Arnts, R. R.; Tejada, S. B. Environ. Sci. Technol. 1989, 23, 1428-1430.• [9] Smith, D. F.; Kleindienst, T. E.; Hudgens, E. E. J. Chromatogr. 1989, 483, 431-436.• [10] Karst, U. et al., U. Fresenius J. Anal. Chem. 1993, 345, 48-52.• [11] Poetter, W.; Karst, U. Anal. Chem. 1996, 68, 3354-3358.
9
O2N
NO2
N3
© 2012 Sigma-Aldrich Co. All rights reserved.
Sampling and Work-up
•Sampling Elution
ManualAutomated &
on-line with HPLC [12]
e.g. Anatune 300 for S10 cartridges
ExampleLpDNPH S10 Cartridge
[12] The Reporter Vol. 53, Feb. 2013
© 2012 Sigma-Aldrich Co. All rights reserved.
Overview on LpDNPH CartridgesName Carbonyl capacity (FA) Specials
S10 <75 μgS10L <75 μg Shorter dimensions, no adapterS10x <75 μg For automated handlingRezorian™ <75 μg Luer lock syringe connections
11
Rezorian54074-U, 54075-U
© 2012 Sigma-Aldrich Co. All rights reserved.
Overview on LpDNPH CartridgesName Carbonyl capacity (FA) Specials
H Series H10: >75 - 225 μgH30: >225 - 643 μgH300: >643 - 6400 µg
Higher loadings of DNPH and bed weights
ORBO™-555 75 - 225 μg 300 mg/150 mg, to detect breakthrough
12
54020-U ORBO-555 DNPH Tube
© 2012 Sigma-Aldrich Co. All rights reserved.
Rezorian S10L
Mean (inches water) 2.4 9.9
Range (inches water) 2.2 – 2.6 6.7 – 14.9
Standard Deviation 0.12 2.57
Sample Size (n) 10 10
The conical shape of the Rezorian cartridge results in unobstructed air flow through the bottom frit.
Pressure Drop at 200mL/min Air Flow
© 2012 Sigma-Aldrich Co. All rights reserved.
High Purity DNPH Packing
•Reproducible low background of DNPH to meet specification
•Purified reagents to needed level (cleanup)
•Use of clean solvents
© 2012 Sigma-Aldrich Co. All rights reserved.
Time (days)0 20 40 60
Form
alde
hyde
(ng)
0
20
40
60
Rezorian - Refrigerated
Rezorian - Room Temperature
S10L Refrigerated
S10L Room Temperature
Storing DNPH cartridges:Changes in Formaldehyde Background
© 2012 Sigma-Aldrich Co. All rights reserved.
Time (days)0 20 40 60
Ace
tald
ehyd
e (n
g)
0
20
40
60
80Rezorian - Refrigerated
Rezorian - Room Temperature
S10L - Refrigerated
S10L - Room Temperature
Storing DNPH cartridges:Changes in Acetaldehyde Background
Concerns for a reliable result:• Temperature• UV Light
© 2012 Sigma-Aldrich Co. All rights reserved.
BPE-DNPH Cartridges
trans-1,2-Bis(2-pyridyl)ethylene (BPE)
•Determination of carbonyls without ozone interference•Parallel Determination of Carbonyls & Ozone•No need for a separate ozone scrubber
– BPE works as a scavenger for ozone (more effective than others)
•Suitable for high humidity conditions•BPE-DNPH 90/260 mg
© 2012 Sigma-Aldrich Co. All rights reserved.
BPE-DNPH - Reaction Principle
Elution: Ozone & Carbonyl derivatives ACN/DMSO, 75/25 v/v, 3mLCarbonyls derivatives only ACN
O+
O O-
N
N
H
H
H2O
N
O
H
2 + H2O2+
DNPH
O2N
NO2
NH
NH2R'
O
R
+H
+
O2N
NO2
NH
N
R'
R + H2O
trans-1,2-Bis(2-pyridyl)ethylene (BPE) Pyridine-2-aldehyde
DNPH
© 2012 Sigma-Aldrich Co. All rights reserved.
BPE-DNPH - Result Column: Ascentis C18, 150 x 4.6 mm, 5 μmMobile phase: 35/65 acetonitrile/2 mM ammonium acetate
(10 min.), gradient to 75% acetonitrile at 25 min. (5 min. hold)
Flow rate: 1.9 mL/min.Det.: UV 360 nmInjection: 20 μL
1. Formaldehyde-DNPH2. Pyridine-2-aldehyde-DNPH3. Acetaldehyde-DNPH4. Acetone-DNPH
Air Sample
Cartridge blank
Note: Pyridine-2-aldehyde-DNPH Standard available as Prod. Nr. 40117-U
© 2012 Sigma-Aldrich Co. All rights reserved.
Determination of Ozone in Chiba City, Japan [13]
20
Slope = 1.01R2 = 0.99
2-BPE/DNPH Method (ug/m3)0 20 40 60 80 100 120 140
Air
Mon
itorin
g S
tatio
n (u
g/m
3 )
0
20
40
60
80
100
120
140
(µg/m3)
(µg/
m3
)
[13] S. Uchiyama et al., Anal. Chem. 2009, 81, 6552-6557
© 2012 Sigma-Aldrich Co. All rights reserved.
Passive Sampling of Carbonyl Compounds
radiello® - radial diffusive sampler• sampling rates similar to active sampling
– for formaldehyde 99 mL/min – for acetaldehyde 84 mL/min
21
• Adsorbent Cartridge• 2,4-DNPH coated Florisil• Supplied in storage container
• Diffusive Body• Blue diff. body
• Support plate• Triangular back plate• With pouch for barcode label
© 2012 Sigma-Aldrich Co. All rights reserved.
Analysis of Hydrazones (DNPH derivatives)
GC• Limited due to degradation of hydrazones of larger carbonyls• Smaller carbonyls exhibit an incresed baseline between syn- and anti
isomers, maybe due to conversion of isomers• Excess of DNPH might need to be removed before analysis (for ECD)• Detection by FID, ECD or MS
HPLC (approx. 70 %)• Often C18• Critical: C3 Carbonyl components (propanal, acrolein, acetone) co-elute
on many columns• Isomers usually not separated• UV Detection @ 340-380 nm; Interferences: dual-wave length detection
at 300 nm [11]
23
© 2012 Sigma-Aldrich Co. All rights reserved. 24
0 2 4 6 8 10 12Time (min)
020
4060
8010
012
014
0m
AU
0 2 4 6 8 10 12Time (min)
020
4060
8010
012
014
0m
AU
Column: 150 x 4.6 mm I.D.Mobile phase:
Ascentis Express C18: 2.7 µm: 25:75, water: acetonitrileAscentis C18 : 3 µm: 30:70, water: acetonitrile
Flow rate: 1.0 mL/min.Temp.: 30 °CDet.: UV at 365 nmInjection: 1 µLSample: 47285-U TO11/IP6A Carbonyl-DNPH Mix
as indicated below in 40:60, water: acetonitrile
Peak IDs
1. Formaldehyde-2,4-DNPH (105 µg/mL)2. Acetaldehyde-2,4- DNPH (76.4 µg/mL)3. Acrolein-2,4- DNPH (63.2 µg/mL)4. Acetone-2,4- DNPH (61.5 µg/mL)5. Propionaldehyde-2,4- DNPH (61.5 µg/mL)6. Crotonaldehyde-2,4- DNPH (53.6 µg/mL)7. Butyraldehyde-2,4- DNPH (52.5 µg/mL)8. Benzaldehyde-2,4- DNPH (40.5 µg/mL)9. Isovaleraldehyde-2,4- DNPH (46.4 µg/mL)10. Valeraldehyde-2,4- DNPH (46.4 µg/mL)11. o-Tolualdehyde-2,4- DNPH (37.5 µg/mL)12. m-Tolualdehyde-2,4- DNPH (37.5 µg/mL)13. p-Tolualdehyde-2,4- DNPH (37.5 µg/mL)14. Hexaldehyde-2,4- DNPH (42 µg/mL)15. 2,5-Dimethylbenzaldehyde-2,4- DNPH (35 µg/mL)
Ascentis Express C18, 2.7 µmPeak 8N = 260,720 p/mN = 39,108 p/col
Ascentis C18, 3 µmPeak 8N = 146,587p/mN = 21,988p/col
TO11/IP6A Carbonyl DNPH Mix
8
8
Sensitivitygap
© 2012 Sigma-Aldrich Co. All rights reserved.
Alternative stationary phase for DNPHydrazones
25
Column: Ascentis RP-Amide, 250 x 4.6 mm, 5 μmMob. phase A: 60:40, water:acetonitrileMob. phase B: 25:75, water:acetonitrileFlow rate: 1.5 mL/min.temp.: 40 °Cdet.: UV at 360 nminjection: 10 µl
Gradient: Min %A %B0 100 05 100 025 40 6040 0 10060 0 100
4. Acetone-2,4-DNPH5. Acrolein-2,4-DNPH6. Propionaldehyde-2,4-DNPH
© 2012 Sigma-Aldrich Co. All rights reserved.
LpDNPH S10 Cartridge – Laboratory Air Sample
26
Column: Ascentis Express C18, 150 x 4.6 mm, 2.7 μmMobile phase A: Water Mobile phase B: Acetonitrile Flow rate: 0.5 mL/min Temp.: ambient Det.: UV at 360 nm Injection: 10 μL
Gradient: Min %A %B0 45 55 4 45 55
13 10 90 20 10 90
1. Formaldehyde-DNPH 2. Acetaldehyde-DNPH 3. Acetone-DNPH
© 2012 Sigma-Aldrich Co. All rights reserved.
Summary
Analysis of Carbonyl Compounds• Derivatization with DNPH on coated sorbent tubes is State of the Art• Different options for different purposes
– active/passive sampling, – manual/automated work-up– wide concentration range (low to high concentrations) – stacking of cartridges
• Interference by ozone can be circumvented by BPE-DNPH• Analysis by HPLC
– Use of high efficiency column for more sensitive and/or faster results– Alternative phase selectivities provide better separation