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Transcript of Niklas Köke, Daniel Zahn, Thomas P. Knepper, Tobias Frömel Wasser 2017 NK.pdf · 0 20 40 60 80...
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ME
T
QU
AD
DP
G
TP
A
CM
Q
DA
MP
PA
MB
PA
AC
E
CY
C
PF
BA
PF
BS
PF
PA
TF
MS
A
MS
A
SA
CC
CY
T
GA
P
AC
P
MIT
4-M
TS
C
TS
C
TU
SU
C
5-F
U
CA
Reco
very
(%
)
mmSPE
HLB
positive negative
zw
itte
rio
nic
neutral
Niklas Köke, Daniel Zahn, Thomas P. Knepper, Tobias Frömel
Hochschule Fresenius, University of Applied Sciences, Institute for Analytical Research (IFAR), Idstein, Germany | Corresponding author: [email protected]
Evaluation of sample preparation methods for
highly polar organic contaminants
from aqueous matrices
Introduction
References: [1] Reemtsma, T. et al. Environmental Science & Technology 2016, 50, 10308-10315
[2] Schmidt, C. K.; Brauch, H.-J. Environmental Science & Technology 2008, 42, 6340
[3] Zahn, D. et al. Water Research 2016, 101, 292-299
Acknowledgement: This work has been funded by the BMBF (02WU1347B) in the frame of the
collaborative international consortium WATERJPI2013 - PROMOTE of the Water
Challenges for a Changing World Joint Programming Initiative (Water JPI) Pilot Call.
Procedure Conclusion
Method comparison
Evaporation
Recovery % = x spiked before -blank
x spiked after ∗100%
ME % = x spiked after -blank
x standard ∗100% -100%
Spike before
enrichment
Nucleodur HILIC
2x150 mm; 5 µm
Tap water Surface water WWTP Effluent
Solid phase extraction Evaporation
ESI – QqQ
Spike after
enrichment
pH: 8.06
Conductivity: 575 µS/cm
TOC: 0.48 mg/mL
DOC: 0.38 mg/mL
pH: 7.33
Conductivity: 193 µS/cm
TOC: 2.3 mg/mL
DOC: 2.1 mg/mL
pH: 6.91
Conductivity: 512 µS/cm
TOC: 4.1 mg/mL
DOC: 4.0 mg/mL
• The developed methods are suitable to enrich a
wide range of very polar organic substances
• Neutral analytes, which are most problematic with
mmSPE, can be enriched with the evaporation
method
• The developed methods are complementary to
each other and to enrichment with HLB material, and
thus may increase the range of organic
micropollutants that can be analysed in aqueous
matrices
Highly polar organic contaminants are mobile (MOCs) in the water
cycle because they are able to pass natural and artificial barriers. If
they are persistent (PMOCs), dilution is the only way of concentration
reduction, and thus these substances may reach raw and drinking
waters in significant concentrations[1]. When PMOCs are present in high
concentrations or toxic[2], their presence in the water cycle may have
adverse effects on aquatic organisms or on human health.
The analysis of MOCs is exacerbated by the same physico-
chemical properties that facilitate their mobility (e.g. low molecular
mass and high polarity). The lack of suitable enrichment methods
for MOCs from aqueous samples is a major problem in their trace
analysis, and thus two independent methods, a multimodal solid
phase extraction (mmSPE) method[3] and an evaporation method,
were developed to facilitate the analysis of MOCs.
• Tap water was enriched with a generic HLB (hydrophilic
and lipophilic balanced) SPE material method and the
mmSPE method
• The mmSPE method shows higher recoveries (mean
mmSPE: 52%; HLB: 21%) for the enrichment of MOCs
9 mbar;
45° C
52%
21%
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ME
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Evap
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eco
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58%
-100
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-20
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Ion
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t (%
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Tap water Surface water WWTP Effluent
Enrichment factor 20
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ME
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MS
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MS
A
SA
CC
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MIT
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5-F
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CA
mm
SP
E
reco
very
(%
)
positive negative neutral
50%
-100
-80
-60
-40
-20
0
20
Ion
su
pp
ressio
n/e
nh
an
ce
men
t (%
)
Tap water
Surface water
WWTP Effluent
Enrichment factor 200
mmSPE method Evaporation method
zw
itte
rio
nic
30 (±5) mg of
Weak Anion
eXchange
Weak Cation
eXchange
Graphatised
Carbon Black
5% NH4OH in MeOH (1 mL) 2% formic acid in MeOH (1 mL) 20% CH2Cl2 in MeOH (0.5 mL) ACN/H2O 95/5 (0.5 mL)
N2 N2
50°C 50°C
0.45 µm
100 mL
pH 5.5 200 fold
enriched
• Non-target screening of ground water sample
enriched with all three enrichment methods
• Analysis with HILIC-HRMS allows rough estimation
of analyte hydrophilicity with retention time
• Number of detected ions was highest for HLB
• Mean and median retention time, and thus
capability to enrich hydrophilic compounds
increases in order HLB, Evaporation, and mmSPE
• The highest number of high intensity ions (>107)
were detected after enrichment with mmSPE
• In total, 17 analytes were determined with the
mmSPE method and 19 analytes for the
evaporation method
• Neutral analytes were most problematic for the
mmSPE method
• Mean recovery was 50% for the mmSPE and 58%
for the evaporation method
• A combination of both methods is able to enrich
84% of the model substances by a threshold of 30%
• For the mmSPE method, matrix effects seem to
correlate well with matrix TOC/DOC
• For the evaporation method, the salt concentration
appears to have a significant influence on matrix
effects
• Matrix effects for the evaporation method increase
significantly if the enrichment factor is increased from
10 to 20 (data not shown)
• Significance of matrix
effects for the
mmSPE method
• Significance of matrix
effects for the
evaporation method < <
< <