0

20

40

60

80

100

120

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)

mmSPE

HLB

positive negative

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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: froemel@hs-fresenius.de

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%

0

20

40

60

80

100

120

140

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

Evap

ora

tio

n r

eco

very

(%

)

58%

-100

-80

-60

-40

-20

0

20

40

60

Ion

su

pp

ressio

n/e

nh

an

ce

men

t (%

)

Tap water Surface water WWTP Effluent

Enrichment factor 20

0

20

40

60

80

100

120

140

ME

T

QU

AD

DP

G

TP

A

CM

Q

DA

MP

PA

MB

PA

AC

E

CY

C

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BS

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PA

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A

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A

SA

CC

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T

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P

AC

P

MIT

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TS

C

TS

C

TU

SU

C

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 < <

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