1. Environmental Degradation of Pharmaceuticals and Pollutants using EC/MS
ASMS 2015
St. Louis, MO, USA

2. Principle of EC upfront MS
Potential (∆E) is the driving force of the reaction
∆E (Potential)
Reduction Oxidation

3. Antec’s Electrochemical Flow (Through) Cells
ChipCell™
Nanoflow applications
nL/min
ReactorCell™
Universal starter cell
1 -20 µL/min
µ-PrepCell™
High yield cell
20 – 200 µL/min

4. Why Coupling EC with MS? EC cell oxidation or reduction
MS for direct identification
incl. unstable & short-lived components
Electrochemically induced reactions show excellent agreement with Nature’s REDOX reactions, e.g., enzymatic, aquatic, microbial, chemical, ROS, UV light, etc.,
Reactions are instantaneously  very fast, no isolation from biological matrix, etc.

5. MS Voltammogram – Quick Assessment of Oxidation Products
Amiodarone

6. Application Areas Electrochemistry/MS
Electrochemistry upfront MS
Disulfide bond reduction
Peptide bond cleavage
Desalting
DNA damage
Signal enhancement
in MS
Skin sensitization
Pollutants
Metabolite synthesis
Drug metabolism
Drug ̶ protein binding
Oxidative tagging of proteins
Purposeful degradation
Combining electrochemistry (EC) with MS and LC/MS has shown great potential for the investigation of drug metabolism. The oxidation of target compounds occurs in the electrochemical cell within seconds and the similarity between reactions catalyzed by cytochrome P450 in nature and simulated in the electrochemical cell is high .
Recently, the use of on-line EC/LC/MS has been extended towards new applications such as:

7. Instrumental Set-up

8. ROXY™ Product Line • ROXY™ Potentiostat*) dual cell control, +/- 4.9 V
ROXY™ EC System*)
all parts included for direct on-line EC/MS
ROXY™ EC/LC System*)
electrochemical cell integrated in autosampler**)
for non-compromised EC, LC and MS
*) all instruments are fully compatible with any MS
**) Intl. Patent Application PCT/NL2010/050309

9. MS Voltammogram Boscalid (Pesticide)
Synonim: PESTANAL® (Sigma Aldrich)

10. Boscalid Degradation Electrochemical oxidation of pesticides
…simulation of pesticide meta-bolism (phase I &II)
minutes vs. weeks excellent agreement with in vivo data
Electrochemical degradation scheme of boscalid
W. Lohmann, J .Am Soc Mass Spectrom, 20, 2009, 138 10

11. Environmental persistence EC starting voltage (mV)
Persistence in Environment, Stability in EC?
Compound
Environmental persistence
EC starting voltage (mV)
Sulfadizine
Medium
1100
Metabenzthiazuron
Stable
1800
Ethidimurin
-1420
Ibuprofen
1200
17ß-estradiol
Unstable
300
Clotrimazol
1750
PCB31
Very Stable
4500
Tetracene
1600
=> QSAR modeling…

12. Stability and Structure
Compound Structure EC starting voltage (mV)
Naphthalene
Anthracene
Phenanthren
Benzo[a]anthracene
Tetracene
Chrysene

13. Environmental Pollutants