Supporting Information For:
Direct Detection of Pharmaceuticals and Personal Care Products from Aqueous
Samples with Thermally Assisted Desorption Electrospray Ionization Mass
Spectrometry
Ian S. Campbell, Alain T. Ton, and Christopher, C. Mulligan*
Department of Chemistry, Illinois State University, Normal, IL 61790
*
Corresponding author: Email: mulligan@ilstu.edu
Table of Contents
Page
Method 1 Analyte Structures (Table S-1)
Diphenhydramine
Loratadine
Pseudoephedrine
Phenylephrine and Chlorpheniramine
2
3
4
5
6
Method 2 Analyte Structures (Table S-2)
Amitriptyline
Atenolol
Bupropion
Citalopram
Chlorpheniramine
Clomipramine
Duloxetine
Estradiol
Fluoxetine
Imipramine
Moxifloxacin
Nortriptyline
Paroxetine
Sertraline
Venlafaxine
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
References
23
S-1
Table S-1. Analytes investigated with Method 1 (Direct Flow Injection DESI-MS)
O
O
N
Cl
OH
H
N
HO
N
N
N
Phenylephrine, MW = 167.21 g/mol
Sudafed PE ® Sinus and Allergy
Dosage = 10 mg
Cl
Chlorpheniramine, MW = 274.79 g/mol
Sudafed PE ® Sinus and Allergy
Dosage = 4 mg
Loratadine, MW = 382.88 g/mol
Claritan®
Dosage = 10 mg
OH
CH3
HN
N
Loperamide, MW = 477.04 g/mol
Imodium A-D®
Dosage = 2 mg
O
OH
N
O
N
Cl
Diphenhydramine, MW = 255.36 g/mol
Benadryl®
Dosage = 25 mg
Pseudoephedrine, MW = 165.23 g/mol
Sudafed® Congestion
Dosage = 30 mg
S-2
100
(a)
Relative Abundance
Relative Abundance
80
60
B
(b)
100
[Diphenhydramine + H]+
40
256
167
m/z 256
50
256
0
100
120
140
160
180
200
m/z
220
240
260
280
300
20
0
150
200
250
300
350
400
450
500
m/z
Figure S-1. (a) Positive ion DESI mass spectrum of an aqueous solution containing ~ 2.5 ppm
diphenhydramine, showing the protonated molecule at m/z 256. (b) MS2 of the m/z 256
precursor gives the major transition at m/z 167, corresponding to the loss of N,N-dimethyl-2aminoethanol.
Diphenhydramine Analysis
Figure S-1a shows a positive ion DESI mass spectrum of an aqueous solution containing
~2.5 ppm pseudoephedrine using Method 1. Diphenhydramine is a common antihistamine and is
the active ingredient in the over the counter (OTC) pharmaceutical tablet Benadryl®. The
protonated molecule [M+H]+ is seen at m/z 256, as well as other ions corresponding to the
sample matrix and common electrospray background. Isolation and fragmentation of m/z 256
leads to a loss of N,N-dimethyl-2-aminoethanol, seen as the ion at m/z 167 (Figure S-1b), similar
to fragmentation reported in literature.1
S-3
100
(a)
Relative Abundance
80
Relative Abundance
337
100
60
m/z 383
B
(b)
50
383
[Loratadine + H]+
40
0
260
280
300
320
340
360
380
400
m/z
20
383
0
150
200
250
300
350
400
450
500
m/z
Figure S-2. (a) Positive ion DESI mass spectrum of an aqueous solution containing ~ 100 ppb
loratadine, showing the protonated molecule as a chlorine doublet at m/z 383 and 385. (b) MS2
of the m/z 383 precursor gives the major transition at m/z 337, corresponding to the loss of
ethanol.
Loratadine Analysis
Figure S-2a shows a positive ion DESI mass spectrum of an aqueous solution containing
~ 100 ppb loratadine using Method 1. Loratadine is a common antihistamine and is the active
ingredient in the OTC pharmaceutical tablet Claritin®. The protonated molecule [M+H]+ is seen
at m/z 383 and 385 as a chlorine doublet, as well as other ions corresponding to the sample
matrix and common electrospray background. Isolation and fragmentation of m/z 383 leads to a
loss of ethanol, seen as the ion at m/z 337 (Figure S-2b), similar to fragmentation reported in
literature.2
S-4
(a)
[Pseudoephedrine +H]+
Relative Abundance
80
60
148
(b)
B
100
Relative Abundance
100
m/z 166
50
166
166
0
100
40
110
120
130
140
150
m/z
160
170
180
190
200
20
0
150
200
250
300
350
400
450
500
m/z
Figure S-3. (a) Positive ion DESI mass spectrum of an aqueous solution containing ~ 3 ppm
pseudoephedrine, showing the protonated molecule at m/z 166. (b) MS2 of the m/z 166 precursor
gives the major transition at m/z 148, corresponding to the loss of water.
Pseudoephedrine Analysis
Figure S-3a shows a positive ion DESI mass spectrum of an aqueous solution containing
~3 ppm pseudoephedrine using Method 1. Pseudoephedrine is a common decongestant and
stimulant, and it is the active ingredient in the OTC pharmaceutical tablet Sudafed® Congestion.
The protonated molecule [M+H]+ is seen at m/z 166, as well as other ions corresponding to the
sample matrix and common electrospray background. Isolation and fragmentation of m/z 166
leads to a loss of water, seen as the ion at m/z 148 (Figure S-3b), similar to fragmentation
reported in literature.3
S-5
Relative Abundance
(a)
150
(b)
B
(c)
C
100
m/z 168
Relative Abundance
100
Relative Abundance
100
50
230
m/z 275
50
80
275
168
0
0
100
60
110
120
130
140
[Phenylephrine + H]+
168
40
150
m/z
160
170
180
190
200
200
210
220
230
240
250
m/z
260
270
280
290
300
[Chlorpheniramine + H]+
275
277
20
0
150
200
250
300
350
400
450
500
m/z
Figure S-4. (a) Positive ion DESI mass spectrum of an aqueous solution containing ~100 ppb
each of phenylephrine and chlorpheniramine, showing the protonated molecules at m/z 168 and
m/z 275/277, respectively. (b) MS2 of the m/z 168 precursor of phenylephrine gives the major
transition at m/z 150, corresponding to the loss of water. (c) MS2 of the m/z 275 precursor of
chloropheniramine gives the major transition at m/z 230, corresponding to the loss of
dimethylamine.
Phenylephrine and Chloropheniramine Analysis
Figure S-4a shows a positive ion DESI mass spectrum of an aqueous solution containing
~100 ppb each of phenylephrine and chloropheniramine, showing the protonated molecules at
m/z 168 and m/z 275/277, respectively, using Method 1.
Phenylephrine is a common
decongestant and chlorpheniramine is a common antihistamine, and they are the active
ingredients in OTC pharmaceutical tablet Sudafed PE® Sinus and Allergy. Isolation and
fragmentation of the m/z 168 precursor of phenylephrine gives the major transition at m/z 150,
corresponding to the loss of water (Figure S-4b).
Isolation and fragmentation of the m/z 275
precursor of chloropheniramine gives the major transition at m/z 230, corresponding to the loss
of dimethylamine (Figure S-4c).4
S-6
Table S-2. Analytes investigated with Method 2 (Thermally-Assisted DESI-MS)
O
H
N
Cl
OH
O
Atenolol (β-blocker)
MW = 266.34 g/mol
N
H
Bupropion (Wellbutrin® )
MW = 239.74 g/mol
N
Acetaminophen (Analgesic)
MW = 151.17 g/mol
Amitriptyline (Elavil®)
MW = 277.40 g/mol
F
N
Cl
O
Carbamazepine (Anticonvulsant)
MW = 236.27 g/mol
Caf f eine (Stimulant)
MW = 194.12 g/mol
N
C
N
Clomipramine (Anaf ranil®)
MW = 314.85 g/mol
Citalopram (Celexa®)
MW = 324.39 g/mol
H
N
S
H
H
N
O
O
CF3
N,N-Diethyl-m-toluamide
(DEET, Insect Repellant)
MW = 191.27 g/mol
Fluoxetine (Prozac ®)
MW = 309.33 g/mol
Estradiol (Hormone)
MW = 272.38 g/mol
Duloxetine (Cymbalta®)
MW = 297.41 g/mol
N
N
Imipramine (Antideprin®)
MW = 280.41 g/mol
NH
H
N
Nortriptyline (Norpress ®)
MW = 263.38 g/mol
Moxif loxacin (Antibacterial)
MW = 401.43 g/mol
H
N
Cl
H
O
OH
O
Cl
O
O
OH
Cl
O
Cl
(Paxil®)
Paroxetine
MW = 329.36 g/mol
(Zolof t ®)
F
Sertraline
MW = 306.23 g/mol
Cl
Triclosan (Antibacterial)
MW = 289.54 g/mol
S-7
Venlaf axine (Ef f exor®)
MW = 277.40 g/mol
N
278
100
(a)
Relative Abundance
Relative Abundance
100
[Amitriptyline +H]+
80
60
B
(b)
233
m/z 278
50
40
278
0
100
200
300
400
500
m/z
20
0
100
150
200
250
300
350
400
450
500
m/z
Figure S-5. (a) Positive ion DESI mass spectrum of an aqueous solution containing 100 ppb
amitriptyline, showing the protonated molecule at m/z 278. (b) MS2 of the m/z 278 precursor
gives the major transition at m/z 233, corresponding to the loss of dimethylamine.
Amitriptyline Analysis
Figure S-5a shows a positive ion DESI mass spectrum of an aqueous solution containing
100 ppb amitriptyline using Method 2, showing the protonated molecule at m/z 278.
Amitriptyline is a tricyclic antidepressant (TCA), and is the active ingredient in Elavil®. Other
spectral peaks correspond to the heated surface and common ESI background. Isolation and
fragmentation of the m/z 278 precursor leads to a loss of dimethylamine seen as the ion at m/z
233 (Figure S-5b), similar to fragmentation reported in literature.5
S-8
(b)
(a)
100
Relative Abundance
100
267
[Atenolol+ H]+
m/z 267
225
50
267
208
116
145
250
162
80
Relative Abundance
190
0
100
150
200
m/z
250
300
350
532
60
[2Atenolol+ H]+
40
[Atenolol+ Na]+
[2Atenolol+ Na]+
20
289
554
0
100
200
300
400
500
600
m/z
Figure S-6. (a) Positive ion DESI mass spectrum of an aqueous solution containing 100 ppb
atenolol, showing the protonated molecule at m/z 267. (b) MS2 of the m/z 267 precursor gives
rise to the major transition at m/z 190, corresponding to an ion of composition [M-H2O - NH3 isopropyl + 2H]+.
Atenolol Analysis
Figure S-6a shows a positive ion DESI mass spectrum of a tap water solution containing
100 ppb atenolol using Method 2, showing the protonated molecule and sodium adduct at m/z
267 and 289, as well as the dimer and sodiated dimer at m/z 532 and 554. Atenolol belongs to
pharmaceutical class of β-blockers (β1 receptor antagonist) and is used extensively in the
treatment of hypertension. Other spectral peaks correspond to the heated surface and common
ESI background. Isolation and fragmentation of the m/z 267 precursor leads to a diverse
fragmentation pattern (Figure S-6b), with the highest intensity transition corresponding to [M H2O - NH3 - isopropyl + 2H]+, similar to fragmentation reported in literature.6
S-9
240
(a)
80
100
Relative Abundance
Relative Abundance
100
[Bupropion +H]+
60
40
184
m/z 240
(b)
B
50
242
240
0
100
20
200
300
400
500
m/z
0
100
150
200
250
300
350
400
450
500
m/z
Figure S-7. (a) Positive ion DESI mass spectrum of an aqueous solution containing 100 ppb
bupropion, showing the protonated molecule as a chlorine doublet at m/z 240 and 242. (b) MS2
of the m/z 240 precursor gives the major transition at m/z 184, corresponding to the loss of
isobutene.
Bupropion Analysis
Figure S-7a is a positive ion DESI mass spectrum of an aqueous solution containing 100
ppb bupropion, showing the protonated molecule as a chlorine doublet at m/z 240 and 242.
Bupropion is an aminoketone antidepressant, and is the active ingredient in Wellbutrin®. Other
spectral peaks correspond to the heated surface and common ESI background. Isolation and
fragmentation of the m/z 240 precursor leads to a loss of isobutene seen as the ion at m/z 184
(Figure S-7b), similar to fragmentation reported in literature.7
S-10
275
100
Relative Abundance
(a)
100
Relative Abundance
80
[Chlorpheniramine + H]+
60
230
B
(b)
m/z 275
50
275
40
0
200
277
220
240
260
280
300
m/z
20
0
100
150
200
250
300
m/z
350
400
450
500
Figure S-8. (a) Positive ion DESI mass spectrum of an aqueous solution containing 100 ppb
chlorpheniramine, showing the protonated molecule as a chlorine doublet at m/z 275 and 277.
(b) (b) MS2 of the m/z 275 precursor ion of chlorpheniramine, yielding a product ion at m/z 230,
corresponding to a loss of ethylamine.
Chlorpheniramine Analysis
Representative spectra obtained for analysis of 100 ppb aqueous solutions of
chlorpheniramine can be seen Figure S-8a. Chlorpheniramine, a histamine receptor antagonist,
is commonly incorporated individually or in conjunction with decongestants in pharmaceutical
compositions.
Positive ion DESI analysis utilizing Method 2 yielded the protonated molecule
for chlorpheniramine with a chlorine isotopic distribution at m/z 275 and 277. Figure S-8b
shows the MS2 spectrum of the m/z 275 precursor ion (corresponding to the 35Cl isotope), which
dissociates by loss of ethylamine to produce an ion of m/z 230.
S-11
325
Relative Abundance
Relative Abundance
80
[Citalopram + H]+
60
262
(b)
D
100
(a)
100
m/z
m/z325
325
50
109
40
234
116 166
280
325
0
20
100
200
300
400
500
m/z
0
100
150
200
250
300
m/z
350
400
450
500
Figure S-9. (a) Positive ion DESI mass spectrum of an aqueous solution containing 100 ppb
citalopram, showing the protonated molecule at m/z 325. (b) Fragmentation of the m/z 325
precursor of citalopram yields several product ions, with the main product at m/z 262
corresponding to a loss of 2-fluoro-ethylamine.
Citalopram Analysis
Figure S-9a shows a positive ion DESI mass spectrum using Method 2 for 100 ppb
citalopram in tap water. Citalopram is in the selective serotonin reuptake inhibitor (SSRI) class
of antidepressants, and is marketed as the product Celexa®. Citalopram is seen as the protonated
molecule at m/z 325. Fragmentation of the m/z 325 precursor yields several product ions, as seen
in Figure S-9b, with the main product at m/z 262 corresponding to a loss of 2-fluoro-ethylamine.
S-12
100
(b)
B
(a)
Relative Abundance
Relative Abundance
100
80
60
270
m/z 315
50
[Clomipramine+H]+
40
0
100
200
300
400
500
m/z
315
20
317
0
100
150
200
250
300
350
400
450
500
m/z
Figure S-10. (a) Positive ion DESI mass spectrum of an aqueous solution containing 100 ppb
clomipramine, showing the protonated molecule as a chlorine doublet at m/z 315 and 317. (b)
MS2 of the m/z 315 precursor gives the major transition at m/z 270, corresponding to the loss of
dimethylamine.
Clomipramine Analysis
Figure S-10a shows a positive ion DESI mass spectrum of an aqueous solution containing
100 ppb clomipramine, yielding the protonated molecule as a chlorine doublet at m/z 315 and
317. Clomipramine is a TCA antidepressant, and is the active ingredient in Anafril®. Other
spectral peaks correspond to the heated surface and common ESI background. Isolation and
fragmentation of the m/z 315 precursor leads to a loss of dimethylamine, seen as the ion at m/z
270 (Figure S-10b).
S-13
267
100
(a)
80
60
[Duloxetine+H]+
Relative Abundance
Relative Abundance
100
m/z 298
(Bb)
50
154
40
298
20
0
100
200
300
m/z
400
500
0
100
150
200
250
300
m/z
350
400
450
500
Figure S-11. (a) Positive ion DESI mass spectrum of an aqueous solution containing 100 ppb
duloxetine, showing the protonated molecule at m/z 298. (b) MS2 of the m/z 298 precursor gives
the major transition at m/z 267, corresponding to the loss of methylamine.
Duloxetine Analysis
Figure S-11a shows a positive ion DESI mass spectrum of an aqueous solution containing
100 ppb duloxetine, yielding the protonated molecule at m/z 298. Duloxetine is a serotoninnorepinephrine reuptake inhibitor antidepressant, and is the active ingredient in Cymbalta®.
Other spectral peaks correspond to the heated surface and common ESI background. Isolation
and fragmentation of the m/z 298 precursor leads to the presence of product ions at m/z 154 and
267, corresponding to a loss of 1-naphthol and methylamine, respectively, similar to
fragmentation reported in literature.7
S-14
255
(a)
100
255
135
100
m/z 273
Relative Abundance
80
Relative Abundance
159
[m/z 273 – H2O]+
60
50
173
133
(b)
273
199
0
100
40
150
200
m/z
250
300
350
273
[Estradiol+ H]+
20
0
100
150
200
250
300
m/z
350
400
450
500
Figure S-12. (a) Positive ion DESI mass spectrum of an aqueous solution containing 100 ppb
estradiol, showing the protonated molecule at m/z 273. Of note, in-source fragmentation is seen
in high intensity, resulting in the loss of water (m/z 255) from the precursor ion. (b) MS2 of the
m/z 273 precursor gives the major transition at m/z 255, corresponding to the loss of water.
Estradiol Analysis
Figure S-12a shows a positive ion DESI mass spectrum of an aqueous solution containing
100 ppb estradiol, yielding the protonated molecule at m/z 273. Estradiol, or 17β-estradiol, is the
predominant female sex hormone, but is also used extensively in mediations that treat
hypoestrogenism. As a result of the thermal assistance, a high intensity ion is seen at m/z 255,
corresponding to a thermal fragmentation that results in a loss of water. Other spectral peaks
correspond to the heated surface and common ESI background. Isolation and fragmentation of
the m/z 273 precursor leads to the major transition seen at m/z 255, corresponding to a loss of
water, as seen in Figure S-12b.
S-15
100
(a)
80
Relative Abundance
Relative Abundance
100
60
148
m/z 310
(b)
B
50
259
[Fluoxetine+H]+
40
310
0
100
20
200
300
m/z
400
500
310
0
100
150
200
250
300
350
400
450
500
m/z
Figure S-13. (a) Positive ion DESI mass spectrum of an aqueous solution containing 100 ppb
fluoxetine, showing the protonated molecule at m/z 310. (b) MS2 of the m/z 310 precursor gives
the major transition at m/z 148, corresponding to the loss of p-hydroxybenzotrifluoride.
Fluoxetine Analysis
Figure S-13a shows a positive ion DESI mass spectrum of an aqueous solution containing
100 ppb fluoxetine, yielding the protonated molecule at m/z 310. Fluoxetine is a selective
serotonin reuptake inhibitor (SSRI) antidepressant, and is the active ingredient in the commonlyused tablet Prozac®. Other spectral peaks correspond to the heated surface and common ESI
background. Isolation and fragmentation of the m/z 310 precursor leads to a loss of phydroxybenzotrifluoride seen as the ion at m/z 148 (Figure S-13b), similar to fragmentation
reported in literature.7
S-16
100
86
80
60
[Imipramine+H]+
m/z 281
(b)
B
(a)
Relative Abundance
Relative Abundance
100
281
50
40
236
20
299
0
281
100
200
300
400
m/z
0
100
150
200
250
300
m/z
350
400
450
500
Figure S-14. (a) Positive ion DESI mass spectrum of an aqueous solution containing 100 ppb
imipramine, showing the protonated molecule at m/z 281. (b) MS2 of the m/z 281 precursor
gives the major transition at m/z 86, corresponding to the loss of 2,2'-iminodibenzyl.
Imipramine Analysis
Figure S-14a shows a positive ion DESI mass spectrum of an aqueous solution containing
100 ppb imipramine, yielding the protonated molecule at m/z 281. Imipramine is a TCA
antidepressant, and is the active ingredient in Antideprin®. Other spectral peaks correspond to
the heated surface and common ESI background. Isolation and fragmentation of the m/z 281
precursor leads to a loss of 2,2'-iminodibenzyl, seen as the ion at m/z 86 (Figure S-14b).
S-17
100
402
(a)
[Moxifloxacin+H]+
384
100
m/z 402
60
40
Relative Abundance
Relative Abundance
80
80
60
(b)
[M+Na]+
40
20
20
358
402
416
[M+K]+
0
200
250
300
350
m/z
400
450
424
500
440
0
100
150
200
250
300
m/z
350
400
450
500
Figure S-15. (a) Positive ion DESI mass spectrum of an aqueous solution containing 1 ppm
moxifloxacin, showing the protonated molecule at m/z 402, as well as sodiated and potassiated
adducts at m/z 424 and 440, respectively.. (b) MS2 of the m/z 402 precursor gives the major
transition at m/z 384, corresponding to the loss of water.
Moxifloxacin Analysis
Figure S-15a shows a positive ion DESI mass spectrum of a tap water solution containing
1 ppm moxifloxacin, yielding the protonated molecule at m/z 402 and adducts with sodium and
potassium at m/z 424 and 440, respectively. Moxifloxacin is a fluoroquinolone antibacterial and
broad spectrum antibiotic, and it is used in both oral (bacterial infections) and ophthalmic
solutions (conjunctivitis). Other spectral peaks correspond to the heated surface and common
ESI background. Isolation and fragmentation of the m/z 402 precursor leads to a loss of water,
seen as the ion at m/z 86 (Figure S-15b).
S-18
264
100
233 264
(Bb)
100
(a)
m/z 264
80
Relative Abundance
Relative Abundance
[Nortriptyline+H]+
60
50
105
40
91
117
155
191
0
100
20
200
300
400
m/z
0
100
150
200
250
300
350
400
450
500
m/z
Figure S-16. (a) Positive ion DESI mass spectrum of an aqueous solution containing 100 ppb
nortriptyline, showing the protonated molecule at m/z 264. (b) MS2 of the m/z 264 precursor
gives the major transition at m/z 233, corresponding to the loss of methylamine.
Nortriptyline Analysis
Figure S-16a shows a positive ion DESI mass spectrum of an aqueous solution containing
100 ppb nortriptyline, yielding the protonated molecule at m/z 264. Nortriptyline is a TCA
antidepressant, and is the active ingredient in Antideprin®. Other spectral peaks correspond to
the heated surface and common ESI background. Isolation and fragmentation of the m/z 281
precursor leads to a loss of methylamine, seen as the ion at m/z 233 (Figure S-16b).6
S-19
(a)
Relative Abundance
[Paroxetine+H]+
80
60
Relative Abundance
100
192
100
330
m/z 330
(b)
B
50
151
330
313
175
123
40
0
100
200
300
m/z
400
500
20
0
100
150
200
250
300
m/z
350
400
450
500
Figure S-17. (a) Positive ion DESI mass spectrum of an aqueous solution containing 100 ppb
paroxetine, showing the protonated molecule at m/z 330. (b) MS2 of the m/z 330 precursor gives
the major transition at m/z 192, corresponding to the loss of 1,3-benzodioxol-5-ol.
Paroxetine Analysis
Figure S-17a shows a positive ion DESI mass spectrum of an aqueous solution containing
100 ppb paroxetine, yielding the protonated molecule at m/z 330. Paroxetine is a SSRI
antidepressant, and is the active ingredient in Paxil®. Other spectral peaks correspond to the
heated surface and common ESI background. Isolation and fragmentation of the m/z 330
precursor leads to a loss of 1,3-benzodioxol-5-ol, seen as the ion at m/z 192 (Figure S-17b).8
S-20
(a)
80
Relative Abundance
306
100
Relative Abundance
100
[Sertraline + H]+
308
60
275
m/z 306
(b)
50
238
40
240
291
306
0
200
220
240
20
0
100
150
200
250
300
350
400
450
260
m/z
280
300
320
500
m/z
Figure S-18. (a) Positive ion DESI mass spectrum of an aqueous solution containing 100 ppb
sertraline, showing the protonated molecule at m/z 306, 308, and 310, corresponding to the
characteristic dichlorinated isotopic signature. (b) MS2 of the m/z 308 precursor gives the major
transition at m/z 275, corresponding to the loss of methylamine.
Sertraline Analysis
Figure S-18a shows a positive ion DESI mass spectrum of an aqueous solution containing
100 ppb sertraline, yielding the protonated molecule at m/z 306, 308, and 310, corresponding to
the characteristic dichlorinated isotopic signature. Sertraline is in the selective serotonin reuptake
inhibitor (SSRI) class of antidepressants, and is marketed as the product Zoloft®. Other spectral
peaks correspond to the heated surface and common ESI background. Isolation and
fragmentation of the m/z 306 precursor leads to a loss of methylamine, seen as the ion at m/z 275
(Figure S-18b).6
S-21
100
100
(a)
260
(Bb)
m/z 278
Relative Abundance
Relative Abundance
[Venlafaxine+H]+
80
60
278
50
40
215
278
0
100
20
200
300
m/z
400
500
0
100
150
200
250
300
m/z
350
400
450
500
Figure S-19. (a) Positive ion DESI mass spectrum of an aqueous solution containing 100 ppb
venlafaxine, showing the protonated molecule at m/z 278. (b) MS2 of the m/z 278 precursor
gives the major transition at m/z 260, corresponding to the loss of water.
Venlafaxine Analysis
Figure S-19a shows a positive ion DESI mass spectrum of an aqueous solution containing
100 ppb venlafaxine, yielding the protonated molecule at m/z 278. Venlafaxine is a serotoninnorepinephrine reuptake inhibitor antidepressant, and is the active ingredient in Effexor®. Other
spectral peaks correspond to the heated surface and common ESI background. Isolation and
fragmentation of the m/z 278 precursor leads to a loss of water, seen as the ion at m/z 260 (Figure
S-19b).8
S-22
References
(1) Wang, C.; Fan, G.; Lin, M.; Chen, Y.; Zhao, W.; Wu, Y. Development and Validation of
a Liquid Chromatography/Tandem Mass Spectrometry Assay for the Simultaneous
Determination of d-Amphetamine and Diphenhydramine in Beagle Dog Plasma and its
Application to a Pharmacokinetic Study. J. Chromatogr., B: Anal. Technol. Biomed. Life
Sci. 2007, 854 (1-2), 48-56.
(2) Cotte-Rodríguez, I.; Mulligan, C. C.; Cooks, R. G. Non-Proximate Detection of Small
and Large Molecules by Desorption Electrospray Ionization and Desoprtion Atmospheric
Pressure Chemical Ionization Mass Spectrometry: Instrumentation and Applications in
Forensics, Chemistry, and Biology. Anal. Chem. 2007, 79, 7069-7077.
(3) Zou, H.; Gao, S.; Chen, W.; Zhong, Y.; Jiang, X.; Pei, Y. Simultaneous Quantitation of
Paracetamol, Pseudoephedrine and Chlorpheniramine in Dog Plasma by LC-MS-MS.
Chromatographia 2008, 68, 251-257.
(4) Marín, A.; Espada, A.; Vidal, P.; Barbas, C. Major Degradation Products Identified in
Several Pharmaceutical Formulations Against the Common Cold. Anal. Chem. 2005, 77,
471-477.
(5) Kirchherr, H.; Kühn-Velten, W. N. Quantitative Determination of Forty-Eight
Antidepressants and Antipsychotics in Human Serum by HPLC Tandem Mass
Spectrometry: A Multi-Level, Single-Sample Approach. J. Chromatogr., B: Anal.
Technol. Biomed. Life Sci. 2006, 843, 100-113.
(6) Hernando, M. D.; Petrovic, M.; Fernández-Alba, A. R.; Barceló. Analysis by Liquid
Chromatography-Electrospray Ionization Mass Spectrometry and Acute Toxicity
Evaluation for β-Blockers and Lipid-Regulating Agents in Wastewater Samples. J.
Chromatogr., A. 2004, 1046, 133-140.
(7) Schultz, M. M.; Furlong, E. T. Trace Analysis of Antidepressant Pharmaceuticals and
Their Select Degradates in Aquatic Matrices by LC/ESI/MS/MS. Anal. Chem. 2008, 80,
1756-1762.
(8) Lajeunesse, A.; Gagnon, C.; Sauvé, S. Determination of Basic Antidepressants and Their
N-Desmethyl Metabolites in Raw Sewage and Wastewater Using Solid-Phase Extraction
and Liquid Chromatography-Tandem Mass Spectrometry. Anal. Chem. 2008, 80, 53255333.
S-23